@article {pmid38616524, year = {2024}, author = {Hardison, EA and Eliason, EJ}, title = {Diet effects on ectotherm thermal performance.}, journal = {Biological reviews of the Cambridge Philosophical Society}, volume = {}, number = {}, pages = {}, doi = {10.1111/brv.13081}, pmid = {38616524}, issn = {1469-185X}, support = {//University of California, Santa Barbara (Eliason Lab Start Up Funds)/ ; OCE-9982105//National Science Foundation (Santa Barbara Coastal Long Term Ecological Research program) under awards/ ; OCE-0620276//National Science Foundation (Santa Barbara Coastal Long Term Ecological Research program) under awards/ ; OCE-1232779//National Science Foundation (Santa Barbara Coastal Long Term Ecological Research program) under awards/ ; OCE-1831937//National Science Foundation (Santa Barbara Coastal Long Term Ecological Research program) under awards/ ; }, abstract = {The environment is changing rapidly, and considerable research is aimed at understanding the capacity of organisms to respond. Changes in environmental temperature are particularly concerning as most animals are ectothermic, with temperature considered a key factor governing their ecology, biogeography, behaviour and physiology. The ability of ectotherms to persist in an increasingly warm, variable, and unpredictable future will depend on their nutritional status. Nutritional resources (e.g. food availability, quality, options) vary across space and time and in response to environmental change, but animals also have the capacity to alter how much they eat and what they eat, which may help them improve their performance under climate change. In this review, we discuss the state of knowledge in the intersection between animal nutrition and temperature. We take a mechanistic approach to describe nutrients (i.e. broad macronutrients, specific lipids, and micronutrients) that may impact thermal performance and discuss what is currently known about their role in ectotherm thermal plasticity, thermoregulatory behaviour, diet preference, and thermal tolerance. We finish by describing how this topic can inform ectotherm biogeography, behaviour, and aquaculture research.}, }
@article {pmid38576091, year = {2024}, author = {Blumstein, M}, title = {The drivers of intraspecific trait variation and their implications for future tree productivity and survival.}, journal = {American journal of botany}, volume = {}, number = {}, pages = {e16312}, doi = {10.1002/ajb2.16312}, pmid = {38576091}, issn = {1537-2197}, abstract = {Forests are facing unprecedented levels of stress from pest and disease outbreaks, disturbance, fragmentation, development, and a changing climate. These selective agents act to alter forest composition from regional to cellular levels. Thus, a central challenge for understanding how forests will be impacted by future change is how to integrate across scales of biology. Phenotype, or an observable trait, is the product of an individual's genes (G) and the environment in which an organism lives (E). To date, researchers have detailed how environment drives variation in tree phenotypes over long time periods (e.g., long-term ecological research sites [LTERs]) and across large spatial scales (e.g., flux network). In parallel, researchers have discovered the genes and pathways that govern phenotypes, finding high degrees of genetic control and signatures of local adaptation in many plant traits. However, the research in these two areas remain largely independent of each other, hindering our ability to generate accurate predictions of plant response to environment, an increasingly urgent need given threats to forest systems. I present the importance of both genes and environment in determining tree responses to climate stress. I highlight why the difference between G versus E in driving variation is critical for our understanding of climate responses, then propose means of accelerating research that examines G and E simultaneously by leveraging existing long-term, large-scale phenotypic data sets from ecological networks and adding newly affordable sequence (-omics) data to both drill down to find the genes and alleles influencing phenotypes and scale up to find how patterns of demography and local adaptation may influence future response to change.}, }
@article {pmid38572766, year = {2024}, author = {Ziadeh, CP and Ziadeh, SB and Aflague, BH and Townley, MA and Ayres, MP and Contosta, AR and Garnas, JR}, title = {Distinct communities under the snow: describing characteristics of subnivium arthropod communities.}, journal = {Environmental entomology}, volume = {}, number = {}, pages = {}, doi = {10.1093/ee/nvae017}, pmid = {38572766}, issn = {1938-2936}, support = {1637685//NSF/ ; //LTER/ ; }, abstract = {Arthropods are active during the winter in temperate regions. Many use the seasonal snowpack as a buffer against harsh ambient conditions and are active in a refugium known as the subnivium. While the use of the subnivium by arthropods is well established, far less is known about subnivium community composition, abundance, biomass, and diversity and how these characteristics compare with the community in the summer. Understanding subnivium communities is especially important given the observed and anticipated changes in snowpack depth and duration due to the changing climate. We compared subnivium arthropod communities with those active during the summer using pitfall trapping in northern New Hampshire. We found that compositions of ground-active arthropod communities in the subnivium differed from those in the summer. The subnivium arthropod community featured moderate levels of richness and other measures of diversity that tended to be lower than the summer community. More strikingly, the subnivium community was much lower in overall abundance and biomass. Interestingly, some arthropods were dominant in the subnivium but either rare or absent in summer collections. These putative "subnivium specialists" included the spider Cicurina brevis (Emerton 1890) (Araneae: Hahniidae) and 3 rove beetles (Coleoptera: Staphylinidae): Arpedium cribratum Fauvel, 1878, Lesteva pallipes LeConte, 1863, and Porrhodites inflatus (Hatch, 1957). This study provides a detailed account of the subnivium arthropod community, establishes baseline information on arthropod communities in temperate forests of northeastern North America, and explores the idea of subnivium specialist taxa that are highly active in winter and might be especially vulnerable to climate change.}, }
@article {pmid38522859, year = {2024}, author = {Liang, M and Lamy, T and Reuman, DC and Wang, S and Bell, TW and Cavanaugh, KC and Castorani, MCN}, title = {A marine heatwave changes the stabilizing effects of biodiversity in kelp forests.}, journal = {Ecology}, volume = {}, number = {}, pages = {e4288}, doi = {10.1002/ecy.4288}, pmid = {38522859}, issn = {1939-9170}, support = {80NSSC22K0169/NASA/NASA/United States ; }, abstract = {Biodiversity can stabilize ecological communities through biological insurance, but climate and other environmental changes may disrupt this process via simultaneous ecosystem destabilization and biodiversity loss. While changes to diversity-stability relationships (DSRs) and the underlying mechanisms have been extensively explored in terrestrial plant communities, this topic remains largely unexplored in benthic marine ecosystems that comprise diverse assemblages of producers and consumers. By analyzing two decades of kelp forest biodiversity survey data, we discovered changes in diversity, stability, and their relationships at multiple scales (biological organizational levels, spatial scales, and functional groups) that were linked with the most severe marine heatwave ever documented in the North Pacific Ocean. Moreover, changes in the strength of DSRs during/after the heatwave were more apparent among functional groups than both biological organizational levels (population vs. ecosystem levels) and spatial scales (local vs. broad scales). Specifically, the strength of DSRs decreased for fishes, increased for mobile invertebrates and understory algae, and were unchanged for sessile invertebrates during/after the heatwave. Our findings suggest that biodiversity plays a key role in stabilizing marine ecosystems, but the resilience of DSRs to adverse climate impacts primarily depends on the functional identities of ecological communities.}, }
@article {pmid38472358, year = {2024}, author = {Ruggiero, MV and Buffoli, M and Wolf, KKE and D'Alelio, D and Di Tuccio, V and Lombardi, E and Manfellotto, F and Vitale, L and Margiotta, F and Sarno, D and John, U and Ferrante, MI and Montresor, M}, title = {Multiannual patterns of genetic structure and mating type ratios highlight the complex bloom dynamics of a marine planktonic diatom.}, journal = {Scientific reports}, volume = {14}, number = {1}, pages = {6028}, pmid = {38472358}, issn = {2045-2322}, support = {Grant number 7978//Gordon and Betty Moore Foundation/ ; Grant number 7978//Gordon and Betty Moore Foundation/ ; Grant number 7978//Gordon and Betty Moore Foundation/ ; Grant number 7978//Gordon and Betty Moore Foundation/ ; Grant number 7978//Gordon and Betty Moore Foundation/ ; Grant number 7978//Gordon and Betty Moore Foundation/ ; Grant number 7978//Gordon and Betty Moore Foundation/ ; Grant number 7978//Gordon and Betty Moore Foundation/ ; LTER-MC program//Stazione Zoologica Anton Dohrn (SZN), Naples (Italy)/ ; LTER-MC program//Stazione Zoologica Anton Dohrn (SZN), Naples (Italy)/ ; LTER-MC program//Stazione Zoologica Anton Dohrn (SZN), Naples (Italy)/ ; LTER-MC program//Stazione Zoologica Anton Dohrn (SZN), Naples (Italy)/ ; LTER-MC program//Stazione Zoologica Anton Dohrn (SZN), Naples (Italy)/ ; LTER-MC program//Stazione Zoologica Anton Dohrn (SZN), Naples (Italy)/ ; LTER-MC program//Stazione Zoologica Anton Dohrn (SZN), Naples (Italy)/ ; LTER-MC program//Stazione Zoologica Anton Dohrn (SZN), Naples (Italy)/ ; LTER-MC program//Stazione Zoologica Anton Dohrn (SZN), Naples (Italy)/ ; }, abstract = {Understanding the genetic structure of populations and the processes responsible for its spatial and temporal dynamics is vital for assessing species' adaptability and survival in changing environments. We investigate the genetic fingerprinting of blooming populations of the marine diatom Pseudo-nitzschia multistriata in the Gulf of Naples (Mediterranean Sea) from 2008 to 2020. Strains were genotyped using microsatellite fingerprinting and natural samples were also analysed with Microsatellite Pool-seq Barcoding based on Illumina sequencing of microsatellite loci. Both approaches revealed a clonal expansion event in 2013 and a more stable genetic structure during 2017-2020 compared to previous years. The identification of a mating type (MT) determination gene allowed to assign MT to strains isolated over the years. MTs were generally at equilibrium with two notable exceptions, including the clonal bloom of 2013. The populations exhibited linkage equilibrium in most blooms, indicating that sexual reproduction leads to genetic homogenization. Our findings show that P. multistriata blooms exhibit a dynamic genetic and demographic composition over time, most probably determined by deeper-layer cell inocula. Occasional clonal expansions and MT imbalances can potentially affect the persistence and ecological success of planktonic diatoms.}, }
@article {pmid38452836, year = {2024}, author = {Gallagher, KL and Cimino, MA and Dinniman, MS and Lynch, HJ}, title = {Quantifying potential marine debris sources and potential threats to penguins on the West Antarctic Peninsula.}, journal = {Environmental pollution (Barking, Essex : 1987)}, volume = {}, number = {}, pages = {123714}, doi = {10.1016/j.envpol.2024.123714}, pmid = {38452836}, issn = {1873-6424}, abstract = {Marine pollution is becoming ubiquitous in the environment. Observations of pollution on beaches, in the coastal ocean, and in organisms in the Antarctic are becoming distressingly common. Increasing human activity, growing tourism, and an expanding krill fishing industry along the West Antarctic Peninsula all represent potential sources of plastic pollution and other debris (collectively referred to as debris) to the region. However, the sources of these pollutants from point (pollutants released from discrete sources) versus non-point (pollutants from a large area rather than a specific source) sources are poorly understood. We used buoyant simulated particles released in a high-resolution physical ocean model to quantify pollutant loads throughout the region. We considered non-point sources of debris from the Antarctic Circumpolar Current, Bellingshausen Sea, Weddell Sea, and point source pollution from human activities including tourism, research, and fishing. We also determined possible origins for observed debris based on data from the Southern Ocean Observing System and Palmer Long-Term Ecological Research program. Our results indicate that point source pollution released in the coastal Antarctic is more likely to serve as a source for observed debris than non-point sources, and that the dominant source of pollution is region-specific. Penguin colonies in the South Shetland and Elephant Islands had the greatest debris load from point sources whereas loads from non-point sources were greatest around the southernmost colonies. Penguin colonies at Cornwallis Island and Fort Point were exposed to the highest theoretical debris loads. While these results do not include physical processes such as windage and Stokes Drift that are known to impact debris distributions and transport in the coastal ocean, these results provide critical insights to building an effective stratified sampling and monitoring effort to better understand debris distributions, concentrations, and origins throughout the West Antarctic Peninsula.}, }
@article {pmid38401392, year = {2024}, author = {Battisti, C and Cesarini, G and Gallitelli, L and Moretti, F and Scalici, M}, title = {Anthropogenic litter in a Mediterranean coastal wetland: A heterogeneous spatial pattern of historical deposition.}, journal = {Marine pollution bulletin}, volume = {201}, number = {}, pages = {116163}, doi = {10.1016/j.marpolbul.2024.116163}, pmid = {38401392}, issn = {1879-3363}, abstract = {Coastal wetlands represent areas that can testify historical accumulation of litter. We analyzed the anthropogenic litter deposited on the channel bottom of a coastal wetland area that experienced water stress due to extreme summer dryness after about 20 years. We hypothesize that the litter accumulated in the different areas over the years reflects the different social user categories (i.e., fishermen, beach users, hunters) and exposure to meteo-marine events. Our findings highlight that historically accumulated litter is composed of plastics (78.8 %), clothes (8.9 %), and glass (4.9 %). Moreover, litter concentration averages 53.6 items/ha in the 8 sectors. The most found categories were common household items (25.4 %), diverse (professional and consumer) items (24.2 %), and food and beverages packaging (21.4 %). Finally, litter diversity indices and the Detrended Correspondence Analysis showed sector and litter type similarities. We reported for the first time the presence of litter accumulated for 20 years testifying non-more occurring recreational activities.}, }
@article {pmid38374154, year = {2024}, author = {Wang, FQ and Bartosik, D and Sidhu, C and Siebers, R and Lu, DC and Trautwein-Schult, A and Becher, D and Huettel, B and Rick, J and Kirstein, IV and Wiltshire, KH and Schweder, T and Fuchs, BM and Bengtsson, MM and Teeling, H and Amann, RI}, title = {Particle-attached bacteria act as gatekeepers in the decomposition of complex phytoplankton polysaccharides.}, journal = {Microbiome}, volume = {12}, number = {1}, pages = {32}, pmid = {38374154}, issn = {2049-2618}, support = {AM 73/9-3//Deutsche Forschungsgemeinschaft,Germany/ ; SCHW 595/10-3//Deutsche Forschungsgemeinschaft,Germany/ ; TE 813/2-3//Deutsche Forschungsgemeinschaft,Germany/ ; RI 969/9-2//Deutsche Forschungsgemeinschaft,Germany/ ; BE 3869/4-3//Deutsche Forschungsgemeinschaft,Germany/ ; SCHW 595/11-3//Deutsche Forschungsgemeinschaft,Germany/ ; FU 627/2-3//Deutsche Forschungsgemeinschaft,Germany/ ; RI 969/9-2//Deutsche Forschungsgemeinschaft,Germany/ ; TE 813/2-3//Deutsche Forschungsgemeinschaft,Germany/ ; AM 73/9-3//Deutsche Forschungsgemeinschaft,Germany/ ; AWI_BAH_o 1//Biological Station Helgoland, Alfred Wegener Institute, Helmholtz Center for Polar and Marine Research/ ; AWI_BAH_o 1//Biological Station Helgoland, Alfred Wegener Institute, Helmholtz Center for Polar and Marine Research/ ; }, mesh = {Phytoplankton/genetics/metabolism ; Eutrophication ; Polysaccharides/metabolism ; *Flavobacteriaceae/metabolism ; *Microalgae/metabolism ; }, abstract = {BACKGROUND: Marine microalgae (phytoplankton) mediate almost half of the worldwide photosynthetic carbon dioxide fixation and therefore play a pivotal role in global carbon cycling, most prominently during massive phytoplankton blooms. Phytoplankton biomass consists of considerable proportions of polysaccharides, substantial parts of which are rapidly remineralized by heterotrophic bacteria. We analyzed the diversity, activity, and functional potential of such polysaccharide-degrading bacteria in different size fractions during a diverse spring phytoplankton bloom at Helgoland Roads (southern North Sea) at high temporal resolution using microscopic, physicochemical, biodiversity, metagenome, and metaproteome analyses.<br><br>RESULTS: Prominent active 0.2-3 &#xb5;m free-living clades comprised Aurantivirga, "Formosa", Cd. Prosiliicoccus, NS4, NS5, Amylibacter, Planktomarina, SAR11 Ia, SAR92, and SAR86, whereas BD1-7, Stappiaceae, Nitrincolaceae, Methylophagaceae, Sulfitobacter, NS9, Polaribacter, Lentimonas, CL500-3, Algibacter, and Glaciecola dominated 3-10 &#xb5;m and > 10 &#xb5;m particles. Particle-attached bacteria were more diverse and exhibited more dynamic adaptive shifts over time in terms of taxonomic composition and repertoires of encoded polysaccharide-targeting enzymes. In total, 305 species-level metagenome-assembled genomes were obtained, including 152 particle-attached bacteria, 100 of which were novel for the sampling site with 76 representing new species. Compared to free-living bacteria, they featured on average larger metagenome-assembled genomes with higher proportions of polysaccharide utilization loci. The latter were predicted to target a broader spectrum of polysaccharide substrates, ranging from readily soluble, simple structured storage polysaccharides (e.g., laminarin, &#x3b1;-glucans) to less soluble, complex structural, or secreted polysaccharides (e.g., xylans, cellulose, pectins). In particular, the potential to target poorly soluble or complex polysaccharides was more widespread among abundant and active particle-attached bacteria.<br><br>CONCLUSIONS: Particle-attached bacteria represented only 1% of all bloom-associated bacteria, yet our data suggest that many abundant active clades played a pivotal gatekeeping role in the solubilization and subsequent degradation of numerous important classes of algal glycans. The high diversity of polysaccharide niches among the most active particle-attached clades therefore is a determining factor for the proportion of algal polysaccharides that can be rapidly remineralized during generally short-lived phytoplankton bloom events. Video Abstract.}, }
@article {pmid38366166, year = {2024}, author = {Nelson, C and Dadi, P and Shah, DD and Garcia-Pichel, F}, title = {Spatial organization of a soil cyanobacterium and its cyanosphere through GABA/Glu signaling to optimize mutualistic nitrogen fixation.}, journal = {The ISME journal}, volume = {18}, number = {1}, pages = {}, pmid = {38366166}, issn = {1751-7370}, support = {2025166//Jornada Basin LTER Graduate Research Fellowship Program/ ; 2129537//National Science Foundation/ ; DEB 2025166//Jornada Basin LTER Graduate Research Fellowship Program/ ; DEB 2129537//National Science Foundation/ ; }, mesh = {*Soil ; Symbiosis ; Nitrogen Fixation ; *Microbiota ; Soil Microbiology ; }, abstract = {Soil biocrusts are characterized by the spatial self-organization of resident microbial populations at small scales. The cyanobacterium Microcoleus vaginatus, a prominent primary producer and pioneer biocrust former, relies on a mutualistic carbon (C) for nitrogen (N) exchange with its heterotrophic cyanosphere microbiome, a mutualism that may be optimized through the ability of the cyanobacterium to aggregate into bundles of trichomes. Testing both environmental populations and representative isolates, we show that the proximity of mutualistic diazotroph populations results in M. vaginatus bundle formation orchestrated through chemophobic and chemokinetic responses to gamma-aminobutyric acid (GABA) /glutamate (Glu) signals. The signaling system is characterized by: a high GABA sensitivity (nM range) and low Glu sensitivity (μM to mM), the fact that GABA and Glu are produced by the cyanobacterium as an autoinduction response to N deficiency, and by the presence of interspecific signaling by heterotrophs in response to C limitation. Further, it crucially switches from a positive to a negative feedback loop with increasing GABA concentration, thus setting maximal bundle sizes. The unprecedented use of GABA/Glu as an intra- and interspecific signal in the spatial organization of microbiomes highlights the pair as truly universal infochemicals.}, }
@article {pmid38273535, year = {2024}, author = {Lewis, ASL and Lau, MP and Jane, SF and Rose, KC and Be'eri-Shlevin, Y and Burnet, SH and Clayer, F and Feuchtmayr, H and Grossart, HP and Howard, DW and Mariash, H and Delgado Martin, J and North, RL and Oleksy, I and Pilla, RM and Smagula, AP and Sommaruga, R and Steiner, SE and Verburg, P and Wain, D and Weyhenmeyer, GA and Carey, CC}, title = {Anoxia begets anoxia: A positive feedback to the deoxygenation of temperate lakes.}, journal = {Global change biology}, volume = {30}, number = {1}, pages = {e17046}, doi = {10.1111/gcb.17046}, pmid = {38273535}, issn = {1365-2486}, support = {//College of Science Roundtable at Virginia Tech/ ; //Cornell Atkinson Center for Sustainability, Cornell University/ ; GR1540/37-1//Deutsche Forschungsgemeinschaft/ ; //EMALCSA Chair/ ; //Institute for Critical Technology and Applied Science/ ; //Leibniz-Institut f&#xfc;r Gew&#xe4;sser&#xf6;kologie und Binnenfischerei/ ; //LTSER Platform Tyrolean Alps (LTER-Austria)/ ; C01X2205//Ministry of Business, Innovation and Employment/ ; //Missouri Department of Natural Resources/ ; 1737424//National Science Foundation/ ; 1753639//National Science Foundation/ ; 1754265//National Science Foundation/ ; 1840995//National Science Foundation/ ; 1933016//National Science Foundation/ ; 2019528//National Science Foundation/ ; 2048031//National Science Foundation/ ; NE/R016429/1//Natural Environment Research Council/ ; //Oak Ridge National Laboratory/ ; 2020-01091//Svenska Forskningsr&#xe5;det Formas/ ; 2020-03222//Vetenskapsr&#xe5;det/ ; //Water Power Technologies Office/ ; }, mesh = {Humans ; *Lakes ; Chlorophyll A/analysis ; *Environmental Monitoring/methods ; Feedback ; Hypoxia ; Phosphorus/analysis ; Oxygen ; Eutrophication ; }, abstract = {Declining oxygen concentrations in the deep waters of lakes worldwide pose a pressing environmental and societal challenge. Existing theory suggests that low deep-water dissolved oxygen (DO) concentrations could trigger a positive feedback through which anoxia (i.e., very low DO) during a given summer begets increasingly severe occurrences of anoxia in following summers. Specifically, anoxic conditions can promote nutrient release from sediments, thereby stimulating phytoplankton growth, and subsequent phytoplankton decomposition can fuel heterotrophic respiration, resulting in increased spatial extent and duration of anoxia. However, while the individual relationships in this feedback are well established, to our knowledge, there has not been a systematic analysis within or across lakes that simultaneously demonstrates all of the mechanisms necessary to produce a positive feedback that reinforces anoxia. Here, we compiled data from 656 widespread temperate lakes and reservoirs to analyze the proposed anoxia begets anoxia feedback. Lakes in the dataset span a broad range of surface area (1-126,909 ha), maximum depth (6-370 m), and morphometry, with a median time-series duration of 30 years at each lake. Using linear mixed models, we found support for each of the positive feedback relationships between anoxia, phosphorus concentrations, chlorophyll a concentrations, and oxygen demand across the 656-lake dataset. Likewise, we found further support for these relationships by analyzing time-series data from individual lakes. Our results indicate that the strength of these feedback relationships may vary with lake-specific characteristics: For example, we found that surface phosphorus concentrations were more positively associated with chlorophyll a in high-phosphorus lakes, and oxygen demand had a stronger influence on the extent of anoxia in deep lakes. Taken together, these results support the existence of a positive feedback that could magnify the effects of climate change and other anthropogenic pressures driving the development of anoxia in lakes around the world.}, }
@article {pmid38273449, year = {2024}, author = {Wojcikiewicz, R and Ji, W and Hanan, NP}, title = {Quantifying shrub-shrub competition in drylands using aerial imagery and a novel landscape competition index.}, journal = {The New phytologist}, volume = {241}, number = {5}, pages = {1973-1984}, doi = {10.1111/nph.19505}, pmid = {38273449}, issn = {1469-8137}, support = {//National Science Foundation/ ; //Agricultural Experiment Station, New Mexico State University/ ; }, mesh = {*Ecosystem ; New Mexico ; Soil ; *Prosopis ; }, abstract = {The Jornada Basin Long-Term Ecological Research Site (JRN-LTER, or JRN) is a semiarid grassland-shrubland in southern New Mexico, USA. The role of intraspecific competition in constraining shrub growth and establishment at the JRN and in arid systems, in general, is an important question in dryland studies. Using information on shrub distributions and growth habits at the JRN, we present a novel landscape-scale (c. 1 ha) metric (the 'competition index', CI), which quantifies the potential intensity of competitive interactions. We map and compare the intensity of honey mesquite (Prosopis glandulosa, Torr.) competition spatially and temporally across the JRN-LTER, investigating associations of CI with shrub distribution, density, and soil types. The CI metric shows strong correlation with values of percent cover. Mapping CI across the Jornada Basin shows that high-intensity intraspecific competition is not prevalent, with few locations where intense competition is likely to be limiting further honey mesquite expansion. Comparison of CI among physiographic provinces shows differences in average CI values associated with geomorphology, topography, and soil type, suggesting that edaphic conditions may impose important constraints on honey mesquite and growth. However, declining and negative growth rates with increasing CI suggest that intraspecific competition constrains growth rates when CI increases above c. 0.5.}, }
@article {pmid38242304, year = {2024}, author = {Battisti, C}, title = {Changes in bird assemblages following an outdoor music festival: A BACI (before-after-control-impact) monitoring from central Italy.}, journal = {Environmental pollution (Barking, Essex : 1987)}, volume = {344}, number = {}, pages = {123384}, doi = {10.1016/j.envpol.2024.123384}, pmid = {38242304}, issn = {1873-6424}, abstract = {An assessment of the short-term effects of an outdoor music festival (Jova Beach Party event; July 2019; central Italy) on bird assemblages has been carried out, adopting a BACI (Before-After-Control-Impact) survey design, and using the point counts method both in the impact site (Impact, I; where the concert was held) and in comparable Control site (C). In the I site, data have been stratified both for urban (U) and agro-mosaic (M) habitats. When comparing before and after the music event, in IU site, the species richness and the Hill diversity index decreased, differently from CU where species richness a species abundance increased. Diversity profiles highlighted the impoverishment of bird assemblages after the event, but only in the Impact urban habitats. After the musical event, individual rarefaction curves for richness were lower in IU after the concert, while, differently in CU curves are higher. These data suggest an impact in bird assemblages limited to the urban site, due to the stress mainly induced by high intensity noise pollution. Musical events may disrupt the structure of synanthropic bird assemblages, inducing a dispersal of individuals towards the surrounding landscape. Starling (Sturnus vulgaris) appeared a particularly sensitive bird. However, further efforts are necessary to study the effects of these events at species level.}, }
@article {pmid38181959, year = {2024}, author = {Vascotto, I and Bernardi Aubry, F and Bastianini, M and Mozetič, P and Finotto, S and Francé, J}, title = {Exploring the mesoscale connectivity of phytoplankton periodic assemblages' succession in northern Adriatic pelagic habitats.}, journal = {The Science of the total environment}, volume = {913}, number = {}, pages = {169814}, doi = {10.1016/j.scitotenv.2023.169814}, pmid = {38181959}, issn = {1879-1026}, mesh = {*Phytoplankton ; *Ecosystem ; Oceans and Seas ; Rivers ; Italy ; Seasons ; }, abstract = {An appropriate model for phytoplankton distribution patterns is critical for understanding biogeochemical cycles and trophic interactions in the oceans and seas. Because phytoplankton dynamics in coastal waters are more complex due to shallow depth and proximity to land, more accurate models applied to the correct spatial and temporal scales are needed. Our study investigates the role of the atmosphere and hydrosphere in pelagic habitat by modelling phytoplankton assemblages at two Long Term Ecological Research sites in the northern Adriatic Sea using niche-forming environmental variables (wind, temperature, salinity, river discharge, rain, and water column stratification). To study the synchronization between the phytoplankton community and these environmental variables at the two LTER sites, we applied current linear and nonlinear numerical methods for ecological modelling. The aim was to use periodic and/or non-periodic properties of the environmental variables to classify the phytoplankton assemblages at one LTER site (Gulf of Trieste - Slovenia) and then predict them at another LTER site 100 km away (Gulf of Venice - Italy). We found that periodicity played a role in the explanatory and predictive power of the environmental variables and that it was more important than non-periodic events in defining the common structure of the two pelagic habitats. The non-linear classification functions of the neural networks further increased the predictive power of these variables. We observed partial synchronization of communities at the mesoscale and differences between the original and predicted assemblages under similar environmental conditions. We conclude that mesoscale connectivity plays an important role in phytoplankton communities in the northern Adriatic. However, the loss of periodicity of niche-forming variables due to more frequent extreme meteorological and hydrological events could loosen these connections and affect the temporal succession of phytoplankton assemblages.}, }
@article {pmid38170360, year = {2024}, author = {Ciaralli, L and Rotini, A and Scalici, M and Battisti, C and Chiesa, S and Christoforou, E and Libralato, G and Manfra, L}, title = {The under-investigated plastic threat on seagrasses worldwide: a comprehensive review.}, journal = {Environmental science and pollution research international}, volume = {31}, number = {6}, pages = {8341-8353}, pmid = {38170360}, issn = {1614-7499}, mesh = {*Ecosystem ; *Plastics ; Environmental Pollution ; Microplastics ; Europe ; }, abstract = {Marine plastic pollution is a well-recognised and debated issue affecting most marine ecosystems. Despite this, the threat of plastic pollution on seagrasses has not received significant scientific attention compared to other marine species and habitats. The present review aims to summarise the scientific data published in the last decade (January 2012-2023), concerning the evaluation of plastic pollution, of all sizes and types, including bio-based polymers, on several seagrass species worldwide. To achieve this goal, a comprehensive and critical review of 26 scientific papers has been carried out, taking into consideration the investigated areas, the seagrass species and the plant parts considered, the experimental design and the type of polymers analysed, both in field monitoring and in laboratory-controlled experiments. The outcomes of the present review clearly showed that the dynamics and effects of plastic pollution in seagrass are still under-explored. Most data emerged from Europe, with little or no data on plastic pollution in North and South America, Australia, Africa and Antarctica. Most of the studies were devoted to microplastics, with limited studies dedicated to macroplastics and only one to nanoplastics. The methodological approach (in terms of experimental design and polymer physico-chemical characterisation) should be carefully standardised, beside the use of a model species, such as Zostera marina, and further laboratory experiments. All these knowledge gaps must be urgently fulfilled, since valuable and reliable scientific knowledge is necessary to improve seagrass habitat protection measures against the current plastic pollution crisis.}, }
@article {pmid38168486, year = {2024}, author = {Duell, EB and Baum, KA and Wilson, GWT}, title = {Drought reduces productivity and anti-herbivore defences, but not mycorrhizal associations, of perennial prairie forbs.}, journal = {Plant biology (Stuttgart, Germany)}, volume = {26}, number = {2}, pages = {204-213}, doi = {10.1111/plb.13604}, pmid = {38168486}, issn = {1438-8677}, support = {1003475//National Institute of Food and Agriculture/ ; OIA 1656006//National Science Foundation/ ; NSF DEB-1440484//National Science Foundation Long-Term Ecological Research/ ; G12AC00002//South Central Climate Adaptation Science Center/ ; }, mesh = {Animals ; *Mycorrhizae ; Herbivory ; Plant Nectar ; Grassland ; Droughts ; Water ; Soil ; }, abstract = {During drought, plants allocate resources to aboveground biomass production and belowground carbohydrate reserves, often at the expense of production of defence traits. Additionally, drought has been shown to alter floral resources, with potential implications for plant-pollinator interactions. Although soil symbionts, such as arbuscular mycorrhizal (AM) fungi, can alleviate drought stress in plants, certain levels of drought may negatively impact this relationship, with potential cascading effects. Because of their importance to plant and animal community diversity, we examined effects of drought on biomass production, physical defence properties, nectar production, and associated AM fungal abundance of five common prairie forb species in a greenhouse study. Reduced soil moisture decreased vegetative biomass production. Production of trichomes and latex decreased under drought, relative to well-watered conditions. Ruellia humilis flowers produced less nectar under drought, relative to well-watered conditions. Intra-radical AM fungal colonization was not significantly affected by drought, although extra-radical AM fungal biomass associated with S. azurea decreased following drought. Overall, grassland forb productivity, defence, and nectar production were negatively impacted by moderate drought, with possible negative implications for biotic interactions. Reduced flower and nectar production may lead to fewer pollinator visitors, which may contribute to seed limitation in forb species. Reduced physical defences increase the likelihood of herbivory, further decreasing the ability to store energy for essential functions, such as reproduction. Together, these results suggest drought can potentially impact biotic interactions between plants and herbivores, pollinators, and soil symbionts, and highlights the need for direct assessments of these relationships under climate change scenarios.}, }
@article {pmid38129676, year = {2023}, author = {Zhu, Q and Larson, KL}, title = {Multi-Scalar Drivers of Residential Vegetation Changes in Metropolitan Phoenix, Arizona.}, journal = {Environmental management}, volume = {}, number = {}, pages = {}, pmid = {38129676}, issn = {1432-1009}, support = {DEB-1832016//National Science Foundation/ ; DEB-1832016//National Science Foundation/ ; DEB-2224662//Central Arizona-Phoenix Long-Term Ecological Research Program/ ; DEB-2224662//Central Arizona-Phoenix Long-Term Ecological Research Program/ ; }, abstract = {In the arid southwestern U.S., urban greening strategies have been promoted to alleviate ecosystem disservices associated with lawns, including the adoption of xeric yards with desert-adapted floras and gravel groundcover and wildlife-friendly yards with complex vegetation structure and composition. Scant studies have investigated the extent of different vegetation changes in urban greening practices and the complexity of associated human drivers. We addressed this gap by analyzing survey data from two survey periods (2017 and 2021) to answer the following questions: to what extent have residents from metropolitan Phoenix made different vegetation changes in their yards over the last decade, and how do multi-scalar human drivers affect different vegetation changes? We found a sustainable trajectory for residential vegetation changes in Phoenix since mid-2010s, with declining additions of grass and increases in trees and desert plants across residential neighborhoods. Esthetics was an influential driver of both tree planting and native gardening. Additionally, tree planting was associated with anthropocentric values (i.e., low-maintenance needs), while desert plant additions reflected the appreciation of nature (i.e., attitudes towards the desert) and environmental concerns (i.e., supporting wildlife). Institutions such as local government programs might shape residents' vegetation choices, as tree planting differed among municipalities. We also found counterintuitive influences of residential tenure controls on landscaping decisions. Specifically, renters were more likely to add yard trees compared to homeowners. Our results inform landscape sustainability by identifying potential pathways to residential yard changes that offer a multitude of services while being appreciated and maintained by residents.}, }
@article {pmid38091643, year = {2024}, author = {Vollrath, SR and Lemos, VM and Vieira, JP and Garcia, AM}, title = {Long-term trends in juvenile Mugil liza abundance in relation to selected environmental and fisheries influences in southern Brazil.}, journal = {Marine environmental research}, volume = {193}, number = {}, pages = {106290}, doi = {10.1016/j.marenvres.2023.106290}, pmid = {38091643}, issn = {1879-0291}, mesh = {Animals ; *Ecosystem ; Fisheries ; Brazil ; Conservation of Natural Resources ; Water ; *Smegmamorpha/physiology ; }, abstract = {Overfishing constitutes a major threat affecting marine fish population worldwide, including mullet species that have been exploited by fisheries during the reproductive migration in temperate and tropical latitudes for millennia. In the present study, we investigated the relationship of fishing intensity of mullet Mugil liza during its reproductive migration and the abundance of their juveniles in an essential nursery ground for the species in the southwest Atlantic Ocean. To carry out this analysis, we used a 23-year standardized long-term time series (1997-2019) of monthly abundance of M. liza juveniles, local/regional (water temperature, salinity, water transparency and river discharge) and global (ENSO) environmental factors, along with compilations of fishing landing data for the species. Generalized Additive Models (GAM) revealed the negative effect of fishing adult populations on the abundance of juveniles when they reach the marine surf-zone and after recruiting into the estuary. Our results reinforce the importance of adequate conservation and fishery regulation policies to prevent the species' stock from collapsing.}, }
@article {pmid38071696, year = {2023}, author = {Peinetti, HR and Bestelmeyer, BT and Chirino, CC and Vivalda, FL and Kin, AG}, title = {Thresholds and alternative states in a Neotropical dry forest in response to fire severity.}, journal = {Ecological applications : a publication of the Ecological Society of America}, volume = {}, number = {}, pages = {e2937}, doi = {10.1002/eap.2937}, pmid = {38071696}, issn = {1051-0761}, support = {agreement 3050-11210-009-51-N//Agricultural Research Service/ ; DEB-1832194//Jornada Basin Long-Term Ecological Research Program/ ; POIRE 2016-18//Universidad Nacional de La Pampa/ ; }, abstract = {Neotropical xerophytic forest ecosystems evolved with fires that shaped their resilience to disturbance events. However, it is unknown whether forest resilience to fires persists under a new fire regime influenced by anthropogenic disturbance and climate change. We asked whether there was evidence for a fire severity threshold causing an abrupt transition from a forest to an alternative shrub thicket state in the presence of typical postfire management. We studied a heterogeneous wildfire event to assess medium-term effects (11 years) of varying fire severity in a xerophytic Caldén forest in central Argentina. We conducted vegetation surveys in patches that were exposed to low (LFS), medium (MFS), and high (HFS) fire severities but had similar prefire woody canopy cover. Satellite images were used to quantify fire severity using a delta Normalized Burning Ratio (dNBR) and to map prefire canopy cover. Postfire total woody canopy cover was higher in low and medium than high severity patches, but the understory woody component was highest in HFS patches. The density of woody plants was over three times higher under HFS than MFS and LFS due to the contribution of small woody plants to the total density. Unlike LFS and MFS patches, the small plants in HFS patches were persistent, multistem shrubs that resulted from the resprouting of top-killed Prosopis caldenia trees and, more importantly, from young shrubs that probably established after the wildfire. Our results suggest that the Caldén forest is resilient to fires of low to moderate severities but not to high-severity fires. Fire severities with dNBR values > ~600 triggered an abrupt transition to a shrub thicket state. Postfire grazing and controlled-fire treatments likely contributed to shrub dominance after high-severity wildfire. Forest to shrub thicket transitions enable recurring high-severity fire events. We propose that repeated fires combined with grazing can trap the system in a shrub thicket state. Further studies are needed to determine whether the relationships between fire and vegetation structure examined in this case study represent general mechanisms of irreversible state changes across the Caldenal forest region and whether analogous threshold relationships exist in other fire-prone woodland ecosystems.}, }
@article {pmid38070183, year = {2024}, author = {Zukswert, JM and Vadeboncoeur, MA and Yanai, RD}, title = {Responses of stomatal density and carbon isotope composition of sugar maple and yellow birch foliage to N, P and CaSiO3 fertilization.}, journal = {Tree physiology}, volume = {44}, number = {1}, pages = {}, doi = {10.1093/treephys/tpad142}, pmid = {38070183}, issn = {1758-4469}, support = {2019-67019-29464//United Stated Department of Agriculture National Institute of Food and Agriculture/ ; DEB-1637685//National Science Foundation Long-Term Ecological Research/ ; //Edna B. Sussman Fellowship/ ; }, mesh = {*Betula/physiology ; *Acer/physiology ; Carbon Isotopes ; Trees/physiology ; Fertilization ; Plant Leaves/physiology ; }, abstract = {Stomatal density, stomatal length and carbon isotope composition can all provide insights into environmental controls on photosynthesis and transpiration. Stomatal measurements can be time-consuming; it is therefore wise to consider efficient sampling schemes. Knowing the variance partitioning at different measurement levels (i.e., among stands, plots, trees, leaves and within leaves) can aid in making informed decisions around where to focus sampling effort. In this study, we explored the effects of nitrogen (N), phosphorus (P) and calcium silicate (CaSiO3) addition on stomatal density, length and carbon isotope composition (δ13C) of sugar maple (Acer saccharum Marsh.) and yellow birch (Betula alleghaniensis Britton). We observed a positive but small (8%) increase in stomatal density with P addition and an increase in δ13C with N and CaSiO3 addition in sugar maple, but we did not observe effects of nutrient addition on these characteristics in yellow birch. Variability was highest within leaves and among trees for stomatal density and highest among stomata for stomatal length. To reduce variability and increase chances of detecting treatment differences in stomatal density and length, future protocols should consider pretreatment and repeated measurements of trees over time or measure more trees per plot, increase the number of leaf impressions or standardize their locations, measure more stomata per image and ensure consistent light availability.}, }
@article {pmid38037301, year = {2024}, author = {Siqueira, T and Hawkins, CP and Olden, JD and Tonkin, J and Comte, L and Saito, VS and Anderson, TL and Barbosa, GP and Bonada, N and Bonecker, CC and Cañedo-Argüelles, M and Datry, T and Flinn, MB and Fortuño, P and Gerrish, GA and Haase, P and Hill, MJ and Hood, JM and Huttunen, KL and Jeffries, MJ and Muotka, T and O'Donnell, DR and Paavola, R and Paril, P and Paterson, MJ and Patrick, CJ and Perbiche-Neves, G and Rodrigues, LC and Schneider, SC and Straka, M and Ruhi, A}, title = {Understanding temporal variability across trophic levels and spatial scales in freshwater ecosystems.}, journal = {Ecology}, volume = {105}, number = {2}, pages = {e4219}, doi = {10.1002/ecy.4219}, pmid = {38037301}, issn = {1939-9170}, support = {2017SGR1643//Ag&#xe8;ncia de Gesti&#xf3; d'Ajuts Universitaris i de Recerca/ ; 309496/2021-7//Conselho Nacional de Desenvolvimento Cient&#xed;fico e Tecnol&#xf3;gico/ ; 871128//eLTER PLUS/ ; FADR65//Fish and Wildlife Service and the Division of Wildlife/ ; FADX09//Fish and Wildlife Service and the Division of Wildlife/ ; FADB02//Fish and Wildlife Service and the Division of Wildlife/ ; 19/04033-7//Funda&#xe7;&#xe3;o de Amparo &#xe0; Pesquisa do Estado de S&#xe3;o Paulo/ ; 2019/06291-3//Funda&#xe7;&#xe3;o de Amparo &#xe0; Pesquisa do Estado de S&#xe3;o Paulo/ ; 21/00619-7//Funda&#xe7;&#xe3;o de Amparo &#xe0; Pesquisa do Estado de S&#xe3;o Paulo/ ; P505-20-17305S//Grantov&#xe1; Agentura &#x10c;esk&#xe9; Republiky/ ; 2047324//National Science Foundation/ ; IOS-1754838//National Science Foundation/ ; #DEB-2025982//NTL LTER/ ; RYC2020-029829-I//Ram&#xf3;n y Cajal Fellowship/ ; RDF-18-UOC-007//Royal Society Te Ap&#x101;rangi/ ; }, mesh = {*Ecosystem ; *Food Chain ; Biodiversity ; Fresh Water ; Time Factors ; }, abstract = {A tenet of ecology is that temporal variability in ecological structure and processes tends to decrease with increasing spatial scales (from locales to regions) and levels of biological organization (from populations to communities). However, patterns in temporal variability across trophic levels and the mechanisms that produce them remain poorly understood. Here we analyzed the abundance time series of spatially structured communities (i.e., metacommunities) spanning basal resources to top predators from 355 freshwater sites across three continents. Specifically, we used a hierarchical partitioning method to disentangle the propagation of temporal variability in abundance across spatial scales and trophic levels. We then used structural equation modeling to determine if the strength and direction of relationships between temporal variability, synchrony, biodiversity, and environmental and spatial settings depended on trophic level and spatial scale. We found that temporal variability in abundance decreased from producers to tertiary consumers but did so mainly at the local scale. Species population synchrony within sites increased with trophic level, whereas synchrony among communities decreased. At the local scale, temporal variability in precipitation and species diversity were associated with population variability (linear partial coefficient, β = 0.23) and population synchrony (β = -0.39) similarly across trophic levels, respectively. At the regional scale, community synchrony was not related to climatic or spatial predictors, but the strength of relationships between metacommunity variability and community synchrony decreased systematically from top predators (β = 0.73) to secondary consumers (β = 0.54), to primary consumers (β = 0.30) to producers (β = 0). Our results suggest that mobile predators may often stabilize metacommunities by buffering variability that originates at the base of food webs. This finding illustrates that the trophic structure of metacommunities, which integrates variation in organismal body size and its correlates, should be considered when investigating ecological stability in natural systems. More broadly, our work advances the notion that temporal stability is an emergent property of ecosystems that may be threatened in complex ways by biodiversity loss and habitat fragmentation.}, }
@article {pmid37991585, year = {2024}, author = {Albuquerque-Lima, S and Lopes, AV and Machado, IC}, title = {Reproductive isolation between two sympatric bat-pollinated Bauhinia (Leguminosae).}, journal = {Journal of plant research}, volume = {137}, number = {1}, pages = {65-77}, pmid = {37991585}, issn = {1618-0860}, support = {PROEX-0487//Coordena&#xe7;&#xe3;o de Aperfei&#xe7;oamento de Pessoal de N&#xed;vel Superior/ ; 001//Coordena&#xe7;&#xe3;o de Aperfei&#xe7;oamento de Pessoal de N&#xed;vel Superior/ ; 88887.898666/2023-00//Coordena&#xe7;&#xe3;o de Aperfei&#xe7;oamento de Pessoal de N&#xed;vel Superior/ ; 459485/2014-8//Conselho Nacional de Desenvolvimento Cient&#xed;fico e Tecnol&#xf3;gico/ ; , 437424/2018-9//Conselho Nacional de Desenvolvimento Cient&#xed;fico e Tecnol&#xf3;gico/ ; LTER-Catimbau 403770/2012-2//Conselho Nacional de Desenvolvimento Cient&#xed;fico e Tecnol&#xf3;gico/ ; 311021/2014-0//Conselho Nacional de Desenvolvimento Cient&#xed;fico e Tecnol&#xf3;gico/ ; 310508/2019-3//Conselho Nacional de Desenvolvimento Cient&#xed;fico e Tecnol&#xf3;gico/ ; 309505/2018-6//Conselho Nacional de Desenvolvimento Cient&#xed;fico e Tecnol&#xf3;gico/ ; 306286/2022-0//Conselho Nacional de Desenvolvimento Cient&#xed;fico e Tecnol&#xf3;gico/ ; }, mesh = {Animals ; *Chiroptera ; *Bauhinia ; *Fabaceae ; Reproductive Isolation ; Pollination ; Flowers/anatomy &amp; histology ; }, abstract = {Several barriers contribute to reproductive isolation between plant species, which can be classified as pre- or post-pollination. Understanding the strength of these barriers could clarify the factors that maintain reproductive isolation and thus species integrity. In this study, we quantified reproductive isolation between two bat-pollinated co-occurring Bauhinia species (B. acuruana and B. pentandra) with similar flower morphology. Over the course of 18 months, we assessed reproductive isolation between these two Bauhinia species by quantifying the individual strengths and absolute contributions of five pre- and post- pollination barriers. Our data showed that both species are completely isolated in their reproduction by a combination of several barriers. Although they co-occur in a few populations, we found a high degree of geographic isolation between them. And although their flowering periods overlap, there is a significant difference in flowering peaks. Both species have the same pollinating bats, but the interspecific transfer of pollen between the plant species may be reduced due to the different length of the flower stamens, resulting in different pollen deposition on the bats' bodies. We have documented complete incompatibility between taxa and conclude that pre- and post-pollination barriers are important factors in preventing gene flow, even in contact zones between these two species of Bauhinia. We highlight that our work is the first study to use methods to estimate the strength of reproductive isolation barriers between bat-pollinated species.}, }
@article {pmid37967209, year = {2023}, author = {Taniguchi, DAA and Menden-Deuer, S}, title = {Planktonic predator selectivity: Eating local with global implications.}, journal = {Proceedings of the National Academy of Sciences of the United States of America}, volume = {120}, number = {48}, pages = {e2317302120}, pmid = {37967209}, issn = {1091-6490}, support = {LTER-1655686//National Science Foundation (NSF)/ ; OCE-1736635//National Science Foundation (NSF)/ ; 80NSSC17K0716//National Aeronautics and Space Administration (NASA)/ ; }, mesh = {Animals ; *Plankton ; *Food Chain ; Predatory Behavior ; Oceans and Seas ; }, }
@article {pmid37933324, year = {2023}, author = {Matthews, SA and Blanco-Bercial, L}, title = {Divergent patterns of zooplankton connectivity in the epipelagic and mesopelagic zones of the eastern North Pacific.}, journal = {Ecology and evolution}, volume = {13}, number = {11}, pages = {e10664}, pmid = {37933324}, issn = {2045-7758}, abstract = {Due to historical under-sampling of the deep ocean, the distributional ranges of mesopelagic zooplankton are not well documented, leading to uncertainty about the mechanisms that shape midwater zooplankton community composition. Using a combination of DNA metabarcoding (18S-V4 and mtCOI) and trait-based analysis, we characterized zooplankton diversity and community composition in the upper 1000 m of the northeast Pacific Ocean. We tested whether the North Pacific Transition Zone is a biogeographic boundary region for mesopelagic zooplankton. We also tested whether zooplankton taxa occupying different vertical habitats and exhibiting different ecological traits differed in the ranges of temperature, Chl-a, and dissolved oxygen conditions inhabited. The depth of the maximum taxonomic richness deepened with increasing latitude in the North Pacific. Community similarity in the mesopelagic zone also increased in comparison with the epipelagic zone, and no evidence was found for a biogeographic boundary between previously delineated mesopelagic biogeochemical provinces. Epipelagic zooplankton exhibited broader temperature and Chl-a ranges than mesopelagic taxa. Within the epipelagic, taxa with broader temperature and Chl-a ranges also had broader distributional ranges. However, mesopelagic taxa were distributed across wider dissolved oxygen ranges, and within the mesopelagic, only oxygen ranges covaried with distributional ranges. Environmental and distributional ranges also varied among traits, both for epipelagic taxa and mesopelagic taxa. The strongest differences in both environmental and distributional ranges were observed for taxa with or without diel vertical migration behavior. Our results suggest that species traits can influence the differential effects of physical dispersal and environmental selection in shaping biogeographic distributions.}, }
@article {pmid37878914, year = {2023}, author = {Bergallo, HG and Rosa, C and Ochoa, AC and Manzatto, AG and Guimaraes, AF and Banhos, A and Castilho, CV and Barros, CF and Norris, D and Drucker, DP and Rodrigues, DJ and Baccaro, FB and Lourenço, IH and Zuanon, J and Stegmann, LF and Anjos, MR and Silveira, M and Araújo, PSG and Bobrowiec, PED and Fadini, R and Neckel-Oliveira, S and Emilio, T and Santorelli Junior, S and Magnusson, WE}, title = {Long-term Ecological Research: Chasing fashions or being prepared for fashion changes?.}, journal = {Anais da Academia Brasileira de Ciencias}, volume = {95}, number = {3}, pages = {e20230051}, doi = {10.1590/0001-3765202320230051}, pmid = {37878914}, issn = {1678-2690}, mesh = {Humans ; *Ecosystem ; *Biodiversity ; Longitudinal Studies ; }, abstract = {Long-term-ecological-research (LTER) faces many challenges, including the difficulty of obtaining long-term funding, changes in research questions and sampling designs, keeping researchers collecting standardized data for many years, impediments to interactions with local people, and the difficulty of integrating the needs of local decision makers with "big science". These issues result in a lack of universally accepted guidelines as to how research should be done and integrated among LTER sites. Here we discuss how the RAPELD (standardized field infrastructure system), can help deal with these issues as a complementary technique in LTER studies, allowing comparisons across landscapes and ecosystems and reducing sampling costs. RAPELD uses local surveys to understand broad spatial and temporal patterns while enhancing decision-making and training of researchers, local indigenous groups and traditional communities. Sampling of ecological data can be carried out by different researchers through standardized protocols, resulting in spatial data that can be used to answer temporal questions, and allow new questions to be investigated. Results can also be integrated into existing biodiversity networks. Integrated systems are the most efficient way to save resources, maximize results, and accumulate information that can be used in the face of the unknown unknowns upon which our future depends.}, }
@article {pmid37841229, year = {2023}, author = {Turner, TF and Bart, HL and McCormick, F and Besser, AC and Bowes, RE and Capps, KA and DeArmon, ES and Dillman, CB and Driscoll, KP and Dugger, A and Hamilton, GL and Harris, PM and Hendrickson, DA and Hoffman, J and Knouft, JH and Lepak, RF and López-Fernández, H and Montaña, CG and Newsome, SD and Pease, AA and Smith, WL and Taylor, CA and Welicky, RL}, title = {Long-term ecological research in freshwaters enabled by regional biodiversity collections, stable isotope analysis, and environmental informatics.}, journal = {Bioscience}, volume = {73}, number = {7}, pages = {479-493}, pmid = {37841229}, issn = {0006-3568}, support = {EPA999999/ImEPA/Intramural EPA/United States ; }, abstract = {Biodiversity collections are experiencing a renaissance fueled by the intersection of informatics, emerging technologies, and the extended use and interpretation of specimens and archived databases. In this article, we explore the potential for transformative research in ecology integrating biodiversity collections, stable isotope analysis (SIA), and environmental informatics. Like genomic DNA, SIA provides a common currency interpreted in the context of biogeochemical principles. Integration of SIA data across collections allows for evaluation of long-term ecological change at local to continental scales. Challenges including the analysis of sparse samples, a lack of information about baseline isotopic composition, and the effects of preservation remain, but none of these challenges is insurmountable. The proposed research framework interfaces with existing databases and observatories to provide benchmarks for retrospective studies and ecological forecasting. Collections and SIA add historical context to fundamental questions in freshwater ecological research, reference points for ecosystem monitoring, and a means of quantitative assessment for ecosystem restoration.}, }
@article {pmid37804992, year = {2024}, author = {Chandrakanthan, K and Fraser, MP and Herckes, P}, title = {Microplastics are ubiquitous and increasing in soil of a sprawling urban area, Phoenix (Arizona).}, journal = {The Science of the total environment}, volume = {906}, number = {}, pages = {167617}, doi = {10.1016/j.scitotenv.2023.167617}, pmid = {37804992}, issn = {1879-1026}, abstract = {Microplastics are environmental contaminants that have been extensively studied in marine and aquatic environments; terrestrial ecosystems, where most microplastics originate and have the potential to accumulate, typically receive less attention. This study aims to investigate the spatial and temporal soil concentrations of microplastics in a large desert metropolitan area, the Central Arizona-Phoenix Long-Term Ecological Research (CAP-LTER) area. Soil samples from the Ecological Survey of Central Arizona (ESCA) surveys (2005 and 2015) were leveraged to study spatial distributions and the temporal change of microplastic abundances. The temporal soil microplastics data were supplemented by microplastics deposition fluxes in a central location within the area (Tempe, AZ) for a period of one year (Oct 5th, 2020 to Sept 22nd, 2021). Samples were processed and microplastics were counted under an optical microscope to obtain quantitative information of their distribution in soil. Results for the spatial variation of the microplastic abundances in soil samples in Phoenix and the surrounding areas of the Sonoran Desert from 2015 depict microplastics as ubiquitous and abundant in soils (122 to 1299 microplastics/kg) with no clear trends between different locations. Microplastics deposition fluxes show substantial deposition in the local area (71 to 389 microplastics/m[2]/day with an average deposition flux of 178 microplastics/m[2]/day) but the role of resuspension and redistribution by dust storms to deposition may contribute to the unclear spatial trends. Comparison between the 2005 and 2015 surveys show a systematic increase in the abundance of microplastics and a decrease in microplastics size. Micro-Raman spectroscopy identified a variety of plastics including PE, PS, PVC, PA, PES and PP. However, a majority of microplastics remained chemically unidentifiable. Polyethylene was present in 75 % of the sampling sites and was the most abundant polymer on average in all soil samples.}, }
@article {pmid37793967, year = {2023}, author = {Brehm, AM and Orrock, JL}, title = {Extensive behavioral data contained within existing ecological datasets.}, journal = {Trends in ecology &amp; evolution}, volume = {38}, number = {12}, pages = {1129-1133}, doi = {10.1016/j.tree.2023.08.016}, pmid = {37793967}, issn = {1872-8383}, mesh = {*Ecology ; }, abstract = {Long-term ecological datasets contain vast behavioral data, enabling the quantification of among-individual behavioral variation at unprecedented spatiotemporal scales. We detail how behaviors can be extracted and describe how such data can be used to test new hypotheses, inform population and community ecology, and address pressing conservation needs.}, }
@article {pmid37759619, year = {2023}, author = {Nativ, H and Galili, O and Almuly, R and Einbinder, S and Tchernov, D and Mass, T}, title = {New Record of Dendronephthya sp. (Family: Nephtheidae) from Mediterranean Israel: Evidence for Tropicalization?.}, journal = {Biology}, volume = {12}, number = {9}, pages = {}, pmid = {37759619}, issn = {2079-7737}, support = {23241//the Ministry of Innovation, Science &amp; Technology, Israel./ ; }, abstract = {Bio-invasions have the potential to provoke cascade effects that can disrupt natural ecosystems and cause ecological regime shifts. The Mediterranean Sea is particularly prone to bio-invasions as the changing water conditions, evoked by climate change, are creating advantageous conditions for Lessepsian migrants from the Red Sea. Recently, in May 2023, a new alien species was documented in the Mediterranean Sea-a soft coral of the genus Dendronephthya. This discovery was made by divers conducting 'Long-Term Ecological Research' surveys, along the coast of Israel, at a depth of 42 m. Genetic and morphological testing suggest that the species identity may be Dendronepthya hemprichi, an Indo-Pacific coral, common in the Red Sea. According to life history traits of this species, such as accelerated attachment to available surfaces and fast growth, we expect it to rapidly expand its distribution and abundance across the Mediterranean Sea.}, }
@article {pmid37694963, year = {2023}, author = {Rodenhizer, H and Natali, SM and Mauritz, M and Taylor, MA and Celis, G and Kadej, S and Kelley, AK and Lathrop, ER and Ledman, J and Pegoraro, EF and Salmon, VG and Schädel, C and See, C and Webb, EE and Schuur, EAG}, title = {Abrupt permafrost thaw drives spatially heterogeneous soil moisture and carbon dioxide fluxes in upland tundra.}, journal = {Global change biology}, volume = {29}, number = {22}, pages = {6286-6302}, doi = {10.1111/gcb.16936}, pmid = {37694963}, issn = {1365-2486}, support = {DE-SC0006982//Biological and Environmental Research, Terrestrial Ecosystem Science Program/ ; DE-SC0014085//Biological and Environmental Research, Terrestrial Ecosystem Science Program/ ; DE-SC0020227//Biological and Environmental Research, Terrestrial Ecosystem Science Program/ ; 1026415//National Science Foundation Bonanza Creek LTER Program/ ; 0747195//National Science Foundation CAREER/ ; }, abstract = {Permafrost thaw causes the seasonally thawed active layer to deepen, causing the Arctic to shift toward carbon release as soil organic matter becomes susceptible to decomposition. Ground subsidence initiated by ice loss can cause these soils to collapse abruptly, rapidly shifting soil moisture as microtopography changes and also accelerating carbon and nutrient mobilization. The uncertainty of soil moisture trajectories during thaw makes it difficult to predict the role of abrupt thaw in suppressing or exacerbating carbon losses. In this study, we investigated the role of shifting soil moisture conditions on carbon dioxide fluxes during a 13-year permafrost warming experiment that exhibited abrupt thaw. Warming deepened the active layer differentially across treatments, leading to variable rates of subsidence and formation of thermokarst depressions. In turn, differential subsidence caused a gradient of moisture conditions, with some plots becoming consistently inundated with water within thermokarst depressions and others exhibiting generally dry, but more variable soil moisture conditions outside of thermokarst depressions. Experimentally induced permafrost thaw initially drove increasing rates of growing season gross primary productivity (GPP), ecosystem respiration (Reco), and net ecosystem exchange (NEE) (higher carbon uptake), but the formation of thermokarst depressions began to reverse this trend with a high level of spatial heterogeneity. Plots that subsided at the slowest rate stayed relatively dry and supported higher CO2 fluxes throughout the 13-year experiment, while plots that subsided very rapidly into the center of a thermokarst feature became consistently wet and experienced a rapid decline in growing season GPP, Reco , and NEE (lower carbon uptake or carbon release). These findings indicate that Earth system models, which do not simulate subsidence and often predict drier active layer conditions, likely overestimate net growing season carbon uptake in abruptly thawing landscapes.}, }
@article {pmid37665531, year = {2023}, author = {Aneaus, S and Rashid, I and Srivastava, PK and Charoo, SA}, title = {Quantifying the landscape changes within and outside the Dachigam National Park, Kashmir Himalaya, India using observations and models.}, journal = {Environmental monitoring and assessment}, volume = {195}, number = {10}, pages = {1139}, doi = {10.1007/s10661-023-11676-x}, pmid = {37665531}, issn = {1573-2959}, mesh = {Humans ; *Ecosystem ; *Parks, Recreational ; Environmental Monitoring ; India ; Agriculture ; }, abstract = {Protected areas are the cornerstone of biodiversity and serve as a haven for biodiversity conservation. However, due to immense anthropic pressures and ongoing changes in climate, the protected reserves are under immense threat. Human interference through land system changes is a major precusor of fragmentation of landscapes resulting in the decline of Himalayan biodiversity. In this context, this research assessed land use land cover changes (LULCCs) and fragmentation within and outside the Dachigam National Park (DNP) using remote sensing data, GIS-based models and ground truth over the past 55 years (1965-2020). Landscape Fragmentation Tool (LFT) helped to compute edge effect, patchiness, perforation and core areas. The Land Change Modeller (LCM) of IDRISI TerrSet was used for simulating the future LULC for the years 2030, 2050, 2700 and 2100. The analysis of LULCCs showed that built-up and aquatic vegetation expanded by 326% and 174%, respectively in the vicinity of the DNP. The area under agriculture, scrub and pasture decreased primarily due to intensified land use activities. Within the DNP, the area under forest cover declined by 7%. A substantial decrease was observed in the core zone both within (39%) and outside (30%) the DNP indicative of fragmentation of natural habitats. LCM analysis projected 10% increase in the built-up extents besides forests, shrublands and pastures. This knowledge generated in this study shall form an important baseline for understanding and characterising the human-wildlife relationship, initiating long-term ecological research (LTER) on naturally vegetated and aquatic ecosystems (primarily Dal Lake) of the region.}, }
@article {pmid37659519, year = {2023}, author = {Gallitelli, L and D'Agostino, M and Battisti, C and Cózar, A and Scalici, M}, title = {Dune plants as a sink for beach litter: The species-specific role and edge effect on litter entrapment by plants.}, journal = {The Science of the total environment}, volume = {904}, number = {}, pages = {166756}, doi = {10.1016/j.scitotenv.2023.166756}, pmid = {37659519}, issn = {1879-1026}, mesh = {*Ecosystem ; *Plants ; Plastics/analysis ; Poaceae ; Sand ; }, abstract = {Anthropogenic litter accumulates along coasts worldwide. In addition to the flowing litter load, wind, sea currents, geomorphology and vegetation determine the distribution of litter trapped on the sandy coasts. Although some studies highlighted the role of dune plants in trapping marine litter, little is known about their efficiency as sinks and about the small-scale spatial distribution of litter across the dune area. Here, we explore these gaps by analysing six plant species widespread in Mediterranean coastal habitats, namely Echinophora spinosa, Limbarda crithmoides, Anthemis maritima, Pancratium maritimum, Thinopyrum junceum, and Salsola kali. The present study analyses for the first time the capture of litter by dune vegetation at a multi-species level, considering their morphological structure. Data on plastic accumulation on dune plants were compared with unvegetated control plots located at embryo-dune and foredune belts. We found that dunal plants mainly entrapped macrolitter (> 0.5 cm). Particularly, E. spinosa, L. crithmoides, A. maritima and P. maritimum mostly accumulated litter in the embryo dune while T. junceum and S. kali entrapped more in the foredune area. Moreover, beach litter was mainly blocked at the edge of the plant patches rather than in the core, highlighting the 'Plant-edge litter effect'. As A. maritima and S. kali entrapped respectively more litter in embryo and foredune habitats, these species could be used to monitor and recollect litter. In this light, our findings provide further insight into the role of dune plants in the beach litter dynamics, suppling useful information for beach clean-up actions.}, }
@article {pmid37658674, year = {2023}, author = {Niu, F and Pierce, NA and Okin, GS and Archer, SR and Fischella, MR and Nadoum, S}, title = {Sandblasting promotes shrub encroachment in arid grasslands.}, journal = {The New phytologist}, volume = {240}, number = {5}, pages = {1817-1829}, doi = {10.1111/nph.19238}, pmid = {37658674}, issn = {1469-8137}, support = {NSF DEB-1556587//National Science Foundation/ ; NSF DEB-1556735//National Science Foundation/ ; DEB 12-35828//the Jornada Basin Long Term Ecological Research Program/ ; DEB 18-32194//the Jornada Basin Long Term Ecological Research Program/ ; }, mesh = {*Grassland ; *Ecosystem ; Desert Climate ; Poaceae/physiology ; Soil ; }, abstract = {Shrub encroachment is a common ecological state transition in global drylands and has myriad adverse effects on grasslands and the services they provide. This physiognomic shift is often ascribed to changes in climate (e.g. precipitation) and disturbance regimes (e.g. grazing and fire), but this remains debated. Aeolian processes are known to impact resource distribution in drylands, but their potential role in grassland-to-shrubland state changes has received little attention. We quantified the effects of 'sandblasting' (abrasive damage by wind-blown soil) on the ecophysiology of dryland grass vs shrub functional types using a portable wind tunnel to test the hypothesis that grasses would be more susceptible to sandblasting than shrubs and, thus, reinforce transitions to shrub dominance in wind-erodible grasslands when climate- or disturbance-induced reductions in ground cover occur. Grasses and shrubs responded differently to sandblasting, wherein water-use efficiency declined substantially in grasses, but only slightly in shrubs, owing to grasses having greater increases in day/nighttime leaf conductance and transpiration. The differential ecophysiological response to sandblasting exhibited by grass and shrub functional types could consequently alter the vegetation dynamics in dryland grasslands in favour of the xerophytic shrubs. Sandblasting could thus be an overlooked driver of shrub encroachment in wind-erodible grasslands.}, }
@article {pmid37552457, year = {2023}, author = {Vaca-Sánchez, MS and Cuevas-Reyes, P and Munck, I and Oki, Y and Moia, N and Freitas, T and Almeida, A and Castelan, K and Fernandes, GW}, title = {Patterns in Wing Morphology and Fluctuating Asymmetry in Eulaema nigrita along an Altitudinal Gradient in the Brazilian Rupestrian Grassland.}, journal = {Neotropical entomology}, volume = {52}, number = {5}, pages = {837-847}, pmid = {37552457}, issn = {1678-8052}, mesh = {Humans ; Bees ; Animals ; *Ecosystem ; *Grassland ; Brazil ; Altitude ; Phenotype ; }, abstract = {Mountain ecosystems experience abrupt abiotic changes that represent environmental filters for many organisms, shaping their phenotypic expressions. However, little is known about the morphological and symmetric adjustments of native bees along altitudinal gradients. We evaluated the changes on wing morphology, wing size, and vein fluctuating asymmetry (FA) of Eulaema nigrita Lepeletier (Apidae: Euglossini) associated with climatic variables along an altitudinal gradient in the rupestrian grassland (known also as campo rupestre or rupestrian field) of Serra do Cipó, Brazil. Seven sampling points along the altitudinal gradient were selected and distributed among 800 and 1400 m.a.s.l., and then, 40 individuals of E. nigrita were collected per each altitudinal point to determine the FA levels and the morphological changes using geometric morphometric techniques. We found that the wing size of E. nigrita decreased with increasing altitude. At the highest altitudes, the levels of FA of the wing veins were greater compared to bees from lower altitudes. We detected significant changes in wing morphology along the altitudinal gradient; bees of lower altitudes showed longer and wider wings than bees of higher altitudes, which had narrower and less elongated wings. Our results show a set of morphological adjustments and phenotypic expressions in E. nigrita associated with the variation in environmental conditions along the altitudinal gradient. We highlight the importance of environmental variables as insect-stressor factors, and that FA and geometric morphometric can be excellent tools for monitoring and evaluating environmental stresses.}, }
@article {pmid37457913, year = {2023}, author = {Perez-Quezada, JF and Barichivich, J and Urrutia-Jalabert, R and Carrasco, E and Aguilera, D and Bacour, C and Lara, A}, title = {Warming and drought weaken the carbon sink capacity of an endangered paleoendemic temperate rainforest in South America.}, journal = {Journal of geophysical research. Biogeosciences}, volume = {128}, number = {4}, pages = {2022jg007258}, pmid = {37457913}, issn = {2169-8953}, abstract = {Measurements of ecosystem carbon (C) fluxes in temperate forests are concentrated in the Northern Hemisphere, leaving the functionally diverse temperate forests in the Southern Hemisphere underrepresented. Here, we report three years (February 2018-January 2021) of C fluxes, studied with eddy-covariance and closed chamber techniques, in an endangered temperate evergreen rainforest of the long-lived paleoendemic South American conifer Fitzroya cupressoides. Using classification and regression trees we analyzed the most relevant drivers and thresholds of daily net ecosystem exchange (NEE) and soil respiration. The annual NEE showed that the forest was a moderate C sink during the period analyzed (-287±38 g C m[-2] year [-1]). We found that the capacity to capture C of the Fitzroya rainforests in the Coastal Range of southern Chile is optimal under cool and rainy conditions in the early austral spring (October-November) and decreases rapidly towards the summer dry season (January-February) and autumn. Although the studied forest type has a narrow geographical coverage, the gross primary productivity measured at the tower was highly representative of Fitzroya and other rainforests in the region. Our results suggest that C fluxes in paleoendemic cool F. cupressoides forests may be negatively affected by the warming and drying predicted by climate change models, reinforcing the importance of maintaining this and other long-term ecological research sites in the Southern Hemisphere.}, }
@article {pmid37435715, year = {2023}, author = {Tennies, NK and Alberto, F}, title = {A tool for detecting giant kelp canopy biomass decline in the Californias.}, journal = {Journal of phycology}, volume = {59}, number = {5}, pages = {1100-1106}, doi = {10.1111/jpy.13365}, pmid = {37435715}, issn = {1529-8817}, support = {DE-FOA-0001726//Advanced Research Projects Agency - Energy/ ; C0874002//California Sea Grant, University of California, San Diego/ ; }, abstract = {Kelp species provide many ecosystem services associated with their three-dimensional structures. Among these, fast-growth, canopy-forming species, like giant kelp Macrocystis pyrifera, are the foundation of kelp forests across many temperate reefs. Giant kelp populations have experienced regional declines in different parts of the world. Giant kelp canopy is very dynamic and can take years to recover from disturbance, challenging comparisons of standing biomass with historical baselines. The Santa Barbara Coastal LTER (SBC LTER), curates a time series of Landsat sensed surface cover and biomass for giant kelp in the west coast of North America. In the last decade, this resource has been fundamental to understanding the species' population dynamics and drivers. However, simple ready-to-use summary statistics aimed at classifying regional kelp decline or recovery are not readily available to stakeholders and coastal managers. To this end, we describe here two simple metrics made available through the R package kelpdecline. First, the proportion of Landsat pixels in decline (PPD), in which current biomass is compared with a historical baseline, and second, a pixel occupancy trend (POT), in which current year pixel occupancy is compared to the time-series long probability of occupancy. The package produces raster maps and output tables summarizing kelp decline and trends over a 0.25 × 0.25° scale. Using kelpdecline, we show how sensitivity analysis on PPD parameter variation can increase the confidence of kelp decline estimates.}, }
@article {pmid37424354, year = {2023}, author = {Hardison, SB and McGlathery, KJ and Castorani, MCN}, title = {Effects of seagrass restoration on coastal fish abundance and diversity.}, journal = {Conservation biology : the journal of the Society for Conservation Biology}, volume = {37}, number = {6}, pages = {e14147}, doi = {10.1111/cobi.14147}, pmid = {37424354}, issn = {1523-1739}, support = {//NSF/ ; DEB-1237733//Virginia Coast Reserve Long Term Ecological Research/ ; DEB-1832221//Virginia Coast Reserve Long Term Ecological Research/ ; }, mesh = {Animals ; *Ecosystem ; Conservation of Natural Resources ; *Zosteraceae ; Biodiversity ; Fishes ; }, abstract = {Restoration is accelerating to reverse global declines of key habitats and recover lost ecosystem functions, particularly in coastal ecosystems. However, there is high uncertainty about the long-term capacity of restored ecosystems to provide habitat and increase biodiversity and the degree to which these ecosystem services are mediated by spatial and temporal environmental variability. We addressed these gaps by sampling fishes biannually for 5-7 years (2012-2018) at 16 sites inside and outside a rapidly expanding restored seagrass meadow in coastal Virginia (USA). Despite substantial among-year variation in abundance and species composition, seine catches in restored seagrass beds were consistently larger (6.4 times more fish, p < 0.001) and more speciose (2.6 times greater species richness, p < 0.001; 3.1 times greater Hill-Shannon diversity, p = 0.03) than seine catches in adjacent unvegetated areas. Catches were particularly larger during summer than autumn (p < 0.01). Structural equation modeling revealed that depth and water residence time interacted to control seagrass presence, leading to higher fish abundance and richness in shallow, well-flushed areas that supported seagrass. Together, our results indicate that seagrass restoration yields large and consistent benefits for many coastal fishes, but that restoration and its benefits are sensitive to the dynamic seascapes in which restoration is conducted. Consideration of how seascape-scale environmental variability affects the success of habitat restoration and subsequent ecosystem function will improve restoration outcomes and the provisioning of ecosystem services.}, }
@article {pmid37362204, year = {2023}, author = {Holzer, JM and Orenstein, DE}, title = {Organizational transformation for greater sustainability impact: recent changes in a scientific research infrastructure in Europe.}, journal = {Landscape ecology}, volume = {38}, number = {12}, pages = {1-15}, pmid = {37362204}, issn = {0921-2973}, abstract = {CONTEXT: Scholars across holistic, transdisciplinary, place-based fields of research, such as landscape ecology and social ecology, have increasingly called for an 'all-hands-on-deck' approach for transformations toward greater sustainability of social-ecological systems. This Perspective showcases organizational transformation toward sustainability in the context of a research network dedicated to place-based, social-ecological research in Europe.<br><br>OBJECTIVES: Using the European LTER research infrastructure (eLTER RI) as a case, we analyze recent organizational-level shifts motivated by desires to increase sustainability impact. These shifts include knowledge integration between the natural and social sciences, stakeholder engagement, and a reformulation of administrative guidelines and practices.<br><br>METHODS: Following a program evaluation, new conversations led to new initiatives in the eLTER RI. As researchers who were involved in the program evaluation and the development of new initiatives, we rely on our professional experience and participant observation to provide insights about this process and its developments.<br><br>RESULTS: Recommendations from a recent assessment that critiqued and provided recommendations for the research infrastructure have recently been implemented in the eLTER RI. eLTER has leveraged a unique and timely opportunity-formal recognition and project funding by the EU-to upscale and standardize its infrastructure by creating novel protocols and enacting steps towards implementation.<br><br>CONCLUSIONS: This Perspective demonstrates how eLTER's research agenda and related protocols have evolved to better integrate multiple knowledge types, promote stakeholder integration into research, and foster greater equity and reflexivity in doing science, all of which are considered necessary to increase sustainability impact. We conclude by considering current and potential future challenges.}, }
@article {pmid37350785, year = {2023}, author = {Hansen, FA and James, DK and Anderson, JP and Meredith, CS and Dominguez, AJ and Pombubpa, N and Stajich, JE and Romero-Olivares, AL and Salley, SW and Pietrasiak, N}, title = {Landscape characteristics shape surface soil microbiomes in the Chihuahuan Desert.}, journal = {Frontiers in microbiology}, volume = {14}, number = {}, pages = {1135800}, pmid = {37350785}, issn = {1664-302X}, abstract = {INTRODUCTION: Soil microbial communities, including biological soil crust microbiomes, play key roles in water, carbon and nitrogen cycling, biological weathering, and other nutrient releasing processes of desert ecosystems. However, our knowledge of microbial distribution patterns and ecological drivers is still poor, especially so for the Chihuahuan Desert.<br><br>METHODS: This project investigated the effects of trampling disturbance on surface soil microbiomes, explored community composition and structure, and related patterns to abiotic and biotic landscape characteristics within the Chihuahuan Desert biome. Composite soil samples were collected in disturbed and undisturbed areas of 15 long-term ecological research plots in the Jornada Basin, New Mexico. Microbial diversity of cross-domain microbial groups (total Bacteria, Cyanobacteria, Archaea, and Fungi) was obtained via DNA amplicon metabarcode sequencing. Sequence data were related to landscape characteristics including vegetation type, landforms, ecological site and state as well as soil properties including gravel content, soil texture, pH, and electrical conductivity.<br><br>RESULTS: Filamentous Cyanobacteria dominated the photoautotrophic community while Proteobacteria and Actinobacteria dominated among the heterotrophic bacteria. Thaumarchaeota were the most abundant Archaea and drought adapted taxa in Dothideomycetes and Agaricomycetes were most abundant fungi in the soil surface microbiomes. Apart from richness within Archaea (p&#x2009;=&#x2009;0.0124), disturbed samples did not differ from undisturbed samples with respect to alpha diversity and community composition (p&#x2009;&#x2265;&#x2009;0.05), possibly due to a lack of frequent or impactful disturbance. Vegetation type and landform showed differences in richness of Bacteria, Archaea, and Cyanobacteria but not in Fungi. Richness lacked strong relationships with soil variables. Landscape features including parent material, vegetation type, landform type, and ecological sites and states, exhibited stronger influence on relative abundances and microbial community composition than on alpha diversity, especially for Cyanobacteria and Fungi. Soil texture, moisture, pH, electrical conductivity, lichen cover, and perennial plant biomass correlated strongly with microbial community gradients detected in NMDS ordinations.<br><br>DISCUSSION: Our study provides first comprehensive insights into the relationships between landscape characteristics, associated soil properties, and cross-domain soil microbiomes in the Chihuahuan Desert. Our findings will inform land management and restoration efforts and aid in the understanding of processes such as desertification and state transitioning, which represent urgent ecological and economical challenges in drylands around the world.}, }
@article {pmid37345539, year = {2023}, author = {Volf, M and Leong, JV and de Lima Ferreira, P and Volfová, T and Kozel, P and Matos-Maraví, P and Hörandl, E and Wagner, ND and Luntamo, N and Salminen, JP and Segar, ST and Sedio, BE}, title = {Contrasting levels of β-diversity and underlying phylogenetic trends indicate different paths to chemical diversity in highland and lowland willow species.}, journal = {Ecology letters}, volume = {26}, number = {9}, pages = {1559-1571}, doi = {10.1111/ele.14273}, pmid = {37345539}, issn = {1461-0248}, support = {MSM200962004//Akademie V&#x11b;d &#x10c;esk&#xe9; Republiky/ ; MEMOVA CZ.02.2.69/0.0/0.0/18_053///EU Operational Programme Research/ ; 20-10543Y//Grantov&#xe1; Agentura &#x10c;esk&#xe9; Republiky/ ; ASCEND BII (DBI 2021898)//National Science Foundation/ ; Cedar Creek LTER (DEB 1831944)//National Science Foundation/ ; DEB 2240430//National Science Foundation/ ; }, mesh = {*Salix/genetics ; Phylogeny ; Ecosystem ; Plants ; Biodiversity ; }, abstract = {Diverse specialised metabolites contributed to the success of vascular plants in colonising most terrestrial habitats. Understanding how distinct aspects of chemical diversity arise through heterogeneous environmental pressures can help us understand the effects of abiotic and biotic stress on plant evolution and community assembly. We examined highland and lowland willow species within a phylogenetic framework to test for trends in their chemical α-diversity (richness) and β-diversity (variation among species sympatric in elevation). We show that differences in chemistry among willows growing at different elevations occur mainly through shifts in chemical β-diversity and due to convergence or divergence among species sharing their elevation level. We also detect contrasting phylogenetic trends in concentration and α-diversity of metabolites in highland and lowland willow species. The resulting elevational patterns contribute to the chemical diversity of willows and suggest that variable selective pressure across ecological gradients may, more generally, underpin complex changes in plant chemistry.}, }
@article {pmid37328644, year = {2023}, author = {Kumar, J and Coffin, AW and Baffaut, C and Ponce-Campos, GE and Witthaus, L and Hargrove, WW}, title = {Quantitative Representativeness and Constituency of the Long-Term Agroecosystem Research Network and Analysis of Complementarity with Existing Ecological Networks.}, journal = {Environmental management}, volume = {72}, number = {4}, pages = {705-726}, pmid = {37328644}, issn = {1432-1009}, mesh = {United States ; Neon ; *Agriculture ; }, abstract = {Studies conducted at sites across ecological research networks usually strive to scale their results to larger areas, trying to reach conclusions that are valid throughout larger enclosing regions. Network representativeness and constituency can show how well conditions at sampling locations represent conditions also found elsewhere and can be used to help scale-up results over larger regions. Multivariate statistical methods have been used to design networks and select sites that optimize regional representation, thereby maximizing the value of datasets and research. However, in networks created from already established sites, an immediate challenge is to understand how well existing sites represent the range of environments in the whole area of interest. We performed an analysis to show how well sites in the USDA Long-Term Agroecosystem Research (LTAR) Network represent all agricultural working lands within the conterminous United States (CONUS). Our analysis of 18 LTAR sites, based on 15 climatic and edaphic characteristics, produced maps of representativeness and constituency. Representativeness of the LTAR sites was quantified through an exhaustive pairwise Euclidean distance calculation in multivariate space, between the locations of experiments within each LTAR site and every 1 km cell across the CONUS. Network representativeness is from the perspective of all CONUS locations, but we also considered the perspective from each LTAR site. For every LTAR site, we identified the region that is best represented by that particular site-its constituency-as the set of 1 km grid locations best represented by the environmental drivers at that particular LTAR site. Representativeness shows how well the combination of characteristics at each CONUS location was represented by the LTAR sites' environments, while constituency shows which LTAR site was the closest match for each location. LTAR representativeness was good across most of the CONUS. Representativeness for croplands was higher than for grazinglands, probably because croplands have more specific environmental criteria. Constituencies resemble ecoregions but have their environmental conditions "centered" on those at particular existing LTAR sites. Constituency of LTAR sites can be used to prioritize the locations of experimental research at or even within particular sites, or to identify the extents that can likely be included when generalizing knowledge across larger regions of the CONUS. Sites with a large constituency have generalist environments, while those with smaller constituency areas have more specialized environmental combinations. These "specialist" sites are the best representatives for smaller, more unusual areas. The potential of sharing complementary sites from the Long-Term Ecological Research (LTER) Network and the National Ecological Observatory Network (NEON) to boost representativeness was also explored. LTAR network representativeness would benefit from borrowing several NEON sites and the Sevilleta LTER site. Later network additions must include such specialist sites that are targeted to represent unique missing environments. While this analysis exhaustively considered principal environmental characteristics related to production on working lands, we did not consider the focal agronomic systems under study, or their socio-economic context.}, }
@article {pmid37289010, year = {2023}, author = {Besser, AC and Manlick, PJ and Blevins, CM and Takacs-Vesbach, CD and Newsome, SD}, title = {Variation in gut microbial contribution of essential amino acids to host protein metabolism in a wild small mammal community.}, journal = {Ecology letters}, volume = {26}, number = {8}, pages = {1359-1369}, doi = {10.1111/ele.14246}, pmid = {37289010}, issn = {1461-0248}, support = {1655499//National Science Foundation/ ; 1755402//National Science Foundation/ ; 1939267//National Science Foundation/ ; }, mesh = {Animals ; *Amino Acids, Essential ; *Gastrointestinal Microbiome ; Mammals ; Amino Acids/analysis/metabolism ; Nitrogen ; }, abstract = {Herbivory is a dominant feeding strategy among animals, yet herbivores are often protein limited. The gut microbiome is hypothesized to help maintain host protein balance by provisioning essential macromolecules, but this has never been tested in wild consumers. Using amino acid carbon (δ[13] C) and nitrogen (δ[15] N) isotope analysis, we estimated the proportional contributions of essential amino acids (AAESS) synthesized by gut microbes to five co-occurring desert rodents representing herbivorous, omnivorous and insectivorous functional groups. We found that herbivorous rodents occupying lower trophic positions (Dipodomys spp.) routed a substantial proportion (~40%-50%) of their AAESS from gut microbes, while higher trophic level omnivores (Peromyscus spp.) and insectivores (Onychomys arenicola) obtained most of their AAESS (~58%) from plant-based energy channels but still received ~20% of their AAESS from gut microbes. These findings empirically demonstrate that gut microbes play a key functional role in host protein metabolism in wild animals.}, }
@article {pmid37286887, year = {2023}, author = {Thompson, GL and Bray, N and Groffman, PM and Kao-Kniffin, J}, title = {Soil microbiomes in lawns reveal land-use legacy impacts on urban landscapes.}, journal = {Oecologia}, volume = {202}, number = {2}, pages = {337-351}, pmid = {37286887}, issn = {1432-1939}, support = {1069193//National Science Foundation/ ; 1615560//National Science Foundation/ ; }, mesh = {*Ecosystem ; Soil ; Forests ; Biodiversity ; Urbanization ; *Microbiota ; Soil Microbiology ; Agriculture ; }, abstract = {Land-use change is highly dynamic globally and there is great uncertainty about the effects of land-use legacies on contemporary environmental performance. We used a chronosequence of urban grasslands (lawns) that were converted from agricultural and forested lands from 10 to over 130 years prior to determine if land-use legacy influences components of soil biodiversity and composition over time. We used historical aerial imagery to identify sites in Baltimore County, MD (USA) with agricultural versus forest land-use history. Soil samples were taken from these sites as well as from existing well-studied agricultural and forest sites used as historical references by the National Science Foundation Long-Term Ecological Research Baltimore Ecosystem Study program. We found that the microbiomes in lawns of agricultural origin were similar to those in agricultural reference sites, which suggests that the ecological parameters on lawns and reference agricultural systems are similar in how they influence soil microbial community dynamics. In contrast, lawns that were previously forest showed distinct shifts in soil bacterial composition upon recent conversion but reverted back in composition similar to forest soils as the lawns aged over decades. Soil fungal communities shifted after forested land was converted to lawns, but unlike bacterial communities, did not revert in composition over time. Our results show that components of bacterial biodiversity and composition are resistant to change in previously forested lawns despite urbanization processes. Therefore land-use legacy, depending on the prior use, is an important factor to consider when examining urban ecological homogenization.}, }
@article {pmid37275172, year = {2023}, author = {Dutta, A and Connors, E and Trinh, R and Erazo, N and Dasarathy, S and Ducklow, HW and Steinberg, DK and Schofield, OM and Bowman, JS}, title = {Depth drives the distribution of microbial ecological functions in the coastal western Antarctic Peninsula.}, journal = {Frontiers in microbiology}, volume = {14}, number = {}, pages = {1168507}, pmid = {37275172}, issn = {1664-302X}, abstract = {The Antarctic marine environment is a dynamic ecosystem where microorganisms play an important role in key biogeochemical cycles. Despite the role that microbes play in this ecosystem, little is known about the genetic and metabolic diversity of Antarctic marine microbes. In this study we leveraged DNA samples collected by the Palmer Long Term Ecological Research (LTER) project to sequence shotgun metagenomes of 48 key samples collected across the marine ecosystem of the western Antarctic Peninsula (wAP). We developed an in silico metagenomics pipeline (iMAGine) for processing metagenomic data and constructing metagenome-assembled genomes (MAGs), identifying a diverse genomic repertoire related to the carbon, sulfur, and nitrogen cycles. A novel analytical approach based on gene coverage was used to understand the differences in microbial community functions across depth and region. Our results showed that microbial community functions were partitioned based on depth. Bacterial members harbored diverse genes for carbohydrate transformation, indicating the availability of processes to convert complex carbons into simpler bioavailable forms. We generated 137 dereplicated MAGs giving us a new perspective on the role of prokaryotes in the coastal wAP. In particular, the presence of mixotrophic prokaryotes capable of autotrophic and heterotrophic lifestyles indicated a metabolically flexible community, which we hypothesize enables survival under rapidly changing conditions. Overall, the study identified key microbial community functions and created a valuable sequence library collection for future Antarctic genomics research.}, }
@article {pmid37186000, year = {2023}, author = {Gou, X and Reich, PB and Qiu, L and Shao, M and Wei, G and Wang, J and Wei, X}, title = {Leguminous plants significantly increase soil nitrogen cycling across global climates and ecosystem types.}, journal = {Global change biology}, volume = {29}, number = {14}, pages = {4028-4043}, doi = {10.1111/gcb.16742}, pmid = {37186000}, issn = {1365-2486}, support = {2022YFF1302804//National Key Research and Development Program/ ; 41977068//National Natural Science Foundation of China/ ; 41977105//National Natural Science Foundation of China/ ; 42277349//National Natural Science Foundation of China/ ; QYZDB-SSW-DQC039//Programs from Chinese Academy of Sciences/ ; XDA23070202//Strategic Priority Research Program of the Chinese Academy of Sciences/ ; XDB40020000//Strategic Priority Research Program of the Chinese Academy of Sciences/ ; NSF-DBI-2021898//the US National Science Foundation (NSF) Biological Integration Institutes grant/ ; DEB-1831944//the US National Science Foundation (NSF) Long-Term Ecological Research (LTER) grant/ ; LTREB DEB-1753859//the US National Science Foundation (NSF) Long-Term Ecological Research (LTER) grant/ ; }, mesh = {*Ecosystem ; *Fabaceae ; Soil ; Forests ; Nitrogen/analysis ; Plants ; }, abstract = {Leguminous plants are an important component of terrestrial ecosystems and significantly increase soil nitrogen (N) cycling and availability, which affects productivity in most ecosystems. Clarifying whether the effects of legumes on N cycling vary with contrasting ecosystem types and climatic regions is crucial for understanding and predicting ecosystem processes, but these effects are currently unknown. By conducting a global meta-analysis, we revealed that legumes increased the soil net N mineralization rate (Rmin) by 67%, which was greater than the recently reported increase associated with N deposition (25%). This effect was similar for tropical (53%) and temperate regions (81%) but was significantly greater in grasslands (151%) and forests (74%) than in croplands (-3%) and was greater in in situ incubation (101%) or short-term experiments (112%) than in laboratory incubation (55%) or long-term experiments (37%). Legumes significantly influenced the dependence of Rmin on N fertilization and experimental factors. The Rmin was significantly increased by N fertilization in the nonlegume soils, but not in the legume soils. In addition, the effects of mean annual temperature, soil nutrients and experimental duration on Rmin were smaller in the legume soils than in the nonlegume soils. Collectively, our results highlighted the significant positive effects of legumes on soil N cycling, and indicated that the effects of legumes should be elucidated when addressing the response of soils to plants.}, }
@article {pmid37182241, year = {2023}, author = {Battisti, C and Fanelli, G and Gallitelli, L and Scalici, M}, title = {Dunal plants as sink for anthropogenic marine litter: The entrapping role of Salsola kali L. (1753) in a Mediterranean remote beach (Sardinia, Italy).}, journal = {Marine pollution bulletin}, volume = {192}, number = {}, pages = {115033}, doi = {10.1016/j.marpolbul.2023.115033}, pmid = {37182241}, issn = {1879-3363}, mesh = {*Salsola ; Plants ; *Chenopodiaceae ; Italy ; *Alismatales ; Plastics ; Waste Products/analysis ; Environmental Monitoring ; Bathing Beaches ; }, abstract = {The ability to retain anthropogenic marine litter by a halo-psammophilous plant formation dominated by a single prostrate species (Salsola kali) on a Sardinian beach was measured. We hypothesized that the anthropogenic litter (i) is trapped by plants to a greater extent than in control areas, and (ii) has more elongated size, mimicking the organic Posidonia wrack, largely occurring locally as 'banquettes'. Salsola kali patches show an apparently higher anthropogenic litter density than control sites without vegetation. Salsola kali plants trap litter items significantly longer and a larger number of size length categories than control plots. These effects may be due to the prostrate structure of the plant with small thorns at the apex. Also, litter entrapped by plants can interfere with the mechanisms of dune deposition and structuration, in turn affecting food chains by decreasing the availability of organic material for pedofauna.}, }
@article {pmid37127731, year = {2023}, author = {Henschke, N and Espinasse, B and Stock, CA and Liu, X and Barrier, N and Pakhomov, EA}, title = {The role of water mass advection in staging of the Southern Ocean Salpa thompsoni populations.}, journal = {Scientific reports}, volume = {13}, number = {1}, pages = {7088}, pmid = {37127731}, issn = {2045-2322}, abstract = {Salpa thompsoni is an important grazer in the Southern Ocean. Their abundance in the western Antarctic Peninsula is highly variable, varying by up to 5000-fold inter-annually. Here, we use a particle-tracking model to simulate the potential dispersal of salp populations from a source location in the Antarctic Circumpolar Current (ACC) to the Palmer Long Term Ecological Research (PAL LTER) study area. Tracking simulations are run from 1998 to 2015, and compared against both a stationary salp population model simulated at the PAL LTER study area and observations from the PAL LTER program. The tracking simulation was able to recreate closely the long-term trend and the higher abundances at the slope stations. The higher abundances observed at slope stations are likely due to the advection of salp populations from a source location in the ACC, highlighting the significant role of water mass circulation in the distribution and abundance of Southern Ocean salp populations.}, }
@article {pmid37127152, year = {2023}, author = {Haubrock, PJ and Pilotto, F and Soto, I and Kühn, I and Verreycken, H and Seebens, H and Cuthbert, RN and Haase, P}, title = {Long-term trends in abundances of non-native species across biomes, realms, and taxonomic groups in Europe.}, journal = {The Science of the total environment}, volume = {884}, number = {}, pages = {163808}, doi = {10.1016/j.scitotenv.2023.163808}, pmid = {37127152}, issn = {1879-1026}, mesh = {Animals ; *Introduced Species ; *Ecosystem ; Temperature ; Fresh Water ; Europe ; Biodiversity ; }, abstract = {Rates of biological invasion have increased over recent centuries and are expected to increase in the future. Whereas increasing rates of non-native species incursions across realms, taxonomic groups, and regions are well-reported, trends in abundances within these contexts have lacked analysis due to a paucity of long-term data at large spatiotemporal scales. These knowledge gaps impede prioritisation of realms, regions, and taxonomic groups for management. We analysed 180 biological time series (median 15 ± 12.8 sampling years) mainly from Long-Term Ecological Research (LTER) sites comprising abundances of marine, freshwater, and terrestrial non-native species in Europe. A high number (150; 83,3 %) of these time series were invaded by at least one non-native species. We tested whether (i) local long-term abundance trends of non-native species are consistent among environmental realms, taxonomic groups, and regions, and (ii) if any detected trend can be explained by climatic conditions. Our results indicate that abundance trends at local scales are highly variable, with evidence of declines in marine and freshwater long-term monitoring sites, despite non-native species reports increasing rapidly since the late 1970s. These declines were driven mostly by abundance trends in non-native fish, birds, and invertebrate species in three biogeographic regions (Continental, Atlantic, and the North Sea). Temperature and precipitation were important predictors of observed abundance trends across Europe. Yet, the response was larger for species with already declining trends and differed among taxa. Our results indicate that trends in biological invasions, especially across different taxonomic groups, are context-dependent and require robust local data to understand long-term trends across contexts at large scales. While the process of biological invasion is spatiotemporally broad, economic or ecological impacts are generally realised on the local level. Accordingly, we urge proactive and coordinated management actions from local to large scales, as invasion impacts are substantial and dynamics are prone to change.}, }
@article {pmid37106790, year = {2023}, author = {Pozojević, I and Dorić, V and Miliša, M and Ternjej, I and Ivković, M}, title = {Defining Patterns and Rates of Natural vs. Drought Driven Aquatic Community Variability Indicates the Ongoing Need for Long Term Ecological Research.}, journal = {Biology}, volume = {12}, number = {4}, pages = {}, pmid = {37106790}, issn = {2079-7737}, abstract = {Most ecologists have used climate change, as an omnipresent pressure, to support their findings in researching the vulnerability of specific taxa, communities, or ecosystems. However, there is a widespread lack of long-term biological, biocoenological, or community data of periods longer than several years to ascertain patterns as to how climate change affects communities. Since the 1950s, southern Europe has faced an ongoing trend of drying and loss of precipitation. A 13-year research program in the Dinaric karst ecoregion of Croatia aimed to comprehensively track emergence patterns of freshwater insects (true flies: Diptera) in a pristine aquatic environment. Three sites, spring, upper, and lower tufa barriers (calcium carbonate barriers on a barrage lake system that act as natural damns), were sampled monthly over 154 months. This coincided with a severe drought event in 2011/2012. This was the most significant drought (very low precipitation rates for an extended period of time) in the Croatian Dinaric ecoregion since the start of detailed records in the early 20th century. Significant shifts in dipteran taxa occurrence were determined using indicator species analysis. Patterns of seasonal and yearly dynamics were presented as Euclidian distance metrics of similarity in true fly community composition compared at increasing time intervals, to ascertain the degree of temporal variability of similarity within the community of a specific site and to define patterns of similarity change over time. Analyses detected significant shifts in community structure linked to changes in discharge regimes, especially to the drought period.}, }
@article {pmid37105953, year = {2023}, author = {Hartline, DK and Cieslak, MC and Castelfranco, AM and Lieberman, B and Roncalli, V and Lenz, PH}, title = {De novo transcriptomes of six calanoid copepods (Crustacea): a resource for the discovery of novel genes.}, journal = {Scientific data}, volume = {10}, number = {1}, pages = {242}, pmid = {37105953}, issn = {2052-4463}, support = {OCE-1756859//National Science Foundation (NSF)/ ; LTER-1656070//National Science Foundation (NSF)/ ; OCE-1756767//National Science Foundation (NSF)/ ; OCE-1756859//National Science Foundation (NSF)/ ; LTER-1656070//National Science Foundation (NSF)/ ; OCE-1756767//National Science Foundation (NSF)/ ; OCE-1756859//National Science Foundation (NSF)/ ; LTER-1656070//National Science Foundation (NSF)/ ; OCE-1756767//National Science Foundation (NSF)/ ; OCE-1756859//National Science Foundation (NSF)/ ; LTER-1656070//National Science Foundation (NSF)/ ; OCE-1756767//National Science Foundation (NSF)/ ; OCE-1756859//National Science Foundation (NSF)/ ; LTER-1656070//National Science Foundation (NSF)/ ; OCE-1756767//National Science Foundation (NSF)/ ; OCE-1756859//National Science Foundation (NSF)/ ; LTER-1656070//National Science Foundation (NSF)/ ; }, mesh = {Animals ; Humans ; Base Sequence ; *Copepoda/genetics ; *Transcriptome ; }, abstract = {This study presents eight new high-quality de novo transcriptomes from six co-occurring species of calanoid copepods, the first published for Neocalanus plumchrus, N. cristatus, Eucalanus bungii and Metridia pacifica and additional ones for N. flemingeri and Calanus marshallae. They are ecologically-important members of sub-arctic North Pacific marine zooplankton communities. 'Omics data for this diverse and numerous taxonomic group are sparse and difficult to obtain. Total RNA from single individuals was used to construct gene libraries that were sequenced on an Illumina Next-Seq platform. Quality filtered reads were assembled with Trinity software and validated using multiple criteria. The study's primary purpose is to provide a resource for gene expression studies. The integrated database can be used for quantitative inter- and intra-species comparisons of gene expression patterns across biological processes. An example of an additional use is provided for discovering novel and evolutionarily-significant proteins within the Calanoida. A workflow was designed to find and characterize unannotated transcripts with homologies across de novo assemblies that have also been shown to be eco-responsive.}, }
@article {pmid37081674, year = {2023}, author = {Rypel, AL}, title = {Ecosystem size filters life-history strategies to shape community assembly in lakes.}, journal = {The Journal of animal ecology}, volume = {92}, number = {6}, pages = {1161-1175}, doi = {10.1111/1365-2656.13925}, pmid = {37081674}, issn = {1365-2656}, mesh = {Animals ; *Ecosystem ; Lakes ; *Life History Traits ; Biological Evolution ; Biodiversity ; }, abstract = {Enhancing understanding of community assembly rules hinges on shared conceptualizations that operate across scales and levels of ecological organization. Knowledge of the biogeography of life-history strategies is especially limited but crucial for building fundamental information on the relationships between trait diversity and species richness. The goals of this study were to (i) demonstrate how life histories can be classified using a previously identified triangular continuum of evolutionary trade-offs; (ii) test whether spatial and temporal heterogeneity in species abundances is linked to life-history strategy; (iii) compare species-area relationships across the primary life-history strategist groups and (iv) explore how species life-history niche spaces are shaped by ecosystem size and landscape architecture. Fish communities were sampled in 40 lakes that varied widely in volume; 11 lakes were sampled annually for 28 or 42 years. Seventy-one species were classified as equilibrium, periodic or opportunistic strategists, and species-area curves were quantified and compared among strategy types. As predicted by life-history theory, relative abundances of opportunistic strategists were extremely variable over space and time, whereas abundances of equilibrium and periodic strategists were more stable. Small lakes were often dominated by only one species, usually an opportunistic strategist. Species richness increased with ecosystem size, but larger ecosystems were increasingly inhabited by equilibrium, and then, periodic strategists. Richness of periodic species increased with ecosystem size at a faster rate compared with opportunistic species showing that colonization-extinction points fundamentally vary by strategy. Similarly, life-history niche space increased with ecosystem size in accord with species-area relationships but showed saturation behaviour. Niche space became increasingly crowded in large lakes, particularly in lakes with higher hydrologic connectance. Ecosystem size mediates the assembly of communities through effects on environmental stability, hydrology and life-history filtering. This finding provides novel insights into community assembly at multiple scales and has broad conservation applications. Because ecosystem size filters towards orthogonal and inverse life histories, conservation actions (e.g. fish stockings) that do not consider life-history and community filtering rules will probably fail.}, }
@article {pmid37069671, year = {2023}, author = {Sidhu, C and Kirstein, IV and Meunier, CL and Rick, J and Fofonova, V and Wiltshire, KH and Steinke, N and Vidal-Melgosa, S and Hehemann, JH and Huettel, B and Schweder, T and Fuchs, BM and Amann, RI and Teeling, H}, title = {Dissolved storage glycans shaped the community composition of abundant bacterioplankton clades during a North Sea spring phytoplankton bloom.}, journal = {Microbiome}, volume = {11}, number = {1}, pages = {77}, pmid = {37069671}, issn = {2049-2618}, mesh = {*Phytoplankton/genetics/metabolism ; North Sea ; *Eutrophication ; Plankton/genetics ; Polysaccharides/metabolism ; Bacteria/genetics/metabolism ; }, abstract = {BACKGROUND: Blooms of marine microalgae play a pivotal role in global carbon cycling. Such blooms entail successive blooms of specialized clades of planktonic bacteria that collectively remineralize gigatons of algal biomass on a global scale. This biomass is largely composed of distinct polysaccharides, and the microbial decomposition of these polysaccharides is therefore a process of prime importance.<br><br>RESULTS: In 2020, we sampled a complete biphasic spring bloom in the German Bight over a 90-day period. Bacterioplankton metagenomes from 30 time points allowed reconstruction of 251 metagenome-assembled genomes (MAGs). Corresponding metatranscriptomes highlighted 50 particularly active MAGs of the most abundant clades, including many polysaccharide degraders. Saccharide measurements together with bacterial polysaccharide utilization loci (PUL) expression data identified &#x3b2;-glucans (diatom laminarin) and &#x3b1;-glucans as the most prominent and actively metabolized dissolved polysaccharide substrates. Both substrates were consumed throughout the bloom, with &#x3b1;-glucan PUL expression peaking at the beginning of the second bloom phase shortly after a peak in flagellate and the nadir in bacterial total cell counts.<br><br>CONCLUSIONS: We show that the amounts and composition of dissolved polysaccharides, in particular abundant storage polysaccharides, have a pronounced influence on the composition of abundant bacterioplankton members during phytoplankton blooms, some of which compete for similar polysaccharide niches. We hypothesize that besides the release of algal glycans, also recycling of bacterial glycans as a result of increased bacterial cell mortality can have a significant influence on bacterioplankton composition during phytoplankton blooms. Video Abstract.}, }
@article {pmid37061583, year = {2023}, author = {Chase, AB and Bogdanov, A and Demko, AM and Jensen, PR}, title = {Biogeographic patterns of biosynthetic potential and specialized metabolites in marine sediments.}, journal = {The ISME journal}, volume = {17}, number = {7}, pages = {976-983}, pmid = {37061583}, issn = {1751-7370}, support = {R01 GM085770/GM/NIGMS NIH HHS/United States ; S10 OD010786/OD/NIH HHS/United States ; }, mesh = {*Geologic Sediments ; *Microbiota/genetics ; Metabolome ; }, abstract = {While the field of microbial biogeography has largely focused on the contributions of abiotic factors to community patterns, the potential influence of biotic interactions in structuring microbial communities, such as those mediated by the production of specialized metabolites, remains largely unknown. Here, we examined the relationship between microbial community structure and specialized metabolism at local spatial scales in marine sediment samples collected from the Long-Term Ecological Research (LTER) site in Moorea, French Polynesia. By employing a multi-omic approach to characterize the taxonomic, functional, and specialized metabolite composition within sediment communities, we find that biogeographic patterns were driven by local scale processes (e.g., biotic interactions) and largely independent of dispersal limitation. Specifically, we observed high variation in biosynthetic potential (based on Bray-Curtis dissimilarity) between samples, even within 1 m[2] plots, that reflected uncharacterized chemical space associated with site-specific metabolomes. Ultimately, connecting biosynthetic potential to community metabolomes facilitated the in situ detection of natural products and revealed new insights into the complex metabolic dynamics associated with sediment microbial communities. Our study demonstrates the potential to integrate biosynthetic genes and metabolite production into assessments of microbial community dynamics.}, }
@article {pmid36988091, year = {2023}, author = {Matthews, TJ and Wayman, JP and Whittaker, RJ and Cardoso, P and Hume, JP and Sayol, F and Proios, K and Martin, TE and Baiser, B and Borges, PAV and Kubota, Y and Dos Anjos, L and Tobias, JA and Soares, FC and Si, X and Ding, P and Mendenhall, CD and Sin, YCK and Rheindt, FE and Triantis, KA and Guilhaumon, F and Watson, DM and Brotons, L and Battisti, C and Chu, O and Rigal, F}, title = {A global analysis of avian island diversity-area relationships in the Anthropocene.}, journal = {Ecology letters}, volume = {26}, number = {6}, pages = {965-982}, doi = {10.1111/ele.14203}, pmid = {36988091}, issn = {1461-0248}, mesh = {Animals ; Phylogeny ; *Biodiversity ; Islands ; *Birds ; Ecosystem ; }, abstract = {Research on island species-area relationships (ISAR) has expanded to incorporate functional (IFDAR) and phylogenetic (IPDAR) diversity. However, relative to the ISAR, we know little about IFDARs and IPDARs, and lack synthetic global analyses of variation in form of these three categories of island diversity-area relationship (IDAR). Here, we undertake the first comparative evaluation of IDARs at the global scale using 51 avian archipelagic data sets representing true and habitat islands. Using null models, we explore how richness-corrected functional and phylogenetic diversity scale with island area. We also provide the largest global assessment of the impacts of species introductions and extinctions on the IDAR. Results show that increasing richness with area is the primary driver of the (non-richness corrected) IPDAR and IFDAR for many data sets. However, for several archipelagos, richness-corrected functional and phylogenetic diversity changes linearly with island area, suggesting that the dominant community assembly processes shift along the island area gradient. We also find that archipelagos with the steepest ISARs exhibit the biggest differences in slope between IDARs, indicating increased functional and phylogenetic redundancy on larger islands in these archipelagos. In several cases introduced species seem to have 're-calibrated' the IDARs such that they resemble the historic period prior to recent extinctions.}, }
@article {pmid36910211, year = {2023}, author = {Bregman, G and Lalzar, M and Livne, L and Bigal, E and Zemah-Shamir, Z and Morick, D and Tchernov, D and Scheinin, A and Meron, D}, title = {Preliminary study of shark microbiota at a unique mix-species shark aggregation site, in the Eastern Mediterranean Sea.}, journal = {Frontiers in microbiology}, volume = {14}, number = {}, pages = {1027804}, pmid = {36910211}, issn = {1664-302X}, abstract = {Sharks, as apex predators, play an essential ecological role in shaping the marine food web and maintaining healthy and balanced marine ecosystems. Sharks are sensitive to environmental changes and anthropogenic pressure and demonstrate a clear and rapid response. This designates them a "keystone" or "sentinel" group that may describe the structure and function of the ecosystem. As a meta-organism, sharks offer selective niches (organs) for microorganisms that can provide benefits for their hosts. However, changes in the microbiota (due to physiological or environmental changes) can turn the symbiosis into a dysbiosis and may affect the physiology, immunity and ecology of the host. Although the importance of sharks within the ecosystem is well known, relatively few studies have focused on the microbiome aspect, especially with long-term sampling. Our study was conducted at a site of coastal development in Israel where a mixed-species shark aggregation (November-May) is observed. The aggregation includes two shark species, the dusky (Carcharhinus obscurus) and sandbar (Carcharhinus plumbeus) which segregate by sex (females and males, respectively). In order to characterize the bacterial profile and examine the physiological and ecological aspects, microbiome samples were collected from different organs (gills, skin, and cloaca) from both shark species over 3 years (sampling seasons: 2019, 2020, and 2021). The bacterial composition was significantly different between the shark individuals and the surrounding seawater and between the shark species. Additionally, differences were apparent between all the organs and the seawater, and between the skin and gills. The most dominant groups for both shark species were Flavobacteriaceae, Moraxellaceae, and Rhodobacteraceae. However, specific microbial biomarkers were also identified for each shark. An unexpected difference in the microbiome profile and diversity between the 2019-2020 and 2021 sampling seasons, revealed an increase in the potential pathogen Streptococcus. The fluctuations in the relative abundance of Streptococcus between the months of the third sampling season were also reflected in the seawater. Our study provides initial information on shark microbiome in the Eastern Mediterranean Sea. In addition, we demonstrated that these methods were also able to describe environmental episodes and the microbiome is a robust measure for long-term ecological research.}, }
@article {pmid36864338, year = {2023}, author = {Ferri, V and Crescia, P and Battisti, C}, title = {Discarded bottles entrap endemic small mammals species in a large Mediterranean island.}, journal = {Environmental science and pollution research international}, volume = {30}, number = {19}, pages = {57164-57173}, pmid = {36864338}, issn = {1614-7499}, mesh = {Animals ; *Shrews ; *Invertebrates ; Food Chain ; Mediterranean Islands ; Biomass ; }, abstract = {We examined the entrapment effect of discarded bottles on small mammals, along a road network located in North-Western Sardinia (Italy). On 162 bottles, 49 (> 30%) contained at least one animal specimen (invertebrate or vertebrate) and 26 (16%) entrapped 151 small mammals: insectivorous shrews (Soricomorpha) were more frequently recorded. Larger bottles (66 cl.) showed a higher number of entrapped mammals, but difference was not significant when compared to smaller bottles (33 cl.). Our data highlighted as abandoned bottles represent a threatening factor for small mammals on a large Mediterranean island with over-represented endemic shrews (predators of high trophic level) attracted by insects entrapped in bottles. Correspondence analysis suggest a weak segregation between bottles of different size, related to the abundance of the most entrapped species, the Mediterranean shrew (Crocidura pachyura). This still neglected type of litter, reducing number and biomass of insectivorous mammals of high trophic level and high ecological value may affect the food web in terrestrial insular communities, yet impoverished for biogeographical reasons. However, discarded bottles may represent as low-cost surrogate pitfall traps useful to improve knowledge in poor studied areas. Following the DPSIR (Driving force, Pressure, State, Impact, Response) approach as a framework to select indicator, we suggest as the effectiveness of removal clean-ups could be monitored using both the density of discarded bottles (as indicator of threat pressure) and the abundance of entrapped animals (as indicator of impact on small mammals).}, }
@article {pmid36847530, year = {2023}, author = {Propster, JR and Schwartz, E and Hayer, M and Miller, S and Monsaint-Queeney, V and Koch, BJ and Morrissey, EM and Mack, MC and Hungate, BA}, title = {Distinct Growth Responses of Tundra Soil Bacteria to Short-Term and Long-Term Warming.}, journal = {Applied and environmental microbiology}, volume = {89}, number = {3}, pages = {e0154322}, pmid = {36847530}, issn = {1098-5336}, mesh = {*Soil ; *Ecosystem ; Phylogeny ; Tundra ; Arctic Regions ; Climate Change ; Carbon/metabolism ; }, abstract = {Increases in Arctic temperatures have thawed permafrost and accelerated tundra soil microbial activity, releasing greenhouse gases that amplify climate warming. Warming over time has also accelerated shrub encroachment in the tundra, altering plant input abundance and quality, and causing further changes to soil microbial processes. To better understand the effects of increased temperature and the accumulated effects of climate change on soil bacterial activity, we quantified the growth responses of individual bacterial taxa to short-term warming (3 months) and long-term warming (29 years) in moist acidic tussock tundra. Intact soil was assayed in the field for 30 days using [18]O-labeled water, from which taxon-specific rates of [18]O incorporation into DNA were estimated as a proxy for growth. Experimental treatments warmed the soil by approximately 1.5°C. Short-term warming increased average relative growth rates across the assemblage by 36%, and this increase was attributable to emergent growing taxa not detected in other treatments that doubled the diversity of growing bacteria. However, long-term warming increased average relative growth rates by 151%, and this was largely attributable to taxa that co-occurred in the ambient temperature controls. There was also coherence in relative growth rates within broad taxonomic levels with orders tending to have similar growth rates in all treatments. Growth responses tended to be neutral in short-term warming and positive in long-term warming for most taxa and phylogenetic groups co-occurring across treatments regardless of phylogeny. Taken together, growing bacteria responded distinctly to short-term and long-term warming, and taxa growing in each treatment exhibited deep phylogenetic organization. IMPORTANCE Soil carbon stocks in the tundra and underlying permafrost have become increasingly vulnerable to microbial decomposition due to climate change. The microbial responses to Arctic warming must be understood in order to predict the effects of future microbial activity on carbon balance in a warming Arctic. In response to our warming treatments, tundra soil bacteria grew faster, consistent with increased rates of decomposition and carbon flux to the atmosphere. Our findings suggest that bacterial growth rates may continue to increase in the coming decades as faster growth is driven by the accumulated effects of long-term warming. Observed phylogenetic organization of bacterial growth rates may also permit taxonomy-based predictions of bacterial responses to climate change and inclusion into ecosystem models.}, }
@article {pmid36816760, year = {2023}, author = {Battisti, C and Cento, M and Circosta, A and Coppola, M and Muratore, S}, title = {Resurrecting seasonal dynamics in waterbirds after wetland restoration: before-after monitoring highlights the role of a single dominant species.}, journal = {Wetlands ecology and management}, volume = {31}, number = {2}, pages = {203-211}, pmid = {36816760}, issn = {0923-4861}, abstract = {We compared a set of uni-varied diversity metrics of a guild of water-related birds (hereafter 'waterbirds') before and after a wetland restoration carried out on uncultivated (reclaimed) lands. Over a period of five years, we observed a restart of seasonal waterbirds dynamics after wetland restoration by flooding of abandoned croplands, with a significant increase in all metrics of diversity, more evident in autumn-winter periods. Seasonal thresholds were evident before (2017-2018) and after (2018-2019) the flooding. These dynamics appeared irregular, probably for a different inter-annual suitability of the flooded meadows due to local ecological factors (e.g., change in meteorological regime and in rush-bed vegetation cover). Rarefaction curves, both for richness and diversity, showed how the waterbird community moved towards a greater complexity. Flooded meadow restoration, particularly favoured wintering species in Mediterranean sites, which explained the strong fluctuations in total abundance. At the species level, Northern Lapwing (Vanellus vanellus), absent before restoration, was the most abundant species after flooding, using flooded meadows with its gregarious behaviour. This 'crowding' may be explained also for a lack of similar habitats in the surrounding. Other dominant species (Anas platyrhynchos, Ardea cinerea, Egretta garzetta) showed a significant increase after restoration. Standardized before-after monitoring on medium term time periods seem suitable to evidence inter-annual season dynamics in diversity metrics of waterbird assemblages.}, }
@article {pmid36734695, year = {2023}, author = {Solokas, MA and Feiner, ZS and Al-Chokachy, R and Budy, P and DeWeber, JT and Sarvala, J and Sass, GG and Tolentino, SA and Walsworth, TE and Jensen, OP}, title = {Shrinking body size and climate warming: Many freshwater salmonids do not follow the rule.}, journal = {Global change biology}, volume = {29}, number = {9}, pages = {2478-2492}, doi = {10.1111/gcb.16626}, pmid = {36734695}, issn = {1365-2486}, support = {//U.S. Geological Survey/ ; //United States Fish and Wildlife Service Federal Aid in Sportfish Restoration Program/ ; //Wisconsin Department of Natural Resources/ ; OPP 9911278//National Science Foundation Arctic Long Term Ecological Research Program/ ; 1637459//National Science Foundation Arctic Long Term Ecological Research Program/ ; 1026843//National Science Foundation Arctic Long Term Ecological Research Program/ ; 0508570//National Science Foundation Arctic Long Term Ecological Research Program/ ; 0423385//National Science Foundation Arctic Long Term Ecological Research Program/ ; 1716066//National Science Foundation/ ; 2025982//National Science Foundation North Temperate Lakes Long Term Ecological Research Program/ ; }, mesh = {Animals ; *Salmonidae ; Fishes ; Climate Change ; Temperature ; Fresh Water ; Body Size ; }, abstract = {Declining body size is believed to be a universal response to climate warming and has been documented in numerous studies of marine and anadromous fishes. The Salmonidae are a family of coldwater fishes considered to be among the most sensitive species to climate warming; however, whether the shrinking body size response holds true for freshwater salmonids has yet to be examined at a broad spatial scale. We compiled observations of individual fish lengths from long-term surveys across the Northern Hemisphere for 12 species of freshwater salmonids and used linear mixed models to test for spatial and temporal trends in body size (fish length) spanning recent decades. Contrary to expectations, we found a significant increase in length overall but with high variability in trends among populations and species. More than two-thirds of the populations we examined increased in length over time. Secondary regressions revealed larger-bodied populations are experiencing greater increases in length than smaller-bodied populations. Mean water temperature was weakly predictive of changes in body length but overall minimal influences of environmental variables suggest that it is difficult to predict an organism's response to changing temperatures by solely looking at climatic factors. Our results suggest that declining body size is not universal, and the response of fishes to climate change may be largely influenced by local factors. It is important to know that we cannot assume the effects of climate change are predictable and negative at a large spatial scale.}, }
@article {pmid36644792, year = {2023}, author = {Pallin, LJ and Kellar, NM and Steel, D and Botero-Acosta, N and Baker, CS and Conroy, JA and Costa, DP and Johnson, CM and Johnston, DW and Nichols, RC and Nowacek, DP and Read, AJ and Savenko, O and Schofield, OM and Stammerjohn, SE and Steinberg, DK and Friedlaender, AS}, title = {A surplus no more? Variation in krill availability impacts reproductive rates of Antarctic baleen whales.}, journal = {Global change biology}, volume = {29}, number = {8}, pages = {2108-2121}, doi = {10.1111/gcb.16559}, pmid = {36644792}, issn = {1365-2486}, support = {//American Cetacean Society-Monterey Bay Chapter/ ; //Dr. Earl H. Myers &amp; Ethel M. Myers Oceanographic &amp; Marine Biology Trust/ ; //Marine Mammal Commission/ ; NGS-909906R-21//National Geographic Society/ ; DGE1339067//NSF GRFP/ ; 1440435//Palmer Long Term Ecological Research Program/ ; 2026045//Palmer Long Term Ecological Research Program/ ; //Scientific Committee of Antarctic Research/ ; //State Special-Purpose Research Program in Antarctica for 2011-2023 of the State Institution National Antarctic Scientific Center, Ministry of Education and Science of Ukraine/ ; //The International Whaling Commission's Southern Ocean Research Partnership/ ; //UC Santa Cruz's Department of Ecology and Evolutionary Biology/ ; //UC Santa Cruz's Graduate Division/ ; //World Wide Fund for Nature - Australia (WWF-Australia)/ ; 1643877//National Science Foundation Office of Polar Programs/ ; //US Biological Adaptations to Environmental Change in Antarctica/ ; V724070//Virginia Sea Grant Project/ ; //National Oceanic and Atmospheric Administration/ ; //U.S. Department of Commerce/ ; }, mesh = {Animals ; Humans ; Antarctic Regions ; Climate ; Ecosystem ; *Euphausiacea ; *Humpback Whale ; Population Dynamics ; Ice Cover ; }, abstract = {The krill surplus hypothesis of unlimited prey resources available for Antarctic predators due to commercial whaling in the 20th century has remained largely untested since the 1970s. Rapid warming of the Western Antarctic Peninsula (WAP) over the past 50 years has resulted in decreased seasonal ice cover and a reduction of krill. The latter is being exacerbated by a commercial krill fishery in the region. Despite this, humpback whale populations have increased but may be at a threshold for growth based on these human-induced changes. Understanding how climate-mediated variation in prey availability influences humpback whale population dynamics is critical for focused management and conservation actions. Using an 8-year dataset (2013-2020), we show that inter-annual humpback whale pregnancy rates, as determined from skin-blubber biopsy samples (n = 616), are positively correlated with krill availability and fluctuations in ice cover in the previous year. Pregnancy rates showed significant inter-annual variability, between 29% and 86%. Our results indicate that krill availability is in fact limiting and affecting reproductive rates, in contrast to the krill surplus hypothesis. This suggests that this population of humpback whales may be at a threshold for population growth due to prey limitations. As a result, continued warming and increased fishing along the WAP, which continue to reduce krill stocks, will likely impact this humpback whale population and other krill predators in the region. Humpback whales are sentinel species of ecosystem health, and changes in pregnancy rates can provide quantifiable signals of the impact of environmental change at the population level. Our findings must be considered paramount in developing new and more restrictive conservation and management plans for the Antarctic marine ecosystem and minimizing the negative impacts of human activities in the region.}, }
@article {pmid36640197, year = {2023}, author = {Griffin-Nolan, RJ and Felton, AJ and Slette, IJ and Smith, MD and Knapp, AK}, title = {Traits that distinguish dominant species across aridity gradients differ from those that respond to soil moisture.}, journal = {Oecologia}, volume = {201}, number = {2}, pages = {311-322}, pmid = {36640197}, issn = {1432-1939}, support = {1137378//Division of Environmental Biology/ ; 1137363//Division of Environmental Biology/ ; 1137342//Division of Environmental Biology/ ; }, mesh = {*Ecosystem ; *Soil ; Poaceae/physiology ; Biomass ; Plant Leaves/physiology ; Water/physiology ; }, abstract = {Many plant traits respond to changes in water availability and might be useful for understanding ecosystem properties such as net primary production (NPP). This is especially evident in grasslands where NPP is water-limited and primarily determined by the traits of dominant species. We measured root and shoot morphology, leaf hydraulic traits, and NPP of four dominant North American prairie grasses in response to four levels of soil moisture in a greenhouse experiment. We expected that traits of species from drier regions would be more responsive to reduced water availability and that this would make these species more resistant to low soil moisture than species from wetter regions. All four species grew taller, produced more biomass, and increased total root length in wetter treatments. Each species reduced its leaf turgor loss point (TLP) in drier conditions, but only two species (one xeric, one mesic) maintained leaf water potential above TLP. We identified a suite of traits that clearly distinguished species from one another, but, surprisingly, these traits were relatively unresponsive to reduced soil moisture. Specifically, more xeric species produced thinner roots with higher specific root length and had a lower root mass fraction. This suggest that root traits are critical for distinguishing species from one another but might not respond strongly to changing water availability, though this warrants further investigation in the field. Overall, we found that NPP of these dominant grass species responded similarly to varying levels of soil moisture despite differences in species morphology, physiology, and habitat of origin.}, }
@article {pmid36638716, year = {2023}, author = {Gallitelli, L and Battisti, C and Scalici, M}, title = {Dunal plants intercepting macrolitter: Implications for beach clean-ups.}, journal = {Marine pollution bulletin}, volume = {187}, number = {}, pages = {114585}, doi = {10.1016/j.marpolbul.2023.114585}, pmid = {36638716}, issn = {1879-3363}, mesh = {*Plants ; *Poaceae ; Plastics ; Waste Products/analysis ; Environmental Monitoring ; Bathing Beaches ; }, abstract = {Coastal vegetation intercepts macroplastics and, consequently, it may represent a reservoir of anthropogenic litter and organic wrack. We aimed at investigating (i) the abundance variation of macrolitter from the beach to foredune and backdune (three cross-shore plots over 20 long-shore sectors) and (ii) the role of the halo-psammophilous plants and Phragmites australis reedbed in intercepting the macrolitter, respectively, in the foredunes and backdunes. The vegetation in the foredunes (mainly halo-psammophilous species) acted as a first interception belt for macrolitter, while the bigger litter reached the backdunes. Our results might be of great concern with implications for beach clean-ups - which must also be mainly focused in foredunes and backdunes, however warning operators in advance that they could damage the vegetation by trampling on.}, }
@article {pmid36630533, year = {2023}, author = {Ueyama, M and Knox, SH and Delwiche, KB and Bansal, S and Riley, WJ and Baldocchi, D and Hirano, T and McNicol, G and Schafer, K and Windham-Myers, L and Poulter, B and Jackson, RB and Chang, KY and Chen, J and Chu, H and Desai, AR and Gogo, S and Iwata, H and Kang, M and Mammarella, I and Peichl, M and Sonnentag, O and Tuittila, ES and Ryu, Y and Euskirchen, ES and Göckede, M and Jacotot, A and Nilsson, MB and Sachs, T}, title = {Modeled production, oxidation, and transport processes of wetland methane emissions in temperate, boreal, and Arctic regions.}, journal = {Global change biology}, volume = {29}, number = {8}, pages = {2313-2334}, doi = {10.1111/gcb.16594}, pmid = {36630533}, issn = {1365-2486}, support = {JPMXD1420318865//Arctic Challenge for Sustainability II/ ; 1936752//Arctic Observatory Program of the National Science Foundation/ ; 1503912//Arctic Observatory Program of the National Science Foundation/ ; 1107892//Arctic Observatory Program of the National Science Foundation/ ; NSF DEB-1026415//Bonanza Creek Long-Term Ecological Research Program funded by the National Science Foundation/ ; DEB-1636476//Bonanza Creek Long-Term Ecological Research Program funded by the National Science Foundation/ ; //California Department of Water Resources, CA Fish and Wildlife/ ; //Canada Research Chairs, Canada Foundation for Innovation Leaders Opportunity Fund/ ; 3119871//ICOS-Finland/ ; 20K21849//JSPS KAKENHI/ ; 2022003640002//Ministry of Environment of Korea/ ; //Natural Sciences and Engineering Research Council Discovery Grant Programs/ ; NSF LTREB 2011276//NSF Long-Term Research in Environmental Biology Program/ ; //Reducing Uncertainties in Biogeochemical Interactions through Synthesis and Computation (RUBISCO) Scientific Focus Area, Office of Biological and Environmental Research of the U.S. Department of Energy Office of Science/ ; PJ014892022022//Rural Development Administration/ ; //SNO Tourbi&#xe8;res, CNRS-INSU/ ; DE-AC02-05CH11231//U.S. Department of Energy/ ; //U.S. Geological Survey, Ecosystems Mission Area, Land Change Science Program/ ; 7544821//US DOE Ameriflux/ ; Order 224//US Geological Survey, Research Work/ ; VH-NG-821//Helmholtz Association of German Research Centres/ ; 341348//Academy of Finland project N-PERM/ ; 101056921//Horizon Europe project GreenFeedBack/ ; //U.S. Geological Survey, John Wesley Powell Center for Analysis and Synthesis/ ; //U.S. Geological Survey, Water Mission Area, Earth Systems Processes Division/ ; }, mesh = {*Wetlands ; *Ecosystem ; Methane/metabolism ; Arctic Regions ; Soil ; Carbon Dioxide/analysis ; }, abstract = {Wetlands are the largest natural source of methane (CH4) to the atmosphere. The eddy covariance method provides robust measurements of net ecosystem exchange of CH4 , but interpreting its spatiotemporal variations is challenging due to the co-occurrence of CH4 production, oxidation, and transport dynamics. Here, we estimate these three processes using a data-model fusion approach across 25 wetlands in temperate, boreal, and Arctic regions. Our data-constrained model-iPEACE-reasonably reproduced CH4 emissions at 19 of the 25 sites with normalized root mean square error of 0.59, correlation coefficient of 0.82, and normalized standard deviation of 0.87. Among the three processes, CH4 production appeared to be the most important process, followed by oxidation in explaining inter-site variations in CH4 emissions. Based on a sensitivity analysis, CH4 emissions were generally more sensitive to decreased water table than to increased gross primary productivity or soil temperature. For periods with leaf area index (LAI) of ≥20% of its annual peak, plant-mediated transport appeared to be the major pathway for CH4 transport. Contributions from ebullition and diffusion were relatively high during low LAI (<20%) periods. The lag time between CH4 production and CH4 emissions tended to be short in fen sites (3 ± 2 days) and long in bog sites (13 ± 10 days). Based on a principal component analysis, we found that parameters for CH4 production, plant-mediated transport, and diffusion through water explained 77% of the variance in the parameters across the 19 sites, highlighting the importance of these parameters for predicting wetland CH4 emissions across biomes. These processes and associated parameters for CH4 emissions among and within the wetlands provide useful insights for interpreting observed net CH4 fluxes, estimating sensitivities to biophysical variables, and modeling global CH4 fluxes.}, }
@article {pmid36607159, year = {2023}, author = {Tang, B and Rocci, KS and Lehmann, A and Rillig, MC}, title = {Nitrogen increases soil organic carbon accrual and alters its functionality.}, journal = {Global change biology}, volume = {29}, number = {7}, pages = {1971-1983}, doi = {10.1111/gcb.16588}, pmid = {36607159}, issn = {1365-2486}, support = {//Cedar Creek LTER/ ; //National Science Foundation Graduate Research Fellowship/ ; //Nutrient Network experiment/ ; //Rising Star Fellowship of the Department of Biology, Chemistry, Pharmacy, Freie Universit&#xe4;t Berlin/ ; }, mesh = {*Soil ; *Carbon ; Nitrogen/analysis ; Biomass ; Plants ; Minerals ; Dust ; }, abstract = {Nitrogen (N) availability has been considered as a critical factor for the cycling and storage of soil organic carbon (SOC), but effects of N enrichment on the SOC pool appear highly variable. Given the complex nature of the SOC pool, recent frameworks suggest that separating this pool into different functional components, for example, particulate organic carbon (POC) and mineral-associated organic carbon (MAOC), is of great importance for understanding and predicting SOC dynamics. Importantly, little is known about how these N-induced changes in SOC components (e.g., changes in the ratios among these fractions) would affect the functionality of the SOC pool, given the differences in nutrient density, resistance to disturbance, and turnover time between POC and MAOC pool. Here, we conducted a global meta-analysis of 803 paired observations from 98 published studies to assess the effect of N addition on these SOC components, and the ratios among these fractions. We found that N addition, on average, significantly increased POC and MAOC pools by 16.4% and 3.7%, respectively. In contrast, both the ratios of MAOC to SOC and MAOC to POC were remarkably decreased by N enrichment (4.1% and 10.1%, respectively). Increases in the POC pool were positively correlated with changes in aboveground plant biomass and with hydrolytic enzymes. However, the positive responses of MAOC to N enrichment were correlated with increases in microbial biomass. Our results suggest that although reactive N deposition could facilitate soil C sequestration to some extent, it might decrease the nutrient density, turnover time, and resistance to disturbance of the SOC pool. Our study provides mechanistic insights into the effects of N enrichment on the SOC pool and its functionality at global scale, which is pivotal for understanding soil C dynamics especially in future scenarios with more frequent and severe perturbations.}, }
@article {pmid36563602, year = {2023}, author = {Battisti, C and Gallitelli, L and Vanadia, S and Scalici, M}, title = {General macro-litter as a proxy for fishing lines, hooks and nets entrapping beach-nesting birds: Implications for clean-ups.}, journal = {Marine pollution bulletin}, volume = {186}, number = {}, pages = {114502}, doi = {10.1016/j.marpolbul.2022.114502}, pmid = {36563602}, issn = {1879-3363}, mesh = {Animals ; *Hunting ; Bathing Beaches ; Environmental Monitoring ; Birds ; *Charadriiformes ; Plastics ; Waste Products/analysis ; }, abstract = {Fishing lines, hooks and nets represent a sub-category of macro-litter potentially entrapping plover birds nesting on sandy beaches. Here, during a winter period, the accumulation pattern of both general beach litter and fishing lines, hooks and nets was analysed on four central Italy beaches. Despite the active monthly litter removal by clean-ups, there was not a decrease in its density during the winter period, due to the continuous accumulation by frequent winter storms. However, the entrapping litter was very low (<2.5 % of the general litter) and appeared directly correlated to the general litter density. Following a DPSIR approach, the general litter can act as an indirect pressure indicator (proxy) of the amount of entrapping litter. Therefore, an increase in general macro-litter should alarm those involved in the conservation of entanglement-sensitive bird species, such as plovers, suggesting that they should implement high-frequency clean-up activities aimed at removing it.}, }
@article {pmid36514542, year = {2022}, author = {Beck, M and Billoir, E and Felten, V and Meyer, A and Usseglio-Polatera, P and Danger, M}, title = {Lessons from linking bio- and ecological traits to stoichiometric traits in stream macroinvertebrates.}, journal = {Ecology and evolution}, volume = {12}, number = {12}, pages = {e9605}, pmid = {36514542}, issn = {2045-7758}, abstract = {Ecologists rely on various functional traits when investigating the functioning of ecological systems and its responses to global changes. Changing nutrient levels, for example, can affect taxa expressing different trait combinations in various ways, e.g., favoring small, fast-growing species under high phosphorus conditions. Stoichiometric traits, describing the elemental composition of organism body tissues, can help in understanding the mechanisms behind such functional shifts. So far, mainly life-history traits have been related to body stoichiometry (e.g., the growth rate hypothesis) on a limited number of taxa, and there is little knowledge of the general link between stoichiometric and other functional traits on a taxonomically large scale. Here, we highlight this link in the freshwater macroinvertebrates, testing predictions from underlying trait-based and Ecological Stoichiometry Theory (EST) in >200 taxa belonging to eight larger taxonomic groups. We applied a series of multivariate analyses on six of their stoichiometric traits (%C, %N, %P, C:N, C:P, and N:P) and 23 biological and ecological traits. We found significant relationships between stoichiometric traits and other types of traits when analyzing single-trait and multi-trait profiles. Patterns found within traits related to organism development or nutrient cycling were in line with our assumptions based on EST, e.g., traits describing predators were associated with high %N; traits suggesting a fast development (small maximum body size and high molting frequency) with high %P. Associations between ecological traits and body stoichiometry could be explained by the longitudinal stream gradient: Taxa preferring headwater habitats (i.e., high altitude, coarse substrate, and cold temperature) exhibited high %N and %P. Demonstrating the link between stoichiometric and both bio- and ecological traits on a large diversity of taxa underlines the potential of integrating stoichiometric traits into ecological analyses to improve our understanding of taxonomic and functional responses of communities-and ecosystems-to changing environmental conditions worldwide.}, }
@article {pmid36424421, year = {2022}, author = {Pallin, LJ and Botero-Acosta, N and Steel, D and Baker, CS and Casey, C and Costa, DP and Goldbogen, JA and Johnston, DW and Kellar, NM and Modest, M and Nichols, R and Roberts, D and Roberts, M and Savenko, O and Friedlaender, AS}, title = {Variation in blubber cortisol levels in a recovering humpback whale population inhabiting a rapidly changing environment.}, journal = {Scientific reports}, volume = {12}, number = {1}, pages = {20250}, pmid = {36424421}, issn = {2045-2322}, support = {DGE1339067//National Science Foundation Graduate Research Fellowship/ ; NGS-909906R-21//National Geographic Society/ ; 1643877//National Science Foundation Office of Polar Programs/ ; 1440435//Palmer Long-term Ecological Research Program/ ; 2026045//Palmer Long-term Ecological Research Program/ ; }, mesh = {Humans ; Animals ; Male ; Female ; *Humpback Whale ; Hydrocortisone ; *COVID-19 ; Antarctic Regions ; Seasons ; }, abstract = {Glucocorticoids are regularly used as biomarkers of relative health for individuals and populations. Around the Western Antarctic Peninsula (WAP), baleen whales have and continue to experience threats, including commercial harvest, prey limitations and habitat change driven by rapid warming, and increased human presence via ecotourism. Here, we measured demographic variation and differences across the foraging season in blubber cortisol levels of humpback whales (Megaptera novaeangliae) over two years around the WAP. Cortisol concentrations were determined from 305 biopsy samples of unique individuals. We found no significant difference in the cortisol concentration between male and female whales. However, we observed significant differences across demographic groups of females and a significant decrease in the population across the feeding season. We also assessed whether COVID-19-related reductions in tourism in 2021 along the WAP correlated with lower cortisol levels across the population. The decline in vessel presence in 2021 was associated with a significant decrease in humpback whale blubber cortisol concentrations at the population level. Our findings provide critical contextual data on how these hormones vary naturally in a population over time, show direct associations between cortisol levels and human presence, and will enable comparisons among species experiencing different levels of human disturbance.}, }
@article {pmid36414893, year = {2023}, author = {Bearzi, G and Bonizzoni, S and Fanesi, F and Tenan, S and Battisti, C}, title = {Seabirds pecking polystyrene items in offshore Adriatic Sea waters.}, journal = {Environmental science and pollution research international}, volume = {30}, number = {3}, pages = {8338-8346}, pmid = {36414893}, issn = {1614-7499}, mesh = {Animals ; *Polystyrenes ; Birds ; *Charadriiformes ; Italy ; Seawater ; Fisheries ; }, abstract = {A number of seabird species have been known to peck, displace, and ingest various plastic items including expanded polystyrene, for reasons that remain largely conjectural. Ingestion of polystyrene parts potentially causes lethal or sublethal effects on birds. Pecking can also result in the damage of polystyrene items, resulting in increased market turnover and environmental build-up, or economic consequences for stakeholders. In January and February, 2022, fishers in a portion of the western Adriatic Sea coast reported pecking damage caused by gulls (Laridae) to polystyrene buoys used to float, signal, and retrieve static fishing nets and traps. We investigated the magnitude of this phenomenon in four fishing harbours of Italy by scoring damage to 470 buoys and interviewing 29 fishers (encompassing 42% of the relevant fleet). Information was complemented by opportunistic observations at sea. Our preliminary assessment suggests that offshore polystyrene pecking increases in winter months, and it occurs sporadically among years. The overall economic damage to the static net fishery appeared generally modest (approximately 3-4 Euro to replace one buoy), with wide variations in the extent of reported damage. We reviewed the hypotheses behind polystyrene pecking, but none of them provide a clear explanation for the observed behaviour. Finally, we discuss potential effects on seabirds and advocate monitoring to investigate causal factors and mitigate damage to seabirds, fisheries, and marine environment.}, }
@article {pmid36389402, year = {2022}, author = {Cordeiro, CAMM and Aued, AW and Barros, F and Bastos, AC and Bender, M and Mendes, TC and Creed, JC and Cruz, ICS and Dias, MS and Fernandes, LDA and Coutinho, R and Gonçalves, JEA and Floeter, SR and Mello-Fonseca, J and Freire, AS and Gherardi, DFM and Gomes, LEO and Lacerda, F and Martins, RL and Longo, GO and Mazzuco, AC and Menezes, R and Muelbert, JH and Paranhos, R and Quimbayo, JP and Valentin, JL and Ferreira, CEL}, title = {Long-term monitoring projects of Brazilian marine and coastal ecosystems.}, journal = {PeerJ}, volume = {10}, number = {}, pages = {e14313}, pmid = {36389402}, issn = {2167-8359}, mesh = {Animals ; Humans ; *Ecosystem ; Brazil ; *Biodiversity ; Oceans and Seas ; Fishes ; }, abstract = {Biodiversity assessment is a mandatory task for sustainable and adaptive management for the next decade, and long-term ecological monitoring programs are a cornerstone for understanding changes in ecosystems. The Brazilian Long-Term Ecological Research Program (PELD) is an integrated effort model supported by public funds that finance ecological studies at 34 locations. By interviewing and compiling data from project coordinators, we assessed monitoring efforts, targeting biological groups and scientific production from nine PELD projects encompassing coastal lagoons to mesophotic reefs and oceanic islands. Reef environments and fish groups were the most often studied within the long-term projects. PELD projects covered priority areas for conservation but missed sensitive areas close to large cities, as well as underrepresenting ecosystems on the North and Northeast Brazilian coast. Long-term monitoring projects in marine and coastal environments in Brazil are recent (<5 years), not yet integrated as a network, but scientifically productive with considerable relevance for academic and human resources training. Scientific production increased exponentially with project age, despite interruption and shortage of funding during their history. From our diagnosis, we recommend some actions to fill in observed gaps, such as: enhancing projects' collaboration and integration; focusing on priority regions for new projects; broadening the scope of monitored variables; and, maintenance of funding for existing projects.}, }
@article {pmid36371717, year = {2022}, author = {Waterton, J and Hammond, M and Lau, JA}, title = {Evolutionary effects of nitrogen are not easily predicted from ecological responses.}, journal = {American journal of botany}, volume = {109}, number = {11}, pages = {1741-1756}, pmid = {36371717}, issn = {1537-2197}, mesh = {*Nitrogen ; *Plant Leaves/physiology ; Biological Evolution ; Poaceae ; Plants ; }, abstract = {PREMISE: Anthropogenic nitrogen (N) addition alters the abiotic and biotic environment, potentially leading to changes in patterns of natural selection (i.e., trait-fitness relationships) and the opportunity for selection (i.e., variance in relative fitness). Because N addition favors species with light acquisition strategies (e.g., tall species), we predicted that N would strengthen selection favoring those same traits. We also predicted that N could alter the opportunity for selection via its effects on mean fitness and/or competitive asymmetries.<br><br>METHODS: We quantified the strength of selection and the opportunity for selection in replicated populations of the annual grass Setaria faberi (giant foxtail) growing in a long-term N addition experiment. We also correlated these population-level parameters with community-level metrics to identify the proximate causes of N-mediated evolutionary effects.<br><br>RESULTS: N addition increased aboveground productivity, light asymmetry, and reduced species diversity. Contrary to expectations, N addition did not strengthen selection for trait values associated with higher light acquisition such as greater height and specific leaf area (SLA); rather, it strengthened selection favoring lower SLA. Light asymmetry and species diversity were associated with selection for height and SLA, suggesting a role for these factors in driving N-mediated selection. The opportunity for selection was not influenced by N addition but was negatively associated with species diversity.<br><br>CONCLUSIONS: Our results indicate that anthropogenic N enrichment can affect evolutionary processes, but that evolutionary changes in plant traits within populations are unlikely to parallel the shifts in plant traits observed at the community level.}, }
@article {pmid36371593, year = {2022}, author = {Hsieh, HY and Vandermeer, J and Perfecto, I}, title = {Surprising effects of cascading higher order interactions.}, journal = {Scientific reports}, volume = {12}, number = {1}, pages = {19378}, pmid = {36371593}, issn = {2045-2322}, support = {NSF- DEB-0349388//National Science Foundation/ ; }, mesh = {Animals ; Female ; Male ; Bayes Theorem ; *Coleoptera/physiology ; Population Dynamics ; *Wasps ; }, abstract = {Most species are embedded in multi-interaction networks. Consequently, theories focusing on simple pair-wise interactions cannot predict ecological and/or evolutionary outcomes. This study explores how cascading higher-order interactions (HOIs) would affect the population dynamics of a focal species. Employing a system that involves a myrmecophylic beetle, a parasitic wasp that attacks the beetle, an ant, and a parasitic fly that attacks the ant, the study explores how none, one, and two HOIs affect the parasitism and the sex ratio of the beetle. We conducted mesocosm experiments to examine these HOIs on beetle survival and sex ratio and found that the 1st degree HOI does not change the beetle's survival rate or sex ratio. However, the 2nd degree HOI significantly reduces the beetle's survival rate and changes its sex ratio from even to strongly female-biased. We applied Bayes' theorem to analyze the per capita survival probability of female vs. male beetles and suggested that the unexpected results might arise from complex eco-evolutionary dynamics involved with the 1st and 2nd degree HOIs. Field data suggested the HOIs significantly regulate the sex ratio of the beetle. As the same structure of HOIs appears in other systems, we believe the complexity associated with the 2nd degree HOI would be more common than known and deserve more scientific attention.}, }
@article {pmid36350890, year = {2022}, author = {Barbosa, FG and Lanari, M}, title = {Bibliometric analysis of peer-reviewed literature on the Patos Lagoon, southern Brazil.}, journal = {Anais da Academia Brasileira de Ciencias}, volume = {94}, number = {3}, pages = {e20210861}, doi = {10.1590/0001-3765202220210861}, pmid = {36350890}, issn = {1678-2690}, mesh = {Brazil ; *Ecosystem ; *Bibliometrics ; Publications ; Estuaries ; }, abstract = {Coastal lagoons provide several ecological resources and services with their functioning being mainly investigated in temperate areas. The Patos Lagoon, a subtropical system in southern Brazil, is one of the largest chocked coastal lagoons in the world. It provides habitat for numerous organisms and a range of ecosystem services. We performed a bibliometric analysis to identify and analyze the characteristics of studies carried out in the Patos Lagoon based on articles published in peer-reviewed journals indexed in the Science Citation Index Expanded database of Clarivate Analytics Web of Science and Scopus database. We found 360 articles published between 1965 and 2019 in 150 journals. The number of articles has increased in the last decades mainly resulting from national collaborative efforts. Most articles were published by Brazilian research institutions. Most studies were performed in the Patos Lagoon estuary, a Long-term Ecological Research program´s study site. Our study thus highlights the importance of long-term projects to the comprehension of subtropical coastal lagoons functioning and indicates knowledge gaps that must be addressed in future studies.}, }
@article {pmid36349470, year = {2023}, author = {Liang, Y and Gustafson, EJ and He, HS and Serra-Diaz, JM and Duveneck, MJ and Thompson, JR}, title = {What is the role of disturbance in catalyzing spatial shifts in forest composition and tree species biomass under climate change?.}, journal = {Global change biology}, volume = {29}, number = {4}, pages = {1160-1177}, doi = {10.1111/gcb.16517}, pmid = {36349470}, issn = {1365-2486}, support = {IAEMP202201//Major Program of Institute of Applied Ecology, Chinese Academy of Sciences/ ; 31961133027//National Natural Science Foundation of China/ ; 31971486//National Natural Science Foundation of China/ ; NSF-DEB 12-37491//the National Science Foundation Harvard Forest Long Term Ecological Research Program/ ; XLYC1907177//Top-notch young talents project of Liaoning Province "Xing Liao Talents" Project/ ; }, mesh = {*Trees ; Biomass ; *Climate Change ; Forests ; New England ; }, abstract = {Mounting evidence suggests that climate change will cause shifts of tree species range and abundance (biomass). Abundance changes under climate change are likely to occur prior to a detectable range shift. Disturbances are expected to directly affect tree species abundance and composition, and could profoundly influence tree species spatial distribution within a geographical region. However, how multiple disturbance regimes will interact with changing climate to alter the spatial distribution of species abundance remains unclear. We simulated such forest demographic processes using a forest landscape succession and disturbance model (LANDIS-II) parameterized with forest inventory data in the northeastern United States. Our study incorporated climate change under a high-emission future and disturbance regimes varying with gradients of intensities and spatial extents. The results suggest that disturbances catalyze changes in tree species abundance and composition under a changing climate, but the effects of disturbances differ by intensity and extent. Moderate disturbances and large extent disturbances have limited effects, while high-intensity disturbances accelerate changes by removing cohorts of mid- and late-successional species, creating opportunities for early-successional species. High-intensity disturbances result in the northern movement of early-successional species and the southern movement of late-successional species abundances. Our study is among the first to systematically investigate how disturbance extent and intensity interact to determine the spatial distribution of changes in species abundance and forest composition.}, }
@article {pmid36340816, year = {2022}, author = {Speed, JDM and Evankow, AM and Petersen, TK and Ranke, PS and Nilsen, NH and Turner, G and Aagaard, K and Bakken, T and Davidsen, JG and Dunshea, G and Finstad, AG and Hassel, K and Husby, M and Hårsaker, K and Koksvik, JI and Prestø, T and Vange, V}, title = {A regionally coherent ecological fingerprint of climate change, evidenced from natural history collections.}, journal = {Ecology and evolution}, volume = {12}, number = {11}, pages = {e9471}, pmid = {36340816}, issn = {2045-7758}, abstract = {Climate change has dramatic impacts on ecological systems, affecting a range of ecological factors including phenology, species abundance, diversity, and distribution. The breadth of climate change impacts on ecological systems leads to the occurrence of fingerprints of climate change. However, climate fingerprints are usually identified across broad geographical scales and are potentially influenced by publication biases. In this study, we used natural history collections spanning over 250 years, to quantify a range of ecological responses to climate change, including phenology, abundance, diversity, and distributions, across a range of taxa, including vertebrates, invertebrates, plants, and fungi, within a single region, Central Norway. We tested the hypotheses that ecological responses to climate change are apparent and coherent at a regional scale, that longer time series show stronger trends over time and in relation to temperature, and that ecological responses change in trajectory at the same time as shifts in temperature. We identified a clear regional coherence in climate signal, with decreasing abundances of limnic zooplankton (on average by 7691 individuals m[-3] °C[-1]) and boreal forest breeding birds (on average by 1.94 territories km[-2] °C[-1]), and earlier plant flowering phenology (on average 2 days °C[-1]) for every degree of temperature increase. In contrast, regional-scale species distributions and species diversity were largely stable. Surprisingly, the effect size of ecological response did not increase with study duration, and shifts in responses did not occur at the same time as shifts in temperature. This may be as the long-term studies include both periods of warming and temperature stability, and that ecological responses lag behind warming. Our findings demonstrate a regional climate fingerprint across a long timescale. We contend that natural history collections provide a unique window on a broad spectrum of ecological responses at timescales beyond most ecological monitoring programs. Natural history collections are thus an essential source for long-term ecological research.}, }
@article {pmid36331671, year = {2022}, author = {Behera, SK and Behera, MD and Tuli, R and Barik, SK}, title = {Atmospheric temperature and humidity demonstrated strong correlation with productivity in tropical moist deciduous forests.}, journal = {Environmental monitoring and assessment}, volume = {195}, number = {1}, pages = {69}, doi = {10.1007/s10661-022-10668-7}, pmid = {36331671}, issn = {1573-2959}, support = {NWP-020//CSIR-NBRI/ ; BSC-0109//CSIR-NBRI/ ; }, mesh = {Humans ; *Tropical Climate ; Temperature ; Humidity ; *Environmental Monitoring ; Forests ; Trees ; Biomass ; }, abstract = {Tropical forests sequester six times higher carbon than that released by humans annually into the atmosphere. These biodiversity-rich tropical forests have high net primary productivity (NPP), which differs among constituent plant communities. Tropical moist deciduous forests occupy 179,335 km[2] of India's geographical area and constitute 44% of the country's total protected area (PA) forests. The productivity of these forests has neither been estimated specifically nor precisely. We measured the annual NPP of three predominant distinct community types, viz., mixed (DM), sal (SM), and teak (TP), in a tropical moist deciduous forest in northern India. The NPP was estimated from tree biomass data collected from nine long-term ecological research (LTER) plots of 1 ha each representing the above three community types. The estimated annual NPP were 10.28, 6.25, and 9.79 Mg ha[-1] year[-1] in DM; 8.93, 7.09, and 10.59 Mg ha[-1] year[-1] in SM; and 14.57, 7.14, and 13.56 Mg ha[-1] year[-1] in TP for the years 2010, 2011, and 2012, respectively. The NPP was correlated with tree density, height and DBH, species richness, diversity, microclimatic and edaphic variables, and leaf area index (LAI) using principal component analysis (PCA) and generalized linear modeling (GLM). Air temperature and humidity were strongly related to NPP in all the community types, while "complementarity" and "selection effects" contributed to the NPP in both the sal and mixed forest communities with equal importance, and the NPP in teak plantation ould point to "dominance effect."}, }
@article {pmid36278303, year = {2022}, author = {Ladouceur, E and Blowes, SA and Chase, JM and Clark, AT and Garbowski, M and Alberti, J and Arnillas, CA and Bakker, JD and Barrio, IC and Bharath, S and Borer, ET and Brudvig, LA and Cadotte, MW and Chen, Q and Collins, SL and Dickman, CR and Donohue, I and Du, G and Ebeling, A and Eisenhauer, N and Fay, PA and Hagenah, N and Hautier, Y and Jentsch, A and Jónsdóttir, IS and Komatsu, K and MacDougall, A and Martina, JP and Moore, JL and Morgan, JW and Peri, PL and Power, SA and Ren, Z and Risch, AC and Roscher, C and Schuchardt, MA and Seabloom, EW and Stevens, CJ and Veen, GFC and Virtanen, R and Wardle, GM and Wilfahrt, PA and Harpole, WS}, title = {Linking changes in species composition and biomass in a globally distributed grassland experiment.}, journal = {Ecology letters}, volume = {25}, number = {12}, pages = {2699-2712}, doi = {10.1111/ele.14126}, pmid = {36278303}, issn = {1461-0248}, support = {DFG-FZT 118//Deutsche Forschungsgemeinschaft/ ; 202548816//Deutsche Forschungsgemeinschaft/ ; NSF-DEB-1234162 &amp; DEB-1831944 to Cedar Creek LTER//National Science Foundation Long-Term Ecological Research/ ; NSF-DEB-1042132//National Science Foundation Research Coordination Network/ ; DG-0001-13//University of Minnesota's Institute on the Environment/ ; //National Science Foundation/ ; //University of Minnesota/ ; //Research Foundation/ ; //Helmholtz Centre for Environmental Research/ ; }, mesh = {Biomass ; *Ecosystem ; *Grassland ; Biodiversity ; Plants ; }, abstract = {Global change drivers, such as anthropogenic nutrient inputs, are increasing globally. Nutrient deposition simultaneously alters plant biodiversity, species composition and ecosystem processes like aboveground biomass production. These changes are underpinned by species extinction, colonisation and shifting relative abundance. Here, we use the Price equation to quantify and link the contributions of species that are lost, gained or that persist to change in aboveground biomass in 59 experimental grassland sites. Under ambient (control) conditions, compositional and biomass turnover was high, and losses (i.e. local extinctions) were balanced by gains (i.e. colonisation). Under fertilisation, the decline in species richness resulted from increased species loss and decreases in species gained. Biomass increase under fertilisation resulted mostly from species that persist and to a lesser extent from species gained. Drivers of ecological change can interact relatively independently with diversity, composition and ecosystem processes and functions such as aboveground biomass due to the individual contributions of species lost, gained or persisting.}, }
@article {pmid36260638, year = {2022}, author = {Brown, JA and Lerman, SB and Basile, AJ and Bateman, HL and Deviche, P and Warren, PS and Sweazea, KL}, title = {No fry zones: How restaurant distribution and abundance influence avian communities in the Phoenix, AZ metropolitan area.}, journal = {PloS one}, volume = {17}, number = {10}, pages = {e0269334}, pmid = {36260638}, issn = {1932-6203}, mesh = {Humans ; Animals ; *Columbidae ; *Restaurants ; Ecosystem ; Urbanization ; Arizona ; }, abstract = {Urbanization is one of the most widespread and extreme examples of habitat alteration. As humans dominate landscapes, they introduce novel elements into environments, including artificial light, noise pollution, and anthropogenic food sources. One understudied form of anthropogenic food is refuse from restaurants, which can alter wildlife populations and, in turn, entire wildlife communities by providing a novel and stable food source. Using data from the Maricopa Association of Governments and the Central Arizona-Phoenix Long Term Ecological Research (CAP LTER) project, we investigated whether and how the distribution of restaurants influences avian communities. The research aimed to identify restaurants, and thus the associated food they may provide, as the driver of potential patterns by controlling for other influences of urbanization, including land cover and the total number of businesses. Using generalized linear mixed models, we tested whether the number of restaurants within 1 km of bird monitoring locations predict avian community richness and abundance and individual species abundance and occurrence patterns. Results indicate that restaurants may decrease avian species diversity and increase overall abundance. Additionally, restaurants may be a significant predictor of the overall abundance of urban-exploiting species, including rock pigeon (Columba livia), mourning dove (Zenaida macroura), and Inca dove (Columbina Inca). Understanding how birds utilize anthropogenic food sources can inform possible conservation or wildlife management practices. As this study highlights only correlations, we suggest further experimental work to address the physiological ramifications of consuming anthropogenic foods provided by restaurants and studies to quantify how frequently anthropogenic food sources are used compared to naturally occurring sources.}, }
@article {pmid36143351, year = {2022}, author = {Amoussou, N and Thomas, M and Pasquet, A and Lecocq, T}, title = {Finding the Best Match: A Ranking Procedure of Fish Species Combinations for Polyculture Development.}, journal = {Life (Basel, Switzerland)}, volume = {12}, number = {9}, pages = {}, pmid = {36143351}, issn = {2075-1729}, abstract = {Polyculture is a potentially interesting rearing practice for future aquaculture developments. Nevertheless, it may result in beneficial as well as detrimental consequences for fish production. One way to maximize the benefits of polyculture is to combine species with high levels of compatibility and complementarity. This requires the development of a ranking procedure, based on a multi-trait assessment, that highlights the most suitable species combinations for polyculture. Moreover, in order to ensure the relevance of such a procedure, it is important to integrate the socio-economic expectations by assigning relative weights to each trait according to the stakeholder priorities. Here, we proposed a ranking procedure of candidate fish polycultures (i.e., species combinations that could be potentially interesting for aquaculture) based on a multi-trait assessment approach and the stakeholder priorities. This procedure aims at successively (i) weighting evaluation results obtained for each candidate polyculture according to stakeholder priorities; (ii) assessing differentiation between candidate species combinations based on these weighted results; and (iii) ranking differentiated candidate polycultures. We applied our procedure on three test cases of fish polycultures in recirculated aquaculture systems. These test cases each focused on a target species (two on Sander lucioperca and one on Carassius auratus), which were reared in two or three different alternative candidate fish polycultures. For each test case, our procedure aimed at ranking alternative combinations according to their benefits for production and/or welfare of the target species. These benefits were evaluated based on survival rate as well as morphology, behavioral, and physiological traits. Three scenarios of stakeholder priorities were considered for weighting evaluation results: placing a premium on production, welfare, or both for the target species. A comparison of our procedure results between these scenarios showed that the ranking changed for candidate polycultures in two test cases. This highlights the need to carefully consider stakeholder priorities when choosing fish polycultures.}, }
@article {pmid36065828, year = {2022}, author = {Kim, H and McComb, BC and Frey, SJK and Bell, DM and Betts, MG}, title = {Forest microclimate and composition mediate long-term trends of breeding bird populations.}, journal = {Global change biology}, volume = {28}, number = {21}, pages = {6180-6193}, pmid = {36065828}, issn = {1365-2486}, mesh = {Animals ; Biodiversity ; Birds ; Climate Change ; Ecosystem ; *Forests ; *Microclimate ; Trees ; }, abstract = {Climate change is contributing to biodiversity redistributions and species declines. However, cooler microclimate conditions provided by old-growth forest structures compared with surrounding open or younger forests have been hypothesized to provide thermal refugia for species that are sensitive to climate warming and dampen the negative effects of warming on population trends of animals (i.e., the microclimate buffering hypothesis). In addition to thermal refugia, the compositional and structural diversity of old-growth forest vegetation itself may provide resources to species that are less available in forests with simpler structure (i.e., the insurance hypothesis). We used 8 years of breeding bird abundance data from a forested watershed, accompanied with sub-canopy temperature data, and ground- and LiDAR-based vegetation data to test these hypotheses and identify factors influencing bird population changes from 2011 to 2018. After accounting for imperfect detection, we found that for 5 of 20 bird species analyzed, abundance trends tended to be less negative or neutral at sites with cooler microclimates, which supports the microclimate buffering hypothesis. Negative effects of warming on two species were also reduced in locations with greater forest compositional diversity supporting the insurance hypothesis. We provide the first empirical evidence that complex forest structure and vegetation diversity confer microclimatic advantages to some animal populations in the face of climate change. Conservation of old-growth forests, or their characteristics in managed forests, could help slow the negative effects of climate warming on some breeding bird populations via microclimate buffering and possibly insurance effects.}, }
@article {pmid36056283, year = {2022}, author = {Banchi, E and Manna, V and Fonti, V and Fabbro, C and Celussi, M}, title = {Improving environmental monitoring of Vibrionaceae in coastal ecosystems through 16S rRNA gene amplicon sequencing.}, journal = {Environmental science and pollution research international}, volume = {29}, number = {44}, pages = {67466-67482}, pmid = {36056283}, issn = {1614-7499}, mesh = {Animals ; Ecosystem ; Environmental Monitoring ; Genes, rRNA ; Humans ; Particulate Matter ; Phylogeny ; RNA, Ribosomal, 16S/genetics ; Seawater/microbiology ; Sewage ; *Vibrionaceae/genetics ; Wastewater ; Water ; }, abstract = {The Vibrionaceae family groups genetically and metabolically diverse bacteria thriving in all marine environments. Despite often representing a minor fraction of bacterial assemblages, members of this family can exploit a wide variety of nutritional sources, which makes them important players in biogeochemical dynamics. Furthermore, several Vibrionaceae species are well-known pathogens, posing a threat to human and animal health. Here, we applied the phylogenetic placement coupled with a consensus-based approach using 16S rRNA gene amplicon sequencing, aiming to reach a reliable and fine-level Vibrionaceae characterization and identify the dynamics of blooming, ecologically important, and potentially pathogenic species in different sites of the northern Adriatic Sea. Water samples were collected monthly at a Long-Term Ecological Research network site from 2018 to 2021, and in spring and summer of 2019 and 2020 at two sites affected by depurated sewage discharge. The 41 identified Vibrionaceae species represented generally below 1% of the sampled communities; blooms (up to ~ 11%) mainly formed by Vibrio chagasii and Vibrio owensii occurred in summer, linked to increasing temperature and particulate matter concentration. Pathogenic species such as Vibrio anguilllarum, Vibrio tapetis, and Photobacterium damselae were found in low abundance. Depuration plant samples were characterized by a lower abundance and diversity of Vibrionaceae species compared to seawater, highlighting that Vibrionaceae dynamics at sea are unlikely to be related to wastewater inputs. Our work represents a further step to improve the molecular approach based on short reads, toward a shared, updated, and curated phylogeny of the Vibrionaceae family.}, }
@article {pmid36034512, year = {2022}, author = {Hudson, AR and Peters, DPC and Blair, JM and Childers, DL and Doran, PT and Geil, K and Gooseff, M and Gross, KL and Haddad, NM and Pastore, MA and Rudgers, JA and Sala, O and Seabloom, EW and Shaver, G}, title = {Cross-Site Comparisons of Dryland Ecosystem Response to Climate Change in the US Long-Term Ecological Research Network.}, journal = {Bioscience}, volume = {72}, number = {9}, pages = {889-907}, pmid = {36034512}, issn = {0006-3568}, abstract = {Long-term observations and experiments in diverse drylands reveal how ecosystems and services are responding to climate change. To develop generalities about climate change impacts at dryland sites, we compared broadscale patterns in climate and synthesized primary production responses among the eight terrestrial, nonforested sites of the United States Long-Term Ecological Research (US LTER) Network located in temperate (Southwest and Midwest) and polar (Arctic and Antarctic) regions. All sites experienced warming in recent decades, whereas drought varied regionally with multidecadal phases. Multiple years of wet or dry conditions had larger effects than single years on primary production. Droughts, floods, and wildfires altered resource availability and restructured plant communities, with greater impacts on primary production than warming alone. During severe regional droughts, air pollution from wildfire and dust events peaked. Studies at US LTER drylands over more than 40 years demonstrate reciprocal links and feedbacks among dryland ecosystems, climate-driven disturbance events, and climate change.}, }
@article {pmid36034511, year = {2022}, author = {Jones, JA and Driscoll, CT}, title = {Long-Term Ecological Research on Ecosystem Responses to Climate Change.}, journal = {Bioscience}, volume = {72}, number = {9}, pages = {814-826}, doi = {10.1093/biosci/biac021}, pmid = {36034511}, issn = {0006-3568}, abstract = {In this article marking the 40th anniversary of the US National Science Foundation's Long Term Ecological Research (LTER) Network, we describe how a long-term ecological research perspective facilitates insights into an ecosystem's response to climate change. At all 28 LTER sites, from the Arctic to Antarctica, air temperature and moisture variability have increased since 1930, with increased disturbance frequency and severity and unprecedented disturbance types. LTER research documents the responses to these changes, including altered primary production, enhanced cycling of organic and inorganic matter, and changes in populations and communities. Although some responses are shared among diverse ecosystems, most are unique, involving region-specific drivers of change, interactions among multiple climate change drivers, and interactions with other human activities. Ecosystem responses to climate change are just beginning to emerge, and as climate change accelerates, long-term ecological research is crucial to understand, mitigate, and adapt to ecosystem responses to climate change.}, }
@article {pmid35961144, year = {2022}, author = {Chaumet, B and Probst, JL and Payré-Suc, V and Granouillac, F and Riboul, D and Probst, A}, title = {Pond mitigation in dissolved and particulate pesticide transfers: Influence of storm events and seasonality (Auradé agricultural catchment, SW-France).}, journal = {Journal of environmental management}, volume = {320}, number = {}, pages = {115911}, doi = {10.1016/j.jenvman.2022.115911}, pmid = {35961144}, issn = {1095-8630}, mesh = {Agriculture ; Environmental Monitoring ; *Pesticides/chemistry ; Ponds ; Soil/chemistry ; Water ; *Water Pollutants, Chemical/chemistry ; }, abstract = {In agricultural headwater catchments, wetlands such as ponds are numerous and well known to partly dissipate contamination. Most of the pesticides are transferred from soils to the aquatic environment during flood events. This study reports the annual/seasonal behaviour of 6 pesticides (metolachlor, boscalid, epoxiconazole, tebuconazole, aclonifen and pendimethalin) in such an environment. Because it is rarely considered, the study focussed on the high frequency of the distribution of pesticides between dissolved and particulate phases, as well as the main controlling factors of their upstream-downstream transfer. The pond removal rate was calculated to evaluate the wetland efficiency in pesticide mitigation. We conducted a one-year high frequency hydrochemical survey, with particular emphasis on flood events, in the upper Auradé catchment (SW-France), an area of long-term conventional agriculture on highly erosive carbonated soils. The inlet and outlet of the pond were instrumented for water level measurements and water sampling. The highest concentrations were observed for tebuconazole and, in general, the presence of the molecules during the year depended on the season. The pond showed satisfactory efficiency in pesticide attenuation for the six molecules considered, although the removal rate depended on the molecule and the bearing phase (from 28.4% for boscalid to 89.4% for aclonifen in the dissolved phase and from 22.1% for pendimethalin to 96.8% for metolachlor in the particulate fraction). Interestingly, the more hydrophilic the molecule (low LogKOW), the more efficient the pesticide removal rate was for its particulate fraction, and the opposite for hydrophobic molecules (high LogKOW). Flood events carried a large amount of Total Suspended Solid (TSS) bearing hydrophobic molecules from a major legacy of upper catchment soils, although 52% of the pesticides were transported by the dissolved fraction. Significant resuspension of TSS from the pond was evidenced by the annual mass balance with four tons of TSS released, while the positive rate of pesticide removal involved other effective mechanisms such as exchange and complexation. Although these constructed wetlands may be beneficial for pesticide mitigation, the results highlighted the need for improved land management in the upstream catchment during the different seasons to avoid bare soils that pose a risk of high surface water contamination, especially due to the presence of hydrophobic molecules in combination with a high erosive context.}, }
@article {pmid35949533, year = {2022}, author = {Percopo, I and Ruggiero, MV and Sarno, D and Longobardi, L and Rossi, R and Piredda, R and Zingone, A}, title = {Phenological segregation suggests speciation by time in the planktonic diatom Pseudo-nitzschia allochrona sp. nov.}, journal = {Ecology and evolution}, volume = {12}, number = {8}, pages = {e9155}, pmid = {35949533}, issn = {2045-7758}, abstract = {The processes leading to the emergence of new species are poorly understood in marine plankton, where weak physical barriers and homogeneous environmental conditions limit spatial and ecological segregation. Here, we combine molecular and ecological information from a long-term time series and propose Pseudo-nitzschia allochrona, a new cryptic planktonic diatom, as a possible case of speciation by temporal segregation. The new species differs in several genetic markers (18S, 28S and ITS rDNA fragments and rbcL) from its closest relatives, which are morphologically very similar or identical, and is reproductively isolated from its sibling species P. arenysensis. Data from a long-term plankton time series show P. allochrona invariably occurring in summer-autumn in the Gulf of Naples, where its closely related species P. arenysensis, P. delicatissima, and P. dolorosa are instead found in winter-spring. Temperature and nutrients are the main factors associated with the occurrence of P. allochrona, which could have evolved in sympatry by switching its phenology and occupying a new ecological niche. This case of possible speciation by time shows the relevance of combining ecological time series with molecular information to shed light on the eco-evolutionary dynamics of marine microorganisms.}, }
@article {pmid35917966, year = {2022}, author = {Wurtzer, S and Levert, M and Dhenain, E and Accrombessi, H and Manco, S and Fagour, N and Goulet, M and Boudaud, N and Gaillard, L and Bertrand, I and Challant, J and Masnada, S and Azimi, S and Gillon-Ritz, M and Robin, A and Mouchel, JM and Sig, O and Moulin, L}, title = {From Alpha to Omicron BA.2: New digital RT-PCR approach and challenges for SARS-CoV-2 VOC monitoring and normalization of variant dynamics in wastewater.}, journal = {The Science of the total environment}, volume = {848}, number = {}, pages = {157740}, pmid = {35917966}, issn = {1879-1026}, mesh = {*COVID-19 ; COVID-19 Testing ; Humans ; Pandemics ; Reverse Transcriptase Polymerase Chain Reaction ; *SARS-CoV-2/genetics ; Sewage ; Wastewater ; }, abstract = {Throughout the COVID-19 pandemic, new variants have continuously emerged and spread in populations. Among these, variants of concern (VOC) have been the main culprits of successive epidemic waves, due to their transmissibility, pathogenicity or ability to escape the immune response. Quantification of the SARS-CoV-2 genomes in raw wastewater is a reliable approach well-described and widely deployed worldwide to monitor the spread of SARS-CoV-2 in human populations connected to sewage systems. Discrimination of VOCs in wastewater is also a major issue and can be achieved by genome sequencing or by detection of specific mutations suggesting the presence of VOCs. This study aimed to date the emergence of these VOCs (from Alpha to Omicron BA.2) by monitoring wastewater from the greater Paris area, France, but also to model the propagation dynamics of these VOCs and to characterize the replacement kinetics of the prevalent populations. These dynamics were compared to various individual-centered public health data, such as regional incidence and the proportions of VOCs identified by sequencing of strains isolated from patient. The viral dynamics in wastewater highlighted the impact of the vaccination strategy on the viral circulation within human populations but also suggested its potential effect on the selection of variants most likely to be propagated in immunized populations. Normalization of concentrations to capture population movements appeared statistically more reliable using variations in local drinking water consumption rather than using PMMoV concentrations because PMMoV fecal shedding was subject to variability and was not sufficiently relevant in this study. The dynamics of viral spread was observed earlier (about 13 days on the wave related to Omicron VOC) in raw wastewater than the regional incidence alerting to a possible risk of decorrelation between incidence and actual virus circulation probably resulting from a lower severity of infection in vaccinated populations.}, }
@article {pmid35835788, year = {2022}, author = {Xu, H and Lian, X and Slette, IJ and Yang, H and Zhang, Y and Chen, A and Piao, S}, title = {Rising ecosystem water demand exacerbates the lengthening of tropical dry seasons.}, journal = {Nature communications}, volume = {13}, number = {1}, pages = {4093}, pmid = {35835788}, issn = {2041-1723}, mesh = {Climate Change ; *Ecosystem ; Rain ; Seasons ; Tropical Climate ; *Water ; }, abstract = {Precipitation-based assessments show a lengthening of tropical dry seasons under climate change, without considering simultaneous changes in ecosystem water demand. Here, we compare changes in tropical dry season length and timing when dry season is defined as the period when precipitation is less than: its climatological average, potential evapotranspiration, or actual evapotranspiration. While all definitions show more widespread tropical drying than wetting for 1983-2016, we find the largest fraction (48.7%) of tropical land probably experiencing longer dry seasons when dry season is defined as the period when precipitation cannot meet the need of actual evapotranspiration. Southern Amazonia (due to delayed end) and central Africa (due to earlier onset and delayed end) are hotspots of dry season lengthening, with greater certainty when accounting for water demand changes. Therefore, it is necessary to account for changing water demand when characterizing changes in tropical dry periods and ecosystem water deficits.}, }
@article {pmid35785720, year = {2022}, author = {Cesarini, G and Secco, S and Battisti, C and Questino, B and Marcello, L and Scalici, M}, title = {Temporal changes of plastic litter and associated encrusting biota: Evidence from Central Italy (Mediterranean Sea).}, journal = {Marine pollution bulletin}, volume = {181}, number = {}, pages = {113890}, doi = {10.1016/j.marpolbul.2022.113890}, pmid = {35785720}, issn = {1879-3363}, mesh = {Animals ; Bathing Beaches ; Biota ; Environmental Monitoring ; Mediterranean Sea ; Mollusca ; *Plastics ; *Waste Products/analysis ; }, abstract = {We investigated the temporal changes from spring to summer of the stranded litter and the composition of plastic encrusting biota along an Italian beach. Our findings highlight a higher quantity of litter (average value 1510.67 ± 581.27 items) in spring, particularly plastic material with a composition driven by currents, winds and waves transported from rivers to sea. During summer the source was caused by anti-social behaviours (e.g. cigarettes). Regarding the plastic size, the most is macroplastic (85.96 %), followed by mesoplastic (13.74 %) and megaplastic (0.30 %) overall, and no seasonal trend was observed. Concerning the encrusting biota, Mollusca was the most frequent phylum found on plastic beach litter, whereas Porifera the most abundant overall. During spring a greater abundance of individuals was recorded compared to summer. The trend of taxa richness was decreasing from spring to summer. Arthropoda, Porifera and Mollusca phyla were significantly more abundant in spring, while Algae in summer.}, }
@article {pmid35763598, year = {2022}, author = {Collins, CG and Elmendorf, SC and Smith, JG and Shoemaker, L and Szojka, M and Swift, M and Suding, KN}, title = {Global change re-structures alpine plant communities through interacting abiotic and biotic effects.}, journal = {Ecology letters}, volume = {25}, number = {8}, pages = {1813-1826}, doi = {10.1111/ele.14060}, pmid = {35763598}, issn = {1461-0248}, support = {1637686//Division of Environmental Biology/ ; 2033292//Division of Environmental Biology/ ; 2044006//Division of Environmental Biology/ ; //Niwot Ridge LTER/ ; }, mesh = {Ecosystem ; *Nitrogen ; *Plants ; }, abstract = {Global change is altering patterns of community assembly, with net outcomes dependent on species' responses to the abiotic environment, both directly and mediated through biotic interactions. Here, we assess alpine plant community responses in a 15-year factorial nitrogen addition, warming and snow manipulation experiment. We used a dynamic competition model to estimate the density-dependent and -independent processes underlying changes in species-group abundances over time. Density-dependent shifts in competitive interactions drove long-term changes in abundance of species-groups under global change while counteracting environmental drivers limited the growth response of the dominant species through density-independent mechanisms. Furthermore, competitive interactions shifted with the environment, primarily with nitrogen and drove non-linear abundance responses across environmental gradients. Our results highlight that global change can either reshuffle species hierarchies or further favour already-dominant species; predicting which outcome will occur requires incorporating both density-dependent and -independent mechanisms and how they interact across multiple global change factors.}, }
@article {pmid35762387, year = {2022}, author = {Hirsch, SL and Ribes, D and Inman, S}, title = {Sedimentary legacy and the disturbing recurrence of the human in long-term ecological research.}, journal = {Social studies of science}, volume = {52}, number = {4}, pages = {561-580}, doi = {10.1177/03063127221101171}, pmid = {35762387}, issn = {1460-3659}, abstract = {Even as new elements of a research infrastructure are added, older parts continue to exert persistent and consequential influence. We introduce the concept of sedimentary legacy to describe the relationship between infrastructure and research objects. Contrary to common accounts of legacy infrastructure that underscore lock-in, static, or constraining outcomes, sedimentary legacy emphasizes how researchers adapt infrastructure to support the investigation of new research objects, even while operating under constraining legacies. To illustrate the implications of sedimentary legacy, we track shifting objects of investigation across the history of the Long-Term Ecological Research (LTER) Network, focusing especially on recurrent ecological investigations of 'human disturbance' as researchers shift to study socioecological objects. We examine the relationship between scientific objects and the resources collected and preserved to render such objects tractable to scientific investigations, and show how the resources of a long-term research infrastructure support the assembly of certain objects of investigation, even while foreclosing others.}, }
@article {pmid35677292, year = {2022}, author = {Aoki, LR and Brisbin, MM and Hounshell, AG and Kincaid, DW and Larson, EI and Sansom, BJ and Shogren, AJ and Smith, RS and Sullivan-Stack, J}, title = {Preparing Aquatic Research for an Extreme Future: Call for Improved Definitions and Responsive, Multidisciplinary Approaches.}, journal = {Bioscience}, volume = {72}, number = {6}, pages = {508-520}, pmid = {35677292}, issn = {0006-3568}, abstract = {Extreme events have increased in frequency globally, with a simultaneous surge in scientific interest about their ecological responses, particularly in sensitive freshwater, coastal, and marine ecosystems. We synthesized observational studies of extreme events in these aquatic ecosystems, finding that many studies do not use consistent definitions of extreme events. Furthermore, many studies do not capture ecological responses across the full spatial scale of the events. In contrast, sampling often extends across longer temporal scales than the event itself, highlighting the usefulness of long-term monitoring. Many ecological studies of extreme events measure biological responses but exclude chemical and physical responses, underscoring the need for integrative and multidisciplinary approaches. To advance extreme event research, we suggest prioritizing pre- and postevent data collection, including leveraging long-term monitoring; making intersite and cross-scale comparisons; adopting novel empirical and statistical approaches; and developing funding streams to support flexible and responsive data collection.}, }
@article {pmid35665886, year = {2022}, author = {Gallitelli, L and Battisti, C and Pietrelli, L and Scalici, M}, title = {Anthropogenic particles in coypu (Myocastor coypus; Mammalia, Rodentia)' faeces: first evidence and considerations about their use as track for detecting microplastic pollution.}, journal = {Environmental science and pollution research international}, volume = {29}, number = {36}, pages = {55293-55301}, pmid = {35665886}, issn = {1614-7499}, mesh = {Animals ; Environmental Monitoring ; Feces/chemistry ; *Microplastics ; Plastics ; Rodentia ; Spectroscopy, Fourier Transform Infrared ; *Water Pollutants, Chemical/analysis ; }, abstract = {Anthropogenic plastic litter is widespread in all environments, with particular emphasis on aquatic habitats. Specifically, although freshwater mammals are important as they are at the top of food web, research mainly focus on marine animals, while only few studies have been carried out on freshwater mammals. The main gap is that microplastics (MP) are completely understudied in freshwater mammals. Here, we reported the first evidence of the presence of anthropogenic particles (including MP) in coypu (Myocastor coypus)' faeces. Coypu is a rodent mammal inhabiting rivers and wetland areas, and we discussed our preliminary data suggesting the use of these tracks as possible future bioindicator of MP pollution in wetlands and freshwaters. We collected 30 coypu's faeces in "Torre Flavia wetland" nature reserve. Then, in laboratory, faeces were digested in 30 ml hydrogen peroxide (30%) for a week a 20 °C and analysed under stereoscope. All the suspected found MP were isolated in a petri dish, using FT-IR analysis to confirm the polymers. Overall, we recorded 444 natural and anthropogenic particles with most of items being fibres. FT-IR analysis of the 10% of the particles recovered revealed that 72% of them was not MP (mainly, polyethylene, polyethylene terephthalate, and polyamide). Also, the number of anthropogenic particles is not correlated with the faecal weight. Given that alien species, such as coypu, are widespread species, our results might have a great importance as these species and MP in faecal tracks may be used as undirect proxy of environmental bioavailability of MP pollution.}, }
@article {pmid35633204, year = {2022}, author = {Rastetter, EB and Kwiatkowski, BL and Kicklighter, DW and Barker Plotkin, A and Genet, H and Nippert, JB and O'Keefe, K and Perakis, SS and Porder, S and Roley, SS and Ruess, RW and Thompson, JR and Wieder, WR and Wilcox, K and Yanai, RD}, title = {N and P constrain C in ecosystems under climate change: Role of nutrient redistribution, accumulation, and stoichiometry.}, journal = {Ecological applications : a publication of the Ecological Society of America}, volume = {32}, number = {8}, pages = {e2684}, pmid = {35633204}, issn = {1939-5582}, mesh = {*Ecosystem ; *Climate Change ; Carbon Dioxide/analysis ; Soil ; Nitrogen/analysis ; Nutrients ; }, abstract = {We use the Multiple Element Limitation (MEL) model to examine responses of 12 ecosystems to elevated carbon dioxide (CO2), warming, and 20% decreases or increases in precipitation. Ecosystems respond synergistically to elevated CO2 , warming, and decreased precipitation combined because higher water-use efficiency with elevated CO2 and higher fertility with warming compensate for responses to drought. Response to elevated CO2 , warming, and increased precipitation combined is additive. We analyze changes in ecosystem carbon (C) based on four nitrogen (N) and four phosphorus (P) attribution factors: (1) changes in total ecosystem N and P, (2) changes in N and P distribution between vegetation and soil, (3) changes in vegetation C:N and C:P ratios, and (4) changes in soil C:N and C:P ratios. In the combined CO2 and climate change simulations, all ecosystems gain C. The contributions of these four attribution factors to changes in ecosystem C storage varies among ecosystems because of differences in the initial distributions of N and P between vegetation and soil and the openness of the ecosystem N and P cycles. The net transfer of N and P from soil to vegetation dominates the C response of forests. For tundra and grasslands, the C gain is also associated with increased soil C:N and C:P. In ecosystems with symbiotic N fixation, C gains resulted from N accumulation. Because of differences in N versus P cycle openness and the distribution of organic matter between vegetation and soil, changes in the N and P attribution factors do not always parallel one another. Differences among ecosystems in C-nutrient interactions and the amount of woody biomass interact to shape ecosystem C sequestration under simulated global change. We suggest that future studies quantify the openness of the N and P cycles and changes in the distribution of C, N, and P among ecosystem components, which currently limit understanding of nutrient effects on C sequestration and responses to elevated CO2 and climate change.}, }
@article {pmid35573027, year = {2022}, author = {Gaiser, EE and Kominoski, JS and McKnight, DM and Bahlai, CA and Cheng, C and Record, S and Wollheim, WM and Christianson, KR and Downs, MR and Hawman, PA and Holbrook, SJ and Kumar, A and Mishra, DR and Molotch, NP and Primack, RB and Rassweiler, A and Schmitt, RJ and Sutter, LA}, title = {Long-term ecological research and the COVID-19 anthropause: A window to understanding social-ecological disturbance.}, journal = {Ecosphere (Washington, D.C)}, volume = {13}, number = {4}, pages = {e4019}, pmid = {35573027}, issn = {2150-8925}, abstract = {The period of disrupted human activity caused by the COVID-19 pandemic, coined the "anthropause," altered the nature of interactions between humans and ecosystems. It is uncertain how the anthropause has changed ecosystem states, functions, and feedback to human systems through shifts in ecosystem services. Here, we used an existing disturbance framework to propose new investigation pathways for coordinated studies of distributed, long-term social-ecological research to capture effects of the anthropause. Although it is still too early to comprehensively evaluate effects due to pandemic-related delays in data availability and ecological response lags, we detail three case studies that show how long-term data can be used to document and interpret changes in air and water quality and wildlife populations and behavior coinciding with the anthropause. These early findings may guide interpretations of effects of the anthropause as it interacts with other ongoing environmental changes in the future, particularly highlighting the importance of long-term data in separating disturbance impacts from natural variation and long-term trends. Effects of this global disturbance have local to global effects on ecosystems with feedback to social systems that may be detectable at spatial scales captured by nationally to globally distributed research networks.}, }
@article {pmid35309738, year = {2021}, author = {Wheeler, MM and Collins, SL and Grimm, NB and Cook, EM and Clark, C and Sponseller, RA and Hall, SJ}, title = {Water and nitrogen shape winter annual plant diversity and community composition in near-urban Sonoran Desert preserves.}, journal = {Ecological monographs}, volume = {91}, number = {3}, pages = {1-19}, pmid = {35309738}, issn = {0012-9615}, support = {EPA999999/ImEPA/Intramural EPA/United States ; }, abstract = {Increased nitrogen (N) deposition threatens global biodiversity, but its effects in arid urban ecosystems are not well studied. In addition to altered N availability, urban environments also experience increases in other pollutants, decreased population connectivity, and altered biotic interactions, which can further impact biodiversity. In deserts, annual plant communities make up most of the plant diversity, support wildlife, and contribute to nutrient cycling and ecosystem processes. Functional tradeoffs allowing coexistence of a diversity of annual plant species are well established, but maintenance of diversity in urban conditions and with increased availability of limiting nutrients has not been explored. We conducted a 13-year N and phosphorus (P) addition experiment in Sonoran Desert preserves in and around Phoenix, AZ, to test how nutrient availability interacts with growing season precipitation, urban location, and microhabitat to affect winter annual plant diversity. Using structural equation modeling and generalized linear mixed modeling, we found that annual plant taxonomic diversity was significantly reduced in N-enriched and urban plots. Water availability in both current and previous growing seasons impacted annual plant diversity, with significant interaction effects showing increased diversity in wetter years and greater responsiveness of the community to water following a wet year. However, there were no significant interactions between N enrichment and water availability, urban location, or microhabitat. Lowered diversity in urban preserves may be partly attributable to increased urban N deposition. Changes in biodiversity of showy species like annual wildflowers in urban preserves can have important implications for connections between urban residents and nature, and reduced diversity and community restructuring with N enrichment represents a challenge for future preservation of aridland biodiversity.}, }
@article {pmid35298255, year = {2022}, author = {Santangelo, JS and Ness, RW and Cohan, B and Fitzpatrick, CR and Innes, SG and Koch, S and Miles, LS and Munim, S and Peres-Neto, PR and Prashad, C and Tong, AT and Aguirre, WE and Akinwole, PO and Alberti, M and Álvarez, J and Anderson, JT and Anderson, JJ and Ando, Y and Andrew, NR and Angeoletto, F and Anstett, DN and Anstett, J and Aoki-Gonçalves, F and Arietta, AZA and Arroyo, MTK and Austen, EJ and Baena-Díaz, F and Barker, CA and Baylis, HA and Beliz, JM and Benitez-Mora, A and Bickford, D and Biedebach, G and Blackburn, GS and Boehm, MMA and Bonser, SP and Bonte, D and Bragger, JR and Branquinho, C and Brans, KI and Bresciano, JC and Brom, PD and Bucharova, A and Burt, B and Cahill, JF and Campbell, KD and Carlen, EJ and Carmona, D and Castellanos, MC and Centenaro, G and Chalen, I and Chaves, JA and Chávez-Pesqueira, M and Chen, XY and Chilton, AM and Chomiak, KM and Cisneros-Heredia, DF and Cisse, IK and Classen, AT and Comerford, MS and Fradinger, CC and Corney, H and Crawford, AJ and Crawford, KM and Dahirel, M and David, S and De Haan, R and Deacon, NJ and Dean, C and Del-Val, E and Deligiannis, EK and Denney, D and Dettlaff, MA and DiLeo, MF and Ding, YY and Domínguez-López, ME and Dominoni, DM and Draud, SL and Dyson, K and Ellers, J and Espinosa, CI and Essi, L and Falahati-Anbaran, M and Falcão, JCF and Fargo, HT and Fellowes, MDE and Fitzpatrick, RM and Flaherty, LE and Flood, PJ and Flores, MF and Fornoni, J and Foster, AG and Frost, CJ and Fuentes, TL and Fulkerson, JR and Gagnon, E and Garbsch, F and Garroway, CJ and Gerstein, AC and Giasson, MM and Girdler, EB and Gkelis, S and Godsoe, W and Golemiec, AM and Golemiec, M and González-Lagos, C and Gorton, AJ and Gotanda, KM and Granath, G and Greiner, S and Griffiths, JS and Grilo, F and Gundel, PE and Hamilton, B and Hardin, JM and He, T and Heard, SB and Henriques, AF and Hernández-Poveda, M and Hetherington-Rauth, MC and Hill, SJ and Hochuli, DF and Hodgins, KA and Hood, GR and Hopkins, GR and Hovanes, KA and Howard, AR and Hubbard, SC and Ibarra-Cerdeña, CN and Iñiguez-Armijos, C and Jara-Arancio, P and Jarrett, BJM and Jeannot, M and Jiménez-Lobato, V and Johnson, M and Johnson, O and Johnson, PP and Johnson, R and Josephson, MP and Jung, MC and Just, MG and Kahilainen, A and Kailing, OS and Kariñho-Betancourt, E and Karousou, R and Kirn, LA and Kirschbaum, A and Laine, AL and LaMontagne, JM and Lampei, C and Lara, C and Larson, EL and Lázaro-Lobo, A and Le, JH and Leandro, DS and Lee, C and Lei, Y and León, CA and Lequerica Tamara, ME and Levesque, DC and Liao, WJ and Ljubotina, M and Locke, H and Lockett, MT and Longo, TC and Lundholm, JT and MacGillavry, T and Mackin, CR and Mahmoud, AR and Manju, IA and Mariën, J and Martínez, DN and Martínez-Bartolomé, M and Meineke, EK and Mendoza-Arroyo, W and Merritt, TJS and Merritt, LEL and Migiani, G and Minor, ES and Mitchell, N and Mohammadi Bazargani, M and Moles, AT and Monk, JD and Moore, CM and Morales-Morales, PA and Moyers, BT and Muñoz-Rojas, M and Munshi-South, J and Murphy, SM and Murúa, MM and Neila, M and Nikolaidis, O and Njunjić, I and Nosko, P and Núñez-Farfán, J and Ohgushi, T and Olsen, KM and Opedal, &#xd8;H and Ornelas, C and Parachnowitsch, AL and Paratore, AS and Parody-Merino, AM and Paule, J and Paulo, OS and Pena, JC and Pfeiffer, VW and Pinho, P and Piot, A and Porth, IM and Poulos, N and Puentes, A and Qu, J and Quintero-Vallejo, E and Raciti, SM and Raeymaekers, JAM and Raveala, KM and Rennison, DJ and Ribeiro, MC and Richardson, JL and Rivas-Torres, G and Rivera, BJ and Roddy, AB and Rodriguez-Muñoz, E and Román, JR and Rossi, LS and Rowntree, JK and Ryan, TJ and Salinas, S and Sanders, NJ and Santiago-Rosario, LY and Savage, AM and Scheepens, JF and Schilthuizen, M and Schneider, AC and Scholier, T and Scott, JL and Shaheed, SA and Shefferson, RP and Shepard, CA and Shykoff, JA and Silveira, G and Smith, AD and Solis-Gabriel, L and Soro, A and Spellman, KV and Whitney, KS and Starke-Ottich, I and Stephan, JG and Stephens, JD and Szulc, J and Szulkin, M and Tack, AJM and Tamburrino, &#xcd; and Tate, TD and Tergemina, E and Theodorou, P and Thompson, KA and Threlfall, CG and Tinghitella, RM and Toledo-Chelala, L and Tong, X and Uroy, L and Utsumi, S and Vandegehuchte, ML and VanWallendael, A and Vidal, PM and Wadgymar, SM and Wang, AY and Wang, N and Warbrick, ML and Whitney, KD and Wiesmeier, M and Wiles, JT and Wu, J and Xirocostas, ZA and Yan, Z and Yao, J and Yoder, JB and Yoshida, O and Zhang, J and Zhao, Z and Ziter, CD and Zuellig, MP and Zufall, RA and Zurita, JE and Zytynska, SE and Johnson, MTJ}, title = {Global urban environmental change drives adaptation in white clover.}, journal = {Science (New York, N.Y.)}, volume = {375}, number = {6586}, pages = {1275-1281}, doi = {10.1126/science.abk0989}, pmid = {35298255}, issn = {1095-9203}, mesh = {*Adaptation, Physiological ; *Biological Evolution ; Cities ; *Ecosystem ; Genes, Plant ; Genome, Plant ; Hydrogen Cyanide/metabolism ; Rural Population ; Trifolium/genetics/*physiology ; *Urbanization ; }, abstract = {Urbanization transforms environments in ways that alter biological evolution. We examined whether urban environmental change drives parallel evolution by sampling 110,019 white clover plants from 6169 populations in 160 cities globally. Plants were assayed for a Mendelian antiherbivore defense that also affects tolerance to abiotic stressors. Urban-rural gradients were associated with the evolution of clines in defense in 47% of cities throughout the world. Variation in the strength of clines was explained by environmental changes in drought stress and vegetation cover that varied among cities. Sequencing 2074 genomes from 26 cities revealed that the evolution of urban-rural clines was best explained by adaptive evolution, but the degree of parallel adaptation varied among cities. Our results demonstrate that urbanization leads to adaptation at a global scale.}, }
@article {pmid35157155, year = {2022}, author = {Schaeffer, B and Salls, W and Coffer, M and Lebreton, C and Werther, M and Stelzer, K and Urquhart, E and Gurlin, D}, title = {Merging of the Case 2 Regional Coast Colour and Maximum-Peak Height chlorophyll-a algorithms: validation and demonstration of satellite-derived retrievals across US lakes.}, journal = {Environmental monitoring and assessment}, volume = {194}, number = {3}, pages = {179}, pmid = {35157155}, issn = {1573-2959}, support = {14-SMDUNSOL14-0001/NASA/NASA/United States ; 730141//Horizon 2020/ ; }, mesh = {Algorithms ; Chlorophyll/analysis ; Chlorophyll A/analysis ; Color ; *Ecosystem ; Environmental Monitoring ; Humans ; *Lakes ; }, abstract = {Water quality monitoring is relevant for protecting the designated, or beneficial uses, of water such as drinking, aquatic life, recreation, irrigation, and food supply that support the economy, human well-being, and aquatic ecosystem health. Managing finite water resources to support these designated uses requires information on water quality so that managers can make sustainable decisions. Chlorophyll-a (chl-a, µg L[-1]) concentration can serve as a proxy for phytoplankton biomass and may be used as an indicator of increased anthropogenic nutrient stress. Satellite remote sensing may present a complement to in situ measures for assessments of water quality through the retrieval of chl-a with in-water algorithms. Validation of chl-a algorithms across US lakes improves algorithm maturity relevant for monitoring applications. This study compares performance of the Case 2 Regional Coast Colour (C2RCC) chl-a retrieval algorithm, a revised version of the Maximum-Peak Height (MPH(P)) algorithm, and three scenarios merging these two approaches. Satellite data were retrieved from the MEdium Resolution Imaging Spectrometer (MERIS) and the Ocean and Land Colour Instrument (OLCI), while field observations were obtained from 181 lakes matched with U.S. Water Quality Portal chl-a data. The best performance based on mean absolute multiplicative error (MAEmult) was demonstrated by the merged algorithm referred to as C15-M10 (MAEmult = 1.8, biasmult = 0.97, n = 836). In the C15-M10 algorithm, the MPH(P) chl-a value was retained if it was > 10 µg L[-1]; if the MPH(P) value was ≤ 10 µg L[-1], the C2RCC value was selected, as long as that value was < 15 µg L[-1]. Time-series and lake-wide gradients compared against independent assessments from Lake Champlain and long-term ecological research stations in Wisconsin were used as complementary examples supporting water quality reporting requirements. Trophic state assessments for Wisconsin lakes provided examples in support of inland water quality monitoring applications. This study presents and assesses merged adaptations of chl-a algorithms previously reported independently. Additionally, it contributes to the transition of chl-a algorithm maturity by quantifying error statistics for a number of locations and times.}, }
@article {pmid35138007, year = {2022}, author = {Sonti, NF and Groffman, PM and Nowak, DJ and Henning, JG and Avolio, ML and Rosi, EJ}, title = {Urban net primary production: Concepts, field methods, and Baltimore, Maryland, USA case study.}, journal = {Ecological applications : a publication of the Ecological Society of America}, volume = {32}, number = {4}, pages = {e2562}, doi = {10.1002/eap.2562}, pmid = {35138007}, issn = {1051-0761}, mesh = {Baltimore ; Biomass ; *Ecosystem ; Grassland ; *Rain ; Trees ; }, abstract = {Given the large and increasing amount of urban, suburban, and exurban land use on Earth, there is a need to accurately assess net primary productivity (NPP) of urban ecosystems. However, the heterogeneous and dynamic urban mosaic presents challenges to the measurement of NPP, creating landscapes that may appear more similar to a savanna than to the native landscape replaced. Studies of urban biomass have tended to focus on one type of vegetation (e.g., lawns or trees). Yet a focus on the ecology of the city should include the entire urban ecosystem rather than the separate investigation of its parts. Furthermore, few studies have attempted to measure urban aboveground NPP (ANPP) using field-based methods. Most studies project growth rates from measurements of tree diameter to estimate annual ANPP or use remote sensing approaches. In addition, field-based methods for measuring NPP do not address any special considerations for adapting such field methods to urban landscapes. Frequent planting and partial or complete removal of herbaceous and woody plants can make it difficult to accurately quantify increments and losses of plant biomass throughout an urban landscape. In this study, we review how ANPP of urban landscapes can be estimated based on field measurements, highlighting the challenges specific to urban areas. We then estimated ANPP of woody and herbaceous vegetation over a 15-year period for Baltimore, MD, USA using a combination of plot-based field data and published values from the literature. Baltimore's citywide ANPP was estimated to be 355.8 g m[-2] , a result that we then put into context through comparison with other North American Long-Term Ecological Research (LTER) sites and mean annual precipitation. We found our estimate of Baltimore citywide ANPP to be only approximately half as much (or less) than ANPP at forested LTER sites of the eastern United States, and more comparable to grassland, oldfield, desert, or boreal forest ANPP. We also found that Baltimore had low productivity for its level of precipitation. We conclude with a discussion of the significance of accurate assessment of primary productivity of urban ecosystems and critical future research needs.}, }
@article {pmid35132623, year = {2022}, author = {Adelizzi, R and O'Brien, EA and Hoellrich, M and Rudgers, JA and Mann, M and Fernandes, VMC and Darrouzet-Nardi, A and Stricker, E}, title = {Disturbance to biocrusts decreased cyanobacteria, N-fixer abundance, and grass leaf N but increased fungal abundance.}, journal = {Ecology}, volume = {103}, number = {4}, pages = {e3656}, doi = {10.1002/ecy.3656}, pmid = {35132623}, issn = {1939-9170}, mesh = {Chlorophyll A ; *Cyanobacteria ; Ecosystem ; Fungi ; Humans ; *Microbiota ; Plant Leaves ; Poaceae ; Soil ; Soil Microbiology ; }, abstract = {Interactions between plants and soil microbes influence plant nutrient transformations, including nitrogen (N) fixation, nutrient mineralization, and resource exchanges through fungal networks. Physical disturbances to soils can disrupt soil microbes and associated processes that support plant and microbial productivity. In low resource drylands, biological soil crusts ("biocrusts") occupy surface soils and house key autotrophic and diazotrophic bacteria, non-vascular plants, or lichens. Interactions among biocrusts, plants, and fungal networks between them are hypothesized to drive carbon and nutrient dynamics; however, comparisons across ecosystems are needed to generalize how soil disturbances alter microbial communities and their contributions to N pools and transformations. To evaluate linkages among plants, fungi, and biocrusts, we disturbed all unvegetated surfaces with human foot trampling twice yearly from 2013-2019 in dry conditions in cyanobacteria-dominated biocrusts in the Chihuahuan Desert grassland and shrubland ecosystems. After 5 years, disturbance decreased the abundances of cyanobacteria (especially Microcoleus steenstrupii clade) and N-fixers (Scytonema sp., and Schizothrix sp.) by >77% and chlorophyll a by up to 55% but, conversely, increased soil fungal abundance by 50% compared with controls. Responses of root-associated fungi differed between the two dominant plant species and ecosystem types, with a maximum of 80% more aseptate hyphae in disturbed than in control plots. Although disturbance did not affect [15] N tracer transfer from biocrusts to the dominant grass, Bouteloua eriopoda, disturbance increased available soil N by 65% in the shrubland, and decreased leaf N of B. eriopoda by up to 16%, suggesting that, although rapid N transfer during peak production was not affected by disturbance, over the long-term plant nutrient content was disrupted. Altogether, the shrubland may be more resilient to detrimental changes due to disturbance than grassland, and these results demonstrated that disturbances to soil microbial communities have the potential to cause substantial changes in N pools by reducing and reordering biocrust taxa.}, }
@article {pmid35019185, year = {2022}, author = {Nevison, C and Goodale, C and Hess, P and Wieder, WR and Vira, J and Groffman, PM}, title = {Nitrification and denitrification in the Community Land Model compared with observations at Hubbard Brook Forest.}, journal = {Ecological applications : a publication of the Ecological Society of America}, volume = {32}, number = {4}, pages = {e2530}, doi = {10.1002/eap.2530}, pmid = {35019185}, issn = {1051-0761}, mesh = {*Denitrification ; Ecosystem ; Forests ; *Nitrification ; Nitrogen/analysis ; Soil ; }, abstract = {Models of terrestrial system dynamics often include nitrogen (N) cycles to better represent N limitations on terrestrial carbon (C) uptake, but simulating the fate of N in ecosystems has proven challenging. Here, key soil N fluxes and flux ratios from the Community Land Model version 5.0 (CLM5.0) are compared with an extensive set of observations from the Hubbard Brook Forest Long-Term Ecological Research site in New Hampshire. Simulated fluxes include microbial immobilization and plant uptake, which compete with nitrification and denitrification, respectively, for available soil ammonium (NH4 [+]) and nitrate (NO3 [-]). In its default configuration, CLM5.0 predicts that both plant uptake and immobilization are strongly dominated by NH4 [+] over NO3 [-] , and that the model ratio of nitrification:denitrification is ~1:1. In contrast, Hubbard Brook observations suggest that NO3 [-] plays a more significant role in plant uptake and that nitrification could exceed denitrification by an order of magnitude. Modifications to the standard CLM5.0 at Hubbard Brook indicate that a simultaneous increase in the competitiveness of nitrifying microbes for NH4 [+] and reduction in the competitiveness of denitrifying bacteria for NO3 [-] are needed to bring soil N flux ratios into better agreement with observations. Such adjustments, combined with evaluation against observations, may help to improve confidence in present and future simulations of N limitation on the C cycle, although C fluxes, such as gross primary productivity and net primary productivity, are less sensitive to the model modifications than soil N fluxes.}, }
@article {pmid35016770, year = {2022}, author = {Ross Brown, A and Lilley, MKS and Shutler, J and Widdicombe, C and Rooks, P and McEvoy, A and Torres, R and Artioli, Y and Rawle, G and Homyard, J and Tyler, CR and Lowe, C}, title = {Harmful Algal Blooms and their impacts on shellfish mariculture follow regionally distinct patterns of water circulation in the western English Channel during the 2018 heatwave.}, journal = {Harmful algae}, volume = {111}, number = {}, pages = {102166}, doi = {10.1016/j.hal.2021.102166}, pmid = {35016770}, issn = {1878-1470}, mesh = {*Ecosystem ; *Harmful Algal Bloom ; Seafood ; Shellfish/analysis ; Water ; }, abstract = {Harmful algal blooms (HABs) can have severe ecological, societal and economic impacts upon marine ecosystems, human health and the seafood industry. We evaluated changes in marine plankton communities with prevailing physico-chemical conditions throughout an exceptionally warm summer (2018), to elucidate key factors governing HABs and their impacts on shellfish mariculture in the western English Channel. Despite warm, stable weather conditions and widespread seasonal stratification throughout the summer, divergent plankton community compositions were observed at two rope-grown mussel (Mytilus edulis) farms (St Austell Bay and Lyme Bay) and a long-term ecological research LTER site (Plymouth L4). There were significant differences between sites in the abundances of HAB species, including Dinophysis spp. and Karenia mikimotoi, whose cell counts bloomed in excess of UK Food Standards Agency (FSA) advisory 'trigger' levels at Plymouth L4 and St Austell Bay, but not at the Lyme Bay site. The K. mikimotoi bloom occurred over two weeks in August and comprised up to 88% of the standing phytoplankton biomass in St Austell Bay. Dinophysis spp. also bloomed here from May to September, constituting up to 28% of phytoplankton biomass. This protracted bloom resulted in concentrations of Dinophysis toxins 1 &amp; 2 and pectenotoxins and okadaic acid in shellfish, which closed shellfish harvesting operations on farms located in St Austell Bay, and other shellfish sites in the west of the western English Channel (but not in the east of the region). Inter-site differences in the abundances of these and other HAB species were associated with variations in water circulation and co-occurring phytoplankton and zooplankton communities. Furthermore, plankton monitoring data obtained from the L4 site over the past 3 decades showed HAB species (including Dinophysis spp.) with abundances commonly occurring above advisory trigger levels during warmer periods, such as that coinciding with our study. Under projected climate warming these blooms are likely to continue to be governed by regionally distinct patterns of water circulation, which need to be taken into account in marine spatial planning, when assessing the suitability of new shellfish mariculture sites.}, }
@article {pmid35016024, year = {2022}, author = {Cáliz, J and Subirats, J and Triadó-Margarit, X and Borrego, CM and Casamayor, EO}, title = {Global dispersal and potential sources of antibiotic resistance genes in atmospheric remote depositions.}, journal = {Environment international}, volume = {160}, number = {}, pages = {107077}, doi = {10.1016/j.envint.2022.107077}, pmid = {35016024}, issn = {1873-6750}, mesh = {*Angiotensin Receptor Antagonists ; Angiotensin-Converting Enzyme Inhibitors ; Anti-Bacterial Agents/pharmacology ; Drug Resistance, Microbial/genetics ; *Genes, Bacterial ; RNA, Ribosomal, 16S/genetics ; }, abstract = {Antibiotic resistance has become a major Global Health concern and a better understanding on the global spread mechanisms of antibiotic resistant bacteria (ARB) and intercontinental ARB exchange is needed. We measured atmospheric depositions of antibiotic resistance genes (ARGs) by quantitative (q)PCR in rain/snow collected fortnightly along 4 y. at a remote high mountain LTER (Long-Term Ecological Research) site located above the atmospheric boundary layer (free troposphere). Bacterial composition was characterized by 16S rRNA gene sequencing, and air mass provenances were determined by modelled back trajectories and rain/snow chemical composition. We hypothesize that the free troposphere may act as permanent reservoir and vector for ARB and ARGs global dispersal. We aimed to i) determine whether ARGs are long-range intercontinental and persistently dispersed through aerosols, ii) assess ARGs long-term atmospheric deposition dynamics in a remote high mountain area, and iii) unveil potential diffuse ARGs pollution sources. We showed that the ARGs sul1 (resistance to sulfonamides), tetO (resistance to tetracyclines), and intI1 (a proxy for horizontal gene transfer and anthropogenic pollution) were long-range and persistently dispersed in free troposphere aerosols. Major depositions of tetracyclines resistance matched with intensification of African dust outbreaks. Potential ARB mostly traced their origin back into agricultural soils. Our study unveils that air masses pathways are shaping ARGs intercontinental dispersal and global spread of antibiotic resistances, with potential predictability for interannual variability and remote deposition rates. Because climate regulates aerosolization and long-range air masses movement patterns, we call for a more careful evaluation of the connections between land use, climate change and ARB long-range intercontinental dispersal.}, }
@article {pmid34991258, year = {2022}, author = {Cluzel, N and Courbariaux, M and Wang, S and Moulin, L and Wurtzer, S and Bertrand, I and Laurent, K and Monfort, P and Gantzer, C and Guyader, SL and Boni, M and Mouchel, JM and Maréchal, V and Nuel, G and Maday, Y and , }, title = {A nationwide indicator to smooth and normalize heterogeneous SARS-CoV-2 RNA data in wastewater.}, journal = {Environment international}, volume = {158}, number = {}, pages = {106998}, pmid = {34991258}, issn = {1873-6750}, mesh = {*COVID-19 ; *Epidemics ; Humans ; RNA, Viral ; SARS-CoV-2 ; Wastewater ; }, abstract = {Since many infected people experience no or few symptoms, the SARS-CoV-2 epidemic is frequently monitored through massive virus testing of the population, an approach that may be biased and may be difficult to sustain in low-income countries. Since SARS-CoV-2 RNA can be detected in stool samples, quantifying SARS-CoV-2 genome by RT-qPCR in wastewater treatment plants (WWTPs) has been carried out as a complementary tool to monitor virus circulation among human populations. However, measuring SARS-CoV-2 viral load in WWTPs can be affected by many experimental and environmental factors. To circumvent these limits, we propose here a novel indicator, the wastewater indicator (WWI), that partly reduces and corrects the noise associated with the SARS-CoV-2 genome quantification in wastewater (average noise reduction of 19%). All data processing results in an average correlation gain of 18% with the incidence rate. The WWI can take into account the censorship linked to the limit of quantification (LOQ), allows the automatic detection of outliers to be integrated into the smoothing algorithm, estimates the average measurement error committed on the samples and proposes a solution for inter-laboratory normalization in the absence of inter-laboratory assays (ILA). This method has been successfully applied in the context of Obépine, a French national network that has been quantifying SARS-CoV-2 genome in a representative sample of French WWTPs since March 5th 2020. By August 26th, 2021, 168 WWTPs were monitored in the French metropolitan and overseas territories of France. We detail the process of elaboration of this indicator, show that it is strongly correlated to the incidence rate and that the optimal time lag between these two signals is only a few days, making our indicator an efficient complement to the incidence rate. This alternative approach may be especially important to evaluate SARS-CoV-2 dynamics in human populations when the testing rate is low.}, }
@article {pmid34909832, year = {2021}, author = {Fadini, RF and Brocardo, CR and Rosa, C and Aragón, S and Lima, AP and Magnusson, WE}, title = {Long-term standardized ecological research in an Amazonian savanna: a laboratory under threat.}, journal = {Anais da Academia Brasileira de Ciencias}, volume = {93}, number = {suppl 4}, pages = {e20210879}, doi = {10.1590/0001-3765202120210879}, pmid = {34909832}, issn = {1678-2690}, mesh = {Biodiversity ; *Ecosystem ; *Grassland ; Laboratories ; Pilot Projects ; }, abstract = {A few decades ago, researchers from the National Institute for Amazonian Research (INPA) started a pilot study to integrate the ecological studies of several organisms using monitoring plots, which then became the embryo for the creation of the RAPELD (Rapid Assessments and Long-term Ecological Research) system used by the Program for Biodiversity Research (PPBio) and the Long-term ecological research site POPA (PELD Western Pará). They installed and maintained permanent plots in an Amazonian-savanna patch near to the village of Alter do Chão. Amazonian savannas constitute a threatened ecosystem comprising only 6% of the Amazon biome. Most of the studies focused on three main long-term ecological research questions, but the site was also of importance for other inquiries and for the training of young researchers, contributing 71 articles so far and 32 masters and doctorate theses. Here, we present the experimental design and results of standardized studies in the savannas and forest fragments near Alter do Chão that have been carried out over the years. We discuss the future prospects and local threats to the area (e.g. soy crops and land speculation), and highlight the need to incorporate Alter do Chão villagers in land-use planning in the region.}, }
@article {pmid34896511, year = {2022}, author = {Wurtzer, S and Waldman, P and Levert, M and Cluzel, N and Almayrac, JL and Charpentier, C and Masnada, S and Gillon-Ritz, M and Mouchel, JM and Maday, Y and Boni, M and ,  and ,  and Marechal, V and Moulin, L}, title = {SARS-CoV-2 genome quantification in wastewaters at regional and city scale allows precise monitoring of the whole outbreaks dynamics and variants spreading in the population.}, journal = {The Science of the total environment}, volume = {810}, number = {}, pages = {152213}, pmid = {34896511}, issn = {1879-1026}, mesh = {*COVID-19 ; Disease Outbreaks ; Humans ; Respiratory Aerosols and Droplets ; *SARS-CoV-2 ; Wastewater ; }, abstract = {SARS-CoV-2 is a coronavirus causing a globalized outbreak called COVID-19. SARS-CoV-2 transmission is associated with inhalation of contaminated respiratory droplets and could causes severe complications. Until today several "waves" of infections have been observed despite implementation of strict health policies. Decisions for such sanitary measures are based on population health monitoring. Unfortunately, for COVID-19, a significant proportion of individuals are asymptomatic but play a role in the virus transmission. To overcome these limitations, several strategies were developed including genome quantification in wastewater that could allow monitoring of the health status of population, since shedding of SARS-CoV-2 in patient stool is frequent. Wastewater-based epidemiology (WBE) was established and several countries implemented this approach to allow COVID-19 outbreak monitoring. In France, the OBEPINE project performed a quantitative analysis of SARS-CoV-2 in raw wastewater samples collected from major wastewater treatment plants (WWTP) since March 2020. In the greater Paris area 1101 samples (507 for five WWTP and 594 for sewer) were collected. This 16 months monitoring allows us to observe the outbreak dynamics. Comparison of WBE indicators with health data lead to several important observation; the good level of correlation with incidence rates, the average 3 days lead time, and the sensitivity (WBE change when incidence is > to 7/100000 inhabitants). We also compared the local monitoring (city level) with the regional monitoring, to help cluster identification. Moreover, variants of concern (VOC) emerged due to the selection pressure. We developed a specific RT-qPCR method targeting the deletion H69-V70 in the spike protein, using this deletion as a proxy of the B.1.1.7 presence in the wastewater. With this data we demonstrate the predominant role played by this strain in the third wave. All these results allow a better description and understanding of the pandemic and highlight the role of such WBE indicators.}, }
@article {pmid34820828, year = {2022}, author = {Roeder, KA and Benson, BR and Weiser, MD and Kaspari, M}, title = {Testing the role of body size and litter depth on invertebrate diversity across six forests in North America.}, journal = {Ecology}, volume = {103}, number = {2}, pages = {e03601}, doi = {10.1002/ecy.3601}, pmid = {34820828}, issn = {1939-9170}, mesh = {Animals ; Biodiversity ; Body Size ; Ecosystem ; Food Chain ; *Forests ; *Invertebrates ; }, abstract = {Ecologists search for rules by which traits dictate the abundance and distribution of species. Here we search for rules that apply across three common taxa of litter invertebrates in six North American forests from Panama to Oregon. We use image analysis to quantify the abundance and body size distributions of mites, springtails, and spiders in 21 1-m[2] plots per forest. We contrast three hypotheses: two of which focus on trait-abundance relationships and a third linking abundance to species richness. Despite three orders of magnitude variation in size, the predicted negative relationship between mean body size and abundance per area occurred in only 18% of cases, never for large bodied taxa like spiders. We likewise found only 18% of tests supported our prediction that increasing litter depth allows for high abundance; two-thirds of which occurred at a single deciduous forest in Massachusetts. In contrast, invertebrate abundance constrained species richness 76% of the time. Our results suggest that body size and habitat volume in brown food webs are rarely good predictors of variation in abundance, but that variation in diversity is generally well predicted by abundance.}, }
@article {pmid34754048, year = {2021}, author = {Juyal, A and Guber, A and Oerther, M and Quigley, M and Kravchenko, A}, title = {Pore architecture and particulate organic matter in soils under monoculture switchgrass and restored prairie in contrasting topography.}, journal = {Scientific reports}, volume = {11}, number = {1}, pages = {21998}, pmid = {34754048}, issn = {2045-2322}, support = {DE-SC0018409//NSF LTER program (DEB 1027253)/ ; DE-SC0018409//NSF LTER program (DEB 1027253)/ ; }, abstract = {Bioenergy cropping systems can substantially contribute to climate change mitigation. However, limited information is available on how they affect soil characteristics, including pores and particulate organic matter (POM), both essential components of the soil C cycle. The objective of this study was to determine effects of bioenergy systems and field topography on soil pore characteristics, POM, and POM decomposition under new plant growth. We collected intact soil cores from two systems: monoculture switchgrass (Panicum virgatum L.) and native prairie, at two contrasting topographical positions (depressions and slopes), planting half of the cores with switchgrass. Pore and POM characteristics were obtained using X-ray computed micro-tomography (μCT) (18.2 µm resolution) before and after new switchgrass growth. Diverse prairie vegetation led to higher soil C than switchgrass, with concomitantly higher volumes of 30-90 μm radius pores and greater solid-pore interface. Yet, that effect was present only in the coarse-textured soils on slopes and coincided with higher root biomass of prairie vegetation. Surprisingly, new switchgrass growth did not intensify decomposition of POM, but even somewhat decreased it in monoculture switchgrass as compared to non-planted controls. Our results suggest that topography can play a substantial role in regulating factors driving C sequestration in bioenergy systems.}, }
@article {pmid34673433, year = {2021}, author = {Gallitelli, L and Battisti, C and Olivieri, Z and Marandola, C and Acosta, ATR and Scalici, M}, title = {Carpobrotus spp. patches as trap for litter: Evidence from a Mediterranean beach.}, journal = {Marine pollution bulletin}, volume = {173}, number = {Pt B}, pages = {113029}, doi = {10.1016/j.marpolbul.2021.113029}, pmid = {34673433}, issn = {1879-3363}, mesh = {*Aizoaceae ; Bathing Beaches ; *Ecosystem ; Environmental Monitoring ; Plants ; Plastics ; Waste Products/analysis ; }, abstract = {Dunal plants may affect the patterns of deposition of beach litter. In this study, we aimed at evaluating if Carpobrotus spp. patches may act as a litter trap in coastal dune systems. To do so, we counted the number of macrolitter occurring in both Carpobrotus and control (embryo dune vegetation) patches classifying each item into categories according to the Marine Strategy. Totally, we observed a significant difference between litter trapped in Carpobrotus (331 items, representing 62.4% of the total beach litter) and control (199, 37.6%). Plastic fragments were the most trapped items by both Carpobrotus (46.2%) and control patches (47.2%). We also calculated the item co-occurrence, obtaining a random aggregated 'litter community'. The main emerging output is that Carpobrotus patches act as filter in respect to different anthropogenic materials (overall plastics), suggesting that alien plant management actions may contribute to solve beach litter issues as well.}, }
@article {pmid34663463, year = {2021}, author = {Trubl, G and Kimbrel, JA and Liquet-Gonzalez, J and Nuccio, EE and Weber, PK and Pett-Ridge, J and Jansson, JK and Waldrop, MP and Blazewicz, SJ}, title = {Active virus-host interactions at sub-freezing temperatures in Arctic peat soil.}, journal = {Microbiome}, volume = {9}, number = {1}, pages = {208}, pmid = {34663463}, issn = {2049-2618}, mesh = {Freezing ; *Microbiota ; *Soil ; Soil Microbiology ; Temperature ; }, abstract = {BACKGROUND: Winter carbon loss in northern ecosystems is estimated to be greater than the average growing season carbon uptake and is primarily driven by microbial decomposers. Viruses modulate microbial carbon cycling via induced mortality and metabolic controls, but it is unknown whether viruses are active under winter conditions (anoxic and sub-freezing temperatures).<br><br>RESULTS: We used stable isotope probing (SIP) targeted metagenomics to reveal the genomic potential of active soil microbial populations under simulated winter conditions, with an emphasis on viruses and virus-host dynamics. Arctic peat soils from the Bonanza Creek Long-Term Ecological Research site in Alaska were incubated under sub-freezing anoxic conditions with H2[18]O or natural abundance water for 184 and 370 days. We sequenced 23 SIP-metagenomes and measured carbon dioxide (CO2) efflux throughout the experiment. We identified 46 bacterial populations (spanning 9 phyla) and 243 viral populations that actively took up [18]O in soil and respired CO2 throughout the incubation. Active bacterial populations represented only a small portion of the detected microbial community and were capable of fermentation and organic matter degradation. In contrast,&#xa0;active viral populations represented a large portion of the detected viral community and one third were linked to active bacterial populations. We identified 86 auxiliary metabolic genes and other environmentally relevant genes. The majority of these genes were carried by active viral populations and had diverse functions such as carbon utilization and scavenging that could provide their host with a fitness advantage for utilizing much-needed carbon sources or acquiring essential nutrients.<br><br>CONCLUSIONS: Overall, there was a stark difference in the identity and function of the active bacterial and viral community compared to the unlabeled community that would have been overlooked with a non-targeted standard metagenomic analysis. Our results illustrate that substantial active virus-host interactions occur in sub-freezing anoxic conditions and highlight viruses as a major community-structuring agent that likely modulates carbon loss in peat soils during winter, which may be pivotal for understanding the future fate of arctic soils'&#xa0;vast carbon stocks. Video abstract.}, }
@article {pmid34627012, year = {2022}, author = {Triadó-Margarit, X and Cáliz, J and Casamayor, EO}, title = {A long-term atmospheric baseline for intercontinental exchange of airborne pathogens.}, journal = {Environment international}, volume = {158}, number = {}, pages = {106916}, doi = {10.1016/j.envint.2021.106916}, pmid = {34627012}, issn = {1873-6750}, mesh = {*Air Microbiology ; Animals ; Atmosphere ; Dust/analysis ; *Environmental Monitoring ; Fungi/genetics ; Humans ; Seasons ; }, abstract = {The atmosphere is a potential pathway for global-scale and long-range dispersal of viable microorganisms, promoting biological interconnections among the total environment. We aimed to provide relevant baseline information for long-range long-term intercontinental exchange of potentially infectious airborne microorganisms of major interest in environmental and health-related disciplines. We used an interannual survey (7-y) with wet depositions fortnightly collected above the boundary layer (free troposphere) at a remote high-elevation LTER (Long-Term-Ecological-Research) site, analyzed by 16S and 18S rRNA genes, and compared to a database of 475 well-known pathogens. We applied a conservative approach on close relatives of pathogenic species (>98% identity) standing their theoretical upper limit for atmospheric baseline relative abundances. We identified c. 2-3% of the total airborne microbiota as potential pathogens. Their most frequent environmental origins were soil, aquatic, and anthropogenic sources. Phytopathogens (mostly fungi) were the potential infectious agents most widely present. We uncovered consistent interannual dynamics with taxa foreseeable over time (i.e., predictable seasonal behavior) and under recurrent environmental scenarios (e.g., Saharan dust intrusions), respectively, being highly valuable microbial forensic environmental indicators. Up to 8 bacterial and 21 fungal genera consistently showed temporal abundances and recurrences unevenly distributed. Incidence of allergenic fungi was lower in summer, and significantly higher in spring. Close relatives to Coccidioides posadasii consistently showed higher signals (i.e., high specificity and high fidelity) in winter, whereas Cryptococcus neoformans had a significant signal in spring. Along Saharan dust intrusions, the bacterial phytopathogens Acidovorax avenae and Agrobacterium tumefaciens and the fungal phytopathogens Pseudozyma hubeiensis and Peniophora sp. consistently showed higher signals. Potential human pathogens showed low proportion, being mostly fungal allergens. Microorganisms related to obligated human, amphibian and fish pathogens were commonly found in winter. More studies in remote field sites above the boundary layer will unveil whether or not a similar trend is found globally.}, }
@article {pmid34624574, year = {2022}, author = {Le Guernic, A and Palos Ladeiro, M and Boudaud, N and Do Nascimento, J and Gantzer, C and Inglard, JC and Mouchel, JM and Pochet, C and Moulin, L and Rocher, V and Waldman, P and Wurtzer, S and Geffard, A}, title = {First evidence of SARS-CoV-2 genome detection in zebra mussel (Dreissena polymorpha).}, journal = {Journal of environmental management}, volume = {301}, number = {}, pages = {113866}, pmid = {34624574}, issn = {1095-8630}, mesh = {Animals ; *Bivalvia ; *COVID-19 ; *Dreissena/genetics ; Humans ; SARS-CoV-2 ; Wastewater ; }, abstract = {The uses of bivalve molluscs in environmental biomonitoring have recently gained momentum due to their ability to indicate and concentrate human pathogenic microorganisms. In the context of the health crisis caused by the COVID-19 epidemic, the objective of this study was to determine if the SARS-CoV-2 ribonucleic acid genome can be detected in zebra mussels (Dreissena polymorpha) exposed to raw and treated urban wastewaters from two separate plants to support its interest as bioindicator of the SARS-CoV-2 genome contamination in water. The zebra mussels were exposed to treated wastewater through caging at the outlet of two plants located in France, as well as to raw wastewater in controlled conditions. Within their digestive tissues, our results showed that SARS-CoV-2 genome was detected in zebra mussels, whether in raw and treated wastewaters. Moreover, the detection of the SARS-CoV-2 genome in such bivalve molluscans appeared even with low concentrations in raw wastewaters. This is the first detection of the SARS-CoV-2 genome in the tissues of a sentinel species exposed to raw and treated urban wastewaters. Despite the need for development for quantitative approaches, these results support the importance of such invertebrate organisms, especially zebra mussel, for the active surveillance of pathogenic microorganisms and their indicators in environmental waters.}, }
@article {pmid34617374, year = {2021}, author = {Radujković, D and Verbruggen, E and Seabloom, EW and Bahn, M and Biederman, LA and Borer, ET and Boughton, EH and Catford, JA and Campioli, M and Donohue, I and Ebeling, A and Eskelinen, A and Fay, PA and Hansart, A and Knops, JMH and MacDougall, AS and Ohlert, T and Olde Venterink, H and Raynaud, X and Risch, AC and Roscher, C and Schütz, M and Silveira, ML and Stevens, CJ and Van Sundert, K and Virtanen, R and Wardle, GM and Wragg, PD and Vicca, S}, title = {Soil properties as key predictors of global grassland production: Have we overlooked micronutrients?.}, journal = {Ecology letters}, volume = {24}, number = {12}, pages = {2713-2725}, doi = {10.1111/ele.13894}, pmid = {34617374}, issn = {1461-0248}, support = {NSF-DEB-1042132//National Science Foundation Research Coordination Network/ ; DG-0001-13//Institute on the Environment/ ; //Long Term Ecological Research/ ; //Research Foundation-Flanders (FWO)/ ; //Methusalem funding of the Research Council UA/ ; ERC-SyG-610028 IMBALANCE-P//European Research Council grant/ ; }, mesh = {Biomass ; Carbon ; Ecosystem ; *Grassland ; Micronutrients ; Nitrogen/analysis ; *Soil ; }, abstract = {Fertilisation experiments have demonstrated that nutrient availability is a key determinant of biomass production and carbon sequestration in grasslands. However, the influence of nutrients in explaining spatial variation in grassland biomass production has rarely been assessed. Using a global dataset comprising 72 sites on six continents, we investigated which of 16 soil factors that shape nutrient availability associate most strongly with variation in grassland aboveground biomass. Climate and N deposition were also considered. Based on theory-driven structural equation modelling, we found that soil micronutrients (particularly Zn and Fe) were important predictors of biomass and, together with soil physicochemical properties and C:N, they explained more unique variation (32%) than climate and N deposition (24%). However, the association between micronutrients and biomass was absent in grasslands limited by NP. These results highlight soil properties as key predictors of global grassland biomass production and point to serial co-limitation by NP and micronutrients.}, }
@article {pmid34599477, year = {2021}, author = {Lin, SY and Hameed, A and Tsai, CF and Young, CC}, title = {Zeimonas arvi gen. nov., sp. nov., of the family Burkholderiaceae, harboring biphenyl- and phenolic acid-metabolizing genes, isolated from a long-term ecological research field.}, journal = {Antonie van Leeuwenhoek}, volume = {114}, number = {12}, pages = {2101-2111}, pmid = {34599477}, issn = {1572-9699}, support = {MOST 109-2634-F-005-002//Ministry of Science and Technology, Taiwan/ ; }, mesh = {Bacterial Typing Techniques ; Biphenyl Compounds ; *Burkholderiaceae ; DNA, Bacterial/genetics ; Fatty Acids ; Hydroxybenzoates ; Phospholipids ; Phylogeny ; RNA, Ribosomal, 16S/genetics ; Sequence Analysis, DNA ; }, abstract = {A polyphasic taxonomic approach was used to characterize a Gram-stain-negative bacterium, designated strain CC-CFT501[T], harboring xenobiotic- and allelochemical-metabolizing genes, isolated from a long-term ecological research field in Taiwan. Cells of strain CC-CFT501[T] were catalase- and oxidase-positive, non-motile and short rods. Optimal growth occurred at 30 °C, pH 8 and 1% NaCl. Strain CC-CFT501[T] was found to share high 16S rRNA gene sequence similarity with the members of genera Quisquiliibacterium (94.3%, n = 1), Pandoraea (93.4-94.0%, n = 23) and Paraburkholderia (93.3-94.0%, n = 9), affiliated to the family Burkholderiaceae. Strain CC-CFT501[T] shared 76.4% orthologous average nucleotide identity (OrthoANI) and 20.9% digital DNA-DNA hybridization (dDDH) values with Quisquiliibacterium transsilvanicum DSM 29781[T]. Draft genome sequence (3.83 Mb) of strain CC-CFT501[T] revealed several genes encoding the proteins involved in biphenyl and phenolic acid metabolism. Fatty acid profile contained C16:0, C18:0, C10:0 3-OH, C16:1 ω7c/C16:1 ω6c and C18:1 ω7c/C18:1 ω6c in predominant amounts. The polar lipid profile consisted of phosphatidylethanolamine, thirteen unidentified amino lipids, two unidentified phospholipids and two unidentified glycolipids. The major polyamine was spermidine and ubiquinone Q-8 was the sole respiratory quinone. The DNA G + C content was 70.0 mol%. Based on its distinct phylogenetic, phenotypic and chemotaxonomic traits together with results of comparative 16S rRNA gene sequence, ANI and dDDH analyses, strain CC-CFT501[T] is considered to represent a novel genus and species of the family Burkholderiaceae, for which the name Zeimonas arvi gen. nov., sp. nov. is proposed. The type strain of the type species is CC-CFT501[T] (= BCRC 81218[T] = JCM 33506[T]).}, }
@article {pmid34564244, year = {2021}, author = {Henschel, JR}, title = {Long-Term Population Dynamics of Namib Desert Tenebrionid Beetles Reveal Complex Relationships to Pulse-Reserve Conditions.}, journal = {Insects}, volume = {12}, number = {9}, pages = {}, pmid = {34564244}, issn = {2075-4450}, abstract = {Noy-Meir's paradigm concerning desert populations being predictably tied to unpredictable productivity pulses was tested by examining abundance trends of 26 species of flightless detritivorous tenebrionid beetles (Coleoptera, Tenebrionidae) in the hyper-arid Namib Desert (MAP = 25 mm). Over 45 years, tenebrionids were continuously pitfall trapped on a gravel plain. Species were categorised according to how their populations increased after 22 effective rainfall events (>11 mm in a week), and declined with decreasing detritus reserves (97.7-0.2 g m[-2]), while sustained by nonrainfall moisture. Six patterns of population variation were recognised: (a) increases triggered by effective summer rainfalls, tracking detritus over time (five species, 41% abundance); (b) irrupting upon summer rainfalls, crashing a year later (three, 18%); (c) increasing gradually after series of heavy (>40 mm) rainfall years, declining over the next decade (eight, 15%); (d) triggered by winter rainfall, population fluctuating moderately (two, 20%); (e) increasing during dry years, declining during wet (one, 0.4%); (f) erratic range expansions following heavy rain (seven, 5%). All species experienced population bottlenecks during a decade of scant reserves, followed by the community cycling back to its earlier composition after 30 years. By responding selectively to alternative configurations of resources, Namib tenebrionids showed temporal patterns and magnitudes of population fluctuation more diverse than predicted by Noy-Meir's original model, underpinning high species diversity.}, }
@article {pmid34534383, year = {2021}, author = {Atkinson, ST and Cale, D and Pinder, A and Chambers, JM and Halse, SA and Robson, BJ}, title = {Substantial long-term loss of alpha and gamma diversity of lake invertebrates in a landscape exposed to a drying climate.}, journal = {Global change biology}, volume = {27}, number = {23}, pages = {6263-6279}, doi = {10.1111/gcb.15890}, pmid = {34534383}, issn = {1365-2486}, mesh = {Animals ; Biodiversity ; Ecosystem ; *Invertebrates ; *Lakes ; Wetlands ; }, abstract = {Many regions across the globe are shifting to more arid climates. For shallow lakes, decreasing rainfall volume and timing, changing regional wind patterns and increased evaporation rates alter water regimes so that dry periods occur more frequently and for longer. Drier conditions may affect fauna directly and indirectly through altered physicochemical conditions in lakes. Although many studies have predicted negative effects of such changes on aquatic biodiversity, empirical studies demonstrating these effects are rare. Global warming has caused severe climatic drying in southwestern Australia since the 1970s, so we aimed to determine whether lakes in this region showed impacts on lake hydroperiod, water quality, and α, β and γ diversity of lake invertebrates from 1998 to 2011. Seventeen lakes across a range of salinities were sampled biennially in spring in the Wheatbelt and Great Southern regions of Western Australia. Multivariate analyses were used to identify changes in α, β and γ diversity and examine patterns in physicochemical data. Salinity and average rainfall partially explained patterns in invertebrate richness and assemblage composition. Climatic drying was associated with significant declines in lake depth, increased frequency of dry periods, and reduced α and γ diversity (γ declined from ~300 to ~100 taxa from 1998 to 2011 in the 17 wetlands). In contrast, β diversity remained consistently high, because each lake retained a distinct fauna. Mean α diversity per-lake declined both in lakes that dried and lakes that did not dry out, but lakes which retained a greater proportion of their maximum depth retained more α diversity. Accumulated losses in α diversity caused the decline in γ diversity likely through shrinking habitat area, fewer stepping stones for dispersal and loss of specific habitat types. Biodiversity loss is thus likely from lakes in drying regions globally. Management actions will need to sustain water depth in lakes to prevent biodiversity loss.}, }
@article {pmid34485651, year = {2021}, author = {Grosse, M and Ahlborn, MC and Hierold, W}, title = {Metadata of agricultural long-term experiments in Europe exclusive of Germany.}, journal = {Data in brief}, volume = {38}, number = {}, pages = {107322}, pmid = {34485651}, issn = {2352-3409}, abstract = {Agricultural long-term experiments (LTEs) are an important research infrastructure for agriculture, plant and soil sciences. The aim of this metadata compilation is to make LTEs easier to find and to facilitate networking. LTEs are here defined as agricultural experiments with a minimum duration of 20 years and research in the context of soil and yield. An extensive literature review was conducted to identify LTEs in Europe exclusive of Germany, because Germany's LTEs were published before. Sources were scientific papers as well as other articles, books, trial guides and websites. The following information was searched for and compiled in this dataset, if available: site and name of the LTE, start and end (if appropriate), holding institution, type of land use (e.g. field crops or grassland), research theme, website (if available), participation in networks, measured parameters, farming category (i.e. conventional or organic), size of the LTE area, longitude and latitude of the LTE, experimental setup including factors, treatments, randomization and replication, number of plots, size of the plots, crop rotation, soil type, substrate, texture, literature which was written in the context of the LTE data, and AGROVOC keywords. LTE from the following countries are included: Austria, Belarus, Belgium, Bulgaria, Czech Republic, Denmark, Estonia, Finland, France, Great Britain, Hungary, Italy, Moldova, Norway, Poland, Romania, Serbia, Slovenia, Spain, Sweden, Switzerland, Ukraine. In total, 186 LTEs could be identified. The LTEs were classified according to the following research themes: fertilization, tillage, crop rotation, other. The majority of LTEs have the research theme "fertilization" (n = 125). Thirty LTEs have the research theme "crop rotation", 26 LTEs have the research theme "tillage", and 26 LTEs have "other" research themes. The following networks could be identified: GLTEN (Global long-term experiment network), ILTER (International long-term ecological research), IOSDV (International Organic Nitrogen Fertilization Experiment), NLFT (National Long-term Fertilization Trials, Hungary), RetiBio 2 (Italy). The oldest LTE was set up 1843, but the largest number of LTEs was established in the second half of the 20th century. Most of the LTEs are held by a scientific institution, i.e. 88 LTEs are held by a non-university scientific institution and 81 LTEs are held by a university or university of applied sciences. The link to the holding institution is provided whenever possible to facilitate contacting.}, }
@article {pmid34453850, year = {2021}, author = {Manlick, PJ and Maldonado, K and Newsome, SD}, title = {Competition shapes individual foraging and survival in a desert rodent ensemble.}, journal = {The Journal of animal ecology}, volume = {90}, number = {12}, pages = {2806-2818}, doi = {10.1111/1365-2656.13583}, pmid = {34453850}, issn = {1365-2656}, mesh = {Animals ; *Diet ; *Rodentia ; }, abstract = {Intraspecific variation, including individual diet variation, can structure populations and communities, but the causes and consequences of individual foraging strategies are often unclear. Interactions between competition and resources are thought to dictate foraging strategies (e.g. specialization vs. generalization), but classical paradigms such as optimal foraging and niche theory offer contrasting predictions for individual consumers. Furthermore, both paradigms assume that individual foraging strategies maximize fitness, yet this prediction is rarely tested. We used repeated stable isotope measurements (δ[13] C, δ[15] N; N = 3,509) and 6 years of capture-mark-recapture data to quantify the relationship between environmental variation, individual foraging and consumer fitness among four species of desert rodents. We tested the relative effects of intraspecific competition, interspecific competition, resource abundance and resource diversity on the foraging strategies of 349 individual animals, and then quantified apparent survival as function of individual foraging strategies. Consistent with niche theory, individuals contracted their trophic niches and increased foraging specialization in response to both intraspecific and interspecific competition, but this effect was offset by resource availability and individuals generalized when plant biomass was high. Nevertheless, individual specialists obtained no apparent fitness benefit from trophic niche contractions as the most specialized individuals exhibited a 10% reduction in monthly survival compared to the most generalized individuals. Ultimately, this resulted in annual survival probabilities nearly 4× higher for generalists compared to specialists. These results indicate that competition is the proximate driver of individual foraging strategies, and that diet-mediated fitness variation regulates population and community dynamics in stochastic resource environments. Furthermore, our findings show dietary generalism is a fitness maximizing strategy, suggesting that plastic foraging strategies may play a key role in species' ability to cope with environmental change.}, }
@article {pmid34391008, year = {2021}, author = {Cresta, E and Battisti, C}, title = {Anthropogenic litter along a coastal-wetland gradient: Reed-bed vegetation in the backdunes may act as a sink for expanded polystyrene.}, journal = {Marine pollution bulletin}, volume = {172}, number = {}, pages = {112829}, doi = {10.1016/j.marpolbul.2021.112829}, pmid = {34391008}, issn = {1879-3363}, mesh = {Ecosystem ; Poaceae ; *Polystyrenes ; Seasons ; *Wetlands ; }, abstract = {We investigated the accumulation of litter along a transition gradient from the dunal beaches (B), to the backdunes (BD), to the channels of a coastal wetland (W), considering both the total litter and a sub-category represented by expanded polystyrene (EPS). Using a removal sampling technique carried out in spring (April and May), we hypothesized that: (i) the total accumulation of litter decreases progressively from the dunes to the backdunes to wet environments while (ii) the lighter polystyrene concentrates in the BD-W fringe where the Phragmites australis reedbeds can have a sink role for this polymer. The total litter density showed a significant decrease along the gradient B-BD-W in both months, with an evident collapse between BD and W. Analogously, EPS showed a significant difference in density along the B-BD-W gradient in both months, although with a different pattern: a maximum in the BD and a significant collapse between BD and W. The presence of backdune hygrophilous vegetation (Phragmites australis' reedbeds) may act as a sink trapping all types of litter in both cases (total litter and EPS). The different accumulation pattern between total litter and the EPS is due to the lower specific weight of the latter polymer: while the generic litter tends to decrease quantitatively moving away from the sea, the lighter EPS is removed by the winds and pushed towards the land, beyond the dune, where it is trapped by the vegetation, thus showing a peak in density in the backdunes. No significant differences were observed between the litter density in the two months (before and after the removal) either considering the total litter and only EPS. This may suggest a continuous supply of litter from the sea, highlighting how clean-ups actions should be carried out with a higher frequency rather than monthly. This may be even more valid in the period of greater frequency of intense weather-marine events (autumn-winter) when a greater quantity of litter is deposited. These are the first data for the Mediterranean regarding a specific role of wetland hygrophilous vegetation as a sink for anthropogenic litter, mainly expanded polystyrene.}, }
@article {pmid34352532, year = {2021}, author = {Cesarini, G and Cera, A and Battisti, C and Taurozzi, D and Scalici, M}, title = {Is the weight of plastic litter correlated with vegetal wrack? A case study from a Central Italian beach.}, journal = {Marine pollution bulletin}, volume = {171}, number = {}, pages = {112794}, doi = {10.1016/j.marpolbul.2021.112794}, pmid = {34352532}, issn = {1879-3363}, mesh = {Bathing Beaches ; *Environmental Monitoring ; Italy ; Microplastics ; *Plastics ; Waste Products/analysis ; }, abstract = {This study analyzes the occurrence and distribution of plastic litter and the entrapment of plastic by wrack beached on a natural reserve. Large microplastics (2.5 - 5 mm) were the most abundant plastic size category detected. The main color and shape were white and fragment, respectively. The plastics entrapped by egagropiles were mainly transparent fibers. We analyzed the correlation between the weights of plastic litter and vegetal wrack in two transects, selected for their different environmental characteristics. The transect closer to a breakwater showed a significant positive correlation between the weights of plastics and wrack, while the other transect suggested a casual pattern of plastic deposition on the beach. Further research is suggested to focus on the role of breakwaters in altering marine currents and enhancing plastic beaching.}, }
@article {pmid34349102, year = {2021}, author = {Pilla, RM and Mette, EM and Williamson, CE and Adamovich, BV and Adrian, R and Anneville, O and Balseiro, E and Ban, S and Chandra, S and Colom-Montero, W and Devlin, SP and Dix, MA and Dokulil, MT and Feldsine, NA and Feuchtmayr, H and Fogarty, NK and Gaiser, EE and Girdner, SF and González, MJ and Hambright, KD and Hamilton, DP and Havens, K and Hessen, DO and Hetzenauer, H and Higgins, SN and Huttula, TH and Huuskonen, H and Isles, PDF and Joehnk, KD and Keller, WB and Klug, J and Knoll, LB and Korhonen, J and Korovchinsky, NM and Köster, O and Kraemer, BM and Leavitt, PR and Leoni, B and Lepori, F and Lepskaya, EV and Lottig, NR and Luger, MS and Maberly, SC and MacIntyre, S and McBride, C and McIntyre, P and Melles, SJ and Modenutti, B and Müller-Navarra, DC and Pacholski, L and Paterson, AM and Pierson, DC and Pislegina, HV and Plisnier, PD and Richardson, DC and Rimmer, A and Rogora, M and Rogozin, DY and Rusak, JA and Rusanovskaya, OO and Sadro, S and Salmaso, N and Saros, JE and Sarvala, J and Saulnier-Talbot, &#xc9; and Schindler, DE and Shimaraeva, SV and Silow, EA and Sitoki, LM and Sommaruga, R and Straile, D and Strock, KE and Swain, H and Tallant, JM and Thiery, W and Timofeyev, MA and Tolomeev, AP and Tominaga, K and Vanni, MJ and Verburg, P and Vinebrooke, RD and Wanzenböck, J and Weathers, K and Weyhenmeyer, GA and Zadereev, ES and Zhukova, TV}, title = {Global data set of long-term summertime vertical temperature profiles in 153 lakes.}, journal = {Scientific data}, volume = {8}, number = {1}, pages = {200}, pmid = {34349102}, issn = {2052-4463}, support = {DEB 1754276//National Science Foundation (NSF)/ ; DEB 1950170//National Science Foundation (NSF)/ ; 0947096//National Science Foundation (NSF)/ ; 9318452//National Science Foundation (NSF)/ ; 9726877//National Science Foundation (NSF)/ ; 0235755//National Science Foundation (NSF)/ ; 0743192//National Science Foundation (NSF)/ ; 1255159//National Science Foundation (NSF)/ ; 1418698//National Science Foundation (NSF)/ ; Arctic LTER DEB-1637459//National Science Foundation (NSF)/ ; UOWX1503//Ministry of Business, Innovation and Employment (MBIE)/ ; #18-44-0620//Russian Science Foundation (RSF)/ ; #20-64-46003//Russian Science Foundation (RSF)/ ; #20-64-46003//Russian Science Foundation (RSF)/ ; #20-64-46003//Russian Science Foundation (RSF)/ ; #20-64-46003//Russian Science Foundation (RSF)/ ; &#x2116; 19-04-00362A//Russian Foundation for Basic Research (RFBR)/ ; 2017-00635//Vetenskapsr&#xe5;det (Swedish Research Council)/ ; }, abstract = {Climate change and other anthropogenic stressors have led to long-term changes in the thermal structure, including surface temperatures, deepwater temperatures, and vertical thermal gradients, in many lakes around the world. Though many studies highlight warming of surface water temperatures in lakes worldwide, less is known about long-term trends in full vertical thermal structure and deepwater temperatures, which have been changing less consistently in both direction and magnitude. Here, we present a globally-expansive data set of summertime in-situ vertical temperature profiles from 153 lakes, with one time series beginning as early as 1894. We also compiled lake geographic, morphometric, and water quality variables that can influence vertical thermal structure through a variety of potential mechanisms in these lakes. These long-term time series of vertical temperature profiles and corresponding lake characteristics serve as valuable data to help understand changes and drivers of lake thermal structure in a time of rapid global and ecological change.}, }
@article {pmid34345225, year = {2021}, author = {Wohner, C and Ohnemus, T and Zacharias, S and Mollenhauer, H and Ellis, EC and Klug, H and Shibata, H and Mirtl, M}, title = {Assessing the biogeographical and socio-ecological representativeness of the ILTER site network.}, journal = {Ecological indicators}, volume = {127}, number = {}, pages = {107785}, pmid = {34345225}, issn = {1470-160X}, abstract = {The challenges posed by climate and land use change are increasingly complex, with rising and accelerating impacts on the global environmental system. Novel environmental and ecosystem research needs to properly interpret system changes and derive management recommendations across scales. This largely depends on advances in the establishment of an internationally harmonised, long-term operating and representative infrastructure for environmental observation. This paper presents an analysis evaluating 743 formally accredited sites of the International Long-Term Ecological Research (ILTER) network in 47 countries with regard to their spatial distribution and related biogeographical and socio-ecological representativeness. "Representedness" values were computed from six global datasets. The analysis revealed a dense coverage of Northern temperate regions and anthropogenic zones most notably in the US, Europe and East Asia. Significant gaps are present in economically less developed and anthropogenically less impacted hot and barren regions like Northern and Central Africa and inner-continental parts of South America. These findings provide the arguments for our recommendations regarding the geographic expansion for the further development of the ILTER network.}, }
@article {pmid34315939, year = {2021}, author = {De Falco, N and Tal-Berger, R and Hjazin, A and Yizhaq, H and Stavi, I and Rachmilevitch, S}, title = {Geodiversity impacts plant community structure in a semi-arid region.}, journal = {Scientific reports}, volume = {11}, number = {1}, pages = {15259}, pmid = {34315939}, issn = {2045-2322}, abstract = {Geodiversity refers to the variety of geological and physical elements as well as to geomorphological processes of the earth surface. Heterogeneity of the physical environment has an impact on plant diversity. In recent years, the relations between geodiversity and biodiversity has gained attention in conservation biology, especially in the context of climate change. In this study, we assessed the spatial and temporal change in plant's community structure in a semi-arid region, Sayeret Shaked Long Term Ecosystem Research (LTER) station, Israel. Vegetation surveys were conducted on different hillslopes, either with or without rock covers in order to study the spatial trends of hillslope geodiversity. The surveys were conducted for two consecutive years (2016 and 2017), of which the second year was drier and hotter and therefore permitted to investigate the temporal change of plant's community structure. The results of the spatial trends show that (1) geodiversity increases vegetation biodiversity and promotes perennial plants and those of the temporal change show that (2) the positive effect of geodiversity on plants' community structure and species richness is greater in the drier year than that in a wetter year. The main insight is that in these drylands, hillslopes with higher geodiversity appear to buffer the effect of drier years, and supported a more diverse plant community than lower geodiversity hillslopes.}, }
@article {pmid34311496, year = {2021}, author = {Seabloom, EW and Borer, ET and Hobbie, SE and MacDougall, AS}, title = {Soil nutrients increase long-term soil carbon gains threefold on retired farmland.}, journal = {Global change biology}, volume = {27}, number = {19}, pages = {4909-4920}, doi = {10.1111/gcb.15778}, pmid = {34311496}, issn = {1365-2486}, mesh = {*Carbon ; Ecosystem ; Farms ; Nitrogen/analysis ; Nutrients ; *Soil ; }, abstract = {Abandoned agricultural lands often accumulate soil carbon (C) following depletion of soil C by cultivation. The potential for this recovery to provide significant C storage benefits depends on the rate of soil C accumulation, which, in turn, may depend on nutrient supply rates. We tracked soil C for almost four decades following intensive agricultural soil disturbance along an experimentally imposed gradient in nitrogen (N) added annually in combination with other macro- and micro-nutrients. Soil %C accumulated over the course of the study in unfertilized control plots leading to a gain of 6.1 Mg C ha[-1] in the top 20 cm of soil. Nutrient addition increased soil %C accumulation leading to a gain of 17.8 Mg C ha[-1] in fertilized plots, nearly a threefold increase over the control plots. These results demonstrate that substantial increases in soil C in successional grasslands following agricultural abandonment occur over decadal timescales, and that C gain is increased by high supply rates of soil nutrients. In addition, soil %C continued to increase for decades under elevated nutrient supply, suggesting that short-term nutrient addition experiments underestimate the effects of soil nutrients on soil C accumulation.}, }
@article {pmid34287849, year = {2021}, author = {Meng, B and Li, J and Maurer, GE and Zhong, S and Yao, Y and Yang, X and Collins, SL and Sun, W}, title = {Nitrogen addition amplifies the nonlinear drought response of grassland productivity to extended growing-season droughts.}, journal = {Ecology}, volume = {102}, number = {11}, pages = {e03483}, doi = {10.1002/ecy.3483}, pmid = {34287849}, issn = {1939-9170}, mesh = {Biomass ; *Droughts ; Ecosystem ; Grassland ; *Nitrogen ; Seasons ; }, abstract = {Understanding the response of grassland production and carbon exchange to intra-annual variation in precipitation and nitrogen addition is critical for sustainable grassland management and ecosystem restoration. We introduced growing-season drought treatments of different lengths (15, 30, 45 and 60 d drought) by delaying growing-season precipitation in a long-term nitrogen addition experiment in a low diversity meadow steppe in northeast China. Response variables included aboveground biomass (AGB), ecosystem net carbon exchange (NEE), and leaf net carbon assimilation rate (A). In unfertilized plots drought decreased AGB by 13.7% after a 45-d drought and 31.7% after a 60-d drought (47.6% in fertilized plots). Progressive increases in the drought response of NEE were also observed. The effects of N addition on the drought response of productivity increased as drought duration increased, and these responses were a function of changes in AGB and biomass allocation, particularly root to shoot ratio. However, no significant effects of drought occurred in fertilized or unfertilized plots in the growing season a year after the experiment, N addition did limit the recovery of AGB from severe drought during the remainder of the current growing season. Our results imply that chronic N enrichment could exacerbate the effects of growing-season drought on grassland productivity caused by altered precipitation seasonality under climate change, but that these effects do not carry over to the next growing season.}, }
@article {pmid34242403, year = {2021}, author = {O'Connell, JL and Mishra, DR and Alber, M and Byrd, KB}, title = {BERM: a Belowground Ecosystem Resiliency Model for estimating Spartina alterniflora belowground biomass.}, journal = {The New phytologist}, volume = {232}, number = {1}, pages = {425-439}, doi = {10.1111/nph.17607}, pmid = {34242403}, issn = {1469-8137}, mesh = {Biomass ; *Ecosystem ; Nitrogen ; *Poaceae ; Wetlands ; }, abstract = {Spatiotemporal patterns of Spartina alterniflora belowground biomass (BGB) are important for evaluating salt marsh resiliency. To solve this, we created the BERM (Belowground Ecosystem Resiliency Model), which estimates monthly BGB (30-m spatial resolution) from freely available data such as Landsat-8 and Daymet climate summaries. Our modeling framework relied on extreme gradient boosting, and used field observations from four Georgia salt marshes as ground-truth data. Model predictors included estimated tidal inundation, elevation, leaf area index, foliar nitrogen, chlorophyll, surface temperature, phenology, and climate data. The final model included 33 variables, and the most important variables were elevation, vapor pressure from the previous four months, Normalized Difference Vegetation Index (NDVI) from the previous five months, and inundation. Root mean squared error for BGB from testing data was 313 g m[-2] (11% of the field data range), explained variance (R[2]) was 0.62-0.77. Testing data results were unbiased across BGB values and were positively correlated with ground-truth data across all sites and years (r = 0.56-0.82 and 0.45-0.95, respectively). BERM can estimate BGB within Spartina alterniflora salt marshes where environmental parameters are within the training data range, and can be readily extended through a reproducible workflow. This provides a powerful approach for evaluating spatiotemporal BGB and associated ecosystem function.}, }
@article {pmid34026023, year = {2021}, author = {Arismendi, I and Bury, G and Zatkos, L and Snyder, J and Lindley, D}, title = {A method to evaluate body length of live aquatic vertebrates using digital images.}, journal = {Ecology and evolution}, volume = {11}, number = {10}, pages = {5497-5502}, pmid = {34026023}, issn = {2045-7758}, abstract = {Traditional methods to measure body lengths of aquatic vertebrates rely on anesthetics, and extended handling times. These procedures can increase stress, potentially affecting the animal's welfare after its release. We developed a simple procedure using digital images to estimate body lengths of coastal cutthroat trout (Oncorhynchus clarkii clarkii) and larval coastal giant salamander (Dicamptodon tenebrosus). Images were postprocessed using ImageJ2. We measured more than 900 individuals of these two species from 200 pool habitats along 9.6 river kilometers. The percent error (mean ± SE) of our approach compared to the use of a traditional graded measuring board was relatively small for all length metrics of the two species. Total length of trout was -2.2% ± 1.0. Snout-vent length and total length of larval salamanders was 3.5% ± 3.3 and -0.6% ± 1.7, respectively. We cross-validated our results by two independent observers that followed our protocol to measure the same animals and found no significant differences (p > .7) in body size distributions for all length metrics of the two species. Our procedure provides reliable information of body size reducing stress and handling time in the field. The method is transferable across taxa and the inclusion of multiple animals per image increases sampling efficiency with stored images that can be reviewed multiple times. This practical tool can improve data collection of animal size over large sampling efforts and broad spatiotemporal contexts.}, }
@article {pmid33962244, year = {2021}, author = {Wurtzer, S and Waldman, P and Ferrier-Rembert, A and Frenois-Veyrat, G and Mouchel, JM and Boni, M and Maday, Y and ,  and Marechal, V and Moulin, L}, title = {Several forms of SARS-CoV-2 RNA can be detected in wastewaters: Implication for wastewater-based epidemiology and risk assessment.}, journal = {Water research}, volume = {198}, number = {}, pages = {117183}, pmid = {33962244}, issn = {1879-2448}, mesh = {*COVID-19 ; Humans ; RNA, Viral ; Risk Assessment ; SARS-CoV-2 ; Wastewater ; *Wastewater-Based Epidemiological Monitoring ; }, abstract = {The ongoing global pandemic of coronavirus disease 2019 (COVID-19) caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) has been a public health emergency of international concern. Although SARS-CoV-2 is considered to be mainly transmitted by inhalation of contaminated droplets and aerosols, SARS-CoV-2 is also detected in human feces and to a less extent in urine, and in raw wastewaters (to date viral RNA only) suggesting that other routes of infection may exist. Monitoring SARS-CoV-2 genomes in wastewaters has been proposed as a complementary approach for tracing the dynamics of virus transmission within human population connected to wastewater network. The understanding on SARS-CoV-2 transmission through wastewater surveillance, the development of epidemic modeling and the evaluation of SARS-CoV-2 transmission from contaminated wastewater are largely limited by our knowledge on viral RNA genome persistence and virus infectivity preservation in such an environment. Using an integrity based RT-qPCR assay this study led to the discovery that SARS-CoV-2 RNA can persist under several forms in wastewaters, which provides important information on the presence of SARS-CoV-2 in raw wastewaters and associated risk assessment.}, }
@article {pmid33944983, year = {2021}, author = {Li, Z and Cupples, AM}, title = {Diversity of nitrogen cycling genes at a Midwest long-term ecological research site with different management practices.}, journal = {Applied microbiology and biotechnology}, volume = {105}, number = {10}, pages = {4309-4327}, pmid = {33944983}, issn = {1432-0614}, mesh = {Denitrification ; Nitrogen ; *Nitrogen Cycle ; Nitrous Oxide/analysis ; Soil ; *Soil Microbiology ; }, abstract = {Nitrogen fertilizer results in the release of nitrous oxide (N2O), a concern because N2O is an ozone-depleting substance and a greenhouse gas. Although the reduction of N2O to nitrogen gas can control emissions, the factors impacting the enzymes involved have not been fully explored. The current study investigated the abundance and diversity of genes involved in nitrogen cycling (primarily denitrification) under four agricultural management practices (no tillage [NT], conventional tillage [CT], reduced input, biologically-based). The work involved examining soil shotgun sequencing data for nine genes (napA, narG, nirK, nirS, norB, nosZ, nirA, nirB, nifH). For each gene, relative abundance values, diversity and richness indices, and taxonomic classification were determined. Additionally, the genes associated with nitrogen metabolism (defined by the KEGG hierarchy) were examined. The data generated were statistically compared between the four management practices. The relative abundance of four genes (nifH, nirK, nirS, and norB) were significantly lower in the NT treatment compared to one or more of the other soils. The abundance values of napA, narG, nifH, nirA, and nirB were not significantly different between NT and CT. The relative abundance of nirS was significantly higher in the CT treatment compared to the others. Diversity and richness values were higher for four of the nine genes (napA, narG, nirA, nirB). Based on nirS/nirK ratios, CT represents the highest N2O consumption potential in four soils. In conclusion, the microbial communities involved in nitrogen metabolism were sensitive to different agricultural practices, which in turn, likely has implications for N2O emissions. KEY POINTS: • Four genes were less abundant in NT compared to one or more of the others soils (nifH, nirK, nirS, norB). • The most abundant sequences for many of the genes classified within the Proteobacteria. • Higher diversity and richness indices were observed for four genes (napA, narG, nirA, nirB). • Based on nirS/nirK ratios, CT represents the highest N2O consumption potential.}, }
@article {pmid33863946, year = {2021}, author = {Pansera, M and Camatti, E and Schroeder, A and Zagami, G and Bergamasco, A}, title = {The non-indigenous Oithona davisae in a Mediterranean transitional environment: coexistence patterns with competing species.}, journal = {Scientific reports}, volume = {11}, number = {1}, pages = {8341}, pmid = {33863946}, issn = {2045-2322}, abstract = {The Venice lagoon (VL) has been recognized as a hot spot of introduction of non-indigenous species (NIS), due to several anthropogenic factors and environmental stressors that combined may facilitate NIS invasions. In the last decades an increasing number of zooplankton NIS have been observed in the VL. This work aims to provide a picture of the annual cycle and distribution of the recently recorded non-indigenous copepod Oithona davisae, considering the coexistence patterns with the congeneric resident Oithona nana. Therefore, zooplankton samplings were carried out monthly from August 2016 to July 2017 at five Long-Term Ecological Research LTER stations in the VL. Oithona davisae showed a persistent occurrence throughout the year with the highest abundances in the warm season and in the inner areas, while the congeneric O. nana, showing a different distribution pattern, resulted more abundant near the inlets of the Lagoon, where O. davisae reached the minimum density. Oithona davisae seems to find local conditions that promote its settlement and distribution, especially in the inner and more trophic lagoon sites. In other European coastal embayments or transitional waters, O. davisae occupied the niche left by the indigenous O. nana or can replace this congeneric species through competitive exclusion mechanisms. Our data indicate that, for now, such species replacement has not occurred in the VL. One of the causes is the extreme variety of habitats and niches offered by this environment allowing a balanced coexistence with O. nana and in general with the resident copepod community.}, }
@article {pmid33852672, year = {2021}, author = {Rosa, C and Baccaro, F and Cronemberger, C and Hipólito, J and Barros, CF and Rodrigues, DJ and Neckel-Oliveira, S and Overbeck, GE and Drechsler-Santos, ER and Anjos, MRD and Ferreguetti, &#xc1;C and Akama, A and Martins, MB and Tomas, WM and Santos, SA and Ferreira, VL and Cunha, CND and Penha, J and Pinho, JB and Salis, SM and Doria, CRDC and Pillar, VD and Podgaiski, LR and Menin, M and Bígio, NC and Aragón, S and Manzatto, AG and Vélez-Martin, E and Silva, ACBLE and Izzo, TJ and Mortati, AF and Giacomin, LL and Almeida, TE and André, T and Silveira, MAPA and Silveira, ALPD and Messias, MR and Marques, MCM and Padial, AA and Marques, R and Bitar, YOC and Silveira, M and Morato, EF and Pagotto, RC and Strussmann, C and Machado, RB and Aguiar, LMS and Fernandes, GW and Oki, Y and Novais, S and Ferreira, GB and Barbosa, FR and Ochoa, AC and Mangione, AM and Gatica, A and Carrizo, MC and Retta, LM and Jofré, LE and Castillo, LL and Neme, AM and Rueda, C and Toledo, JJ and Grelle, CEV and Vale, MM and Vieira, MV and Cerqueira, R and Higashikawa, EM and Mendonça, FP and Guerreiro, QLM and Banhos, A and Hero, JM and Koblitz, R and Collevatti, RG and Silveira, LF and Vasconcelos, HL and Vieira, CR and Colli, GR and Cechin, SZ and Santos, TGD and Fontana, CS and Jarenkow, JA and Malabarba, LR and Rueda, MP and Araujo, PA and Palomo, L and Iturre, MC and Bergallo, HG and Magnusson, WE}, title = {The Program for Biodiversity Research in Brazil: The role of regional networks for biodiversity knowledge, dissemination, and conservation.}, journal = {Anais da Academia Brasileira de Ciencias}, volume = {93}, number = {2}, pages = {e20201604}, doi = {10.1590/0001-3765202120201604}, pmid = {33852672}, issn = {1678-2690}, mesh = {*Biodiversity ; Brazil ; Conservation of Natural Resources ; *Ecosystem ; Humans ; Knowledge ; }, abstract = {The Program for Biodiversity Research (PPBio) is an innovative program designed to integrate all biodiversity research stakeholders. Operating since 2004, it has installed long-term ecological research sites throughout Brazil and its logic has been applied in some other southern-hemisphere countries. The program supports all aspects of research necessary to understand biodiversity and the processes that affect it. There are presently 161 sampling sites (see some of them at Supplementary Appendix), most of which use a standardized methodology that allows comparisons across biomes and through time. To date, there are about 1200 publications associated with PPBio that cover topics ranging from natural history to genetics and species distributions. Most of the field data and metadata are available through PPBio web sites or DataONE. Metadata is available for researchers that intend to explore the different faces of Brazilian biodiversity spatio-temporal variation, as well as for managers intending to improve conservation strategies. The Program also fostered, directly and indirectly, local technical capacity building, and supported the training of hundreds of undergraduate and graduate students. The main challenge is maintaining the long-term funding necessary to understand biodiversity patterns and processes under pressure from global environmental changes.}, }
@article {pmid33850149, year = {2021}, author = {Scotti, A and Bottarin, R}, title = {Fine-scale multiannual survey of benthic invertebrates in a glacier-fed stream used for hydropower generation.}, journal = {Scientific data}, volume = {8}, number = {1}, pages = {105}, pmid = {33850149}, issn = {2052-4463}, mesh = {Animals ; *Energy-Generating Resources ; *Ice Cover ; Invertebrates/*classification ; Italy ; *Steam ; Surveys and Questionnaires ; }, abstract = {The present dataset contains information about aquatic macroinvertebrates and environmental variables collected before and after the implementation of a small "run-of-river" hydropower plant on the Saldur stream, a glacier-fed stream located in the Italian Central-Eastern Alps. Between 2015 and 2019, with two sampling events per year, we collected and identified 34,836 organisms in 6 sampling sites located within a 6 km stretch of the stream. Given the current boom of the hydropower sector worldwide, and the growing contribution of small hydropower plants to energy production, data here included may represent an important - and long advocated - baseline to assess the effects that these kinds of powerplants have on the riverine ecosystem. Moreover, since the Saldur stream is part of the International Long Term Ecological Research network, this dataset also constitutes part of the data gathered within this research programme. All samples are preserved at Eurac Research facilities.}, }
@article {pmid33797757, year = {2021}, author = {Wilcots, ME and Harpole, WS and Seabloom, EW and Borer, ET}, title = {Community change can buffer chronic nitrogen impacts, but multiple nutrients tip the scale.}, journal = {Ecology}, volume = {102}, number = {6}, pages = {e03355}, doi = {10.1002/ecy.3355}, pmid = {33797757}, issn = {1939-9170}, support = {NSF-DEB-1042132//National Science Foundation Research Coordination Network/ ; DG-0001-13//University of Minnesota Institute on the Environment/ ; NSF-DEB-1234162//National Science Foundation Long Term Ecological Research/ ; NSF-DEB-1831944//National Science Foundation Long Term Ecological Research/ ; //NSF-GRFP/ ; //Graduate School Fellowship from the University of Minnesota/ ; }, mesh = {Ecosystem ; *Grassland ; *Nitrogen ; Nutrients ; Plants ; }, abstract = {Anthropogenic nitrogen (N) inputs are causing large changes in ecosystems worldwide. Many previous studies have examined the impact of N on terrestrial ecosystems; however, most have added N at rates that are much higher than predicted future deposition rates. Here, we present the results from a gradient of experimental N addition (0-10 g·N·m[-2]) in a temperate grassland. After a decade of N addition, we found that all levels of N addition changed plant functional group composition, likely indicating altered function for plant communities exposed to 10 yr of N inputs. However, N addition only had weak impacts on species composition and this functional group shift was not driven by any particular species, suggesting high levels of functional redundancy among grasslands species. Adding other nutrients (P, K, and micronutrients) in combination with N caused substantially greater changes in the relative abundance of species and functional groups. Together, these results suggest that compositional change within functional groups may buffer grasslands from impacts of N deposition, but concurrent eutrophication with other elements will likely lead to substantial changes in plant composition and biomass.}, }
@article {pmid37938231, year = {2021}, author = {Damashek, J and Okotie-Oyekan, AO and Gifford, SM and Vorobev, A and Moran, MA and Hollibaugh, JT}, title = {Transcriptional activity differentiates families of Marine Group II Euryarchaeota in the coastal ocean.}, journal = {ISME communications}, volume = {1}, number = {1}, pages = {5}, pmid = {37938231}, issn = {2730-6151}, support = {1656311//National Science Foundation (NSF)/ ; }, abstract = {Marine Group II Euryarchaeota (Candidatus Poseidoniales), abundant but yet-uncultivated members of marine microbial communities, are thought to be (photo)heterotrophs that metabolize dissolved organic matter (DOM), such as lipids and peptides. However, little is known about their transcriptional activity. We mapped reads from a metatranscriptomic time series collected at Sapelo Island (GA, USA) to metagenome-assembled genomes to determine the diversity of transcriptionally active Ca. Poseidoniales. Summer metatranscriptomes had the highest abundance of Ca. Poseidoniales transcripts, mostly from the O1 and O3 genera within Ca. Thalassarchaeaceae (MGIIb). In contrast, transcripts from fall and winter samples were predominantly from Ca. Poseidoniaceae (MGIIa). Genes encoding proteorhodopsin, membrane-bound pyrophosphatase, peptidase/proteases, and part of the ß-oxidation pathway were highly transcribed across abundant genera. Highly transcribed genes specific to Ca. Thalassarchaeaceae included xanthine/uracil permease and receptors for amino acid transporters. Enrichment of Ca. Thalassarchaeaceae transcript reads related to protein/peptide, nucleic acid, and amino acid transport and metabolism, as well as transcript depletion during dark incubations, provided further evidence of heterotrophic metabolism. Quantitative PCR analysis of South Atlantic Bight samples indicated consistently abundant Ca. Poseidoniales in nearshore and inshore waters. Together, our data suggest that Ca. Thalassarchaeaceae are important photoheterotrophs potentially linking DOM and nitrogen cycling in coastal waters.}, }
@article {pmid33676206, year = {2021}, author = {Haubrock, PJ and Balzani, P and Matsuzaki, SS and Tarkan, AS and Kourantidou, M and Haase, P}, title = {Spatio-temporal niche plasticity of a freshwater invader as a harbinger of impact variability.}, journal = {The Science of the total environment}, volume = {777}, number = {}, pages = {145947}, doi = {10.1016/j.scitotenv.2021.145947}, pmid = {33676206}, issn = {1879-1026}, mesh = {Animals ; *Ecosystem ; *Fishes ; Food Chain ; Japan ; Lakes ; Nitrogen Isotopes/analysis ; }, abstract = {Invasive alien fishes have detrimental ecological effects on aquatic ecosystems and the services they provide. Impacts from an invasion in a single ecosystem may differ across space and time due to variability in prey availability and environmental conditions. We hypothesize that such variability can be profound, even within a single ecosystem. Stable isotopes analysis (SIA) is commonly used to quantitatively describe the trophic niche of a species. However, spatial and temporal variability in occupied niches are often not incorporated into management strategies and policy options. Here, we used long-term monitoring data to investigate the invasion stage as well as SIA to analyse the trophic niche of the invasive channel catfish Ictalurus punctatus in Lake Kasumigaura (Japan), a long-term ecological research site (LTER), across distant sampling sites and years. We found a significant spatio-temporal variability in relative growth and isotopic niche occupation. Moreover, we defined a new index, the Isotopic Plasticity Index (IPI), which is the ratio between core and total home range of an occupied isotopic niche, to be used as a proxy for the trophic niche stretch or density. We found that this IPI varied considerably, confirming the spatio-temporal variability in trophic niches, suggesting the IPI to be an adequate new isotopic metric. Our results further provide evidence for the existence of variation across invaded landscapes, implying heterogeneous impacts on recipient native communities. Therefore, our work emphasizes the importance of exploring trophic plasticity in feeding ecology and growth as such information enables a better understanding of impacts and can inform the design and implementation of effective management responses.}, }
@article {pmid33675118, year = {2021}, author = {Van Sundert, K and Arfin Khan, MAS and Bharath, S and Buckley, YM and Caldeira, MC and Donohue, I and Dubbert, M and Ebeling, A and Eisenhauer, N and Eskelinen, A and Finn, A and Gebauer, T and Haider, S and Hansart, A and Jentsch, A and Kübert, A and Nijs, I and Nock, CA and Nogueira, C and Porath-Krause, AJ and Radujković, D and Raynaud, X and Risch, AC and Roscher, C and Scherer-Lorenzen, M and Schuchardt, MA and Schütz, M and Siebert, J and Sitters, J and Spohn, M and Virtanen, R and Werner, C and Wilfahrt, P and Vicca, S}, title = {Fertilized graminoids intensify negative drought effects on grassland productivity.}, journal = {Global change biology}, volume = {27}, number = {11}, pages = {2441-2457}, doi = {10.1111/gcb.15583}, pmid = {33675118}, issn = {1365-2486}, support = {253385//Academy of Finland/ ; 297191//Academy of Finland/ ; NSF-DEB-1234162//National Science Foundation Long Term Ecological Research/ ; NSF-DEB-1831944//National Science Foundation Cedar Creek Long Term Ecological Research/ ; //Fonds Wetenschappelijk Onderzoek/ ; DG-0001-13//Institute on the Environment, University of Minnesota/ ; ANR-10-IDEX-0001-02 PSL//AnaEE France/ ; ANR-11-INBS-0001//AnaEE France/ ; FKZ 031B0516C//Bundesministerium f&#xfc;r Bildung und Forschung/ ; NSF-DEB-1042132//National Science Foundation Research Coordination Network/ ; I-05-098/R//Regional Council of Ile-de-France/ ; UID/AGR/00239/2019//Faculdade de Ci&#xea;ncias e Tecnologia, Universidade Nova de Lisboa/ ; }, mesh = {Biodiversity ; Biomass ; *Droughts ; Ecosystem ; Europe ; *Grassland ; }, abstract = {Droughts can strongly affect grassland productivity and biodiversity, but responses differ widely. Nutrient availability may be a critical factor explaining this variation, but is often ignored in analyses of drought responses. Here, we used a standardized nutrient addition experiment covering 10 European grasslands to test if full-factorial nitrogen, phosphorus, and potassium addition affected plant community responses to inter-annual variation in drought stress and to the extreme summer drought of 2018 in Europe. We found that nutrient addition amplified detrimental drought effects on community aboveground biomass production. Drought effects also differed between functional groups, with a negative effect on graminoid but not forb biomass production. Our results imply that eutrophication in grasslands, which promotes dominance of drought-sensitive graminoids over forbs, amplifies detrimental drought effects. In terms of climate change adaptation, agricultural management would benefit from taking into account differential drought impacts on fertilized versus unfertilized grasslands, which differ in ecosystem services they provide to society.}, }
@article {pmid33655567, year = {2021}, author = {Liang, L and Henebry, GM and Liu, L and Zhang, X and Hsu, LC}, title = {Trends in land surface phenology across the conterminous United States (1982-2016) analyzed by NEON domains.}, journal = {Ecological applications : a publication of the Ecological Society of America}, volume = {31}, number = {5}, pages = {e02323}, doi = {10.1002/eap.2323}, pmid = {33655567}, issn = {1051-0761}, support = {80NSSC18K0626/NASA/NASA/United States ; NNX14AJ32G/NASA/NASA/United States ; }, mesh = {Climate Change ; *Ecosystem ; *Plant Development ; Satellite Imagery ; Seasons ; United States ; }, abstract = {Tracking phenological change in a regionally explicit context is a key to understanding ecosystem status and change. The current study investigated long-term trends of satellite-observed land surface phenology (LSP) in the 17 National Ecological Observatory Network (NEON) domains across the conterminous United States (CONUS). Characterization of LSP trends was based on a high temporal resolution (3-d) time series of the two-band enhanced vegetation index (EVI2) derived from a long-term data record (LTDR) of the Advanced Very High Resolution Radiometer (AVHRR) and the Moderate Resolution Imaging Spectroradiometer (MODIS). We identified significant trend patterns in LSP and their seasonal climate and land use/land cover drivers for each NEON domain. Key findings include (1) the start of season (SOS) predominantly shifted later in 13 out of 17 domains (24.3% of CONUS by area) due potentially to both a lack of spring warming in the eastern United States and changes in agronomic practices over agricultural lands; (2) the end of season (EOS) became predominantly later in nine domains dominated by natural vegetation (14.1% of CONUS by area) in response to widespread warming in autumn; (3) the EOS predominantly shifted earlier in three domains (10.6% of CONUS by area) over primarily agricultural lands as potentially affected by changes in crop growth cycles; and (4) earlier shift in the SOS was mostly found in the Northwest (3.6% of CONUS by area) and was predominant only in the moist Pacific Northwest (27.7% of the domain by area) in response to more pronounced spring warming in the region. The overall patterns of SOS and EOS trends across CONUS appeared constrained by continental-scale temperature trends as characterized by a west-east dipole and the distribution of the nation's agricultural lands. In addition, seasonal trend analysis revealed that most NEON domains (15/17) became predominantly greener in part of or throughout the growing season, potentially contributed by both climate change-induced growth increase and improved agricultural productivity. The domain-wide LSP trends with their underlying drivers identified here provide important contextual information for NEON science as well as for investigations within CONUS using other distributed observatories (e.g., LTER, LTAR, FLUXNET, USA-NPN, etc.).}, }
@article {pmid33650497, year = {2021}, author = {Wurtzer, S and Maréchal, V and Bertrand, I and Boni, M and Le Guyader, S and Moulin, L and Maday, Y and Gantzer, C and Mouchel, JM}, title = {[Viral infectious diseases seen through wastewater].}, journal = {Virologie (Montrouge, France)}, volume = {25}, number = {1}, pages = {8-11}, doi = {10.1684/vir.2021.0881}, pmid = {33650497}, issn = {1267-8694}, mesh = {*Communicable Diseases ; Humans ; Wastewater ; *Water Purification ; }, }
@article {pmid33650494, year = {2021}, author = {Wurtzer, S and Maréchal, V and Bertrand, I and Boni, M and Le Guyader, S and Moulin, L and Maday, Y and Gantzer, C and Mouchel, JM}, title = {Viral infectious diseases seen through wastewater.}, journal = {Virologie (Montrouge, France)}, volume = {25}, number = {1}, pages = {1-4}, doi = {10.1684/vir.2021.0882}, pmid = {33650494}, issn = {1267-8694}, mesh = {*Communicable Diseases ; Humans ; Wastewater ; *Water Purification ; }, }
@article {pmid33616295, year = {2021}, author = {Cusser, S and Helms, J and Bahlai, CA and Haddad, NM}, title = {How long do population level field experiments need to be? Utilising data from the 40-year-old LTER network.}, journal = {Ecology letters}, volume = {24}, number = {5}, pages = {1103-1111}, doi = {10.1111/ele.13710}, pmid = {33616295}, issn = {1461-0248}, support = {//Michigan State University AgBioResearch/ ; OAC 1838807//National Science Foundation Directorate for Computer and Information Science and Engineering/ ; DEB 1832042//National Science Foundation Long-term Ecological Research Program/ ; DEB 1637459//National Science Foundation Long-term Ecological Research Program/ ; DEB 1026843//National Science Foundation Long-term Ecological Research Program/ ; DEB 0423385//National Science Foundation Long-term Ecological Research Program/ ; DEB 9810222//National Science Foundation Long-term Ecological Research Program/ ; DEB 9211775//National Science Foundation Long-term Ecological Research Program/ ; DEB 8702328//National Science Foundation Long-term Ecological Research Program/ ; DEB 1831944//National Science Foundation Long-term Ecological Research Program/ ; DEB 9211768//National Science Foundation Long-term Ecological Research Program/ ; DEB 9810221//National Science Foundation Long-term Ecological Research Program/ ; DEB 0423259//National Science Foundation Long-term Ecological Research Program/ ; DEB 0218039//National Science Foundation Long-term Ecological Research Program/ ; DEB 0620910//National Science Foundation Long-term Ecological Research Program/ ; OPP 1637708//National Science Foundation Long-term Ecological Research Program/ ; LTREB 9815519//National Science Foundation Long-term Ecological Research Program/ ; LTREB 9527669//National Science Foundation Long-term Ecological Research Program/ ; OCE 1637630//National Science Foundation Long-term Ecological Research Program/ ; OCE 1232779//National Science Foundation Long-term Ecological Research Program/ ; OCE 1831937//National Science Foundation Long-term Ecological Research Program/ ; DEB 1655499//National Science Foundation Long-term Ecological Research Program/ ; DEB 1027319//National Science Foundation Long-term Ecological Research Program/ ; //USDA National Institute on Food and Agriculture/ ; }, mesh = {Animals ; *Plants ; *Research Design ; }, abstract = {We utilise the wealth of data accessible through the 40-year-old Long-Term Ecological Research (LTER) network to ask if aspects of the study environment or taxa alter the duration of research necessary to detect consistent results. To do this, we use a moving-window algorithm. We limit our analysis to long-term (> 10 year) press experiments recording organismal abundance. We find that studies conducted in dynamic abiotic environments need longer periods of study to reach consistent results, as compared to those conducted in more moderated environments. Studies of plants were more often characterised by spurious results than those on animals. Nearly half of the studies we investigated required 10 years or longer to become consistent, where all significant trends agreed in direction, and four studies (of 100) required longer than 20 years. Here, we champion the importance of long-term data and bolster the value of multi-decadal experiments in understanding, explaining and predicting long-term trends.}, }
@article {pmid33586192, year = {2021}, author = {Evers, SM and Knight, TM and Inouye, DW and Miller, TEX and Salguero-Gómez, R and Iler, AM and Compagnoni, A}, title = {Lagged and dormant season climate better predict plant vital rates than climate during the growing season.}, journal = {Global change biology}, volume = {27}, number = {9}, pages = {1927-1941}, doi = {10.1111/gcb.15519}, pmid = {33586192}, issn = {1365-2486}, support = {//Sigma Xi/ ; IRF NE/M018458/1//Natural Environment Research Council/ ; 1440478//Sevilleta LTER/ ; 1655499//Sevilleta LTER/ ; 1748133//Sevilleta LTER/ ; 1543651//National Science Foundation, Division of Environmental Biology/ ; 1754468//National Science Foundation, Division of Environmental Biology/ ; BSR 81-08387//National Science Foundation/ ; DEB 0238331//National Science Foundation/ ; DEB 0922080//National Science Foundation/ ; DEB 1354104//National Science Foundation/ ; DEB 1912006//National Science Foundation/ ; DEB 75-15422//National Science Foundation/ ; DEB 78-07784//National Science Foundation/ ; DEB 94-08382//National Science Foundation/ ; IBN 95-27833//National Science Foundation/ ; IBN 98-14509//National Science Foundation/ ; //Max planck institute for Demographic Research/ ; //Lewis and Clark fund/ ; FZT 118//Deutsche Forschungsgemeinschaft/ ; //Helmholtz Association/ ; //Alexander von Humboldt-Stiftung/ ; }, mesh = {*Climate Change ; *Plants ; Population Dynamics ; Seasons ; }, abstract = {Understanding the effects of climate on the vital rates (e.g., survival, development, reproduction) and dynamics of natural populations is a long-standing quest in ecology, with ever-increasing relevance in the face of climate change. However, linking climate drivers to demographic processes requires identifying the appropriate time windows during which climate influences vital rates. Researchers often do not have access to the long-term data required to test a large number of windows, and are thus forced to make a priori choices. In this study, we first synthesize the literature to assess current a priori choices employed in studies performed on 104 plant species that link climate drivers with demographic responses. Second, we use a sliding-window approach to investigate which combination of climate drivers and temporal window have the best predictive ability for vital rates of four perennial plant species that each have over a decade of demographic data (Helianthella quinquenervis, Frasera speciosa, Cylindriopuntia imbricata, and Cryptantha flava). Our literature review shows that most studies consider time windows in only the year preceding the measurement of the vital rate(s) of interest, and focus on annual or growing season temporal scales. In contrast, our sliding-window analysis shows that in only four out of 13 vital rates the selected climate drivers have time windows that align with, or are similar to, the growing season. For many vital rates, the best window lagged more than 1 year and up to 4 years before the measurement of the vital rate. Our results demonstrate that for the vital rates of these four species, climate drivers that are lagged or outside of the growing season are the norm. Our study suggests that considering climatic predictors that fall outside of the most recent growing season will improve our understanding of how climate affects population dynamics.}, }
@article {pmid33571316, year = {2021}, author = {Paciorek, CJ and Cogbill, CV and Peters, JA and Williams, JW and Mladenoff, DJ and Dawson, A and McLachlan, JS}, title = {The forests of the midwestern United States at Euro-American settlement: Spatial and physical structure based on contemporaneous survey data.}, journal = {PloS one}, volume = {16}, number = {2}, pages = {e0246473}, pmid = {33571316}, issn = {1932-6203}, mesh = {Bayes Theorem ; *Biomass ; *Forests ; Midwestern United States ; Plant Components, Aerial/growth &amp; development ; Spatio-Temporal Analysis ; Trees/*growth &amp; development ; }, abstract = {We present gridded 8 km-resolution data products of the estimated stem density, basal area, and biomass of tree taxa at Euro-American settlement of the midwestern United States during the middle to late 19th century for the states of Minnesota, Wisconsin, Michigan, Illinois, and Indiana. The data come from settlement-era Public Land Survey (PLS) data (ca. 0.8-km resolution) of trees recorded by land surveyors. The surveyor notes have been transcribed, cleaned, and processed to estimate stem density, basal area, and biomass at individual points. The point-level data are aggregated within 8 km grid cells and smoothed using a generalized additive statistical model that accounts for zero-inflated continuous data and provides approximate Bayesian uncertainty estimates. The statistical modeling smooths out sharp spatial features (likely arising from statistical noise) within areas smaller than about 200 km2. Based on this modeling, presettlement Midwestern landscapes supported multiple dominant species, vegetation types, forest types, and ecological formations. The prairies, oak savannas, and forests each had distinctive structures and spatial distributions across the domain. Forest structure varied from savanna (averaging 27 Mg/ha biomass) to northern hardwood (104 Mg/ha) and mesic southern forests (211 Mg/ha). The presettlement forests were neither unbroken and massively-statured nor dominated by young forests constantly structured by broad-scale disturbances such as fire, drought, insect outbreaks, or hurricanes. Most forests were structurally between modern second growth and old growth. We expect the data product to be useful as a baseline for investigating how forest ecosystems have changed in response to the last several centuries of climate change and intensive Euro-American land use and as a calibration dataset for paleoecological proxy-based reconstructions of forest composition and structure for earlier time periods. The data products (including raw and smoothed estimates at the 8-km scale) are available at the LTER Network Data Portal as version 1.0.}, }
@article {pmid33433068, year = {2021}, author = {}, title = {Erratum.}, journal = {Ecological applications : a publication of the Ecological Society of America}, volume = {31}, number = {1}, pages = {e02231}, doi = {10.1002/eap.2231}, pmid = {33433068}, issn = {1051-0761}, support = {DEB 1832042//NSF Long-term Ecological Research Program/ ; //Michigan State University AgBioResearch/ ; }, }
@article {pmid33411833, year = {2021}, author = {Käse, L and Metfies, K and Neuhaus, S and Boersma, M and Wiltshire, KH and Kraberg, AC}, title = {Host-parasitoid associations in marine planktonic time series: Can metabarcoding help reveal them?.}, journal = {PloS one}, volume = {16}, number = {1}, pages = {e0244817}, pmid = {33411833}, issn = {1932-6203}, mesh = {Animals ; DNA Barcoding, Taxonomic/methods ; Eukaryota ; Food Chain ; Host-Parasite Interactions/*genetics ; Oceans and Seas ; Plankton/*genetics ; RNA, Ribosomal, 18S/*genetics ; Seasons ; }, abstract = {In this study, we created a dataset of a continuous three-year 18S metabarcoding survey to identify eukaryotic parasitoids, and potential connections to hosts at the Long-Term Ecological Research station Helgoland Roads. The importance of parasites and parasitoids for food web dynamics has previously been recognized mostly in terrestrial and freshwater systems, while marine planktonic parasitoids have been understudied in comparison to those. Therefore, the occurrence and role of parasites and parasitoids remains mostly unconsidered in the marine environment. We observed high abundances and diversity of parasitoid operational taxonomic units in our dataset all year round. While some parasitoid groups were present throughout the year and merely fluctuated in abundances, we also detected a succession of parasitoid groups with peaks of individual species only during certain seasons. Using co-occurrence and patterns of seasonal occurrence, we were able to identify known host-parasitoid dynamics, however identification of new potential host-parasitoid interactions was not possible due to their high dynamics and variability in the dataset.}, }
@article {pmid33380749, year = {2020}, author = {Sherman, J and Gorbunov, MY and Schofield, O and Falkowski, PG}, title = {Photosynthetic energy conversion efficiency in the West Antarctic Peninsula.}, journal = {Limnology and oceanography}, volume = {65}, number = {12}, pages = {2912-2925}, pmid = {33380749}, issn = {0024-3590}, abstract = {The West Antarctic Peninsula (WAP) is a highly productive polar ecosystem where phytoplankton dynamics are regulated by intense bottom-up control from light and iron availability. Rapid climate change along the WAP is driving shifts in the mixed layer depth and iron availability. Elucidating the relative role of each of these controls and their interactions is crucial for understanding of how primary productivity will change in coming decades. Using a combination of ultra-high-resolution variable chlorophyll fluorescence together with fluorescence lifetime analyses on the 2017 Palmer Long Term Ecological Research cruise, we mapped the temporal and spatial variability in phytoplankton photophysiology across the WAP. Highest photosynthetic energy conversion efficiencies and lowest fluorescence quantum yields were observed in iron replete coastal regions. Photosynthetic energy conversion efficiencies decreased by ~ 60% with a proportional increase in quantum yields of thermal dissipation and fluorescence on the outer continental shelf and slope. The combined analysis of variable fluorescence and lifetimes revealed that, in addition to the decrease in the fraction of inactive reaction centers, up to 20% of light harvesting chlorophyll-protein antenna complexes were energetically uncoupled from photosystem II reaction centers in iron-limited phytoplankton. These biophysical signatures strongly suggest severe iron limitation of photosynthesis in the surface waters along the continental slope of the WAP.}, }
@article {pmid33376455, year = {2020}, author = {Bowen, JL and Giblin, AE and Murphy, AE and Bulseco, AN and Deegan, LA and Johnson, DS and Nelson, JA and Mozdzer, TJ and Sullivan, HL}, title = {Not All Nitrogen Is Created Equal: Differential Effects of Nitrate and Ammonium Enrichment in Coastal Wetlands.}, journal = {Bioscience}, volume = {70}, number = {12}, pages = {1108-1119}, pmid = {33376455}, issn = {0006-3568}, abstract = {Excess reactive nitrogen (N) flows from agricultural, suburban, and urban systems to coasts, where it causes eutrophication. Coastal wetlands take up some of this N, thereby ameliorating the impacts on nearshore waters. Although the consequences of N on coastal wetlands have been extensively studied, the effect of the specific form of N is not often considered. Both oxidized N forms (nitrate, NO3-) and reduced forms (ammonium, NH4[+]) can relieve nutrient limitation and increase primary production. However, unlike NH4[+], NO3- can also be used as an electron acceptor for microbial respiration. We present results demonstrating that, in salt marshes, microbes use NO3- to support organic matter decomposition and primary production is less stimulated than when enriched with reduced N. Understanding how different forms of N mediate the balance between primary production and decomposition is essential for managing coastal wetlands as N enrichment and sea level rise continue to assail our coasts.}, }
@article {pmid33334397, year = {2020}, author = {Wurtzer, S and Marechal, V and Mouchel, JM and Maday, Y and Teyssou, R and Richard, E and Almayrac, JL and Moulin, L}, title = {Evaluation of lockdown effect on SARS-CoV-2 dynamics through viral genome quantification in waste water, Greater Paris, France, 5 March to 23 April 2020.}, journal = {Euro surveillance : bulletin Europeen sur les maladies transmissibles = European communicable disease bulletin}, volume = {25}, number = {50}, pages = {}, pmid = {33334397}, issn = {1560-7917}, mesh = {COVID-19/*epidemiology/transmission ; Communicable Disease Control/*methods/statistics &amp; numerical data ; France ; *Genome, Viral ; Humans ; Paris/epidemiology ; *Physical Distancing ; *Quarantine ; RNA, Viral/*analysis ; Reverse Transcriptase Polymerase Chain Reaction ; SARS-CoV-2/*isolation &amp; purification ; Viral Load ; *Virus Shedding ; Wastewater/*virology ; }, abstract = {IntroductionSevere acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is the etiological agent of coronavirus disease (COVID-19). People infected with SARS-CoV-2 may exhibit no or mild non-specific symptoms; thus, they may contribute to silent circulation of the virus among humans. Since SARS-CoV-2 RNA can be detected in stool samples, monitoring SARS-CoV-2 RNA in waste water (WW) has been proposed as a complementary tool to investigate virus circulation in human populations.AimTo test if the quantification of SARS-CoV-2 genomes in WW correlates with the number of symptomatic or non-symptomatic carriers.MethodWe performed a time-course quantitative analysis of SARS-CoV-2 by RT-qPCR in raw WW samples collected from several major WW treatment plants in Greater Paris. The study period was 5 March to 23 April 2020, including the lockdown period in France (from 17 March).ResultsWe showed that the increase of genome units in raw WW accurately followed the increase of human COVID-19 cases observed at the regional level. Of note, the viral genome could be detected before the epidemic grew massively (around 8 March). Equally importantly, a marked decrease in the quantities of genome units was observed concomitantly with the reduction in the number of new COVID-19 cases, 29 days following the lockdown.ConclusionThis work suggests that a quantitative monitoring of SARS-CoV-2 genomes in WW could generate important additional information for improved monitoring of SARS-CoV-2 circulation at local or regional levels and emphasises the role of WW-based epidemiology.}, }
@article {pmid33300281, year = {2021}, author = {Kohli, M and Henning, JA and Borer, ET and Kinkel, L and Seabloom, EW}, title = {Foliar fungi and plant diversity drive ecosystem carbon fluxes in experimental prairies.}, journal = {Ecology letters}, volume = {24}, number = {3}, pages = {487-497}, doi = {10.1111/ele.13663}, pmid = {33300281}, issn = {1461-0248}, support = {DEB-1234162//NSF-LTER/ ; DEB-1831944//NSF-LTER/ ; //National Science Foundation/ ; }, mesh = {Animals ; Biodiversity ; Biomass ; Carbon ; Carbon Cycle ; *Ecosystem ; Fungi ; *Grassland ; Soil ; }, abstract = {Plant diversity and plant-consumer/pathogen interactions likely interact to influence ecosystem carbon fluxes but experimental evidence is scarce. We examined how experimental removal of foliar fungi, soil fungi and arthropods from experimental prairies planted with 1, 4 or 16 plant species affected instantaneous rates of carbon uptake (GPP), ecosystem respiration (Re) and net ecosystem exchange (NEE). Increasing plant diversity increased plant biomass, GPP and Re , but NEE remained unchanged. Removing foliar fungi increased GPP and NEE, with the greatest effects at low plant diversity. After accounting for plant biomass, we found that removing foliar fungi increased mass-specific flux rates in the low-diversity plant communities by altering plant species composition and community-wide foliar nitrogen content. However, this effect disappeared when soil fungi and arthropods were also removed, demonstrating that both plant diversity and interactions among consumer groups determine the ecosystem-scale effects of plant-fungal interactions.}, }
@article {pmid33288265, year = {2021}, author = {Baker, NJ and Pilotto, F and Jourdan, J and Beudert, B and Haase, P}, title = {Recovery from air pollution and subsequent acidification masks the effects of climate change on a freshwater macroinvertebrate community.}, journal = {The Science of the total environment}, volume = {758}, number = {}, pages = {143685}, doi = {10.1016/j.scitotenv.2020.143685}, pmid = {33288265}, issn = {1879-1026}, mesh = {*Air Pollution ; Animals ; *Climate Change ; Ecosystem ; Fresh Water ; Germany ; Hydrogen-Ion Concentration ; Invertebrates ; Rivers ; }, abstract = {Freshwater ecosystems are dynamic, complex systems with a multitude of physical and ecological processes and stressors which drive fluctuations on the community-level. Disentangling the effects of different processes and stressors is challenging due to their interconnected nature. However, as protected areas (i.e. national parks) are less anthropogenically impacted, they are ideal for investigating single stressors. We focus on the Bavarian Forest National Park, a Long-Term Ecological Research (LTER) site in Germany, where the major stressors are climate warming, air pollution (i.e. acidification) and bark beetle infestations. We investigated the effects of these stressors on freshwater macroinvertebrates using comprehensive long-term (1983-2014) datasets comprising high-resolution macroinvertebrate and physico-chemical data from a near-natural stream. Macroinvertebrate communities have undergone substantial changes over the past 32 years, highlighted by increases in overall community abundance (+173%) and richness (+51.6%) as well as taxonomic restructuring driven by a disproportional increase of dipterans. Prior to the year 2000, regression analyses revealed a decline in sulphate deposition and subsequent recovery from historical acidification as potential drivers of the increases in abundance and richness rather than to increases in water temperature (1.5 °C overall increase). Post 2000, however, alterations to nutrient cycling caused by bark beetle infestations coupled with warming temperatures were correlated to taxonomic restructuring and disproportional increases of dipterans at the expense of sensitive taxa such as plecopterans and trichopterans. Our results highlight the challenges when investigating the effects of climate change within a multi-stressor context. Even in conservation areas, recovery from previous disturbance might mask the effects of ongoing disturbances like climate change. Overall, we observed strong community restructuring, demonstrating that stenothermal headwater communities face additional stress due to emerging competition with tolerant taxa. Conservation efforts should consider the temporal variability of communities and their recovery from disturbances to adequately identify species vulnerable to local or widespread extinction.}, }
@article {pmid33182822, year = {2020}, author = {Sakio, H and Masuzawa, T}, title = {Advancing Timberline on Mt. Fuji between 1978 and 2018.}, journal = {Plants (Basel, Switzerland)}, volume = {9}, number = {11}, pages = {}, pmid = {33182822}, issn = {2223-7747}, support = {(B) (No. 19310008)//Grant-in-Aid for Scientific Research from the Ministry of Education, Culture, Sports, Science and Technology, Japan/ ; }, abstract = {Climate change is a major cause of changes in alpine and polar vegetation, particularly at the edges of distributions. In temperate regions, these changes are expected to occur at the timberline of alpine zones. On Mt. Fuji, the highest mountain in Japan, the timberline is located 2400-2500 m above sea level. Over a 40-year period (1978-2018), we researched changes in the timberline vegetation of Mt. Fuji. A permanent belt transect extending from the upper timberline to subalpine zones was set up in August 1978. Tree diameters and heights were recorded at the establishment of the transect and every 20 years afterwards. Over the 40 years of the study, the timberline advanced rapidly upwards, and the degree of vegetation cover above the timberline increased remarkably. Notably, the expansion of Salix reinii into the upper part of the timberline facilitated the subsequent spread of Larix kaempferi into this zone. Seedlings of L. kaempferi were particularly abundant at the upper timberline and became established on the uppermost part of the slope. The shape of L. kaempferi at the upper timberline changed from a prostrate form to an upright tree form. We conclude that the upward advance of the alpine timberline observed on Mt. Fuji is due to climate change.}, }
@article {pmid33141324, year = {2020}, author = {Anthony, MA and Stinson, KA and Moore, JAM and Frey, SD}, title = {Plant invasion impacts on fungal community structure and function depend on soil warming and nitrogen enrichment.}, journal = {Oecologia}, volume = {194}, number = {4}, pages = {659-672}, pmid = {33141324}, issn = {1432-1939}, support = {NRC2326//Strategic Environmental Research and Development Program/ ; LTER; DEB-1832110//National Science Foundation/ ; DGE 1450271//National Science Foundation/ ; LTREB; DEB-1456610//Directorate for Biological Sciences/ ; }, mesh = {*Mycobiome ; *Mycorrhizae ; Nitrogen/analysis ; North America ; Soil ; Soil Microbiology ; }, abstract = {The impacts of invasive species on biodiversity may be mitigated or exacerbated by abiotic environmental changes. Invasive plants can restructure soil fungal communities with important implications for native biodiversity and nutrient cycling, yet fungal responses to invasion may depend on numerous anthropogenic stressors. In this study, we experimentally invaded a long-term soil warming and simulated nitrogen deposition experiment with the widespread invasive plant Alliaria petiolata (garlic mustard) and tested the responses of soil fungal communities to invasion, abiotic factors, and their interaction. We focused on the phytotoxic garlic mustard because it suppresses native mycorrhizae across forests of North America. We found that invasion in combination with warming, but not under ambient conditions or elevated nitrogen, significantly reduced soil fungal biomass and ectomycorrhizal relative abundances and increased relative abundances of general soil saprotrophs and fungal genes encoding for hydrolytic enzymes. These results suggest that warming potentially exacerbates fungal responses to plant invasion. Soils collected from uninvaded and invaded plots across eight forests spanning a 4 °C temperature gradient further demonstrated that the magnitude of fungal responses to invasion was positively correlated with mean annual temperature. Our study is one of the first empirical tests to show that the impacts of invasion on fungal communities depends on additional anthropogenic pressures and were greater in concert with warming than under elevated nitrogen or ambient conditions.}, }
@article {pmid32907718, year = {2020}, author = {Margiotta, F and Balestra, C and Buondonno, A and Casotti, R and D'Ambra, I and Di Capua, I and Gallia, R and Mazzocchi, MG and Merquiol, L and Pepi, M and Percopo, I and Saggiomo, M and Sarno, D and Zingone, A}, title = {Do plankton reflect the environmental quality status? The case of a post-industrial Mediterranean Bay.}, journal = {Marine environmental research}, volume = {160}, number = {}, pages = {104980}, doi = {10.1016/j.marenvres.2020.104980}, pmid = {32907718}, issn = {1879-0291}, mesh = {*Bays ; Biomass ; Mediterranean Sea ; *Phytoplankton ; *Plankton ; }, abstract = {While the effects of industrial contamination in coastal areas may persist for years in benthos communities, plankton should not show permanent impairments because of their high spatial dynamics, fast turnover times and pronounced seasonality. To test this hypothesis, in 2019 we conducted five surveys in the Bay of Pozzuoli (Gulf of Naples, Mediterranean Sea), in front of a dismissed steel factory and in the adjacent inshore coastal waters. High seasonal variability was observed for bacteria, phytoplankton and mesozooplankton, whereas plankton spatial gradients were relatively smooth during each survey. Plankton biomass and diversity did not reveal any effects of past industrial activities not even at the innermost stations of the Bay, which however showed some signals of present anthropogenic pressure. Hydrodynamic and morphological features likely play a prominent role in maintaining a relatively good status of the plankton of the Bay, which hints at the relevance of coastal circulation and meteorological dynamics to revitalize areas impacted by human activities.}, }
@article {pmid32852804, year = {2020}, author = {Harrison, JL and Sanders-DeMott, R and Reinmann, AB and Sorensen, PO and Phillips, NG and Templer, PH}, title = {Growing-season warming and winter soil freeze/thaw cycles increase transpiration in a northern hardwood forest.}, journal = {Ecology}, volume = {101}, number = {11}, pages = {e03173}, doi = {10.1002/ecy.3173}, pmid = {32852804}, issn = {1939-9170}, support = {NSF 1114804//National Science Foundation (NSF) Long Term Ecological Research (LTER) Grant/ ; 1637685//National Science Foundation (NSF) Long Term Ecological Research (LTER) Grant/ ; NSF DEB1149929//NSF CAREER/ ; }, mesh = {Climate Change ; *Ecosystem ; Forests ; New Hampshire ; Seasons ; Snow ; *Soil ; }, abstract = {Climate models project higher growing-season temperatures and a decline in the depth and duration of winter snowpack throughout many north temperate ecosystems over the next century. A smaller snowpack is projected to induce more frequent soil freeze/thaw cycles in winter in northern hardwood forests of the northeastern United States. We measured the combined effects of warmer growing-season soil temperatures and increased winter freeze/thaw cycles on rates of leaf-level photosynthesis and transpiration (sap flow) of red maple (Acer rubrum) trees in a northern hardwood forest at the Climate Change Across Seasons Experiment at Hubbard Brook Experimental Forest in New Hampshire. Soil temperatures were warmed 5°C above ambient temperatures during the growing season and soil freeze/thaw cycles were induced in winter to mimic the projected changes in soil temperature over the next century. Relative to reference plots, growing-season soil warming increased rates of leaf-level photosynthesis by up to 85.32 ± 4.33%, but these gains were completely offset by soil freeze/thaw cycles in winter, suggesting that increased freeze/thaw cycles in winter over the next 100 yr will reduce the effect of warming on leaf-level carbon gains. Soil warming in the growing season increased rates of transpiration per kilopascal of vapor pressure deficit (VPD) by up to 727.39 ± 0.28%, even when trees were exposed to increased frequency of soil freeze/thaw cycles in the previous winter, which could influence regional hydrology in the future. Using climate projections downscaled from the Coupled Model Intercomparison Project, we project increased rates of whole-season transpiration in these forests over the next century by 42-61%. We also project 52-77 additional days when daily air temperatures will be above the long-term average daily maximum during the growing season at Hubbard Brook. Together, these results show that projected changes in climate across both the growing season and winter are likely to cause greater rates of water uptake and have no effect on rates of leaf-level carbon uptake by trees, with potential ecosystem consequences for hydrology and carbon cycling in northern hardwood forests.}, }
@article {pmid32808477, year = {2020}, author = {Albrecht, M and Kleijn, D and Williams, NM and Tschumi, M and Blaauw, BR and Bommarco, R and Campbell, AJ and Dainese, M and Drummond, FA and Entling, MH and Ganser, D and Arjen de Groot, G and Goulson, D and Grab, H and Hamilton, H and Herzog, F and Isaacs, R and Jacot, K and Jeanneret, P and Jonsson, M and Knop, E and Kremen, C and Landis, DA and Loeb, GM and Marini, L and McKerchar, M and Morandin, L and Pfister, SC and Potts, SG and Rundlöf, M and Sardiñas, H and Sciligo, A and Thies, C and Tscharntke, T and Venturini, E and Veromann, E and Vollhardt, IMG and Wäckers, F and Ward, K and Westbury, DB and Wilby, A and Woltz, M and Wratten, S and Sutter, L}, title = {The effectiveness of flower strips and hedgerows on pest control, pollination services and crop yield: a quantitative synthesis.}, journal = {Ecology letters}, volume = {23}, number = {10}, pages = {1488-1498}, pmid = {32808477}, issn = {1461-0248}, support = {DEB 1832042//National Science Foundation Long-term Ecological Research Program/ ; //University of Maine School of Biology and Ecology/ ; //Michigan State University AgBioResearch/ ; //Hauser and Sur-La-Croix foundations/ ; //Tertiary Education Commission through the Bio-Protection Research Centre at Lincoln University, New Zealand/ ; //Great Lakes Bioenergy Research Center, U.S. Department of Energy, Office of Science, Office of Biological and Environmental Research/ ; FA1307 "SUPER-B"//EU COST/ ; //EU FP7/ ; /WT_/Wellcome Trust/United Kingdom ; //USDA Sustainable Agriculture Research and Education program/ ; 1518739//Biotechnology and Biological Sciences Research Council (BBSRC) and Syngenta UK/ ; //AgBioResearch/ ; BB/P003664/1//SMOOPS project funded by BBSRC, Worldwide Fruit Limited, Avalon and Syngenta/ ; IUT36-2//Estonian Research Council Institutional Research Funding project/ ; 2011-51181-30673//United States Department of Agriculture - National Institute of Food and Agriculture Specialty Crops Research Initiative/ ; BB/1000348/1//Insect Pollinators Initiative UK Crop pollination project funded by BBSRC, Defra, NERC, the Scottish Government and the Wellcome Trust/ ; }, mesh = {Agriculture ; Bees ; Biodiversity ; *Ecosystem ; Europe ; Flowers ; New Zealand ; North America ; Pest Control ; *Pollination ; }, abstract = {Floral plantings are promoted to foster ecological intensification of agriculture through provisioning of ecosystem services. However, a comprehensive assessment of the effectiveness of different floral plantings, their characteristics and consequences for crop yield is lacking. Here we quantified the impacts of flower strips and hedgerows on pest control (18 studies) and pollination services (17 studies) in adjacent crops in North America, Europe and New Zealand. Flower strips, but not hedgerows, enhanced pest control services in adjacent fields by 16% on average. However, effects on crop pollination and yield were more variable. Our synthesis identifies several important drivers of variability in effectiveness of plantings: pollination services declined exponentially with distance from plantings, and perennial and older flower strips with higher flowering plant diversity enhanced pollination more effectively. These findings provide promising pathways to optimise floral plantings to more effectively contribute to ecosystem service delivery and ecological intensification of agriculture in the future.}, }
@article {pmid32786128, year = {2020}, author = {Risch, AC and Zimmermann, S and Moser, B and Schütz, M and Hagedorn, F and Firn, J and Fay, PA and Adler, PB and Biederman, LA and Blair, JM and Borer, ET and Broadbent, AAD and Brown, CS and Cadotte, MW and Caldeira, MC and Davies, KF and di Virgilio, A and Eisenhauer, N and Eskelinen, A and Knops, JMH and MacDougall, AS and McCulley, RL and Melbourne, BA and Moore, JL and Power, SA and Prober, SM and Seabloom, EW and Siebert, J and Silveira, ML and Speziale, KL and Stevens, CJ and Tognetti, PM and Virtanen, R and Yahdjian, L and Ochoa-Hueso, R}, title = {Global impacts of fertilization and herbivore removal on soil net nitrogen mineralization are modulated by local climate and soil properties.}, journal = {Global change biology}, volume = {26}, number = {12}, pages = {7173-7185}, doi = {10.1111/gcb.15308}, pmid = {32786128}, issn = {1365-2486}, support = {//WSL/ ; NSF-DEB-1042132//National Science Foundation Research Coordination Network/ ; NSF-DEB-1234162//Long-Term Ecological Research (LTER) program/ ; DG-0001-13//Institute on the Environment at the University of Minnesota/ ; FZT 118//German Research Foundation/ ; //TERN Great Western Woodlands Supersite/ ; UIDB/00239/2020//CEF/ ; //USDA-ARS/ ; }, mesh = {Animals ; Ecosystem ; Fertilization ; Grassland ; Herbivory ; Humans ; *Nitrogen/analysis ; *Soil ; }, abstract = {Soil nitrogen (N) availability is critical for grassland functioning. However, human activities have increased the supply of biologically limiting nutrients, and changed the density and identity of mammalian herbivores. These anthropogenic changes may alter net soil N mineralization (soil net Nmin), that is, the net balance between N mineralization and immobilization, which could severely impact grassland structure and functioning. Yet, to date, little is known about how fertilization and herbivore removal individually, or jointly, affect soil net Nmin across a wide range of grasslands that vary in soil and climatic properties. Here we collected data from 22 grasslands on five continents, all part of a globally replicated experiment, to assess how fertilization and herbivore removal affected potential (laboratory-based) and realized (field-based) soil net Nmin . Herbivore removal in the absence of fertilization did not alter potential and realized soil net Nmin . However, fertilization alone and in combination with herbivore removal consistently increased potential soil net Nmin. Realized soil net Nmin , in contrast, significantly decreased in fertilized plots where herbivores were removed. Treatment effects on potential and realized soil net Nmin were contingent on site-specific soil and climatic properties. Fertilization effects on potential soil net Nmin were larger at sites with higher mean annual precipitation (MAP) and temperature of the wettest quarter (T.q.wet). Reciprocally, realized soil net Nmin declined most strongly with fertilization and herbivore removal at sites with lower MAP and higher T.q.wet. In summary, our findings show that anthropogenic nutrient enrichment, herbivore exclusion and alterations in future climatic conditions can negatively impact soil net Nmin across global grasslands under realistic field conditions. This is an important context-dependent knowledge for grassland management worldwide.}, }
@article {pmid32778751, year = {2020}, author = {Crossley, MS and Meier, AR and Baldwin, EM and Berry, LL and Crenshaw, LC and Hartman, GL and Lagos-Kutz, D and Nichols, DH and Patel, K and Varriano, S and Snyder, WE and Moran, MD}, title = {No net insect abundance and diversity declines across US Long Term Ecological Research sites.}, journal = {Nature ecology &amp; evolution}, volume = {4}, number = {10}, pages = {1368-1376}, pmid = {32778751}, issn = {2397-334X}, mesh = {Animals ; *Biodiversity ; *Ecosystem ; Europe ; Humans ; Insecta ; Research ; }, abstract = {Recent reports of dramatic declines in insect abundance suggest grave consequences for global ecosystems and human society. Most evidence comes from Europe, however, leaving uncertainty about insect population trends worldwide. We used >5,300 time series for insects and other arthropods, collected over 4-36 years at monitoring sites representing 68 different natural and managed areas, to search for evidence of declines across the United States. Some taxa and sites showed decreases in abundance and diversity while others increased or were unchanged, yielding net abundance and biodiversity trends generally indistinguishable from zero. This lack of overall increase or decline was consistent across arthropod feeding groups and was similar for heavily disturbed versus relatively natural sites. The apparent robustness of US arthropod populations is reassuring. Yet, this result does not diminish the need for continued monitoring and could mask subtler changes in species composition that nonetheless endanger insect-provided ecosystem services.}, }
@article {pmid32740923, year = {2020}, author = {Gade, MR and Connette, GM and Crawford, JA and Hocking, DJ and Maerz, JC and Milanovich, JR and Peterman, WE}, title = {Predicted alteration of surface activity as a consequence of climate change.}, journal = {Ecology}, volume = {101}, number = {11}, pages = {e03154}, doi = {10.1002/ecy.3154}, pmid = {32740923}, issn = {1939-9170}, support = {//Bruce Family Scholarship in Herpetology Grant-in-Aid from Highlands Biological Station/ ; //Herpetologist's League EE Williams Research Grant/ ; //University of Missouri Life Science Fellowship/ ; //EPA STAR Fellowship/ ; //Charles W. Ash Scholarship from Highlands Biological Station/ ; //GAANN Fellowship from the U.S. Department of Education/ ; //Bruce Family Scholarship in Herpetology from Highlands Biological Station/ ; W203-11//National Geographic Society Waitt Grant Program/ ; DEB-0823293//National Science Foundation Long Term Ecological Research Program to the Coweeta LTER Program at the University of Georgia/ ; DEB-1637522//National Science Foundation Long Term Ecological Research Program to the Coweeta LTER Program at the University of Georgia/ ; }, mesh = {Animals ; *Climate Change ; Cold Temperature ; Seasons ; Temperature ; *Urodela ; }, abstract = {Wildlife are faced with numerous threats to survival, none more pressing than that of climate change. Understanding how species will respond behaviorally, physiologically, and demographically to a changing climate is a cornerstone of many contemporary ecological studies, especially for organisms, such as amphibians, whose persistence is closely tied to abiotic conditions. Activity is a useful parameter for understanding the effects of climate change because activity is directly linked to fitness as it dictates foraging times, energy budgets, and mating opportunities. However, activity can be challenging to measure directly, especially for secretive organisms like plethodontid salamanders, which only become surface active when conditions are cool and moist because of their anatomical and physiological restrictions. We estimated abiotic predictors of surface activity for the seven species of the Plethodon jordani complex. Five independent data sets collected from 2004 to 2017 were used to determine the parameters driving salamander surface activity in the present day, which were then used to predict potential activity changes over the next 80 yrs. Average active seasonal temperature and vapor pressure deficit were the strongest predictors of salamander surface activity and, without physiological or behavioral modifications, salamanders were predicted to exhibit a higher probability of surface activity during peak active season under future climate conditions. Temperatures during the active season likely do not exceed salamander thermal maxima to cause activity suppression and, until physiological limits are reached, future conditions may continue to increase activity. Our model is the first comprehensive field-based study to assess current and future surface activity probability. Our study provides insights into how a key behavior driving fitness may be affected by climate change.}, }
@article {pmid32724553, year = {2020}, author = {Schoenrock, KM and Chan, KM and O'Callaghan, T and O'Callaghan, R and Golden, A and Krueger-Hadfield, SA and Power, AM}, title = {A review of subtidal kelp forests in Ireland: From first descriptions to new habitat monitoring techniques.}, journal = {Ecology and evolution}, volume = {10}, number = {13}, pages = {6819-6832}, pmid = {32724553}, issn = {2045-7758}, abstract = {AIM: Kelp forests worldwide are important marine ecosystems that foster high primary to secondary productivity and multiple ecosystem services. These ecosystems are increasingly under threat from extreme storms, changing ocean temperatures, harvesting, and greater herbivore pressure at regional and global scales, necessitating urgent documentation of their historical to present-day distributions. Species range shifts to higher latitudes have already been documented in some species that dominate subtidal habitats within Europe. Very little is known about kelp forest ecosystems in Ireland, where rocky coastlines are dominated by Laminaria hyperborea. In order to rectify this substantial knowledge gap, we compiled historical records from an array of sources to present historical distribution, kelp and kelp forest recording effort over time, and present rational for the monitoring of kelp habitats to better understand ecosystem resilience.<br><br>LOCATION: Ireland (Northern Ireland and &#xc9;ire).<br><br>METHODS: Herbaria, literature from the Linnaean society dating back to late 1700s, journal articles, government reports, and online databases were scoured for information on L.&#xa0;hyperborea. Information about kelp ecosystems was solicited from dive clubs and citizen science groups that are active along Ireland's coastlines.<br><br>RESULTS: Data were used to create distribution maps and analyze methodology and technology used to record L.&#xa0;hyperborea presence and kelp ecosystems within Ireland. We discuss the recent surge in studies on Irish kelp ecosystems, fauna associated with kelp ecosystems that may be used as indicators of ecosystem health and suggest methodologies for continued monitoring.<br><br>MAIN CONCLUSIONS: While there has been a steady increase in recording effort of the dominant subtidal kelp forest species, L.&#xa0;hyperborea, only recently have studies begun to address other important eco-evolutionary processes at work in kelp forests including connectivity among kelp populations in Ireland. Further monitoring, using suggested methodologies, is required to better understand the resilience of kelp ecosystems in Ireland.}, }
@article {pmid32711307, year = {2020}, author = {Serra, AA and Bittebière, AK and Mony, C and Slimani, K and Pallois, F and Renault, D and Couée, I and Gouesbet, G and Sulmon, C}, title = {Local-scale dynamics of plant-pesticide interactions in a northern Brittany agricultural landscape.}, journal = {The Science of the total environment}, volume = {744}, number = {}, pages = {140772}, doi = {10.1016/j.scitotenv.2020.140772}, pmid = {32711307}, issn = {1879-1026}, mesh = {Agriculture ; *Ecosystem ; France ; *Pesticides ; Soil ; }, abstract = {Soil pollution by anthropogenic chemicals is a major concern for sustainability of crop production and of ecosystem functions mediated by natural plant biodiversity. Understanding the complex effects of soil pollution requires multi-level and multi-scale approaches. Non-target and agri-environmental plant communities of field margins and vegetative filter strips are confronted with agricultural xenobiotics through soil contamination, drift, run-off and leaching events that result from chemical applications. Plant-pesticide dynamics in vegetative filter strips was studied at field scale in the agricultural landscape of a long-term ecological research network in northern Brittany (France). Vegetative filter strips effected significant pesticide abatement between the field and riparian compartments. However, comparison of pesticide usage modalities and soil chemical analysis revealed the extent and complexity of pesticide persistence in fields and vegetative filter strips, and suggested the contribution of multiple sources (yearly carry-over, interannual persistence, landscape-scale contamination). In order to determine the impact of such persistence, plant dynamics was followed in experimentally-designed vegetative filter strips of identical initial composition (Agrostis stolonifera, Anthemis tinctoria/Cota tinctoria, Centaurea cyanus, Fagopyrum esculentum, Festuca rubra, Lolium perenne, Lotus corniculatus, Phleum pratense, Trifolium pratense). After homogeneous vegetation establishment, experimental vegetative filter strips underwent rapid changes within the following two years, with Agrostis stolonifera, Festuca rubra, Lolium perenne and Phleum pratense becoming dominant and with the establishment of spontaneous vegetation. Co-inertia analysis showed that plant dynamics and soil residual pesticides could be significantly correlated, with the triazole fungicide epoxiconazole, the imidazole fungicide prochloraz and the neonicotinoid insecticide thiamethoxam as strong drivers of the correlation. However, the correlation was vegetative-filter-strip-specific, thus showing that correlation between plant dynamics and soil pesticides likely involved additional factors, such as threshold levels of residual pesticides. This situation of complex interactions between plants and soil contamination is further discussed in terms of agronomical, environmental and health issues.}, }
@article {pmid32654309, year = {2020}, author = {Goldberg, L and Lagomasino, D and Thomas, N and Fatoyinbo, T}, title = {Global declines in human-driven mangrove loss.}, journal = {Global change biology}, volume = {26}, number = {10}, pages = {5844-5855}, pmid = {32654309}, issn = {1365-2486}, support = {15-NIP15-0068//NASA New Investigator Program/ ; DBI-0620409//Florida Coastal Everglades Long-Term Ecological Research Program/ ; DEB-1237517//Florida Coastal Everglades Long-Term Ecological Research Program/ ; 16-CMS16-0073//NASA Carbon Monitoring Systems/ ; 16-Carbon16-103//USDA-NIFA Carbon Cycle Science Program/ ; //National Space Club Scholars Program/ ; }, mesh = {Agriculture ; Asia, Southeastern ; *Conservation of Natural Resources ; *Ecosystem ; Humans ; Wetlands ; }, abstract = {Global mangrove loss has been attributed primarily to human activity. Anthropogenic loss hotspots across Southeast Asia and around the world have characterized the ecosystem as highly threatened, though natural processes such as erosion can also play a significant role in forest vulnerability. However, the extent of human and natural threats has not been fully quantified at the global scale. Here, using a Random Forest-based analysis of over one million Landsat images, we present the first 30 m resolution global maps of the drivers of mangrove loss from 2000 to 2016, capturing both human-driven and natural stressors. We estimate that 62% of global losses between 2000 and 2016 resulted from land-use change, primarily through conversion to aquaculture and agriculture. Up to 80% of these human-driven losses occurred within six Southeast Asian nations, reflecting the regional emphasis on enhancing aquaculture for export to support economic development. Both anthropogenic and natural losses declined between 2000 and 2016, though slower declines in natural loss caused an increase in their relative contribution to total global loss area. We attribute the decline in anthropogenic losses to the regionally dependent combination of increased emphasis on conservation efforts and a lack of remaining mangroves viable for conversion. While efforts to restore and protect mangroves appear to be effective over decadal timescales, the emergence of natural drivers of loss presents an immediate challenge for coastal adaptation. We anticipate that our results will inform decision-making within conservation and restoration initiatives by providing a locally relevant understanding of the causes of mangrove loss.}, }
@article {pmid32569285, year = {2020}, author = {Metfies, K and Hessel, J and Klenk, R and Petersen, W and Wiltshire, KH and Kraberg, A}, title = {Uncovering the intricacies of microbial community dynamics at Helgoland Roads at the end of a spring bloom using automated sampling and 18S meta-barcoding.}, journal = {PloS one}, volume = {15}, number = {6}, pages = {e0233921}, pmid = {32569285}, issn = {1932-6203}, mesh = {DNA Barcoding, Taxonomic ; Eukaryota/*classification/genetics ; High-Throughput Nucleotide Sequencing ; *Microbiota ; North Sea ; Phylogeny ; Phytoplankton/*classification/genetics/growth &amp; development ; RNA, Ribosomal, 18S/genetics ; Seasons ; Seawater ; }, abstract = {In May 2016, the remote-controlled Automated Filtration System for Marine Microbes (AUTOFIM) was implemented in parallel to the Long Term Ecological Research (LTER) observatory Helgoland Roads in the German Bight. We collected samples for characterization of dynamics within the eukaryotic microbial communities at the end of a phytoplankton bloom via 18S meta-barcoding. Understanding consequences of environmental change for key marine ecosystem processes, such as phytoplankton bloom dynamics requires information on biodiversity and species occurrences with adequate temporal and taxonomic resolution via time series observations. Sampling automation and molecular high throughput methods can serve these needs by improving the resolution of current conventional marine time series observations. A technical evaluation based on an investigation of eukaryotic microbes using the partial 18S rRNA gene suggests that automated filtration with the AUTOFIM device and preservation of the plankton samples leads to highly similar 18S community profiles, compared to manual filtration and snap freezing. The molecular data were correlated with conventional microscopic counts. Overall, we observed substantial change in the eukaryotic microbial community structure during the observation period. A simultaneous decline of diatom and ciliate sequences succeeded a peak of Miracula helgolandica, suggesting a potential impact of these oomycete parasites on diatom bloom dynamics and phenology in the North Sea. As oomycetes are not routinely counted at Helgoland Roads LTER, our findings illustrate the benefits of combining automated filtration with metabarcodingto augment classical time series observations, particularly for taxa currently neglected due to methodological constraints.}, }
@article {pmid32495034, year = {2020}, author = {Rowe, L and Gibson, D and Bahlai, CA and Gibbs, J and Landis, DA and Isaacs, R}, title = {Flower traits associated with the visitation patterns of bees.}, journal = {Oecologia}, volume = {193}, number = {2}, pages = {511-522}, doi = {10.1007/s00442-020-04674-0}, pmid = {32495034}, issn = {1432-1939}, support = {GR14-011//Michigan State University/ ; NCR13-075//USDA NC-SARE/ ; DEB 1637653//NSF-Long Term Ecological Research Program/ ; }, mesh = {Animals ; Bees ; *Flowers ; Phenotype ; Plants ; Pollen ; *Pollination ; }, abstract = {Plant-pollinator interactions are partially driven by the expression of plant traits that signal and attract bees to the nutritional resources within flowers. Although multiple physical and chemical floral traits are known to influence the visitation patterns of bees, how distinct bee groups vary in their responses to floral traits has yet to be elucidated. In this study, we used a common garden experiment to test for morphological floral traits associated with pollen quantity at the plant species level, and examined how the visitation patterns of taxonomically and functionally distinct bee groups are related to flower trait characteristics of 39 wildflower species. We also determined how floral traits influence the structure of wild bee communities visiting plants and whether this varies among geographic localities. Our results suggest that floral area is the primary morphological floral trait related to bee visitation of several distinct bee groups, but that wild bee families and functionally distinct bee groups have unique responses to floral trait expression. The composition of the wild bee communities visiting different plants was most strongly associated with variability in floral area, flower height, and the quantity of pollen retained in flowers. Our results inform wildflower habitat management for bees by demonstrating that the visitation patterns of distinct bee taxa can be predicted by floral traits, and highlight that variability in these traits should be considered when selecting plants to support pollinators.}, }
@article {pmid32494090, year = {2020}, author = {Käse, L and Kraberg, AC and Metfies, K and Neuhaus, S and Sprong, PAA and Fuchs, BM and Boersma, M and Wiltshire, KH}, title = {Rapid succession drives spring community dynamics of small protists at Helgoland Roads, North Sea.}, journal = {Journal of plankton research}, volume = {42}, number = {3}, pages = {305-319}, pmid = {32494090}, issn = {0142-7873}, abstract = {The dynamics of diatoms and dinoflagellates have been monitored for many decades at the Helgoland Roads Long-Term Ecological Research site and are relatively well understood. In contrast, small-sized eukaryotic microbes and their community changes are still much more elusive, mainly due to their small size and uniform morphology, which makes them difficult to identify microscopically. By using next-generation sequencing, we wanted to shed light on the Helgoland planktonic community dynamics, including nano- and picoplankton, during a spring bloom. We took samples from March to May 2016 and sequenced the V4 region of the 18S rDNA. Our results showed that mixotrophic and heterotrophic taxa were more abundant than autotrophic diatoms. Dinoflagellates dominated the sequence assemblage, and several small-sized eukaryotic microbes like Haptophyta, Choanoflagellata, Marine Stramenopiles and Syndiniales were identified. A diverse background community including taxa from all size classes was present during the whole sampling period. Five phases with several communities were distinguished. The fastest changes in community composition took place in phase 3, while the communities from phases 1 to 5 were more similar to each other despite contrasting environmental conditions. Synergy effects of next-generation sequencing and traditional methods may be exploited in future long-term observations.}, }
@article {pmid32469785, year = {2020}, author = {Battisti, C and Fanelli, G and Filpa, A and Cerfolli, F}, title = {Giant Reed (Arundo donax) wrack as sink for plastic beach litter: First evidence and implication.}, journal = {Marine pollution bulletin}, volume = {155}, number = {}, pages = {111179}, doi = {10.1016/j.marpolbul.2020.111179}, pmid = {32469785}, issn = {1879-3363}, mesh = {Animals ; *Bathing Beaches ; Ecosystem ; Invertebrates ; *Plastics ; Poaceae ; }, abstract = {In order to maintain the hydraulic outflow in land reclaimed canalizations, the competent agencies provide to mechanically mow the Giant Reed (Arundo donax, L. 1753) along the aquatic ecosystem banks. Nevertheless, the reeds mowed can be transported away from the waters following storm surges and can be deposited in large quantities along the sandy beaches. We carried out a stratified study in a Mediterranean sandy beach to test the hypothesis that Giant Reed wrack may act as a sink and barrier for plastic beach litter. We observed a large amount of plastic litter entrapped in the Arundo donax wrack (density of 0.868 items/m[2]), with a higher density when compared to both the inner and the shoreline belts. Density of litter is significantly higher considering the categories of meso- and micro-plastics. Organic macrophyte wrack is useful for dunal macrodetritivorous invertebrates and generally for fauna communities, which use this litter as refuge and trophic pabulum. Significant accumulations of organic wrack can mitigate coastal erosion; nevertheless, for its structural characteristics, Arundo wrack can also act as a barrier for litter towards the inner vegetated dunes, so entrapping a large amount of anthropogenic litter. In this regard, Arundo wrack can represent a sink habitat, first attracting (due to large availability of detritus with a relative high rate of decomposition) and then, entrapping many organisms in anthropogenic litter. We suggest that, once mechanically mowed, the land reclaimed agencies should periodically remove from the channel banks the Arundo donax reeds, impeding the accumulation of incoherent vegetated matter along the aquatic ecosystem banks.}, }
@article {pmid32455611, year = {2020}, author = {Fanelli, E and Aguzzi, J and Marini, S and Del Rio, JD and Nogueras, M and Canese, S and Stefanni, S and Danovaro, R and Conversano, F}, title = {Towards Naples Ecological REsearch for Augmented Observatories (NEREA): The NEREA-Fix Module, a Stand-Alone Platform for Long-Term Deep-Sea Ecosystem Monitoring.}, journal = {Sensors (Basel, Switzerland)}, volume = {20}, number = {10}, pages = {}, pmid = {32455611}, issn = {1424-8220}, support = {PIR01_00030//Ministero dell'Istruzione, dell'Universit&#xe0; e della Ricerca/ ; }, mesh = {Animals ; *Ecosystem ; Environmental Monitoring ; Female ; Horses ; Humans ; Mediterranean Sea ; *Oceanography ; }, abstract = {Deep-sea ecological monitoring is increasingly recognized as indispensable for the comprehension of the largest biome on Earth, but at the same time it is subjected to growing human impacts for the exploitation of biotic and abiotic resources. Here, we present the Naples Ecological REsearch (NEREA) stand-alone observatory concept (NEREA-fix), an integrated observatory with a modular, adaptive structure, characterized by a multiparametric video-platform to be deployed in the Dohrn canyon (Gulf of Naples, Tyrrhenian Sea) at ca. 650 m depth. The observatory integrates a seabed platform with optoacoustic and oceanographic/geochemical sensors connected to a surface transmission buoy, plus a mooring line (also equipped with depth-staged environmental sensors). This reinforced high-frequency and long-lasting ecological monitoring will integrate the historical data conducted over 40 years for the Long-Term Ecological Research (LTER) at the station "Mare Chiara", and ongoing vessel-assisted plankton (and future environmental DNA-eDNA) sampling. NEREA aims at expanding the observational capacity in a key area of the Mediterranean Sea, representing a first step towards the establishment of a bentho-pelagic network to enforce an end-to-end transdisciplinary approach for the monitoring of marine ecosystems across a wide range of animal sizes (from bacteria to megafauna).}, }
@article {pmid32427910, year = {2020}, author = {Wood, LK and Hays, S and Zinnert, JC}, title = {Decreased temperature variance associated with biotic composition enhances coastal shrub encroachment.}, journal = {Scientific reports}, volume = {10}, number = {1}, pages = {8210}, pmid = {32427910}, issn = {2045-2322}, abstract = {Regime shift from grasslands to shrub-dominated landscapes occur worldwide driven by altered land-use and climate change, affecting landscape function, biodiversity, and productivity. Warming winter temperatures are a main driver of expansion of the native, evergreen shrub, Morella cerifera, in coastal landscapes. Shrub establishment in these habitats alters microclimate, but little is known about seasonal differences and microclimate variance. We assessed influence of shrubs on microclimate variance, community composition, and community physiological functioning across three vegetation zones: grass, transitional, and shrub in a coastal grassland. Using a novel application of a time-series analysis, we interpret microclimatic variance modification and elucidate mechanisms of shrub encroachment at the Virginia Coast Reserve, Long-Term Ecological Research site. As shrub thickets form, diversity is reduced with little grass/forb cover, while transpiration and annual productivity increase. Shrub thickets significantly reduced temperature variance with a positive influence of one day on the next in maximum air, minimum air, and maximum ground temperature. We also show that microclimatic temperature moderation reduces summer extreme temperatures in transition areas, even before coalescence into full thickets. Encroachment of Morella cerifera on the Virginia barrier islands is driven by reduced local exposure to cold temperatures and enhanced by abiotic microclimatic modification and biotic physiological functioning. This shift in plant community composition from grassland to shrub thicket alters the role of barrier islands in productivity and can have impacts on the natural resilience of the islands.}, }
@article {pmid32328343, year = {2020}, author = {Bush, ER and Jeffery, K and Bunnefeld, N and Tutin, C and Musgrave, R and Moussavou, G and Mihindou, V and Malhi, Y and Lehmann, D and Edzang Ndong, J and Makaga, L and Abernethy, K}, title = {Rare ground data confirm significant warming and drying in western equatorial Africa.}, journal = {PeerJ}, volume = {8}, number = {}, pages = {e8732}, pmid = {32328343}, issn = {2167-8359}, abstract = {BACKGROUND: The humid tropical forests of Central Africa influence weather worldwide and play a major role in the global carbon cycle. However, they are also an ecological anomaly, with evergreen forests dominating the western equatorial region despite less than 2,000 mm total annual rainfall. Meteorological data for Central Africa are notoriously sparse and incomplete and there are substantial issues with satellite-derived data because of persistent cloudiness and inability to ground-truth estimates. Long-term climate observations are urgently needed to verify regional climate and vegetation models, shed light on the mechanisms that drive climatic variability and assess the viability of evergreen forests under future climate scenarios.<br><br>METHODS: We have the rare opportunity to analyse a 34 year dataset of rainfall and temperature (and shorter periods of absolute humidity, wind speed, solar radiation and aerosol optical depth) from Lop&#xe9; National Park, a long-term ecological research site in Gabon, western equatorial Africa. We used (generalized) linear mixed models and spectral analyses to assess seasonal and inter-annual variation, long-term trends and oceanic influences on local weather patterns.<br><br>RESULTS: Lop&#xe9;'s weather is characterised by a cool, light-deficient, long dry season. Long-term climatic means have changed significantly over the last 34 years, with warming occurring at a rate of +0.25 &#xb0;C per decade (minimum daily temperature) and drying at a rate of -75 mm per decade (total annual rainfall). Inter-annual climatic variability at Lop&#xe9; is highly influenced by global weather patterns. Sea surface temperatures of the Pacific and Atlantic oceans have strong coherence with Lop&#xe9; temperature and rainfall on multi-annual scales.<br><br>CONCLUSIONS: The Lop&#xe9; long-term weather record has not previously been made public and is of high value in such a data poor region. Our results support regional analyses of climatic seasonality, long-term warming and the influences of the oceans on temperature and rainfall variability. However, warming has occurred more rapidly than the regional products suggest and while there remains much uncertainty in the wider region, rainfall has declined over the last three decades at Lop&#xe9;. The association between rainfall and the Atlantic cold tongue at Lop&#xe9; lends some support for the 'dry' models of climate change for the region. In the context of a rapidly warming and drying climate, urgent research is needed into the sensitivity of dry season clouds to ocean temperatures and the viability of humid evergreen forests in this dry region should the clouds disappear.}, }
@article {pmid32307066, year = {2020}, author = {Turk Dermastia, T and Cerino, F and Stanković, D and Francé, J and Ramšak, A and Žnidarič Tušek, M and Beran, A and Natali, V and Cabrini, M and Mozetič, P}, title = {Ecological time series and integrative taxonomy unveil seasonality and diversity of the toxic diatom Pseudo-nitzschia H. Peragallo in the northern Adriatic Sea.}, journal = {Harmful algae}, volume = {93}, number = {}, pages = {101773}, doi = {10.1016/j.hal.2020.101773}, pmid = {32307066}, issn = {1878-1470}, mesh = {*Diatoms/genetics ; Phylogeny ; Phytoplankton/genetics ; Seasons ; }, abstract = {Pseudo-nitzschia H. Peragallo (1900) is a globally distributed genus of pennate diatoms that are important components of phytoplankton communities worldwide. Some members of the genus produce the neurotoxin domoic acid, so regular monitoring is in place. However, the identification of toxic members in routine samplings remains problematic. In this study, the diversity and seasonal occurrence of Pseudo-nitzschia species were investigated in the Gulf of Trieste, a shallow gulf in the northern Adriatic Sea. We used time series data from 2005 to 2018 to describe the seasonal and inter-annual occurrence of the genus in the area and its contribution to the phytoplankton community. On average, the genus accounted for about 15 % of total diatom abundance and peaked in spring and autumn, with occasional outbreaks during summer and large inter-annual fluctuations. Increased water temperature and decreased salinity positively affected the presence of some members of the genus, while strong effects could be masked by an unsuitable definition of the species complexes used for monitoring purposes. Therefore, combining morphological (TEM) and molecular analyses by sequencing the ITS, 28S and rbcL markers, eight species were identified from 83 isolated monoclonal strains: P. calliantha, P. fraudulenta, P. delicatissima, P. galaxiae, P. mannii, P. multistriata, P. pungens and P. subfraudulenta. A genetic comparison between the isolated strains and other strains in the Mediterranean was carried out and rbcL was inspected as a potential barcode marker in respect to our results. This is the first study in the Gulf of Trieste on Pseudo-nitzschia time series from a long-term ecological research (LTER) site coupled with molecular data. We show that meaningful ecological conclusions can be drawn by applying integrative methodology, as opposed to the approach that only considers species complexes. The results of this work will provide guidance for further monitoring efforts as well as research activities, including population genetics and genomics, associated with seasonal distribution and toxicity profiles.}, }
@article {pmid32297657, year = {2020}, author = {Peters, DPC and Okin, GS and Herrick, JE and Savoy, HM and Anderson, JP and Scroggs, SLP and Zhang, J}, title = {Modifying connectivity to promote state change reversal: the importance of geomorphic context and plant-soil feedbacks.}, journal = {Ecology}, volume = {101}, number = {9}, pages = {e03069}, pmid = {32297657}, issn = {1939-9170}, support = {12-35828//Division of Environmental Biology/ ; 14-40166//Division of Environmental Biology/ ; 18-32194//Division of Environmental Biology/ ; }, mesh = {*Ecosystem ; Feedback ; Plants ; Poaceae ; *Soil ; }, abstract = {Alternative states maintained by feedbacks are notoriously difficult, if not impossible, to reverse. Although positive interactions that modify soil conditions may have the greatest potential to alter self-reinforcing feedbacks, the conditions leading to these state change reversals have not been resolved. In a 9-yr study, we modified horizontal connectivity of resources by wind or water on different geomorphic surfaces in an attempt to alter plant-soil feedbacks and shift woody-plant-dominated states back toward perennial grass dominance. Modifying connectivity resulted in an increase in litter cover regardless of the vector of transport (wind, water) followed by an increase in perennial grass cover 2 yr later. Modifying connectivity was most effective on sandy soils where wind is the dominant vector, and least effective on gravelly soils on stable surfaces with low sediment movement by water. We found that grass cover was related to precipitation in the first 5 yr of our study, and plant-soil feedbacks developed following 6 yr of modified connectivity to overwhelm effects of precipitation on sandy, wind-blown soils. These feedbacks persisted through time under variable annual rainfall. On alluvial soils, either plant-soil feedbacks developed after 7 yr that were not persistent (active soils) or did not develop (stable soils). This novel approach has application to drylands globally where desertified lands have suffered losses in ecosystem services, and to other ecosystems where connectivity-mediated feedbacks modified at fine scales can be expected to impact plant recovery and state change reversals at larger scales, in particular for wind-impacted sites.}, }
@article {pmid32250815, year = {2020}, author = {Leitner, S and Dirnböck, T and Kobler, J and Zechmeister-Boltenstern, S}, title = {Legacy effects of drought on nitrate leaching in a temperate mixed forest on karst.}, journal = {Journal of environmental management}, volume = {262}, number = {}, pages = {110338}, doi = {10.1016/j.jenvman.2020.110338}, pmid = {32250815}, issn = {1095-8630}, mesh = {Animals ; Austria ; *Droughts ; Europe ; *Forests ; Soil ; Trees ; }, abstract = {With climate change the occurrence of summer droughts is expected to increase in Central Europe. This could lead to increased nitrate (NO3[-]) leaching when water scarcity affects the N-uptake capacity of trees and increases soil N availability due to early leaf senescence and higher litter input. In the present study, we used 16 years of ecological monitoring data from the LTER research site "Zöbelboden" in Austria. The monitoring site is a mixed Spruce-Sycamore-Ash-Beech forest on karst, which is representative for many watersheds that supply drinking water in Austria. We found that in the year after a summer drought, NO3[-] leaching via soil water seepage was significantly elevated compared to the long-term mean. While in normal years, NO3[-] leaching was primarily affected by soil water seepage volume, after a summer drought these controls changed and NO3[-] leaching was controlled by NO3[-] input via precipitation, tree N uptake, and vapor-pressure deficit. Furthermore, higher aboveground litter input during dry years was correlated with increased NO3[-] leaching in the following year. Our findings show that NO3[-] leaching from temperate mountain forests on karst is susceptible to summer drought, which could affect drinking water quality in the Central European Alps in the future, especially in combination with forest disturbances like bark beetle outbreaks, which are often a direct consequence of drought damage to trees.}, }
@article {pmid32246093, year = {2020}, author = {Plum, C and Hillebrand, H and Moorthi, S}, title = {Krill vs salps: dominance shift from krill to salps is associated with higher dissolved N:P ratios.}, journal = {Scientific reports}, volume = {10}, number = {1}, pages = {5911}, pmid = {32246093}, issn = {2045-2322}, abstract = {Pronounced atmospheric and oceanic warming along the West Antarctic Peninsula (WAP) has resulted in abundance shifts in populations of Antarctic krill and Salpa thompsoni determined by changes in the timing of sea-ice advance, the duration of sea-ice cover and food availability. Krill and salps represent the most important macrozooplankton grazers at the WAP, but differ profoundly in their feeding biology, population dynamics and stoichiometry of excretion products with potential consequences for the relative availability of dissolved nitrogen and phosphorus. Alternation of the dissolved nutrient pool due to shifts in krill and salp densities have been hypothesized but never explicitly tested by using observational data. We therefore used the Palmer LTER dataset in order to investigate whether the dominance of either grazer is related with the observed dissolved nitrogen:phosphorus (N:P) ratios at the WAP. Across the whole sampling grid, the dominance of salps over krill was significantly correlated to higher concentrations of both N and P as well as a higher N:P ratios. Using actual long-term data, our study shows for the first time that changes in key grazer dominance may have consequences for the dynamics of dissolved nitrogen and phosphorus at the WAP.}, }
@article {pmid32175629, year = {2020}, author = {Cusser, S and Bahlai, C and Swinton, SM and Robertson, GP and Haddad, NM}, title = {Long-term research avoids spurious and misleading trends in sustainability attributes of no-till.}, journal = {Global change biology}, volume = {26}, number = {6}, pages = {3715-3725}, doi = {10.1111/gcb.15080}, pmid = {32175629}, issn = {1365-2486}, support = {//AgBioResearch, Michigan State University/International ; DEB 1832042//National Science Foundation/International ; OAC 1838807//National Science Foundation/International ; //National Institute of Food and Agriculture/International ; }, mesh = {Agriculture ; *Crops, Agricultural ; *Soil ; }, abstract = {Agricultural management recommendations based on short-term studies can produce findings inconsistent with long-term reality. Here, we test the long-term environmental sustainability and profitability of continuous no-till agriculture on yield, soil water availability, and N2 O fluxes. Using a moving window approach, we investigate the development and stability of several attributes of continuous no-till as compared to conventional till agriculture over a 29-year period at a site in the upper Midwest, US. Over a decade is needed to detect the consistent effects of no-till. Both crop yield and soil water availability required 15 years or longer to generate patterns consistent with 29-year trends. Only marginal trends for N2 O fluxes appeared in this period. Relative profitability analysis suggests that after initial implementation, 86% of periods between 10 and 29 years recuperated the initial expense of no-till implementation, with the probability of higher relative profit increasing with longevity. Importantly, statistically significant but misleading short-term trends appeared in more than 20% of the periods examined. Results underscore the importance of decadal and longer studies for revealing consistent dynamics and emergent outcomes of no-till agriculture, shown to be beneficial in the long term.}, }
@article {pmid32153026, year = {2020}, author = {Caruso, T and Melecis, V and Kagainis, U and Bolger, T}, title = {Population asynchrony alone does not explain stability in species-rich soil animal assemblages: The stabilizing role of forest age on oribatid mite communities.}, journal = {The Journal of animal ecology}, volume = {89}, number = {6}, pages = {1520-1531}, doi = {10.1111/1365-2656.13203}, pmid = {32153026}, issn = {1365-2656}, mesh = {Animals ; Biodiversity ; Forests ; *Mites ; Plants ; *Soil ; Soil Microbiology ; }, abstract = {The importance of microbial and plant communities in the control of the diversity and structure of soil animal communities has been clarified over the last decade. Previous research focused on abiotic factors, niche separation and spatial patterns. Significant gaps still exist in our knowledge of the factors that control the stability of these communities over time. We analysed a 9-year dataset from the national Long-term Ecological Research Network of Latvia. We focused on 117 oribatid species from three Scots pine forests of different age (<40, 65 and >150 years) and structure. For each forest type, 100 samples were collected each year, providing very high replication and long time series for a soil community. We assessed different aspects of stability: we used a dynamic null model, parameterized on observed growth rates, to test the hypothesis that asynchrony in species populations stabilizes total community size; we also analysed alpha and beta diversity over time to test the hypothesis that temporal variation in species composition and relative abundances is controlled by forest attributes. Real communities can be more stable than their stochastic counterparts if species are asynchronous, confirming for the first time the role of asynchrony in stabilizing soil communities. Yet, while some real communities were more stable and had higher abundance and growth rates than others, they were not necessarily more asynchronous than the less stable communities. Species composition and relative abundances were also less variable in the more stable communities. Species asynchrony generally stabilizes species-rich communities but is not sufficient to explain the different levels of stability between forests. Forest age is a key factor explaining the different levels of overyielding and so stability. Data suggest that both asynchrony and high diversity of microhabitat structure of Scots pine forests promote the stability of soil animal communities.}, }
@article {pmid32134187, year = {2020}, author = {Trout-Haney, JV and Heindel, RC and Virginia, RA}, title = {Picocyanobacterial cells in near-surface air above terrestrial and freshwater substrates in Greenland and Antarctica.}, journal = {Environmental microbiology reports}, volume = {12}, number = {3}, pages = {296-305}, doi = {10.1111/1758-2229.12832}, pmid = {32134187}, issn = {1758-2229}, support = {1115245//NSF LTER (Long Term Ecological Research)/International ; 1506155//NSF LTER (Long Term Ecological Research)/International ; 1637708//NSF LTER (Long Term Ecological Research)/International ; }, mesh = {*Aerosols ; Air Microbiology ; Antarctic Regions ; Cyanobacteria/*isolation &amp; purification ; Ecosystem ; Fresh Water ; Greenland ; Tundra ; }, abstract = {Bioaerosols are an important component of the total atmospheric aerosol load, with implications for human health, climate feedbacks and the distribution and dispersal of microbial taxa. Bioaerosols are sourced from marine, freshwater and terrestrial surfaces, with different mechanisms potentially responsible for releasing biological particles from these substrates. Little is known about the production of freshwater and terrestrial bioaerosols in polar regions. We used portable collection devices to test for the presence of picocyanobacterial aerosols above freshwater and soil substrates in the southwestern Greenland tundra and the McMurdo Dry Valleys of Antarctica. We show that picocyanobacterial cells are present in the near-surface air at concentrations ranging from 2,431 to 28,355 cells m[-3] of air, with no significant differences among substrates or between polar regions. Our concentrations are lower than those measured using the same methods in temperate ecosystems. We suggest that aerosolization is an important process linking terrestrial and aquatic ecosystems in these polar environments, and that future work is needed to explore aerosolization mechanisms and taxon-specific aerosolization rates. Our study is a first step toward understanding the production of bioaerosols in extreme environments dominated by microbial life.}, }
@article {pmid32052180, year = {2020}, author = {Prager, CM and Boelman, NT and Eitel, JUH and Gersony, JT and Greaves, HE and Heskel, MA and Magney, TS and Menge, DNL and Naeem, S and Shen, C and Vierling, LA and Griffin, KL}, title = {A mechanism of expansion: Arctic deciduous shrubs capitalize on warming-induced nutrient availability.}, journal = {Oecologia}, volume = {192}, number = {3}, pages = {671-685}, pmid = {32052180}, issn = {1432-1939}, support = {NNX12AK83G/NASA/NASA/United States ; DGE-11-44155//National Science Foundation/ ; NNX12AK83G/NASA/NASA/United States ; }, mesh = {Alaska ; Arctic Regions ; *Ecosystem ; Nutrients ; *Tundra ; }, abstract = {Warming-induced nutrient enrichment in the Arctic may lead to shifts in leaf-level physiological properties and processes with potential consequences for plant community dynamics and ecosystem function. To explore the physiological responses of Arctic tundra vegetation to increasing nutrient availability, we examined how a set of leaf nutrient and physiological characteristics of eight plant species (representing four plant functional groups) respond to a gradient of experimental nitrogen (N) and phosphorus (P) enrichment. Specifically, we examined a set of chlorophyll fluorescence measures related to photosynthetic efficiency, performance and stress, and two leaf nutrient traits (leaf %C and %N), across an experimental nutrient gradient at the Arctic Long Term Ecological Research site, located in the northern foothills of the Brooks Range, Alaska. In addition, we explicitly assessed the direct relationships between chlorophyll fluorescence and leaf %N. We found significant differences in physiological and nutrient traits between species and plant functional groups, and we found that species within one functional group (deciduous shrubs) have significantly greater leaf %N at high levels of nutrient addition. In addition, we found positive, saturating relationships between leaf %N and chlorophyll fluorescence measures across all species. Our results highlight species-specific differences in leaf nutrient traits and physiology in this ecosystem. In particular, the effects of a gradient of nutrient enrichment were most prominent in deciduous plant species, the plant functional group known to be increasing in relative abundance with warming in this ecosystem.}, }
@article {pmid32050007, year = {2020}, author = {, }, title = {Correction: Long-term ecological research in southern Brazil grasslands: Effects of grazing exclusion and deferred grazing on plant and arthropod communities.}, journal = {PloS one}, volume = {15}, number = {2}, pages = {e0229219}, pmid = {32050007}, issn = {1932-6203}, abstract = {[This corrects the article DOI: 10.1371/journal.pone.0227706.].}, }
@article {pmid32038505, year = {2019}, author = {Armeli Minicante, S and Piredda, R and Quero, GM and Finotto, S and Bernardi Aubry, F and Bastianini, M and Pugnetti, A and Zingone, A}, title = {Habitat Heterogeneity and Connectivity: Effects on the Planktonic Protist Community Structure at Two Adjacent Coastal Sites (the Lagoon and the Gulf of Venice, Northern Adriatic Sea, Italy) Revealed by Metabarcoding.}, journal = {Frontiers in microbiology}, volume = {10}, number = {}, pages = {2736}, pmid = {32038505}, issn = {1664-302X}, abstract = {The Lagoon of Venice (LoV) and the Gulf of Venice (GoV), two adjacent coastal Long Term Ecological Research (LTER) sites in the northern Adriatic Sea, represent a transitional/marine coupled ecosystem under the influence of regional and local factors. In this study, these sites were sampled on four dates from April 2016 to February 2017 for environmental DNA and relevant abiotic variables, aiming to assess the relative importance of habitat heterogeneity and connectivity in structuring the protist community. High Throughput Sequencing of V4-18S rRNA gene from 56 samples collected at seven stations produced ca 6 million reads, grouped into 7,336 Operational Taxonomic Units (OTUs) at 97% similarity, which were affiliated to protists belonging to 34 taxonomic groups. The whole community was dominated by Bacillariophyta, especially in spring-summer in the LoV, and by Dinophyta, mainly in the GoV. Ciliophora, Syndiniales, and Cryptophyceae were the next more abundant groups. The community structure varied across the seasons and was different in the two ecosystems, which shared 96% of the reads but showed a high proportion of OTUs distributed preferentially in one of the two sites (specialists) and a different partitioning of trophic categories. GoV specialists were mainly Dinophyceae (>56%), followed by Syndiniales and Bacillariophyta, while the LoV specialists were distributed among several groups, including Bacillariophyta, Syndiniales, Ciliophora, Cryptophyceae, and Trebouxiophyceae. The main abiotic drivers of the differences between protist communities were salinity and temperature, which however explained a minor part of the variance (17%), pointing at a higher relevance of biotic factors and inter-taxa relationships. This was more evident in the LoV, where the network analysis highlighted a higher number of OTUs' connections than in the GoV. Overall, the metabarcoding approach allowed to depict the composition of the whole protist community in the lagoon and adjacent coastal waters with high resolution, revealing many taxa so far not reported in the area. In addition, despite no clear barrier to dispersal processes, differences in the relative abundance and temporal variability of local protist communities indicate that environmental heterogeneity, in these adjacent and connected ecosystems, can be strong enough to allow for ecological segregation.}, }
@article {pmid32019686, year = {2020}, author = {Alejandre-Colomo, C and Harder, J and Fuchs, BM and Rosselló-Móra, R and Amann, R}, title = {High-throughput cultivation of heterotrophic bacteria during a spring phytoplankton bloom in the North Sea.}, journal = {Systematic and applied microbiology}, volume = {43}, number = {2}, pages = {126066}, doi = {10.1016/j.syapm.2020.126066}, pmid = {32019686}, issn = {1618-0984}, mesh = {Bacteria/classification/genetics/*growth &amp; development/*metabolism ; Culture Media ; DNA, Bacterial/genetics ; Eutrophication ; Heterotrophic Processes ; North Sea ; Phylogeny ; Phytoplankton/classification/genetics/*growth &amp; development/*metabolism ; RNA, Ribosomal, 16S/genetics ; Seasons ; Seawater/chemistry/*microbiology ; Sequence Analysis, DNA ; }, abstract = {On-going studies of phytoplankton-bacterioplankton interactions at the long-term ecological research site Helgoland Roads have indicated that many of the heterotrophic bacterial taxa have not yet been cultivated. A high-throughput approach combining whole cell matrix-assisted laser desorption ionization - time of flight mass spectroscopy with 16S rRNA gene sequencing was applied to the spring bloom of 2016. Aiming at an assessment of cultivability during a spring bloom, cultivation on solid marine media had to be used since dilution to extinction would not have been feasible for a high-throughput approach, as performed in this study. A total of 5023 isolates were obtained from nine weekly samples on eight different solid media between the early-bloom and post-bloom periods. Most of the 4136 strains identified affiliated with Bacteroidetes (13.3%), Gammaproteobacteria (26.9%), Alphaproteobacteria (40.6%) and Actinobacteria (6.7%). Of the 271 operational phylogenetic units (OPUs) identified, 13 are likely to represent novel genera and 143 novel species. A comparison with 16S rRNA gene tag data indicated that most of the isolates were rather rare in surface waters, with the exception of five OPUs affiliating with Rhodobacteraceae, Polaribacter, Psychromonas and Pseudoalteromonas. The effort yielded many novel isolates, yet most of the abundant heterotrophic bacteria still remained elusive. The large strain collection obtained will not only provide insights into the succession of the cultivable fraction of the bacterioplankton, but also enable fine-tuned taxonomic and physiological follow-up studies for improving our knowledge on heterotrophic bacteria in North Sea waters.}, }
@article {pmid32012210, year = {2020}, author = {, }, title = {Correction: Long-term ecological research in southern Brazil grasslands: Effects of grazing exclusion and deferred grazing on plant and arthropod communities.}, journal = {PloS one}, volume = {15}, number = {2}, pages = {e0228886}, pmid = {32012210}, issn = {1932-6203}, abstract = {[This corrects the article DOI: 10.1371/journal.pone.0227706.].}, }
@article {pmid31958144, year = {2020}, author = {Kominoski, JS and Gaiser, EE and Castañeda-Moya, E and Davis, SE and Dessu, SB and Julian, P and Lee, DY and Marazzi, L and Rivera-Monroy, VH and Sola, A and Stingl, U and Stumpf, S and Surratt, D and Travieso, R and Troxler, TG}, title = {Disturbance legacies increase and synchronize nutrient concentrations and bacterial productivity in coastal ecosystems.}, journal = {Ecology}, volume = {101}, number = {5}, pages = {e02988}, pmid = {31958144}, issn = {1939-9170}, support = {DBI-0620409//National Science Foundation/International ; DEB-1237517//National Science Foundation/International ; DEB-1832229//National Science Foundation/International ; DEB-9910514//National Science Foundation/International ; //Cooperative Agreements with Everglades National Park/International ; //South Florida Water Management District/International ; }, mesh = {*Ecosystem ; Fresh Water ; Nutrients ; Rivers ; *Wetlands ; }, abstract = {Long-term ecological research can resolve effects of disturbance on ecosystem dynamics by capturing the scale of disturbance and interactions with environmental changes. To quantify how disturbances interact with long-term directional changes (sea-level rise, freshwater restoration), we studied 17 yr of monthly dissolved organic carbon (DOC), total nitrogen (TN), and phosphorus (TP) concentrations and bacterioplankton productivity across freshwater-to-marine estuary gradients exposed to multiple disturbance events (e.g., droughts, fire, hurricanes, and low-temperature anomalies) and long-term increases in water levels. By studying two neighboring drainages that differ in hydrologic connectivity, we additionally tested how disturbance legacies are shaped by hydrologic connectivity. We predicted that disturbance events would interact with long-term increases in water levels in freshwater and marine ecosystems to increase spatiotemporal similarity (i.e., synchrony) of organic matter, nutrients, and microbial activities. Wetlands along the larger, deeper, and tidally influenced Shark River Slough (SRS) drainage had higher and more variable DOC, TN, and TP concentrations than wetlands along the smaller, shallower, tidally restricted Taylor River Slough/Panhandle (TS/Ph) drainage. Along SRS, DOC concentrations declined with proximity to coast, and increased in magnitude and variability following drought and flooding in 2015 and a hurricane in 2017. Along TS/Ph, DOC concentrations varied by site (higher in marine than freshwater wetlands) but not year. In both drainages, increases in TN from upstream freshwater marshes occurred following fire in 2008 and droughts in 2010 and 2015, whereas downstream increases in TP occurred with coastal storm surge from hurricanes in 2005 and 2017. Decreases in DOC:TN and DOC:TP were explained by increased TN and TP. Increases in bacterioplankton productivity occurred throughout both drainages following low-temperature events (2010 and 2011) and a hurricane (2017). Long-term TN and TP concentrations and bacterioplankton productivity were correlated (r > 0.5) across a range of sampling distances (1-50 km), indicating spatiotemporal synchrony. DOC concentrations were not synchronized across space or time. Our study advances disturbance ecology theory by illustrating how disturbance events interact with long-term environmental changes and hydrologic connectivity to determine the magnitude and extent of disturbance legacies. Understanding disturbance legacies will enhance prediction and enable more effective management of rapidly changing ecosystems.}, }
@article {pmid31931512, year = {2020}, author = {Ferreira, PMA and Andrade, BO and Podgaiski, LR and Dias, AC and Pillar, VD and Overbeck, GE and Mendonça, MS and Boldrini, II}, title = {Long-term ecological research in southern Brazil grasslands: Effects of grazing exclusion and deferred grazing on plant and arthropod communities.}, journal = {PloS one}, volume = {15}, number = {1}, pages = {e0227706}, pmid = {31931512}, issn = {1932-6203}, mesh = {Animals ; Arthropods/classification/*physiology ; Biodiversity ; Biomass ; Brazil ; Conservation of Natural Resources ; Ecosystem ; Grassland ; *Herbivory ; Poaceae/classification/*physiology ; }, abstract = {Grazing exclusion may lead to biodiversity loss and homogenization of naturally heterogeneous and species-rich grassland ecosystems, and these effects may cascade to higher trophic levels and ecosystem properties. Although grazing exclusion has been studied elsewhere, the consequences of alleviating the disturbance regime in grassland ecosystems remain unclear. In this paper, we present results of the first five years of an experiment in native grasslands of southern Brazil. Using a randomized block experimental design, we examined the effects of three grazing treatments on plant and arthropod communities: (i) deferred grazing (i.e., intermittent grazing), (ii) grazing exclusion and (iii) a control under traditional continuous grazing, which were applied to 70 x 70 m experimental plots, in six regionally distributed blocks. We evaluated plant community responses regarding taxonomic and functional diversity (life-forms) in separate spatial components: alpha (1 x 1 m subplots), beta, and gamma (70 x 70 m plots), as well as the cascading effects on arthropod high-taxa. By estimating effect sizes (treatments vs. control) by bootstrap resampling, both deferred grazing and grazing exclusion mostly increased vegetation height, plant biomass and standing dead biomass. The effect of grazing exclusion on plant taxonomic diversity was negative. Conversely, deferred grazing increased plant taxonomic diversity, but both treatments reduced plant functional diversity. Reduced grazing pressure in both treatments promoted the break of dominance by prostrate species, followed by fast homogenization of vegetation structure towards dominance of ligneous and erect species. These changes in the plant community led to increases in high-taxa richness and abundance of vegetation-dwelling arthropod groups under both treatments, but had no detectable effects on epigeic arthropods. Our results indicate that decision-making regarding the conservation of southern Brazil grasslands should include both intensive and alleviated levels of grazing management, but not complete grazing exclusion, to maximize conservation results when considering plant and arthropod communities.}, }
@article {pmid31872508, year = {2020}, author = {Mazzei, V and Wilson, BJ and Servais, S and Charles, SP and Kominoski, JS and Gaiser, EE}, title = {Periphyton as an indicator of saltwater intrusion into freshwater wetlands: insights from experimental manipulations.}, journal = {Ecological applications : a publication of the Ecological Society of America}, volume = {30}, number = {3}, pages = {e02067}, doi = {10.1002/eap.2067}, pmid = {31872508}, issn = {1051-0761}, support = {DEB-1237517//National Science Foundation's Florida Coastal Everglades Long Term Ecological Research Program/International ; R/C-S-56//Florida Sea Grant/International ; }, mesh = {Caribbean Region ; Florida ; Fresh Water ; *Periphyton ; *Wetlands ; }, abstract = {Saltwater intrusion has particularly large impacts on karstic wetlands of the Caribbean Basin due to their porous, carbonate bedrock and low elevation. Increases in salinity and phosphorus (P) accompanying saltwater intrusion into these freshwater, P-limited wetlands are expected to alter biogeochemical cycles along with the structure and function of plant and algal communities. Calcareous periphyton is a characteristic feature of karstic wetlands and plays a central role in trophic dynamics, carbon storage, and nutrient cycling. Periphyton is extremely sensitive to water quality and quantity, but the effects of saltwater intrusion on these microbial mats remain to be understood. We conducted an ex situ mesocosm experiment to test the independent and combined effects of elevated salinity and P on the productivity, nutrient content, and diatom composition of calcareous periphyton from the Florida Everglades. We measured periphyton total carbon, nitrogen, and P concentrations and used settlement plates to measure periphyton accumulation rates and diatom species composition. The light and dark bottle method was used to measure periphyton productivity and respiration. We found that exposure to ~1 g P·m[-2] ·yr[-1] significantly increased periphyton mat total P concentrations, but had no effect on any other response variable. Mats exposed to elevated salinity (~22 kg salt·m[-2] ·yr[-1]) had significantly lower total carbon and tended to have lower biomass and reduced productivity and respiration rates; however, mats exposed to salinity and P simultaneously had greater gross and net productivity. We found strong diatom species dissimilarity between fresh- and saltwater-treated periphyton, while P additions only elicited compositional changes in periphyton also treated with saltwater. This study contributes to our understanding of how the ecologically important calcareous periphyton mats unique to karstic, freshwater wetlands respond to increased salinity and P caused saltwater intrusion and provides a guide to diatom indicator taxa for these two important environmental drivers.}, }
@article {pmid31865578, year = {2020}, author = {Battisti, C and Dodaro, G and Fanelli, G}, title = {Polystyrene seedling trays used as substrate by native plants.}, journal = {Environmental science and pollution research international}, volume = {27}, number = {6}, pages = {6690-6694}, pmid = {31865578}, issn = {1614-7499}, mesh = {Ecosystem ; Italy ; Plants ; *Polystyrenes ; *Seedlings ; }, abstract = {Among polymers, expanded polystyrene (EPS) is increasingly abundant as a form of anthropogenic litter in natural environments, particularly along waterways. Nevertheless, there is still no research focusing on the interaction between this type of litter and biodiversity components. In this note, we reported the first evidence of an interaction between EPS and living native plants along an artificial drainage channel in a land reclaimed area of Tyrrhenian central Italy. We sampled a number of EPS seedling trays, deriving from agricultural activities, obtaining evidence for an interaction between this polymer and plants: on a total of 231 available seedling holes, 16.88% have been occupied from six species (Lycopus europaeus, Poa cfr. trivialis, Stachys palustris, Silene sp., Phragmites australis, Parietariajudaica). The set of species occurring on floating polystyrene trays appears comparable to that occurring on the sides of the land reclaimed channels (locally, L. europaeus and S. palustris are among the most common species of the riverine vegetation). Therefore, it is very probable that floating trays are a random sample of the seed rain of the vegetation of the sides of the channels. However, more research is needed to assess if the plant assemblage growing on EPS is random process or if peculiar substrate exerts some sort of selection on the plant community.}, }
@article {pmid31832526, year = {2019}, author = {Suari, Y and Dadon-Pilosof, A and Sade, T and Amit, T and Gilboa, M and Gafny, S and Topaz, T and Zedaka, H and Boneh, S and Yahel, G}, title = {A long term physical and biogeochemical database of a hyper-eutrophicated Mediterranean micro-estuary.}, journal = {Data in brief}, volume = {27}, number = {}, pages = {104809}, pmid = {31832526}, issn = {2352-3409}, abstract = {Ruppin's Estuarine and Coastal Observatory (RECO) is a Long-Term Ecological Research station positioned on the East Mediterranean shoreline between Tel-Aviv and Haifa, Israel. We present a comprehensive online database and an accompanying website that provides direct access to the physical, chemical, and biological characteristics of the local coastal marine ecosystem and the Alexander micro estuary. It includes three databases that are updated continuously since 2014: a) In situ stationary sensors data (10 min intervals) of surface and bottom temperature, salinity, oxygen and water level measured at three stations along the estuary. b) Monthly profiles and discrete biogeochemical samples (surface and bottom water) of multiple parameters at four stations located at the inland part of the estuary. Measured parameters include concentrations of chlorophyll-a, microalgae and bacteria (counted with a flow cytometer), Nitrate, Nitrite, Ammonium, Phosphate, total N, total P, particulate organic matter (POM), total suspended solids (TSS), biochemical oxygen demand (BOD), as well as Secchi depth in each station c) Bi-weekly profiles, chlorophyll-a concentrations and cell counts at two marine stations adjacent to the estuary, (1, and 7 Km from the estuary mouth, at bottom depths of 8 and 48 m). The database also includes historical data for the Taninim micro-estuary (2014-2016). The RECO observatory provides a unique data set documenting the interaction of highly eutrophicated estuarine water with the ultra-oligotrophic seawater of the Eastern Mediterranean. This combination results in sharp gradients of salinity, temperature, dissolved oxygen, and nutrients over very small scales (centimeters to meters) and therefore offers an important data set for the coastal shelf research community. The data set also provide a long-term baseline of the estuary hydrography and geochemistry with the hope to foster effective science-based management and environmental planning of this and similar systems.}, }
@article {pmid31823370, year = {2020}, author = {Pimentel, CR and Andrades, R and Ferreira, CEL and Gadig, OBF and Harvey, ES and Joyeux, JC and Giarrizzo, T}, title = {BRUVS reveal locally extinct shark and the way for shark monitoring in Brazilian oceanic islands.}, journal = {Journal of fish biology}, volume = {96}, number = {2}, pages = {539-542}, doi = {10.1111/jfb.14228}, pmid = {31823370}, issn = {1095-8649}, support = {//Conselho Nacional de Desenvolvimento Cient&#xed;fico e Tecnol&#xf3;gico/ ; PELD-ILOC grant 441241/2016-6//scientific programs LTER/ ; PELD-HCES grant 441243/2016-9//scientific programs LTER/ ; //Funda&#xe7;&#xe3;o Estadual de Amparo &#xe0; Pesquisa do Estado do Esp&#xed;rito Santo/ ; grant 405426/2012-7//PROTRINDADE/ ; 001//Coordena&#xe7;&#xe3;o de Aperfei&#xe7;oamento de Pessoal de N&#xed;vel Superior/ ; }, mesh = {Animals ; Atlantic Ocean ; Brazil ; Conservation of Natural Resources ; Extinction, Biological ; Islands ; Population Density ; Sharks/*physiology ; Species Specificity ; Telemetry ; }, abstract = {Here we present records of sharks obtained using baited remote underwater stereo-video systems (stereo-BRUVS) at two Brazilian oceanic islands. Fourteen of the 60 deployments recorded 19 sharks in Trindade Island. In Saint Peter and Saint Paul Archipelago (SPSPA), two pelagic and two demersal deployments recorded two and one shark, respectively, including the locally extinct Galapagos shark Carcharhinus galapagensis. Stereo-BRUVS should be considered as adjuncts to other non-invasive methods to monitor shark populations.}, }
@article {pmid31780156, year = {2020}, author = {Virdis, SGP and Soodcharoen, N and Lugliè, A and Padedda, BM}, title = {Estimation of satellite-derived lake water surface temperatures in the western Mediterranean: Integrating multi-source, multi-resolution imagery and a long-term field dataset using a time series approach.}, journal = {The Science of the total environment}, volume = {707}, number = {}, pages = {135567}, doi = {10.1016/j.scitotenv.2019.135567}, pmid = {31780156}, issn = {1879-1026}, abstract = {Lake surface water temperature (LSWT) is a key parameter to help study the environmental and ecological impacts of climate change. In this work, we measured the LSWT of 1 natural and 23 artificial lakes located on the island of Sardinia in the western Mediterranean, which is a region where changes in climate are projected to have significant impacts. By integrating multi-source and multi-resolution datasets of the Moderate Resolution Imaging Spectroradiometer (MODIS) and Landsat and long-term in situ temperature observations, we detected, measured, and analysed the LSWT trends during the period of 2000-2018 across all the investigated lakes. Methodologically, we demonstrated that a simplified approached based on Planck's equation for Landsat thermal infrared (TIR) data could be a valid alternative to radiative transfer equation retrieval methods for the retrieval of LSWT without loss of accuracy. Moreover, we demonstrated that rescaled and independently validated MOD112A-derived LSWT showed good accuracy, efficiently filled the spatial and temporal gaps in long-term in situ LSWT, and could be used for long-term LSWT trend detection and measurement. All 24 lakes showed an annual warming trend of +0.010 °C/y, warming winter trend of +0.013 °C/y, and cooling summer trend of -0.038 °C/y during the period of 2000-2018. This study demonstrated that the measured trend rates could be explained by and were strongly correlated with the climatology of Italy for the 2000-2018 period. Finally, we demonstrated the key role and the importance of the availability of long-term in situ temperature datasets. The approach used in this study is up-scalable to other medium to low-resolution TIR sensors as well as to other long-term monitoring sites, such as LTER-Italy, LTER-Europe, or ILTER sites.}, }
@article {pmid31771134, year = {2019}, author = {Kang, JY and Kwon, YS and Jeong, G and An, I and Park, S}, title = {Characteristics of Microbial Communities of Pachygrontha antennata (Hemiptera: Pachygronthidae) in Relation to Habitat Variables.}, journal = {International journal of environmental research and public health}, volume = {16}, number = {23}, pages = {}, pmid = {31771134}, issn = {1660-4601}, mesh = {Animals ; Bacteria/*classification/isolation &amp; purification ; *Ecosystem ; Forests ; Hemiptera/*microbiology/physiology ; *Microbiota ; }, abstract = {The microbial community interacts with the environment and the health and immune function of its host both directly and indirectly. However, very few studies about microbial communities have considered habitat and external environmental variables. This study examined environmental influences on the microbial community of Pachygrontha antennata, which is found in various habitats (e.g., urban, forested, and agricultural areas). The results demonstrated that the composition of the microbial community differed according to land use, while the bacterial diversity did not. In urban areas with high environmental heterogeneity, microbial community diversity tended to be high. Furthermore, bacteria in forests and agricultural areas (e.g., Paraburkholderia, Burkholderia) have been found to be highly correlated with habitat variables. Therefore, we suggest that habitat variables should be considered in future symbiotic studies.}, }
@article {pmid31746458, year = {2020}, author = {O'Connor, RC and Taylor, JH and Nippert, JB}, title = {Browsing and fire decreases dominance of a resprouting shrub in woody encroached grassland.}, journal = {Ecology}, volume = {101}, number = {2}, pages = {e02935}, doi = {10.1002/ecy.2935}, pmid = {31746458}, issn = {1939-9170}, support = {LTER/144048//DEB/International ; }, mesh = {Animals ; *Deer ; Ecosystem ; *Fires ; Grassland ; Wood ; }, abstract = {North American grasslands have experienced increased relative abundance of shrubs and trees over the last 150 yr. Alterations in herbivore composition, abundance, and grazing pressure along with changes in fire frequency are drivers that can regulate the transition from grassland to shrubland or woodland (a process known as woody encroachment). Historically, North American grasslands had a suite of large herbivores that grazed and/or browsed (i.e., bison, elk, pronghorn, deer), as well as frequent and intense fires. In the tallgrass prairie, many large native ungulates were extirpated by the 1860s, corresponding with increased homesteading (which led to decreased fire frequencies and intensities). Changes in the frequency and intensity of these two drivers (browsing and fire) have coincided with woody encroachment in tallgrass prairie. Within tallgrass prairie, woody encroachment can be categorized in to two groups: non-resprouting species that can be killed with fire and resprouting species that cannot be killed with fire. Resprouting species require additional active management strategies to decrease abundance and eventually be removed from the ecosystem. In this study, we investigated plant cover, ramet density, and physiological effects of continuous simulated browsing and prescribed fire on Cornus drummondii C.A. Mey, a resprouting clonal native shrub species. Browsing reduced C. drummondii canopy cover and increased grass cover. We also observed decreased ramet density, which allowed for more infilling of grasses. Photosynthetic rates between browsed and unbrowsed control shrubs did not increase in 2015 or 2016. In 2017, photosynthetic rates for browsed shrubs were higher in the unburned site than the unbrowsed control shrubs at the end of the growing season. Additionally, after the prescribed fire, browsed shrubs had ~90% decreased cover, ~50% reduced ramet density, and grass cover increased by ~80%. In the roots of browsed shrubs after the prescribed fire, nonstructural carbohydrates (NSC) experienced a twofold reduction in glucose and a threefold reduction in both sucrose and starch. The combined effects of browsing and fire show strong potential as a successful management tool to decrease the abundance of clonal-resprouting woody plants in mesic grasslands and illustrate the potential significance of browsers as a key driver in this ecosystem.}, }
@article {pmid31715005, year = {2020}, author = {Gross, A and Lin, Y and Weber, PK and Pett-Ridge, J and Silver, WL}, title = {The role of soil redox conditions in microbial phosphorus cycling in humid tropical forests.}, journal = {Ecology}, volume = {101}, number = {2}, pages = {e02928}, doi = {10.1002/ecy.2928}, pmid = {31715005}, issn = {1939-9170}, support = {//US-Israeli Bi National Agricultural Research and Development Postdoctoral Fellowship/International ; TES-DE-FOA-0000749//Department of Energy/International ; DEB-1457805//National Science Foundation/International ; SCW1478//OBER Genomic Sciences Early Career Research Program Award/International ; EAR-1331841//Luquillo CZO/International ; DEB-0620910//LTER/International ; CA-B-ECO-7673-MS//USDA National Institute of Food and Agriculture, McIntire Stennis Project/International ; }, mesh = {Carbon ; Ecosystem ; Forests ; Nitrogen ; Oxidation-Reduction ; *Phosphorus ; Puerto Rico ; *Soil ; Soil Microbiology ; }, abstract = {Humid tropical forests are among the most productive ecosystems globally, yet they often occur on soils with high phosphorus (P) sorption capacity, lowering P availability to biota. Short-term anoxic events are thought to release sorbed P and enhance its acquisition by soil microbes. However, the actual effects of anoxic conditions on microbial P acquisition in humid tropical forest soils are surprisingly poorly studied. We used laboratory incubations of bulk soils, NanoSIMS analysis of single microbial cells, and landscape-scale measurements in the Luquillo Experimental Forest (LEF), Puerto Rico to test the hypothesis that anoxic conditions increase microbial P acquisition in humid tropical forests. In laboratory and field experiments, we found that microbial P uptake generally decreased under anoxic conditions, leading to high microbial carbon (C) to P ratios in anoxic soils. The decreased P acquisition under anoxic conditions was correlated with lower microbial C use efficiency (CUE), an index of microbial energy transfer in ecosystems. Phosphorus amendments to anoxic soils led to increased microbial P uptake and higher CUE suggesting that microbes were less able to access and utilize P under natural low redox conditions. Under oxic conditions, microbial C:P ratios and CUE did not respond to changes in substrate stoichiometry. These results challenge the existing paradigm by showing that anoxic conditions can decrease microbial P uptake and ultimately constrain microbial CUE. Our findings indicate that soil redox conditions tightly couple soil P and C cycles and advance our understanding of controls on P cycling in humid tropical forest ecosystems.}, }
@article {pmid31706726, year = {2020}, author = {Battisti, C}, title = {Heterogeneous composition of anthropogenic litter recorded in nests of Yellow-legged gull (Larus michahellis) from a small Mediterranean island.}, journal = {Marine pollution bulletin}, volume = {150}, number = {}, pages = {110682}, doi = {10.1016/j.marpolbul.2019.110682}, pmid = {31706726}, issn = {1879-3363}, mesh = {Animals ; *Charadriiformes ; *Environmental Monitoring ; Mediterranean Islands ; Plastics ; *Waste Products ; }, abstract = {This note reports data about a heterogeneous assemblage of anthropogenic litter recorded in 307 nesting and roosting sites of Yellow-legged Gull (Larus michahellis) from a small Mediterranean island. I obtained items of anthropogenic litter on > 30% on the total, with plastic, glass and paper the significantly more abundant litter categories. Litter items were found in the nests mainly as a dry remnant in the regurgitated pellets. Fragments of expanded polystyrene (EPS) with peck marks were also recorded, these last transported to the nests because of their resemblance to the cuttlebones of the Sepia cuttlefish. Ingestion of this litter and the pecking on EPS can negatively impact on seabirds. Moreover, the presence of this litter highlights a transport of polluting material even at considerable distance from anthropized areas. Finally, the presence of scavenger species (an endemic lizard and terrestrial molluscs) feeding on food remains could suggest an assimilation of litter into the trophic webs.}, }
@article {pmid31482599, year = {2019}, author = {Obertegger, U and Pindo, M and Flaim, G}, title = {Multifaceted aspects of synchrony between freshwater prokaryotes and protists.}, journal = {Molecular ecology}, volume = {28}, number = {19}, pages = {4500-4512}, doi = {10.1111/mec.15228}, pmid = {31482599}, issn = {1365-294X}, mesh = {Bacteria/*classification/genetics ; Ecology ; Ecosystem ; Eukaryota/*classification/genetics ; High-Throughput Nucleotide Sequencing ; Italy ; Lakes ; *Microbiota ; RNA, Ribosomal, 18S/genetics ; Seasons ; Sequence Analysis, RNA ; }, abstract = {Community composition of freshwater prokaryotes and protists varies through time. Few studies contemporarily investigate temporal variation of these freshwater communities for more than 1 year. We compared the temporal patterns of prokaryotes and protists in three distinct habitats for 4 years (2014-2017) in Lake Tovel, a cold-water lake. This lake showed a marked temperature increase in 2017 linked to altered precipitation patterns. We investigated whether microbial communities reflected this change across habitats and whether changes occurred at the same time and to the same extent. Furthermore, we tested the concept of hydrological year emphasizing the ecological effect of water renewal on communities for its explanatory power of community changes. Microbe diversity was assessed by Illumina sequencing of the V3-V4 hypervariable region of the 16S rRNA gene and 18S rRNA gene, and we applied co-inertia analysis and asymmetric eigenvector maps modelling to infer synchrony and temporal patterns of prokaryotes and protists. When considering community composition, microbes were invariable in synchrony across habitats and indicated a temporal gradient linked to decreasing precipitation; however, when looking at temporal patterns, the extent of synchrony was reduced. Small-scale patterns were similar across habitats and microbes and linked to seasonally varying environmental variables, while large-scale patterns were different and partially linked to an ecosystem change as indicated by increasing water transparency and temperature and decreasing dissolved oxygen. Our advanced statistical approach outlined the multifaceted aspect of synchrony when linked to community composition and temporal patterns.}, }
@article {pmid31427510, year = {2019}, author = {Komatsu, KJ and Avolio, ML and Lemoine, NP and Isbell, F and Grman, E and Houseman, GR and Koerner, SE and Johnson, DS and Wilcox, KR and Alatalo, JM and Anderson, JP and Aerts, R and Baer, SG and Baldwin, AH and Bates, J and Beierkuhnlein, C and Belote, RT and Blair, J and Bloor, JMG and Bohlen, PJ and Bork, EW and Boughton, EH and Bowman, WD and Britton, AJ and Cahill, JF and Chaneton, E and Chiariello, NR and Cheng, J and Collins, SL and Cornelissen, JHC and Du, G and Eskelinen, A and Firn, J and Foster, B and Gough, L and Gross, K and Hallett, LM and Han, X and Harmens, H and Hovenden, MJ and Jagerbrand, A and Jentsch, A and Kern, C and Klanderud, K and Knapp, AK and Kreyling, J and Li, W and Luo, Y and McCulley, RL and McLaren, JR and Megonigal, JP and Morgan, JW and Onipchenko, V and Pennings, SC and Prevéy, JS and Price, JN and Reich, PB and Robinson, CH and Russell, FL and Sala, OE and Seabloom, EW and Smith, MD and Soudzilovskaia, NA and Souza, L and Suding, K and Suttle, KB and Svejcar, T and Tilman, D and Tognetti, P and Turkington, R and White, S and Xu, Z and Yahdjian, L and Yu, Q and Zhang, P and Zhang, Y}, title = {Global change effects on plant communities are magnified by time and the number of global change factors imposed.}, journal = {Proceedings of the National Academy of Sciences of the United States of America}, volume = {116}, number = {36}, pages = {17867-17873}, pmid = {31427510}, issn = {1091-6490}, mesh = {Bayes Theorem ; *Biodiversity ; Climate Change ; *Ecosystem ; Human Activities ; Humans ; *Plants ; }, abstract = {Global change drivers (GCDs) are expected to alter community structure and consequently, the services that ecosystems provide. Yet, few experimental investigations have examined effects of GCDs on plant community structure across multiple ecosystem types, and those that do exist present conflicting patterns. In an unprecedented global synthesis of over 100 experiments that manipulated factors linked to GCDs, we show that herbaceous plant community responses depend on experimental manipulation length and number of factors manipulated. We found that plant communities are fairly resistant to experimentally manipulated GCDs in the short term (<10 y). In contrast, long-term (≥10 y) experiments show increasing community divergence of treatments from control conditions. Surprisingly, these community responses occurred with similar frequency across the GCD types manipulated in our database. However, community responses were more common when 3 or more GCDs were simultaneously manipulated, suggesting the emergence of additive or synergistic effects of multiple drivers, particularly over long time periods. In half of the cases, GCD manipulations caused a difference in community composition without a corresponding species richness difference, indicating that species reordering or replacement is an important mechanism of community responses to GCDs and should be given greater consideration when examining consequences of GCDs for the biodiversity-ecosystem function relationship. Human activities are currently driving unparalleled global changes worldwide. Our analyses provide the most comprehensive evidence to date that these human activities may have widespread impacts on plant community composition globally, which will increase in frequency over time and be greater in areas where communities face multiple GCDs simultaneously.}, }
@article {pmid31423150, year = {2019}, author = {Smith, AL and Kujala, H and Lahoz-Monfort, JJ and Guja, LK and Burns, EL and Nathan, R and Alacs, E and Barton, PS and Bau, S and Driscoll, DA and Lentini, PE and Mortelliti, A and Rowe, R and Buckley, YM}, title = {Managing uncertainty in movement knowledge for environmental decisions.}, journal = {Conservation letters}, volume = {12}, number = {3}, pages = {e12620}, pmid = {31423150}, issn = {1755-263X}, abstract = {Species' movements affect their response to environmental change but movement knowledge is often highly uncertain. We now have well-established methods to integrate movement knowledge into conservation practice but still lack a framework to deal with uncertainty in movement knowledge for environmental decisions. We provide a framework that distinguishes two dimensions of species' movement that are heavily influenced by uncertainty: knowledge about movement and relevance of movement to environmental decisions. Management decisions can be informed by their position in this knowledge-relevance space. We then outline a framework to support decisions around (1) increasing understanding of the relevance of movement knowledge, (2) increasing robustness of decisions to uncertainties and (3) improving knowledge on species' movement. Our decision-support framework provides guidance for managing movement-related uncertainty in systematic conservation planning, agri-environment schemes, habitat restoration and international biodiversity policy. It caters to different resource levels (time and funding) so that species' movement knowledge can be more effectively integrated into environmental decisions.}, }
@article {pmid31397887, year = {2019}, author = {Mai, ACG and Albuquerque, CQ and Lemos, VM and Schwingel, PR and Ceni, GF and Saint'Pierre, TD and Vieira, JP}, title = {Coastal zone use and migratory behaviour of the southern population of Mugil liza in Brazil.}, journal = {Journal of fish biology}, volume = {95}, number = {5}, pages = {1207-1214}, doi = {10.1111/jfb.14120}, pmid = {31397887}, issn = {1095-8649}, support = {PQ 309575/2013-3//postdoctoral/ ; A101/2013//CAPES- PVE/ ; //Brazilian Long-Term Ecological Research Program (PELD)/ ; Proc.441492/2016-9//CNPq/ ; (Proc. 16/2551-0000102-2)//Funda&#xe7;&#xe3;o de Amparo &#xe0; Pesquisa do Estado do Rio Grande do Sul/ ; 406563/2012-8//CNPq-Universal Proc/ ; 472123/2012-2//CNPq-Universal Proc/ ; }, mesh = {*Animal Migration ; Animals ; Brazil ; *Ecosystem ; Estuaries ; Female ; Fresh Water ; Life Cycle Stages ; Otolithic Membrane/*chemistry ; Seawater ; Sexual Behavior, Animal ; Smegmamorpha/*physiology ; }, abstract = {We analysed the ratios Sr:Ca and Ba:Ca in the otoliths of 55 adults of the southern population of Mugil liza in Brazil (Paraná to Rio Grande do Sul) to investigate its coastal zone use and migratory behaviour. All individual M. liza analysed had Sr:Ca and Ba:Ca values indicating that their birth was in the marine environment, which is consistent with the southern population migration to spawn in the ocean,. Juveniles exhibited at least three coastal use and recruitment strategies (contingents): the majority (89%) of M. liza juveniles migrated toward brackish water. They entered the estuary before completing the first year of life (64%) or after (25%) their first year of life. The remaining 11% did not appear to enter brackish or freshwater water as a nursery or at any point in their life cycle. Some adults returned to the estuary after spawning in the ocean but others (of both sexes) never returned to the estuary after spawning, remaining in the marine environment. The pattern of juvenile habitat use in the Brazilian southern population of M. liza seems to be recurrent throughout the extent of its distribution as a consequence of the reproductive spawning aggregation behaviour, which mixes all contingents (with marine or estuarine preferences).}, }
@article {pmid31386797, year = {2020}, author = {Felton, AJ and Slette, IJ and Smith, MD and Knapp, AK}, title = {Precipitation amount and event size interact to reduce ecosystem functioning during dry years in a mesic grassland.}, journal = {Global change biology}, volume = {26}, number = {2}, pages = {658-668}, doi = {10.1111/gcb.14789}, pmid = {31386797}, issn = {1365-2486}, support = {//Konza Prairie Long-Term Ecological Research Program/International ; DEB-1354732//National Science Foundation/International ; EF-1239559//National Science Foundation/International ; EF-1137378//National Science Foundation/International ; }, mesh = {*Ecosystem ; *Grassland ; Poaceae ; Rain ; Water Cycle ; }, abstract = {Ongoing intensification of the hydrological cycle is altering rainfall regimes by increasing the frequency of extreme wet and dry years and the size of individual rainfall events. Despite long-standing recognition of the importance of precipitation amount and variability for most terrestrial ecosystem processes, we lack understanding of their interactive effects on ecosystem functioning. We quantified this interaction in native grassland by experimentally eliminating temporal variability in growing season rainfall over a wide range of precipitation amounts, from extreme wet to dry conditions. We contrasted the rain use efficiency (RUE) of above-ground net primary productivity (ANPP) under conditions of experimentally reduced versus naturally high rainfall variability using a 32-year precipitation-ANPP dataset from the same site as our experiment. We found that increased growing season rainfall variability can reduce RUE and thus ecosystem functioning by as much as 42% during dry years, but that such impacts weaken as years become wetter. During low precipitation years, RUE is lowest when rainfall event sizes are relatively large, and when a larger proportion of total rainfall is derived from large events. Thus, a shift towards precipitation regimes dominated by fewer but larger rainfall events, already documented over much of the globe, can be expected to reduce the functioning of mesic ecosystems primarily during drought, when ecosystem processes are already compromised by low water availability.}, }
@article {pmid35645457, year = {2019}, author = {Seidl, R and Albrich, K and Erb, K and Formayer, H and Leidinger, D and Leitinger, G and Tappeiner, U and Tasser, E and Rammer, W}, title = {What drives the future supply of regulating ecosystem services in a mountain forest landscape?.}, journal = {Forest ecology and management}, volume = {445}, number = {}, pages = {37-47}, pmid = {35645457}, issn = {0378-1127}, support = {Y 895/FWF_/Austrian Science Fund FWF/Austria ; }, abstract = {Forest ecosystems provide a wide variety of ecosystem services to society. In harsh mountain environments, the regulating services of forests are of particular importance. Managing mountain forests for regulating services is a cost- and labor intensive endeavor. Yet, also unmanaged forests regulate the environment. In the context of evidence-based decision making it is thus important to scrutinize if current management recommendations improve the supply of regulating ecosystem services over unmanaged development trajectories. A further issue complicating decision making in the context of regulating ecosystem services is their high sensitivity to climate change. Climate-mediated increases in natural disturbances, for instance, could strongly reduce the supply of regulating services from forests in the future. Given the profound environmental changes expected for the coming decades it remains unclear whether forest management will still be able to significantly control the future trajectories of mountain forest development, or whether the management effect will be superseded by a much stronger climate and disturbance effect. Here, our objectives were (i) to quantify the future regulating service supply from a 6456 ha landscape in the Stubai valley in Tyrol, Austria, and (ii) to assess the relative importance of management, climate, and natural disturbances on the future supply of regulating ecosystem services. We focused our analysis on climate regulation, water regulation, and erosion regulation, and used the landscape simulation model iLand to quantify their development under different climate scenarios and management strategies. Our results show that unmanaged forests are efficient in providing regulating ecosystem services. Both climate regulation and erosion regulation were higher in unmanaged systems compared to managed systems, while water regulation was slightly enhanced by management. Overall, direct effects of climate change had a stronger influence on the future supply of regulating services than management and natural disturbances. The ability of management to control ecosystem service supply decreased sharply with the severity of future climate change. This finding highlights that forest management could be severely stymied in the future if climate change continues to proceed at its current rate. An improved quantitative understanding of the drivers of future ecosystem service supply is needed to more effectively combine targeted management efforts and natural ecosystem dynamics towards sustaining the benefits society derives from forests in a rapidly changing world.}, }
@article {pmid31332947, year = {2019}, author = {da Silva, LP and Mata, VA and Lopes, PB and Pereira, P and Jarman, SN and Lopes, RJ and Beja, P}, title = {Advancing the integration of multi-marker metabarcoding data in dietary analysis of trophic generalists.}, journal = {Molecular ecology resources}, volume = {19}, number = {6}, pages = {1420-1432}, pmid = {31332947}, issn = {1755-0998}, support = {CEECIND/02064/2017//Funda&#xe7;&#xe3;o para a Ci&#xea;ncia e a Tecnologia/ ; LTER/BIA-BEC/0004/2009//Funda&#xe7;&#xe3;o para a Ci&#xea;ncia e a Tecnologia/ ; PD/BD/113462/2015//Funda&#xe7;&#xe3;o para a Ci&#xea;ncia e a Tecnologia/ ; PD/BD/128492/2017//Funda&#xe7;&#xe3;o para a Ci&#xea;ncia e a Tecnologia/ ; SFRH/BPD/84141/2012//Funda&#xe7;&#xe3;o para a Ci&#xea;ncia e a Tecnologia/ ; 668981//H2020-EU.4.c. - Establishing 'ERA Chairs'/ ; NORTE-01- 0145-FEDER-AGRIGEN//NORTE2020/ ; }, mesh = {Animals ; Biomarkers/*metabolism ; DNA/genetics ; DNA Barcoding, Taxonomic/methods ; Diet/methods ; Feces ; High-Throughput Nucleotide Sequencing/methods ; Passeriformes/*genetics/*metabolism ; }, abstract = {The application of DNA metabarcoding to dietary analysis of trophic generalists requires using multiple markers in order to overcome problems of primer specificity and bias. However, limited attention has been given to the integration of information from multiple markers, particularly when they partly overlap in the taxa amplified, and vary in taxonomic resolution and biases. Here, we test the use of a mix of universal and specific markers, provide criteria to integrate multi-marker metabarcoding data and a python script to implement such criteria and produce a single list of taxa ingested per sample. We then compare the results of dietary analysis based on morphological methods, single markers, and the proposed combination of multiple markers. The study was based on the analysis of 115 faeces from a small passerine, the Black Wheatears (Oenanthe leucura). Morphological analysis detected far fewer plant taxa (12) than either a universal 18S marker (57) or the plant trnL marker (124). This may partly reflect the detection of secondary ingestion by molecular methods. Morphological identification also detected far fewer taxa (23) than when using 18S (91) or the arthropod markers IN16STK (244) and ZBJ (231), though each method missed or underestimated some prey items. Integration of multi-marker data provided far more detailed dietary information than any single marker and estimated higher frequencies of occurrence of all taxa. Overall, our results show the value of integrating data from multiple, taxonomically overlapping markers in an example dietary data set.}, }
@article {pmid31247436, year = {2019}, author = {Colombo, N and Salerno, F and Martin, M and Malandrino, M and Giardino, M and Serra, E and Godone, D and Said-Pullicino, D and Fratianni, S and Paro, L and Tartari, G and Freppaz, M}, title = {Influence of permafrost, rock and ice glaciers on chemistry of high-elevation ponds (NW Italian Alps).}, journal = {The Science of the total environment}, volume = {685}, number = {}, pages = {886-901}, doi = {10.1016/j.scitotenv.2019.06.233}, pmid = {31247436}, issn = {1879-1026}, abstract = {Permafrost degradation, rock-glacier thawing, and glacier retreat are influencing surface water quality at high elevations. However, there is a lack of knowledge on the dominant geochemical reactions occurring in different cryospheric conditions and how these reactions change during the ice-free season. In the Col d'Olen area (LTER site, NW Italian Alps), four ponds with similar sizes, located in basins with different cryospheric features (glacier, permafrost, rock glacier, none of these), are present in a geographically limited area. All ponds were sampled weekly in 2015 and partially in 2014. Major ions, selected trace elements, and biotic parameters (dissolved organic carbon-DOC, fluorescence index-FI, and nitrate) are examined to evidence the effect of different cryospheric features on water characteristics. Where cryospheric conditions occur chemical weathering is more intensive, with strong seasonal increase of major ions. Sulphide oxidation dominates in glacier and permafrost lying on acid rocks, probably driven by enhanced weathering of freshly exposed rocks in subglacial environment and recently deglaciated areas, and active layer thickness increase. Differently, carbonation dominates for the rock glacier lying on ultramafic rocks. There, high Ni concentrations originate from dissolution of Mg-bearing rocks in the landform. In all settings, pH neutralisation occurs because of the presence of secondary carbonate lithology and ultramafic rocks. Nitrate highest concentrations and changes occur in cryospheric settings while DOC and FI do not show strong differences and seasonal variations. The establishment of more frequent monitoring for water quality in high-elevated surface waters is necessary to provide greater statistical power to detect changes on longer time scales.}, }
@article {pmid31186334, year = {2019}, author = {Roy Chowdhury, T and Lee, JY and Bottos, EM and Brislawn, CJ and White, RA and Bramer, LM and Brown, J and Zucker, JD and Kim, YM and Jumpponen, A and Rice, CW and Fansler, SJ and Metz, TO and McCue, LA and Callister, SJ and Song, HS and Jansson, JK}, title = {Metaphenomic Responses of a Native Prairie Soil Microbiome to Moisture Perturbations.}, journal = {mSystems}, volume = {4}, number = {4}, pages = {}, pmid = {31186334}, issn = {2379-5077}, abstract = {Climate change is causing shifts in precipitation patterns in the central grasslands of the United States, with largely unknown consequences on the collective physiological responses of the soil microbial community, i.e., the metaphenome. Here, we used an untargeted omics approach to determine the soil microbial community's metaphenomic response to soil moisture and to define specific metabolic signatures of the response. Specifically, we aimed to develop the technical approaches and metabolic mapping framework necessary for future systematic ecological studies. We collected soil from three locations at the Konza Long-Term Ecological Research (LTER) field station in Kansas, and the soils were incubated for 15 days under dry or wet conditions and compared to field-moist controls. The microbiome response to wetting or drying was determined by 16S rRNA amplicon sequencing, metatranscriptomics, and metabolomics, and the resulting shifts in taxa, gene expression, and metabolites were assessed. Soil drying resulted in significant shifts in both the composition and function of the soil microbiome. In contrast, there were few changes following wetting. The combined metabolic and metatranscriptomic data were used to generate reaction networks to determine the metaphenomic response to soil moisture transitions. Site location was a strong determinant of the response of the soil microbiome to moisture perturbations. However, some specific metabolic pathways changed consistently across sites, including an increase in pathways and metabolites for production of sugars and other osmolytes as a response to drying. Using this approach, we demonstrate that despite the high complexity of the soil habitat, it is possible to generate insight into the effect of environmental change on the soil microbiome and its physiology and functions, thus laying the groundwork for future, targeted studies.IMPORTANCE Climate change is predicted to result in increased drought extent and intensity in the highly productive, former tallgrass prairie region of the continental United States. These soils store large reserves of carbon. The decrease in soil moisture due to drought has largely unknown consequences on soil carbon cycling and other key biogeochemical cycles carried out by soil microbiomes. In this study, we found that soil drying had a significant impact on the structure and function of soil microbial communities, including shifts in expression of specific metabolic pathways, such as those leading toward production of osmoprotectant compounds. This study demonstrates the application of an untargeted multi-omics approach to decipher details of the soil microbial community's metaphenotypic response to environmental perturbations and should be applicable to studies of other complex microbial systems as well.}, }
@article {pmid31180158, year = {2019}, author = {Petrie, MD and Peters, DPC and Burruss, ND and Ji, W and Savoy, HM}, title = {Differing climate and landscape effects on regional dryland vegetation responses during wet periods allude to future patterns.}, journal = {Global change biology}, volume = {25}, number = {10}, pages = {3305-3318}, doi = {10.1111/gcb.14724}, pmid = {31180158}, issn = {1365-2486}, mesh = {*Climate Change ; Environment ; *Soil ; }, abstract = {Dryland vegetation is influenced by biotic and abiotic land surface template (LST) conditions and precipitation (PPT), such that enhanced vegetation responses to periods of high PPT may be shaped by multiple factors. High PPT stochasticity in the Chihuahuan Desert suggests that enhanced responses across broad geographic areas are improbable. Yet, multiyear wet periods may homogenize PPT patterns, interact with favorable LST conditions, and in this way produce enhanced responses. In contrast, periods containing multiple extreme high PPT pulse events could overwhelm LST influences, suggesting a divergence in how climate change could influence vegetation by altering PPT periods. Using a suite of stacked remote sensing and LST datasets from the 1980s to the present, we evaluated PPT-LST-Vegetation relationships across this region and tested the hypothesis that enhanced vegetation responses would be initiated by high PPT, but that LST favorability would underlie response magnitude, producing geographic differences between wet periods. We focused on two multiyear wet periods; one of above average, regionally distributed PPT (1990-1993) and a second with locally distributed PPT that contained two extreme wet pulses (2006-2008). 1990-1993 had regional vegetation responses that were correlated with soil properties. 2006-2008 had higher vegetation responses over a smaller area that were correlated primarily with PPT and secondarily to soil properties. Within the overlapping PPT area of both periods, enhanced vegetation responses occurred in similar locations. Thus, LST favorability underlied the geographic pattern of vegetation responses, whereas PPT initiated the response and controlled response area and maximum response magnitude. Multiyear periods provide foresight on the differing impacts that directional changes in mean climate and changes in extreme PPT pulses could have in drylands. Our study shows that future vegetation responses during wet periods will be tied to LST favorability, yet will be shaped by the pattern and magnitude of multiyear PPT events.}, }
@article {pmid31178628, year = {2019}, author = {Ilyashuk, EA and Heiri, O and Ilyashuk, BP and Koinig, KA and Psenner, R}, title = {The Little Ice Age signature in a 700-year high-resolution chironomid record of summer temperatures in the Central Eastern Alps.}, journal = {Climate dynamics}, volume = {52}, number = {11}, pages = {6953-6967}, pmid = {31178628}, issn = {0930-7575}, support = {P 28469/FWF_/Austrian Science Fund FWF/Austria ; }, abstract = {Despite the fact that the Little Ice Age (LIA) is well documented for the European Alps, substantial uncertainties concerning the regional spatio-temporal patterns of temperature changes associated with the LIA still exist, especially for their eastern sector. Here we present a high-resolution (4-10 years) 700-year long mean July air temperature reconstruction based on subfossil chironomid assemblages from a remote lake in the Austrian Eastern Alps to gain further insights into the LIA climatic deterioration in the region. The record provides evidence for a prolonged period of predominantly cooler conditions during AD 1530-1920, broadly equivalent to the climatically defined LIA in Europe. The main LIA phase appears to have consisted of two cold time intervals divided by slightly warmer episodes in the second half of the 1600s. The most severe cooling occurred during the eighteenth century. The LIA temperature minimum about 1.5 °C below the long-term mean recorded in the mid-1780 s coincides with the strongest volcanic signal found in the Greenland ice cores over the past 700 years and may be, at least in part, a manifestation of cooling that followed the long-lasting AD 1783-1784 Laki eruption. A continuous warming trend is evident since ca AD 1890 (1.1 °C in 120 years). The chironomid-inferred temperatures show a clear correlation with the instrumental data and reveal a close agreement with paleotemperature evidence from regional high-elevation tree-ring chronologies. A considerable amount of the variability in the temperature record may be linked to changes in the North Atlantic Oscillation.}, }
@article {pmid31134712, year = {2019}, author = {Zettlemoyer, MA and Schultheis, EH and Lau, JA}, title = {Phenology in a warming world: differences between native and non-native plant species.}, journal = {Ecology letters}, volume = {22}, number = {8}, pages = {1253-1263}, doi = {10.1111/ele.13290}, pmid = {31134712}, issn = {1461-0248}, support = {//Michigan State University AgBioResearch/ ; 2124//Kellogg Biological Station/ ; DEB 1637653//NSF Long-term Ecological Research Program/ ; }, mesh = {*Climate Change ; Flowers ; *Plant Development ; *Plants ; Seasons ; Temperature ; }, abstract = {Phenology is a harbinger of climate change, with many species advancing flowering in response to rising temperatures. However, there is tremendous variation among species in phenological response to warming, and any phenological differences between native and non-native species may influence invasion outcomes under global warming. We simulated global warming in the field and found that non-native species flowered earlier and were more phenologically plastic to temperature than natives, which did not accelerate flowering in response to warming. Non-native species' flowering also became more synchronous with other community members under warming. Earlier flowering was associated with greater geographic spread of non-native species, implicating phenology as a potential trait associated with the successful establishment of non-native species across large geographic regions. Such phenological differences in both timing and plasticity between native and non-natives are hypothesised to promote invasion success and population persistence, potentially benefiting non-native over native species under climate change.}, }
@article {pmid31074933, year = {2019}, author = {Borer, ET and Lind, EM and Firn, J and Seabloom, EW and Anderson, TM and Bakker, ES and Biederman, L and La Pierre, KJ and MacDougall, AS and Moore, JL and Risch, AC and Schutz, M and Stevens, CJ}, title = {More salt, please: global patterns, responses and impacts of foliar sodium in grasslands.}, journal = {Ecology letters}, volume = {22}, number = {7}, pages = {1136-1144}, doi = {10.1111/ele.13270}, pmid = {31074933}, issn = {1461-0248}, support = {NSF-DEB-1042132//National Science Foundation Research Coordination Network/ ; NSF-DEB-1234162//Long Term Ecological Research/ ; DG-0001-13//Institute on the Environment/ ; }, mesh = {Adaptation, Physiological ; Animals ; *Grassland ; *Herbivory ; Nitrogen ; Plants ; *Sodium ; Soil ; }, abstract = {Sodium is unique among abundant elemental nutrients, because most plant species do not require it for growth or development, whereas animals physiologically require sodium. Foliar sodium influences consumption rates by animals and can structure herbivores across landscapes. We quantified foliar sodium in 201 locally abundant, herbaceous species representing 32 families and, at 26 sites on four continents, experimentally manipulated vertebrate herbivores and elemental nutrients to determine their effect on foliar sodium. Foliar sodium varied taxonomically and geographically, spanning five orders of magnitude. Site-level foliar sodium increased most strongly with site aridity and soil sodium; nutrient addition weakened the relationship between aridity and mean foliar sodium. Within sites, high sodium plants declined in abundance with fertilisation, whereas low sodium plants increased. Herbivory provided an explanation: herbivores selectively reduced high nutrient, high sodium plants. Thus, interactions among climate, nutrients and the resulting nutritional value for herbivores determine foliar sodium biogeography in herbaceous-dominated systems.}, }
@article {pmid31071155, year = {2019}, author = {Hofman, MPG and Hayward, MW and Heim, M and Marchand, P and Rolandsen, CM and Mattisson, J and Urbano, F and Heurich, M and Mysterud, A and Melzheimer, J and Morellet, N and Voigt, U and Allen, BL and Gehr, B and Rouco, C and Ullmann, W and Holand, &#xd8; and Jørgensen, NH and Steinheim, G and Cagnacci, F and Kroeschel, M and Kaczensky, P and Buuveibaatar, B and Payne, JC and Palmegiani, I and Jerina, K and Kjellander, P and Johansson, &#xd6; and LaPoint, S and Bayrakcismith, R and Linnell, JDC and Zaccaroni, M and Jorge, MLS and Oshima, JEF and Songhurst, A and Fischer, C and Mc Bride, RT and Thompson, JJ and Streif, S and Sandfort, R and Bonenfant, C and Drouilly, M and Klapproth, M and Zinner, D and Yarnell, R and Stronza, A and Wilmott, L and Meisingset, E and Thaker, M and Vanak, AT and Nicoloso, S and Graeber, R and Said, S and Boudreau, MR and Devlin, A and Hoogesteijn, R and May-Junior, JA and Nifong, JC and Odden, J and Quigley, HB and Tortato, F and Parker, DM and Caso, A and Perrine, J and Tellaeche, C and Zieba, F and Zwijacz-Kozica, T and Appel, CL and Axsom, I and Bean, WT and Cristescu, B and Périquet, S and Teichman, KJ and Karpanty, S and Licoppe, A and Menges, V and Black, K and Scheppers, TL and Schai-Braun, SC and Azevedo, FC and Lemos, FG and Payne, A and Swanepoel, LH and Weckworth, BV and Berger, A and Bertassoni, A and McCulloch, G and Šustr, P and Athreya, V and Bockmuhl, D and Casaer, J and Ekori, A and Melovski, D and Richard-Hansen, C and van de Vyver, D and Reyna-Hurtado, R and Robardet, E and Selva, N and Sergiel, A and Farhadinia, MS and Sunde, P and Portas, R and Ambarli, H and Berzins, R and Kappeler, PM and Mann, GK and Pyritz, L and Bissett, C and Grant, T and Steinmetz, R and Swedell, L and Welch, RJ and Armenteras, D and Bidder, OR and González, TM and Rosenblatt, A and Kachel, S and Balkenhol, N}, title = {Right on track? Performance of satellite telemetry in terrestrial wildlife research.}, journal = {PloS one}, volume = {14}, number = {5}, pages = {e0216223}, pmid = {31071155}, issn = {1932-6203}, support = {/WT_/Wellcome Trust/United Kingdom ; }, mesh = {Animals ; Animals, Wild/*physiology ; *Ecosystem ; *Environmental Monitoring ; *Geographic Information Systems ; *Spacecraft ; *Telemetry ; }, abstract = {Satellite telemetry is an increasingly utilized technology in wildlife research, and current devices can track individual animal movements at unprecedented spatial and temporal resolutions. However, as we enter the golden age of satellite telemetry, we need an in-depth understanding of the main technological, species-specific and environmental factors that determine the success and failure of satellite tracking devices across species and habitats. Here, we assess the relative influence of such factors on the ability of satellite telemetry units to provide the expected amount and quality of data by analyzing data from over 3,000 devices deployed on 62 terrestrial species in 167 projects worldwide. We evaluate the success rate in obtaining GPS fixes as well as in transferring these fixes to the user and we evaluate failure rates. Average fix success and data transfer rates were high and were generally better predicted by species and unit characteristics, while environmental characteristics influenced the variability of performance. However, 48% of the unit deployments ended prematurely, half of them due to technical failure. Nonetheless, this study shows that the performance of satellite telemetry applications has shown improvements over time, and based on our findings, we provide further recommendations for both users and manufacturers.}, }
@article {pmid30967554, year = {2019}, author = {Mortelmans, J and Deneudt, K and Cattrijsse, A and Beauchard, O and Daveloose, I and Vyverman, W and Vanaverbeke, J and Timmermans, K and Peene, J and Roose, P and Knockaert, M and Chou, L and Sanders, R and Stinchcombe, M and Kimpe, P and Lammens, S and Theetaert, H and Gkritzalis, T and Hernandez, F and Mees, J}, title = {Nutrient, pigment, suspended matter and turbidity measurements in the Belgian part of the North Sea.}, journal = {Scientific data}, volume = {6}, number = {1}, pages = {22}, pmid = {30967554}, issn = {2052-4463}, abstract = {Through regular sampling surveys, the Flanders Marine Institute is generating long term data series for the Belgian coastal water and sand bank systems, a designated site in the Long Term Ecological Research (LTER) network. The data series is built on sampling activities initiated in 2002, but gradually upgraded and extended in the framework of the LifeWatch marine observatory and the Integrated Carbon Observation System (ICOS) participation. Nine nearshore stations are sampled monthly, with additional seasonal sampling of eight offshore stations. This paper presents the generated data series for nutrients, pigments, suspended matter and turbidity. The collection, methodology and processing of the 2002-2018 dataset is described, along with its data curation, integration and quality control. Yearly versions of the data are published online in a standardized format, accompanied with extensive metadata description and labelled with digital identifiers for traceability. Data is published under a CC-BY license, allowing use of the data under the condition of providing reference to the original source.}, }
@article {pmid30945532, year = {2019}, author = {Yeung, LY and Haslun, JA and Ostrom, NE and Sun, T and Young, ED and van Kessel, MAHJ and Lücker, S and Jetten, MSM}, title = {In Situ Quantification of Biological N2 Production Using Naturally Occurring [15]N[15]N.}, journal = {Environmental science &amp; technology}, volume = {53}, number = {9}, pages = {5168-5175}, pmid = {30945532}, issn = {1520-5851}, mesh = {Agriculture ; Denitrification ; Nitrogen ; *Nitrous Oxide ; *Soil ; Soil Microbiology ; }, abstract = {We describe an approach for determining biological N2 production in soils based on the proportions of naturally occurring [15]N[15]N in N2. Laboratory incubation experiments reveal that biological N2 production, whether by denitrification or anaerobic ammonia oxidation, yields proportions of [15]N[15]N in N2 that are within 1‰ of that predicted for a random distribution of [15]N and [14]N atoms. This relatively invariant isotopic signature contrasts with that of the atmosphere, which has [15]N[15]N proportions in excess of the random distribution by 19.1 ± 0.1‰. Depth profiles of gases in agricultural soils from the Kellogg Biological Station Long-Term Ecological Research site show biological N2 accumulation that accounts for up to 1.6% of the soil N2. One-dimensional reaction-diffusion modeling of these soil profiles suggests that subsurface N2 pulses leading to surface emission rates as low as 0.3 mmol N2 m[-2] d[-1] can be detected with current analytical precision, decoupled from N2O production.}, }
@article {pmid30942486, year = {2019}, author = {Wilson, BJ and Servais, S and Charles, SP and Mazzei, V and Gaiser, EE and Kominoski, JS and Richards, JH and Troxler, TG}, title = {Phosphorus alleviation of salinity stress: effects of saltwater intrusion on an Everglades freshwater peat marsh.}, journal = {Ecology}, volume = {100}, number = {5}, pages = {e02672}, doi = {10.1002/ecy.2672}, pmid = {30942486}, issn = {1939-9170}, support = {DEB-1237517//National Science Foundation's Florida Coastal Everglades Long Term Ecological Research Program/International ; R/C-S-56//Florida Sea Grant/International ; //Everglades Section of the South Florida Water Management District/International ; //Everglades Foundation/International ; //Everglades National Park/International ; }, mesh = {Ecosystem ; Fresh Water ; Phosphorus ; Salinity ; Salt Stress ; *Soil ; *Wetlands ; }, abstract = {Saltwater intrusion and salinization of coastal wetlands around the world are becoming a pressing issue due to sea level rise. Here, we assessed how a freshwater coastal wetland ecosystem responds to saltwater intrusion. In wetland mesocosms, we continuously exposed Cladium jamaicense Crantz (sawgrass) plants and their peat soil collected from a freshwater marsh to two factors associated with saltwater intrusion in karstic ecosystems: elevated loading of salinity and phosphorus (P) inputs. We took repeated measures using a 2 × 2 factorial experimental design (n = 6) with treatments composed of elevated salinity (~9 ppt), P loading (14.66 μmol P/d), or a combination of both. We measured changes in water physicochemistry, ecosystem productivity, and plant biomass change over two years to assess monthly and two-year responses to saltwater intrusion. In the short-term, plants exhibited positive growth responses with simulated saltwater intrusion (salinity + P), driven by increased P availability. Despite relatively high salinity levels for a freshwater marsh (~9 ppt), gross ecosystem productivity (GEP), net ecosystem productivity (NEP), and aboveground biomass were significantly higher in the elevated salinity + P treated monoliths compared to the freshwater controls. Salinity stress became evident after extended exposure. Although still higher than freshwater controls, GEP and NEP were significantly lower in the elevated salinity + P treatment than the +P treatment after two years. However, elevated salinity decreased live root biomass regardless of whether P was added. Our results suggest that saltwater intrusion into karstic freshwater wetlands may initially act as a subsidy by stimulating aboveground primary productivity of marsh plants. However, chronic exposure to elevated salinity results in plant stress, negatively impacting belowground peat soil structure and stability through a reduction in plant roots.}, }
@article {pmid30941153, year = {2019}, author = {Chun, JH and Lee, CB}, title = {Temporal Changes in Species, Phylogenetic, and Functional Diversity of Temperate Tree Communities: Insights From Assembly Patterns.}, journal = {Frontiers in plant science}, volume = {10}, number = {}, pages = {294}, pmid = {30941153}, issn = {1664-462X}, abstract = {Species-based approaches to the analysis of changes in successional community assemblages are limited in the ability to reflect long-term evolutionary and functional trait responses of organisms to environment change. Recent advances in concepts and analyses of community phylogenetics and functional traits have improved the interpretation and understanding of community assembly processes. Here, we examined phylogenetic signals of four functional traits such as maximum height, leaf size, seed mass and wood density in woody plant species and temporal changes in species, phylogenetic, and functional diversity among forest strata (i.e., whole, overstory, and understory strata) at four forest long term ecological research sites in South Korea. A census of woody plant species was implemented in a 1-ha permanent plot of each study site every 5 years. We analyzed community structure and compositional turnover using twenty-five 20 × 20 m[2] quadrat data converted from 1-ha plot data of each site. We found that phylogenetic signals for four functional traits were low but significant, indicating that phylogenetic diversity may be used as a crude surrogate measure of functional diversity. Temporal changes in alpha and beta components of the three diversity differed among forest strata and four study sites over time. This study also revealed that the temporal changes of phylogenetic and functional diversity for understory strata in a forest, which were consecutively damaged by typhoon, were more extreme and larger than those of understory strata in the other sites. Therefore, our study supports recent studies that plant community structures differ among forest strata and such differences of community structure among sites can be accelerated by disturbance. Although the role and relative importance of niche-based deterministic and neutral processes for the patterns of successional community structure differed among the study sites, we found niche-based deterministic processes are the dominant drivers in structuring plant community assembly regardless of forest age and disturbance in this study. From these results, our study suggests that contemporary forest ecosystems are composed of mosaics of plant communities that are formed by interactions among various processes.}, }
@article {pmid30884085, year = {2019}, author = {Crowther, TW and Riggs, C and Lind, EM and Borer, ET and Seabloom, EW and Hobbie, SE and Wubs, J and Adler, PB and Firn, J and Gherardi, L and Hagenah, N and Hofmockel, KS and Knops, JMH and McCulley, RL and MacDougall, AS and Peri, PL and Prober, SM and Stevens, CJ and Routh, D}, title = {Sensitivity of global soil carbon stocks to combined nutrient enrichment.}, journal = {Ecology letters}, volume = {22}, number = {6}, pages = {936-945}, doi = {10.1111/ele.13258}, pmid = {30884085}, issn = {1461-0248}, support = {//Plant For The Planet Foundation/ ; //DOB Ecology/ ; NSF-DEB-1042132//National Science Foundation Research Coordination Network/ ; NSF-DEB-1234162//Long Term Ecological Research/ ; }, mesh = {*Carbon ; Ecosystem ; Nitrogen ; Nutrients ; *Soil/chemistry ; }, abstract = {Soil stores approximately twice as much carbon as the atmosphere and fluctuations in the size of the soil carbon pool directly influence climate conditions. We used the Nutrient Network global change experiment to examine how anthropogenic nutrient enrichment might influence grassland soil carbon storage at a global scale. In isolation, enrichment of nitrogen and phosphorous had minimal impacts on soil carbon storage. However, when these nutrients were added in combination with potassium and micronutrients, soil carbon stocks changed considerably, with an average increase of 0.04 KgCm[-2 ] year[-1] (standard deviation 0.18 KgCm[-2 ] year[-1]). These effects did not correlate with changes in primary productivity, suggesting that soil carbon decomposition may have been restricted. Although nutrient enrichment caused soil carbon gains most dry, sandy regions, considerable absolute losses of soil carbon may occur in high-latitude regions that store the majority of the world's soil carbon. These mechanistic insights into the sensitivity of grassland carbon stocks to nutrient enrichment can facilitate biochemical modelling efforts to project carbon cycling under future climate scenarios.}, }
@article {pmid30872941, year = {2019}, author = {Scotti, A and Tappeiner, U and Bottarin, R}, title = {Stream benthic macroinvertebrates abundances over a 6-year monitoring period of an Italian glacier-fed stream.}, journal = {Biodiversity data journal}, volume = {7}, number = {}, pages = {e33576}, pmid = {30872941}, issn = {1314-2828}, abstract = {BACKGROUND: Aquatic macroinvertebrates are widely used as bioindicators for water quality assessments involving different kinds of disruptive factors, such as hydrological regime variations or pollutant spills. Recently, they demonstrated to be effective in monitoring effects of climate change in alpine stream and rivers. Indeed, since the distribution of macroinvertebrates in glacier-fed streams has been succesfully investigated and described by several authors, the discrepancy in presence/absence and quantity of specific taxa from the established models may represent an early warning of the effects of climatic changes occurring in alpine riverine ecosystems.<br><br>NEW INFORMATION: Together with the present paper, we provide a dataset covering a period of 6 years (2010-2015) sampling of aquatic macroinvertebrates along a longitudinal transect of a glacier-fed stream located in the Italian Alps, inside the International Long Term Ecological Research (ILTER) macrosite of Matsch|Mazia (IT-25). Data were collected during the glacial melt period (April - September), with monthly resolution. Owing to the unique temporal resolution of the dataset, we aim to produce a reliable tool (i.e. reference point) for future ecological assessment on the same stream, but also to similar streams worldwide.}, }
@article {pmid30861108, year = {2019}, author = {Zhang, Y and Pennings, SC and Li, B and Wu, J}, title = {Biotic homogenization of wetland nematode communities by exotic Spartina alterniflora in China.}, journal = {Ecology}, volume = {100}, number = {4}, pages = {e02596}, doi = {10.1002/ecy.2596}, pmid = {30861108}, issn = {1939-9170}, support = {2017YFC1200103//National Key R&amp;D Program of China/International ; 41630528//NSFC/International ; 41871035//NSFC/International ; OCE12-37140//U.S. National Science Foundation through the Georgia Coastal Ecosystems Long-Term Ecological Research program/International ; }, mesh = {Animals ; China ; Introduced Species ; *Nematoda ; Poaceae ; Soil ; *Wetlands ; }, abstract = {Introduced species may homogenize biotic communities. Whether this homogenization can erase latitudinal patterns of species diversity and composition has not been well studied. We examined this by comparing nematode and microbial communities in stands of native Phragmites australis and exotic Spartina alterniflora in coastal wetlands across 18° of latitude in China. We found clear latitudinal clines in nematode diversity and functional composition, and in microbial composition, for soils collected from native P. australis. These latitudinal patterns were weak or absent for soils collected from nearby stands of the exotic S. alterniflora. Climatic and edaphic variables varied across latitude in similar ways in both community types. In P. australis there were strong correlations between community structure and environmental variables, whereas in S. alterniflora these correlations were weak. These results suggest that the invasion of S. alterniflora into the Chinese coastal wetlands has caused profound biotic homogenization of soil communities across latitude. We speculate that the variation in P. australis nematode and microbial communities across latitude is primarily driven by geographic variation in plant traits, but that such variation in plant traits is largely lacking for the recently introduced exotic S. alterniflora. These results indicate that widespread exotic species can homogenize nematode communities at large spatial scales.}, }
@article {pmid30850884, year = {2019}, author = {Whitney, KD and Mudge, J and Natvig, DO and Sundararajan, A and Pockman, WT and Bell, J and Collins, SL and Rudgers, JA}, title = {Experimental drought reduces genetic diversity in the grassland foundation species Bouteloua eriopoda.}, journal = {Oecologia}, volume = {189}, number = {4}, pages = {1107-1120}, pmid = {30850884}, issn = {1432-1939}, support = {P20GM103451//National Institute of General Medical Sciences/ ; EF-01137363//National Science Foundation/ ; EAGER 1748133//National Science Foundation/ ; P20 GM103451/GM/NIGMS NIH HHS/United States ; DEB 1257965//National Science Foundation/ ; DEB 1456955//National Science Foundation/ ; }, mesh = {*Droughts ; *Ecosystem ; Genetic Variation ; Grassland ; New Mexico ; Poaceae ; }, abstract = {Understanding the resistance and resilience of foundation plant species to climate change is a critical issue because the loss of these species would fundamentally reshape communities and ecosystem processes. High levels of population genetic diversity may buffer foundation species against climate disruptions, but the strong selective pressures associated with climatic shifts may also rapidly reduce such diversity. We characterized genetic diversity and its responsiveness to experimental drought in the foundation plant, black grama grass (Bouteloua eriopoda), which dominates many western North American grasslands and shrublands. Previous studies suggested that in arid ecosystems, black grama reproduces largely asexually via stolons, and thus is likely to have low genetic variability, which might limit its potential to respond to climate disruptions. Using genotyping-by-sequencing, we demonstrated unexpectedly high genetic variability among black grama plants in a 1 ha site within the Sevilleta National Wildlife Refuge in central New Mexico, suggesting some level of sexual reproduction. Three years of experimental, growing season drought reduced black grama survival and biomass (the latter by 96%), with clear genetic differentiation (higher FST) between plants succumbing to drought and those remaining alive. Reduced genetic variability in the surviving plants in drought plots indicated that the experimental drought had forced black grama populations through selection bottlenecks. These results suggest that foundation grass species, such as black grama, may experience rapid evolutionary change if future climates include more severe droughts.}, }
@article {pmid30805155, year = {2019}, author = {Wentz, KF and Neff, JC and Suding, KN}, title = {Leaf temperatures mediate alpine plant communities' response to a simulated extended summer.}, journal = {Ecology and evolution}, volume = {9}, number = {3}, pages = {1227-1243}, pmid = {30805155}, issn = {2045-7758}, abstract = {We use a quantitative model of photosynthesis to explore leaf-level limitations to plant growth in an alpine tundra ecosystem that is expected to have longer, warmer, and drier growing seasons. The model is parameterized with abiotic and leaf trait data that is characteristic of two dominant plant communities in the alpine tundra and specifically at the Niwot Ridge Long Term Ecological Research Site: the dry and wet meadows. Model results produce realistic estimates of photosynthesis, nitrogen-use efficiency, water-use efficiency, and other gas exchange processes in the alpine tundra. Model simulations suggest that dry and wet meadow plant species do not significantly respond to changes in the volumetric soil moisture content but are sensitive to variation in foliar nitrogen content. In addition, model simulations indicate that dry and wet meadow species have different maximum rates of assimilation (normalized for leaf nitrogen content) because of differences in leaf temperature. These differences arise from the interaction of plant height and the abiotic environment characteristic of each plant community. The leaf temperature of dry meadow species is higher than wet meadow species and close to the optimal temperature for photosynthesis under current conditions. As a result, 2°C higher air temperatures in the future will likely lead to declines in dry meadow species' carbon assimilation. On the other hand, a longer and warmer growing season could increase nitrogen availability and assimilation rates in both plant communities. Nonetheless, a temperature increase of 4°C may lower rates of assimilation in both dry and wet meadow plant communities because of higher, and suboptimal, leaf temperatures.}, }
@article {pmid30802858, year = {2019}, author = {Kazemi, M and Kavehvash, Z and Shabany, M}, title = {K-Space Aware Multi-Static Millimeter-Wave Imaging.}, journal = {IEEE transactions on image processing : a publication of the IEEE Signal Processing Society}, volume = {}, number = {}, pages = {}, doi = {10.1109/TIP.2019.2900588}, pmid = {30802858}, issn = {1941-0042}, abstract = {This paper focuses on an ef?cient approach of designing multi-static arrays for millimeter-wave imaging, based on the k-space or Fourier-spatial domain characteristic of imaging systems. Our goal is to decrease the redundancy of the data measured by each antenna, and to improve the resolution of the reconstructed image. The proposed technique is based on determining the role of each transmitter and receiver, in collecting the data from each voxel of the target in k-space domain and then rotating transmitters' beams to measure the desirable information. The effect of non-uniform redundant k-space domain frequency samples that act as an undesirable ?lter, is compensated using a modi?ed SAR back-projection algorithm. Experimental and simulation results are presented and compared with that of a sparse multi-static array with the same number of transmitters and receivers. Our simulations and measurements show signi?cant improvement in terms of overall quality and edge preservation in the reconstructed images. Also, the obtained results demonstrate that using the proposed structure and algorithm, the average improvement in peak-signalto-noise ratio (PSNR), structural similarity index measure (SSIM) and digital image correlation (DIC) metrics of 3.03 dB, 0.22 and 0.173, are achieved, respectively.}, }
@article {pmid30677684, year = {2019}, author = {Liang, D and Harris, LA and Testa, JM and Lyubchich, V and Filoso, S}, title = {Detection of the effects of stormwater control measure in streams using a Bayesian BACI power analysis.}, journal = {The Science of the total environment}, volume = {661}, number = {}, pages = {386-392}, doi = {10.1016/j.scitotenv.2019.01.125}, pmid = {30677684}, issn = {1879-1026}, abstract = {The unpredictable timing and magnitude of precipitation events and the spatiotemporal variability of constituent concentrations are major complications to effective monitoring of watershed nutrient and sediment loads. Furthermore, detecting small changes in constituent loads in response to implementation of Stormwater control measures (SCMs) against natural variability is a challenge. Nevertheless, regulatory frameworks that direct reductions of pollutants to streams frequently depend on the ability to quantify changes in loads after management interventions. The before-after-control impact (BACI) sampling design is often used to assess the effects of an environmental change made at a known point in time. However, this approach may be complicated to apply to nutrient and sediment loads in streams as the relative impact of SCMs on nutrient concentration conditional on the long term variability of discharges has not been evaluated. Multi-scale monitoring studies that provide estimates of the natural temporal and spatial variability of discharge and concentrations could provide useful information in designing a BACI study. Here we use data from the Baltimore Long Term Ecological Research (LTER) sites and urban restoration sites to develop multiple statistical measures of the effectiveness of a given monitoring scheme in revealing the hypothesized restoration effects in terms of hydrology and nutrient loads. Stratified sampling over baseflow and stormflow and the use of multiple control streams were useful tools to detect long term cumulative reductions in concentrations due to SCMs. Moderate reductions in concentration (20%), however, were not detectable with the design options considered. We emphasize that appropriate pre-planning of monitoring schemes and sampling frequency is essential to determine if the effects on constituent loads resulting from a given watershed restoration activity are measurable.}, }
@article {pmid30660318, year = {2019}, author = {Battisti, C and Staffieri, E and Poeta, G and Sorace, A and Luiselli, L and Amori, G}, title = {Interactions between anthropogenic litter and birds: A global review with a 'black-list' of species.}, journal = {Marine pollution bulletin}, volume = {138}, number = {}, pages = {93-114}, doi = {10.1016/j.marpolbul.2018.11.017}, pmid = {30660318}, issn = {1879-3363}, mesh = {Animals ; *Birds ; Dietary Exposure/adverse effects ; Ecosystem ; Ecotoxicology/trends ; Environmental Exposure/*adverse effects ; Environmental Pollution/*adverse effects ; Serial Publications/trends ; Solid Waste/*adverse effects ; }, abstract = {The interaction of anthropogenic litter (by incorporation litter in nests, ingestion, and entanglement) with birds was systematically reviewed using Google Scholar database. A 'black-list' of 258 species was compiled. Among them 206 (79.8%) were seabirds. Four seabird orders (Gaviiformes, Phaetontiformes, Procellariformes, Sphenisciformes) showed the highest percentage of interacting species. At family level, >70% of species of Gaviidae, Diomedeidae, Sulidae, Stercoraridae and Alcidae were involved in interactions with litter. We observed (i) a significant correlation between Scholar recurrences and species citations about anthropogenic litter only when considering seabirds; (ii) a low number of references before 1981 with a bimodal pattern showing a first peak in 1986-90 and a progressively increasing trend in the 2000s. Regarding the type of interaction, there was a significantly higher percentage of species involved in ingestion when compared to the percentage involved in entanglement. We suggest the use of consolidated standardized litter nomenclature and characterization and the adoption of a logical causal chain helping researchers in defining suitable frameworks.}, }
@article {pmid30612185, year = {2019}, author = {Murphy, AE and Kolkmeyer, R and Song, B and Anderson, IC and Bowen, J}, title = {Bioreactivity and Microbiome of Biodeposits from Filter-Feeding Bivalves.}, journal = {Microbial ecology}, volume = {77}, number = {2}, pages = {343-357}, pmid = {30612185}, issn = {1432-184X}, support = {OCE 1062882//National Science Foundation/ ; OCE 1233801//National Science Foundation/ ; LTER 0080381//National Science Foundation/ ; NA10OAR4170085//Virginia Sea Grant, Virginia Institute of Marine Science/ ; }, mesh = {Ammonium Compounds/metabolism ; Animals ; Bacteria/classification/genetics/*isolation &amp; purification/metabolism ; Bivalvia/metabolism/*microbiology ; Carbon/metabolism ; Crassostrea/metabolism/microbiology ; Eutrophication ; Geologic Sediments/chemistry/microbiology ; Mercenaria/metabolism/microbiology ; *Microbiota ; Phylogeny ; Seawater/chemistry/microbiology ; }, abstract = {Bivalves serve an important ecosystem function in delivering organic matter from pelagic to benthic zones and are important in mediating eutrophication. However, the fate of this organic matter (i.e., biodeposits) is an important consideration when assessing the ecological roles of these organisms in coastal ecosystems. In addition to environmental conditions, the processing of biodeposits is dependent on its composition and the metabolic capacity of the associated microbial community. The objectives of this study were to compare the biological reactivity, potential denitrification rates, and microbial communities of biodeposits sourced from different bivalve species: hard clam (Mercenaria mercenaria), eastern oyster (Crassostrea virginica), and ribbed mussel (Geukensia demissa). To our knowledge, this is the first study to investigate and compare the microbiome of bivalve biodeposits using high-throughput sequencing and provide important insight into the mechanisms by which bivalves may alter sediment microbial communities and benthic biogeochemical cycles. We show that clam biodeposits had significantly higher bioreactivity compared to mussel and oyster biodeposits, as reflected in higher dissolved inorganic carbon and ammonium production rates in controlled incubations. Potential denitrification rates were also significantly higher for clam biodeposits compared to oyster and mussel biodeposits. The microbial communities associated with the biodeposits were significantly different across bivalve species, with significantly greater abundances of Alteromonadales, Chitinophagales, Rhodobacterales, and Thiotrichales associated with the clam biodeposits. These bioreactivity and microbial differences across bivalve species are likely due to differences in bivalve physiology and feeding behavior and should be considered when evaluating the effects of bivalves on water quality and ecosystem function.}, }
@article {pmid34470179, year = {2018}, author = {Bachmann, CM and Eon, RS and Lapszynski, CS and Badura, GP and Vodacek, A and Hoffman, MJ and McKeown, D and Kremens, RL and Richardson, M and Bauch, T and Foote, M}, title = {A Low-Rate Video Approach to Hyperspectral Imaging of Dynamic Scenes.}, journal = {Journal of imaging}, volume = {5}, number = {1}, pages = {}, pmid = {34470179}, issn = {2313-433X}, abstract = {The increased sensitivity of modern hyperspectral line-scanning systems has led to the development of imaging systems that can acquire each line of hyperspectral pixels at very high data rates (in the 200-400 Hz range). These data acquisition rates present an opportunity to acquire full hyperspectral scenes at rapid rates, enabling the use of traditional push-broom imaging systems as low-rate video hyperspectral imaging systems. This paper provides an overview of the design of an integrated system that produces low-rate video hyperspectral image sequences by merging a hyperspectral line scanner, operating in the visible and near infra-red, with a high-speed pan-tilt system and an integrated IMU-GPS that provides system pointing. The integrated unit is operated from atop a telescopic mast, which also allows imaging of the same surface area or objects from multiple view zenith directions, useful for bi-directional reflectance data acquisition and analysis. The telescopic mast platform also enables stereo hyperspectral image acquisition, and therefore, the ability to construct a digital elevation model of the surface. Imaging near the shoreline in a coastal setting, we provide an example of hyperspectral imagery time series acquired during a field experiment in July 2017 with our integrated system, which produced hyperspectral image sequences with 371 spectral bands, spatial dimensions of 1600 × 212, and 16 bits per pixel, every 0.67 s. A second example times series acquired during a rooftop experiment conducted on the Rochester Institute of Technology campus in August 2017 illustrates a second application, moving vehicle imaging, with 371 spectral bands, 16 bit dynamic range, and 1600 × 300 spatial dimensions every second.}, }
@article {pmid30499218, year = {2019}, author = {Taylor, SD and Meiners, JM and Riemer, K and Orr, MC and White, EP}, title = {Comparison of large-scale citizen science data and long-term study data for phenology modeling.}, journal = {Ecology}, volume = {100}, number = {2}, pages = {e02568}, pmid = {30499218}, issn = {0012-9658}, support = {GBMF4563//Gordon and Betty Moore Foundation/International ; //University of Florida Biodiversity Institute Graduate Research Fellowship/International ; }, mesh = {*Climate Change ; Longitudinal Studies ; *Models, Theoretical ; Seasons ; }, abstract = {Large-scale observational data from citizen science efforts are becoming increasingly common in ecology, and researchers often choose between these and data from intensive local-scale studies for their analyses. This choice has potential trade-offs related to spatial scale, observer variance, and interannual variability. Here we explored this issue with phenology by comparing models built using data from the large-scale, citizen science USA National Phenology Network (USA-NPN) effort with models built using data from more intensive studies at Long Term Ecological Research (LTER) sites. We built statistical and process based phenology models for species common to each data set. From these models, we compared parameter estimates, estimates of phenological events, and out-of-sample errors between models derived from both USA-NPN and LTER data. We found that model parameter estimates for the same species were most similar between the two data sets when using simple models, but parameter estimates varied widely as model complexity increased. Despite this, estimates for the date of phenological events and out-of-sample errors were similar, regardless of the model chosen. Predictions for USA-NPN data had the lowest error when using models built from the USA-NPN data, while LTER predictions were best made using LTER-derived models, confirming that models perform best when applied at the same scale they were built. This difference in the cross-scale model comparison is likely due to variation in phenological requirements within species. Models using the USA-NPN data set can integrate parameters over a large spatial scale while those using an LTER data set can only estimate parameters for a single location. Accordingly, the choice of data set depends on the research question. Inferences about species-specific phenological requirements are best made with LTER data, and if USA-NPN or similar data are all that is available, then analyses should be limited to simple models. Large-scale predictive modeling is best done with the larger-scale USA-NPN data, which has high spatial representation and a large regional species pool. LTER data sets, on the other hand, have high site fidelity and thus characterize inter-annual variability extremely well. Future research aimed at forecasting phenology events for particular species over larger scales should develop models that integrate the strengths of both data sets.}, }
@article {pmid30485407, year = {2018}, author = {Ricono, A and Dixon, R and Eaton, I and Brightbill, CM and Yaziji, Y and Puzey, JR and Dalgleish, HJ}, title = {Long- and short-term responses of Asclepias species differ in respect to fire, grazing, and nutrient addition.}, journal = {American journal of botany}, volume = {105}, number = {12}, pages = {2008-2017}, doi = {10.1002/ajb2.1197}, pmid = {30485407}, issn = {1537-2197}, support = {//Max and Victoria Dreyfus Foundation/International ; //National Geographic Foundation/International ; //Dominion Educational Partnership/International ; //National Science Foundation Long Term Ecological Research Program at Konza Prairie Biological Station/International ; }, mesh = {Asclepias/*physiology ; Fertilizers ; *Herbivory ; Population Dynamics ; *Wildfires ; }, abstract = {PREMISE OF THE STUDY: The tallgrass prairie ecosystem has experienced a dramatic reduction over the past 150 yr. This reduction has impacted the abundance of native grassland species, including milkweeds (Asclepias).<br><br>METHODS: We used two long-term (27 yr) data sets to examine how fire, grazing, and nutrient addition shape milkweed abundance in tallgrass prairie. We compared these results to those of a greenhouse experiment that varied nutrient levels in the absence of competition, herbivory, and mutualistic relationships.<br><br>KEY RESULTS: Asclepias species exhibited broad patterns in response to burning regimes that did not include grazing, but experienced more species-specific patterns in other combinations. Asclepias syriaca was the only species to increase in abundance in plots that included burning and nutrient addition. In the greenhouse we found that nitrogen significantly increased biomass, while no effect of phosphorus was detected.<br><br>CONCLUSIONS: These results indicate that A. syriaca will do best in settings with high nutrient loads, low competition, and no grazers. These characteristics define a small portion of the tallgrass prairie but exemplify modern agricultural settings, which have replaced prairies. However, other milkweeds examined did not share this pattern, which indicates that milkweed species will respond differently when exposed to agricultural settings, with some less able to cope with land conversion to pasture or row-crop agriculture.}, }
@article {pmid30456619, year = {2019}, author = {Battisti, C and Kroha, S and Kozhuharova, E and De Michelis, S and Fanelli, G and Poeta, G and Pietrelli, L and Cerfolli, F}, title = {Fishing lines and fish hooks as neglected marine litter: first data on chemical composition, densities, and biological entrapment from a Mediterranean beach.}, journal = {Environmental science and pollution research international}, volume = {26}, number = {1}, pages = {1000-1007}, pmid = {30456619}, issn = {1614-7499}, mesh = {Alismatales ; Animals ; Bathing Beaches/statistics &amp; numerical data ; *Environmental Monitoring ; *Fisheries ; Mediterranean Sea ; Plastics/*analysis ; Seafood ; Waste Products/*analysis ; }, abstract = {We reported first data on the densities and chemical composition of fishing lines and fish hooks deposited on a Mediterranean beach. On a sampling area of 1.5 ha, we removed a total of 185,028 cm of fishing lines (density 12.34 cm/m[2]) and 33 hooks (density 22 units/ha). Totally, 637.62 g (42.5 mg/m[2]) of fishing lines were collected. We sampled 120 items entangled belongings to 7 animal taxa (density 6.49 items/100 m of fishing lines). We also observed a not quantifiable number of egagropiles (Posidonia oceanica spheroids), Rhodophyceae (Halymenia sp.) and segments of reeds of Phragmites communis, trapped in the fishing lines. Fourier transform infrared (FTIR) spectroscopy was used in order to identify the chemical composition of the fishing lines: 92% was made of nylon while 8.0% was determined as fluorocarbon based polymers (polyvinylidene fluoride). Because of their subtlety and reduced size, sandy beach cleaning operations should include at least two consecutive removal samplings: indeed, a part of this litter (12.14%) is not removed in the first sampling. The unexpected high density of fishing lines suggests specific management actions aimed to periodically remove this neglected anthropogenic litter.}, }
@article {pmid30420511, year = {2018}, author = {Cáliz, J and Triadó-Margarit, X and Camarero, L and Casamayor, EO}, title = {A long-term survey unveils strong seasonal patterns in the airborne microbiome coupled to general and regional atmospheric circulations.}, journal = {Proceedings of the National Academy of Sciences of the United States of America}, volume = {115}, number = {48}, pages = {12229-12234}, pmid = {30420511}, issn = {1091-6490}, mesh = {Aerosols/analysis ; *Air Microbiology ; Archaea/classification/genetics/*isolation &amp; purification ; Atmosphere ; Bacteria/classification/genetics/*isolation &amp; purification ; Biodiversity ; Fungi/classification/genetics/*isolation &amp; purification ; *Microbiota ; Phylogeny ; Seasons ; Spain ; }, abstract = {Airborne microbes (bacteria, archaea, protists, and fungi) were surveyed over a 7-y period via high-throughput massive sequencing of 16S and 18S rRNA genes in rain and snow samples collected fortnightly at a high-elevation mountain Long-Term Ecological Research (LTER) Network site (LTER-Aigüestortes, Central Pyrenees, Spain). This survey constitutes the most comprehensive mountain-top aerobiology study reported to date. The air mass origins were tracked through modeled back-trajectories and analysis of rain water chemical composition. Consistent microbial seasonal patterns were observed with highly divergent summer and winter communities recurrent in time. Indicative microbial taxa were unveiled as a forensic signature, and ubiquitous taxa were observed as common atmosphere inhabitants, highlighting aerosols as a potentially successful mechanism for global microbial dispersal. Source-tracking analyses identified freshwater, cropland, and urban biomes as the most important sources for airborne bacteria in summer, while marine and forest biomes prevailed in winter, in agreement with air mass retrotrajectories and the prevailing general and regional atmospheric circulation.}, }
@article {pmid30417235, year = {2019}, author = {Staffieri, E and de Lucia, GA and Camedda, A and Poeta, G and Battisti, C}, title = {Pressure and impact of anthropogenic litter on marine and estuarine reptiles: an updated "blacklist" highlighting gaps of evidence.}, journal = {Environmental science and pollution research international}, volume = {26}, number = {2}, pages = {1238-1249}, pmid = {30417235}, issn = {1614-7499}, mesh = {Animals ; Aquatic Organisms/*physiology ; *Environmental Monitoring ; Estuaries ; Plastics/*analysis ; Reptiles/*physiology ; Waste Products/*analysis ; }, abstract = {We report an arrangement on the effect of anthropogenic litter on marine and estuarine reptiles, checking for evidence about different types of impact (ingestion vs. entanglement) and pressure (three size-based categories). From 1976 to 2018, we obtained a "blacklist" of 11 species impacted by marine litter (about 13% of 85 species of marine and estuarine reptiles), belonging to three orders (Testudines, Squamata, and Crocodilia). We obtained only occasional evidence of an impact for Squamata (Hidrophis elegans, Disteira major) and Crocodilia (Crocodylus porosus). Regarding the different types of pressure, the highest number of evidence has been obtained for macro-litter (10 species) and the lowest for micro-litter (4 species, all Chelonidae). Among Testudines, Lepidochelys kempii and Natator depressus evidenced a lack of data for micro-plastic. In Squamata, information is lacking for micro-plastic with only occasional references for meso-plastic (in Hydrophis elegans) and macro-plastic (Disteira major and Crocodylus porosus). We obtained a direct correlation between the research effort and the number of citations regarding different types of pressure and impact of marine litter: therefore, our blacklist of impacted species could be increased, carrying out further research focused on other poorly studied marine and estuarine reptiles. We suggest the use of a standardized nomenclature to reduce the amount of lost information.}, }
@article {pmid30376192, year = {2018}, author = {Wilson, BJ and Servais, S and Mazzei, V and Kominoski, JS and Hu, M and Davis, SE and Gaiser, E and Sklar, F and Bauman, L and Kelly, S and Madden, C and Richards, J and Rudnick, D and Stachelek, J and Troxler, TG}, title = {Salinity pulses interact with seasonal dry-down to increase ecosystem carbon loss in marshes of the Florida Everglades.}, journal = {Ecological applications : a publication of the Ecological Society of America}, volume = {28}, number = {8}, pages = {2092-2108}, doi = {10.1002/eap.1798}, pmid = {30376192}, issn = {1051-0761}, support = {DEB-1237517//National Science Foundation's Florida Coastal Everglades Long Term Ecological Research (FCE LTER) Program/International ; 2018M630731//China Postdoctoral Science Foundation/International ; 41601102//National Science Foundation of China/International ; }, mesh = {*Carbon Cycle ; Carbon Dioxide/analysis ; Florida ; Methane/analysis ; *Salinity ; Seasons ; *Wetlands ; }, abstract = {Coastal wetlands are globally important sinks of organic carbon (C). However, to what extent wetland C cycling will be affected by accelerated sea-level rise (SLR) and saltwater intrusion is unknown, especially in coastal peat marshes where water flow is highly managed. Our objective was to determine how the ecosystem C balance in coastal peat marshes is influenced by elevated salinity. For two years, we made monthly in situ manipulations of elevated salinity in freshwater (FW) and brackish water (BW) sites within Everglades National Park, Florida, USA. Salinity pulses interacted with marsh-specific variability in seasonal hydroperiods whereby effects of elevated pulsed salinity on gross ecosystem productivity (GEP), ecosystem respiration (ER), and net ecosystem productivity (NEP) were dependent on marsh inundation level. We found little effect of elevated salinity on C cycling when both marsh sites were inundated, but when water levels receded below the soil surface, the BW marsh shifted from a C sink to a C source. During these exposed periods, we observed an approximately threefold increase in CO2 efflux from the marsh as a result of elevated salinity. Initially, elevated salinity pulses did not affect Cladium jamaicense biomass, but aboveground biomass began to be significantly decreased in the saltwater amended plots after two years of exposure at the BW site. We found a 65% (FW) and 72% (BW) reduction in live root biomass in the soil after two years of exposure to elevated salinity pulses. Regardless of salinity treatment, the FW site was C neutral while the BW site was a strong C source (-334 to -454 g C·m[-2] ·yr[-1]), particularly during dry-down events. A loss of live roots coupled with annual net CO2 losses as marshes transition from FW to BW likely contributes to the collapse of peat soils observed in the coastal Everglades. As SLR increases the rate of saltwater intrusion into coastal wetlands globally, understanding how water management influences C gains and losses from these systems is crucial. Under current Everglades' water management, drought lengthens marsh dry-down periods, which, coupled with saltwater intrusion, accelerates CO2 loss from the marsh.}, }
@article {pmid30376156, year = {2018}, author = {Rudgers, JA and Dettweiler-Robinson, E and Belnap, J and Green, LE and Sinsabaugh, RL and Young, KE and Cort, CE and Darrouzet-Nardi, A}, title = {Are fungal networks key to dryland primary production?.}, journal = {American journal of botany}, volume = {105}, number = {11}, pages = {1783-1787}, doi = {10.1002/ajb2.1184}, pmid = {30376156}, issn = {1537-2197}, support = {1557135//National Science Foundation/International ; 1503898//National Science Foundation/International ; 1456955//National Science Foundation/International ; //University of New Mexico for Long-term Ecological Research/International ; //U.S. Geological Survey Ecosystems program/International ; }, mesh = {*Biomass ; *Desert Climate ; *Soil Microbiology ; }, }
@article {pmid30376154, year = {2018}, author = {Castorani, MCN and Reed, DC and Miller, RJ}, title = {Loss of foundation species: disturbance frequency outweighs severity in structuring kelp forest communities.}, journal = {Ecology}, volume = {99}, number = {11}, pages = {2442-2454}, doi = {10.1002/ecy.2485}, pmid = {30376154}, issn = {0012-9658}, support = {1232779//National Science Foundation/International ; }, mesh = {Animals ; Ecosystem ; Forests ; Invertebrates ; *Kelp ; *Macrocystis ; }, abstract = {Disturbances often cause the disproportionate loss of foundation species but understanding how the frequency and severity of disturbance to such organisms influence biological communities remains unresolved. This gap in knowledge exists in part because of the rarity of ecologically meaningful studies capable of disentangling different elements of disturbance. Hence, we carried out a long-term (9 yr), large-scale (2,000 m[2] plots), spatially replicated (4 sites) field experiment in which we manipulated disturbance to a globally distributed marine foundation species, the giant kelp Macrocystis pyrifera, and tracked community responses over time. To distinguish the effects of disturbance frequency and severity on the biodiversity and composition of temperate rocky reef communities, we simulated the repeated loss of giant kelp from destructive winter waves across a background of natural variation in disturbance. By following the response of over 200 taxa from the surrounding community, we discovered that the frequency of disturbance to giant kelp changed the biomass, diversity, and composition of community guilds in a manner commensurate with their dependence on the physical (i.e., benthic light and space), trophic (i.e., living and detrital biomass), and habitat (i.e., biogenic structure) resources mediated by this foundation species. Annual winter disturbance to giant kelp reduced living and detrital giant kelp biomass by 57% and 40%, respectively, enhanced bottom light by 22%, and halved the seafloor area covered by giant kelp holdfasts. Concomitantly, the biomass of understory algae and epilithic sessile invertebrates more than doubled, while the biomass of rock-boring clams, mobile invertebrates, and fishes decreased 30-61%. Frequent loss of giant kelp boosted understory algal richness by 82% and lowered sessile invertebrate richness by 13% but did not affect the biodiversity of mobile fauna. In contrast to changes driven by disturbance frequency, interannual variation in the severity of disturbance to giant kelp had weaker, less consistent effects, causing only modest changes in assemblages of sessile invertebrates, mobile invertebrate herbivores, and fishes. Our results broaden the foundation species concept by demonstrating that repeated disturbance to a dominant habitat-forming species can outweigh the influence of less frequent but severe disturbances for the surrounding community.}, }
@article {pmid30374174, year = {2018}, author = {Koerner, SE and Smith, MD and Burkepile, DE and Hanan, NP and Avolio, ML and Collins, SL and Knapp, AK and Lemoine, NP and Forrestel, EJ and Eby, S and Thompson, DI and Aguado-Santacruz, GA and Anderson, JP and Anderson, TM and Angassa, A and Bagchi, S and Bakker, ES and Bastin, G and Baur, LE and Beard, KH and Beever, EA and Bohlen, PJ and Boughton, EH and Canestro, D and Cesa, A and Chaneton, E and Cheng, J and D'Antonio, CM and Deleglise, C and Dembélé, F and Dorrough, J and Eldridge, DJ and Fernandez-Going, B and Fernández-Lugo, S and Fraser, LH and Freedman, B and García-Salgado, G and Goheen, JR and Guo, L and Husheer, S and Karembé, M and Knops, JMH and Kraaij, T and Kulmatiski, A and Kytöviita, MM and Lezama, F and Loucougaray, G and Loydi, A and Milchunas, DG and Milton, SJ and Morgan, JW and Moxham, C and Nehring, KC and Olff, H and Palmer, TM and Rebollo, S and Riginos, C and Risch, AC and Rueda, M and Sankaran, M and Sasaki, T and Schoenecker, KA and Schultz, NL and Schütz, M and Schwabe, A and Siebert, F and Smit, C and Stahlheber, KA and Storm, C and Strong, DJ and Su, J and Tiruvaimozhi, YV and Tyler, C and Val, J and Vandegehuchte, ML and Veblen, KE and Vermeire, LT and Ward, D and Wu, J and Young, TP and Yu, Q and Zelikova, TJ}, title = {Change in dominance determines herbivore effects on plant biodiversity.}, journal = {Nature ecology &amp; evolution}, volume = {2}, number = {12}, pages = {1925-1932}, doi = {10.1038/s41559-018-0696-y}, pmid = {30374174}, issn = {2397-334X}, mesh = {Animals ; *Biodiversity ; Desert Climate ; *Grassland ; *Herbivory ; Mammals/*physiology ; *Plants ; }, abstract = {Herbivores alter plant biodiversity (species richness) in many of the world's ecosystems, but the magnitude and the direction of herbivore effects on biodiversity vary widely within and among ecosystems. One current theory predicts that herbivores enhance plant biodiversity at high productivity but have the opposite effect at low productivity. Yet, empirical support for the importance of site productivity as a mediator of these herbivore impacts is equivocal. Here, we synthesize data from 252 large-herbivore exclusion studies, spanning a 20-fold range in site productivity, to test an alternative hypothesis-that herbivore-induced changes in the competitive environment determine the response of plant biodiversity to herbivory irrespective of productivity. Under this hypothesis, when herbivores reduce the abundance (biomass, cover) of dominant species (for example, because the dominant plant is palatable), additional resources become available to support new species, thereby increasing biodiversity. By contrast, if herbivores promote high dominance by increasing the abundance of herbivory-resistant, unpalatable species, then resource availability for other species decreases reducing biodiversity. We show that herbivore-induced change in dominance, independent of site productivity or precipitation (a proxy for productivity), is the best predictor of herbivore effects on biodiversity in grassland and savannah sites. Given that most herbaceous ecosystems are dominated by one or a few species, altering the competitive environment via herbivores or by other means may be an effective strategy for conserving biodiversity in grasslands and savannahs globally.}, }
@article {pmid30368825, year = {2019}, author = {Furze, ME and Huggett, BA and Aubrecht, DM and Stolz, CD and Carbone, MS and Richardson, AD}, title = {Whole-tree nonstructural carbohydrate storage and seasonal dynamics in five temperate species.}, journal = {The New phytologist}, volume = {221}, number = {3}, pages = {1466-1477}, pmid = {30368825}, issn = {1469-8137}, support = {DGE-1144152//National Science Foundation Graduate Research Fellowship program/International ; //Garden Club of New Jersey/International ; DEB-1237491//National Science Foundation's LTER program/International ; //US Department of Energy's Office of Science, Office of Biological and Environmental Research/International ; }, mesh = {Biomass ; Carbohydrates/*chemistry ; Ecosystem ; *Seasons ; Species Specificity ; Starch/metabolism ; Sugars/metabolism ; Trees/*metabolism ; }, abstract = {Despite the importance of nonstructural carbohydrates (NSC) for growth and survival in woody plants, we know little about whole-tree NSC storage. The conventional theory suggests that NSC reserves will increase over the growing season and decrease over the dormant season. Here, we compare storage in five temperate tree species to determine the size and seasonal fluctuation of whole-tree total NSC pools as well as the contribution of individual organs. NSC concentrations in the branches, stemwood, and roots of 24 trees were measured across 12 months. We then scaled up concentrations to the whole-tree and ecosystem levels using allometric equations and forest stand inventory data. While whole-tree total NSC pools followed the conventional theory, sugar pools peaked in the dormant season and starch pools in the growing season. Seasonal depletion of total NSCs was minimal at the whole-tree level, but substantial at the organ level, particularly in branches. Surprisingly, roots were not the major storage organ as branches stored comparable amounts of starch throughout the year, and root reserves were not used to support springtime growth. Scaling up NSC concentrations to the ecosystem level, we find that commonly used, process-based ecosystem and land surface models all overpredict NSC storage.}, }
@article {pmid30368793, year = {2018}, author = {Sullivan, LL and Clark, AT and Tilman, D and Shaw, AK}, title = {Mechanistically derived dispersal kernels explain species-level patterns of recruitment and succession.}, journal = {Ecology}, volume = {99}, number = {11}, pages = {2415-2420}, doi = {10.1002/ecy.2498}, pmid = {30368793}, issn = {0012-9658}, support = {//University of Minnesota (U of M) Graduate Excellence Grant/International ; DEB 8114302//US NSF LTER Program/International ; 8811884//US NSF LTER Program/International ; 9411972//US NSF LTER Program/International ; 0080382//US NSF LTER Program/International ; 0620652//US NSF LTER Program/International ; 1234162//US NSF LTER Program/International ; 00006595//NSF GRF/International ; //Balzan Prize Foundation/International ; }, mesh = {*Ecology ; Plants ; *Seed Dispersal ; }, abstract = {Species-level dispersal information can give mechanistic insights into how spatial processes impact plant communities. Unfortunately, field-based estimates of the dispersal abilities of multiple members of a community are often lacking for many plant systems. Here, we provide a simple method for measuring dispersal ability for large numbers of grassland plant species based on functional traits. Using this method, we estimated the dispersal ability of 50 co-occurring grassland species using the Wald Analytical Long-distance Dispersal (WALD) model. Grassland plants species are often used for developing community theory, yet species-level estimates of their dispersal abilities are comparatively rare. We use these dispersal measurements to examine the relationship between species dispersal abilities and successional dynamics using data from a 90-yr old field chronosequence. We find that our estimated dispersal measurements matched field-based establishment observations well, and estimated species colonization, competitive, and establishment abilities. We hope that this method for measuring dispersal ability of multiple species within a community, and its demonstrated ability to generate predictions for spatial ecology, will encourage more studies of the explicit role of dispersal in plant community ecology.}, }
@article {pmid30322922, year = {2018}, author = {Lister, BC and Garcia, A}, title = {Climate-driven declines in arthropod abundance restructure a rainforest food web.}, journal = {Proceedings of the National Academy of Sciences of the United States of America}, volume = {115}, number = {44}, pages = {E10397-E10406}, pmid = {30322922}, issn = {1091-6490}, mesh = {Animals ; Arthropods/*growth &amp; development ; Biodiversity ; Biomass ; Birds/growth &amp; development ; Ecosystem ; El Nino-Southern Oscillation/adverse effects ; Food Chain ; Forests ; Puerto Rico ; Rainforest ; Trees/growth &amp; development ; Tropical Climate/*adverse effects ; }, abstract = {A number of studies indicate that tropical arthropods should be particularly vulnerable to climate warming. If these predictions are realized, climate warming may have a more profound impact on the functioning and diversity of tropical forests than currently anticipated. Although arthropods comprise over two-thirds of terrestrial species, information on their abundance and extinction rates in tropical habitats is severely limited. Here we analyze data on arthropod and insectivore abundances taken between 1976 and 2012 at two midelevation habitats in Puerto Rico's Luquillo rainforest. During this time, mean maximum temperatures have risen by 2.0 °C. Using the same study area and methods employed by Lister in the 1970s, we discovered that the dry weight biomass of arthropods captured in sweep samples had declined 4 to 8 times, and 30 to 60 times in sticky traps. Analysis of long-term data on canopy arthropods and walking sticks taken as part of the Luquillo Long-Term Ecological Research program revealed sustained declines in abundance over two decades, as well as negative regressions of abundance on mean maximum temperatures. We also document parallel decreases in Luquillo's insectivorous lizards, frogs, and birds. While El Niño/Southern Oscillation influences the abundance of forest arthropods, climate warming is the major driver of reductions in arthropod abundance, indirectly precipitating a bottom-up trophic cascade and consequent collapse of the forest food web.}, }
@article {pmid30312496, year = {2019}, author = {Baker, CM and Bode, M and Dexter, N and Lindenmayer, DB and Foster, C and MacGregor, C and Plein, M and McDonald-Madden, E}, title = {A novel approach to assessing the ecosystem-wide impacts of reintroductions.}, journal = {Ecological applications : a publication of the Ecological Society of America}, volume = {29}, number = {1}, pages = {e01811}, doi = {10.1002/eap.1811}, pmid = {30312496}, issn = {1051-0761}, mesh = {Animals ; Australia ; Conservation of Natural Resources ; *Ecosystem ; *Marsupialia ; Parks, Recreational ; }, abstract = {Reintroducing a species to an ecosystem can have significant impacts on the recipient ecological community. Although reintroductions can have striking and positive outcomes, they also carry risks; many well-intentioned conservation actions have had surprising and unsatisfactory outcomes. A range of network-based mathematical methods has been developed to make quantitative predictions of how communities will respond to management interventions. These methods are based on the limited knowledge of which species interact with each other and in what way. However, expert knowledge isn't perfect and can only take models so far. Fortunately, other types of data, such as abundance time series, is often available, but, to date, no quantitative method exists to integrate these various data types into these models, allowing more precise ecosystem-wide predictions. In this paper, we develop mathematical methods that combine time-series data of multiple species with knowledge of species interactions and we apply it to proposed reintroductions at Booderee National Park in Australia. There have been large fluctuations in species abundances at Booderee National Park in recent history, following intense feral fox (Vulpes vulpes) control, including the local extinction of the greater glider (Petauroides volans). These fluctuations can provide information about the system isn't readily obtained from a stable system, and we use them to inform models that we then use to predict potential outcomes of eastern quoll (Dasyurus viverrinus) and long-nosed potoroo (Potorous tridactylus) reintroductions. One of the key species of conservation concern in the park is the Eastern Bristlebird (Dasyornis brachypterus), and we find that long-nosed potoroo introduction would have very little impact on the Eastern Bristlebird population, while the eastern quoll introduction increased the likelihood of Eastern Bristlebird decline, although that depends on the strength and form of any possible interaction.}, }
@article {pmid30250196, year = {2018}, author = {Kallenbach, CM and Frey, SD and Grandy, AS}, title = {Author Correction: Direct evidence for microbial-derived soil organic matter formation and its ecophysiological controls.}, journal = {Nature communications}, volume = {9}, number = {1}, pages = {3929}, doi = {10.1038/s41467-018-06427-3}, pmid = {30250196}, issn = {2041-1723}, abstract = {In the originally published version of this Article, financial support was not fully acknowledged. The PDF and HTML versions of the Article have now been corrected to include support from the NSF Long-term Ecological Research Program (DEB 1637653) at the Kellogg Biological Station and from Michigan State University AgBioResearch.}, }
@article {pmid30220785, year = {2017}, author = {Kaushal, SS and Duan, S and Doody, TR and Haq, S and Smith, RM and Newcomer Johnson, TA and Newcomb, KD and Gorman, J and Bowman, N and Mayer, PM and Wood, KL and Belt, KT and Stack, WP}, title = {Human-accelerated weathering increases salinization, major ions, and alkalinization in fresh water across land use.}, journal = {Applied geochemistry : journal of the International Association of Geochemistry and Cosmochemistry}, volume = {83}, number = {}, pages = {121-135}, pmid = {30220785}, issn = {0883-2927}, support = {EPA999999//Intramural EPA/United States ; }, abstract = {Human-dominated land uses can increase transport of major ions in streams due to the combination of human-accelerated weathering and anthropogenic salts. Calcium, magnesium, sodium, alkalinity, and hardness significantly increased in the drinking water supply for Baltimore, Maryland over almost 50 years (p<0.05) coinciding with regional urbanization. Across a nearby land use gradient at the Baltimore Long-Term Ecological Research (LTER) site, there were significant increases in concentrations of dissolved inorganic carbon (DIC), Ca[2+], Mg[2+], Na[+], and Si and pH with increasing impervious surfaces in 9 streams monitored bi-weekly over a 3-4 year period (p<0.05). Base cations in urban streams were up to 60 times greater than forest and agricultural streams, and elemental ratios suggested road salt and carbonate weathering from impervious surfaces as potential sources. Laboratory weathering experiments with concrete also indicated that impervious surfaces increased pH and DIC with potential to alkalinize urban waters. Ratios of Na[+] and Cl[-] suggested that there was enhanced ion exchange in the watersheds from road salts, which could mobilize other base cations from soils to streams. There were significant relationships between Ca[2+], Mg[2+], Na[+], and K[+] concentrations and Cl[-], SO4[2-], NO3[-] and DIC across land use (p<0.05), which suggested tight coupling of geochemical cycles. Finally, concentrations of Na[+], Ca[2+], Mg[2+], and pH significantly increased with distance downstream (p<0.05) along a stream network draining 170 km[2] of the Baltimore LTER site contributing to river alkalinization. Our results suggest that urbanization may dramatically increase major ions, ionic strength, and pH over decades from headwaters to coastal zones, which can impact integrity of aquatic life, infrastructure, drinking water, and coastal ocean alkalinization.}, }
@article {pmid30218544, year = {2018}, author = {Kendrick, MR and Huryn, AD and Bowden, WB and Deegan, LA and Findlay, RH and Hershey, AE and Peterson, BJ and Beneš, JP and Schuett, EB}, title = {Linking permafrost thaw to shifting biogeochemistry and food web resources in an arctic river.}, journal = {Global change biology}, volume = {24}, number = {12}, pages = {5738-5750}, doi = {10.1111/gcb.14448}, pmid = {30218544}, issn = {1365-2486}, mesh = {Alaska ; Arctic Regions ; Carbon/analysis ; Ecosystem ; *Food Chain ; *Global Warming ; Lakes ; Nitrogen/analysis ; *Permafrost ; Phosphorus/analysis ; *Rivers ; }, abstract = {Rapidly, increasing air temperatures across the Arctic are thawing permafrost and exposing vast quantities of organic carbon, nitrogen, and phosphorus to microbial processing. Shifts in the absolute and relative supplies of these elements will likely alter patterns of ecosystem productivity and change the way carbon and nutrients are delivered from upland areas to surface waters such as rivers and lakes. The ultra-oligotrophic nature of surface waters across the Arctic renders these ecosystems particularly susceptible to changes in productivity and food web dynamics as permafrost thaw alters terrestrial-aquatic linkages. The objectives of this study were to evaluate decadal-scale patterns in surface water chemistry and assess potential implications of changing water chemistry to benthic organic matter and aquatic food webs. Data were collected from the upper Kuparuk River on the North Slope of Alaska by the U.S. National Science Foundation's Long-Term Ecological Research program during 1978-2014. Analyses of these data show increases in stream water alkalinity and cation concentrations consistent with signatures of permafrost thaw. Changes are also documented for discharge-corrected nitrate concentrations (+), discharge-corrected dissolved organic carbon concentrations (-), total phosphorus concentrations (-), and δ[13] C isotope values of aquatic invertebrate consumers (-). These changes show that warming temperatures and thawing permafrost in the upland environment are leading to shifts in the supply of carbon and nutrients available to surface waters and consequently changing resources that support aquatic food webs. This demonstrates that physical, geochemical, and biological changes associated with warming permafrost are fundamentally altering linkages between upland and aquatic ecosystems in rapidly changing arctic environments.}, }
@article {pmid30179279, year = {2018}, author = {Bowman, WD and Ayyad, A and Bueno de Mesquita, CP and Fierer, N and Potter, TS and Sternagel, S}, title = {Limited ecosystem recovery from simulated chronic nitrogen deposition.}, journal = {Ecological applications : a publication of the Ecological Society of America}, volume = {28}, number = {7}, pages = {1762-1772}, doi = {10.1002/eap.1783}, pmid = {30179279}, issn = {1051-0761}, support = {//National Science Foundation through the Niwot Ridge Long-Term Ecological Research Program/International ; }, mesh = {Bacterial Physiological Phenomena ; *Conservation of Natural Resources ; Cyperaceae/*physiology ; Fungi/physiology ; *Grassland ; *Nitrogen Cycle ; Soil/*chemistry ; Soil Microbiology ; }, abstract = {The realization that anthropogenic nitrogen (N) deposition is causing significant environmental change in many ecosystems has led to lower emissions of reactive N and deposition rates in many regions. However, the impacts of N deposition on terrestrial ecosystems can be long lasting, with significant inertia in the return of the biota and biogeochemical processes to baseline levels. To better understand patterns of recovery and the factors that may contribute to slow or no responses following declines in N deposition, we followed plant species composition, microbial abundance, N cycling rates, soil pH, and pools of NO3[-] and extractable cations in an impacted alpine ecosystem following cessation of 12-yr experiment increasing N deposition rates by 0, 20, 40, and 60 kg N·ha[-1] ·yr[-1] . Simulated N deposition had resulted in a tripling in the cover of the nitrophilic species Carex rupestris, while the dominant sedge Kobresia myosuroides had decreased by more than half at the highest N input level. In addition, nitrification rates were elevated, soil extractable magnesium (Mg[2+]) and pH decreased, and aluminum (Al[3+]) and manganese (Mn[2+]) were elevated at the highest N treatment inputs. Over the nine years following cessation of N additions to the impacted plots, only the cover of the nitrophilic C. rupestris showed any recovery to prior levels. Abundances of both bacteria and fungi were lower with N addition in both treatment and recovery plots. Rates of nitrification and pools of NO3[-] remained elevated in the recovery plots, likely contributing to the lack of biotic response to the cessation of N inputs. In addition, nutrient base cations (Ca[2+] and Mg[2+]) and soil pH remained depressed, and the toxic metal cations (Al[3+] and Mn[2+]) remained elevated in recovery plots, also potentially influencing biotic recovery. These results emphasize the importance of considering long-term environmental impacts of N deposition associated with legacy effects, such as elevated N cycling and losses of base cations, in determining environmental standards such as the metrics used for critical loads.}, }
@article {pmid30176079, year = {2018}, author = {Obertegger, U and Bertilsson, S and Pindo, M and Larger, S and Flaim, G}, title = {Temporal variability of bacterioplankton is habitat driven.}, journal = {Molecular ecology}, volume = {27}, number = {21}, pages = {4322-4335}, doi = {10.1111/mec.14855}, pmid = {30176079}, issn = {1365-294X}, mesh = {Bacteria/*classification ; Biodiversity ; *Ecosystem ; High-Throughput Nucleotide Sequencing ; Italy ; Lakes/microbiology ; Plankton/*classification ; RNA, Ribosomal, 16S/genetics ; *Seasons ; }, abstract = {Temporal dynamics of bacterioplankton are rarely investigated for multiple habitats and years within individual lakes, limiting our understanding of the variability of bacterioplankton community (BC) composition with respect to environmental factors. We assessed the BC composition of a littoral and two pelagic habitats (euphotic zone and hypolimnion) of Lake Tovel monthly from April 2014 to May 2017 by high-throughput sequencing of the V3-V4 hypervariable region of the 16S rRNA gene. The three habitats differed in temperature, light, oxygen and hydrology. In particular, the littoral was the most hydrologically unstable because it receives most of the lake inflow, the hypolimnion was the most stable because of its hydrologically sheltered position, and the pelagic euphotic habitat was intermediate. Consequently, we hypothesized different temporal patterns of BC composition for all three habitats according to their environmental differences. We applied PERMANOVA, nonmetric multidimensional scaling and source-sink analysis to characterize BC composition. Overall, BCs were different among habitats with the littoral showing the highest variability and the hypolimnion the highest stability. The BC of rainy 2014 was distinct from the BCs of other years irrespective of the habitats considered. Seasonal differences in BCs were limited to spring, probably linked to meltwater inflow and mixing. Thus, temporal effects related to year and season were linked to the hydrological gradient of habitats. We suggest that despite potential within-lake dispersal of bacterioplankton by water flow and mixing, local environmental conditions played a major role in Lake Tovel, fostering distinct BCs in the three habitats.}, }
@article {pmid30144047, year = {2018}, author = {Berdanier, AB and Clark, JS}, title = {Tree water balance drives temperate forest responses to drought.}, journal = {Ecology}, volume = {99}, number = {11}, pages = {2506-2514}, doi = {10.1002/ecy.2499}, pmid = {30144047}, issn = {0012-9658}, support = {//Coweeta Long Term Ecological Research Program/International ; //Duke University Nicholas School of the Environment/International ; }, mesh = {Biomass ; *Droughts ; Forests ; *Trees ; Water ; }, abstract = {Intensifying drought is increasingly linked to global forest diebacks. Improved understanding of drought impacts on individual trees has provided limited insight into drought vulnerability in part because tree moisture access and depletion is difficult to quantify. In forests, moisture reservoir depletion occurs through water use by the trees themselves. Here, we show that drought impacts on tree fitness and demographic performance can be predicted by tracking the moisture reservoir available to trees as a mass balance, estimated in a hierarchical state-space framework. We apply this model to multiple seasonal droughts with tree transpiration measurements to demonstrate how species and size differences modulate moisture availability across landscapes. The depletion of individual moisture reservoirs can be tracked over the course of droughts and linked to biomass growth and reproductive output. This mass balance approach can predict individual moisture deficit, tree demographic performance, and drought vulnerability throughout forest stands based on measurements from a sample of trees.}, }
@article {pmid30109688, year = {2018}, author = {Iannilli, V and Di Gennaro, A and Lecce, F and Sighicelli, M and Falconieri, M and Pietrelli, L and Poeta, G and Battisti, C}, title = {Microplastics in Talitrus saltator (Crustacea, Amphipoda): new evidence of ingestion from natural contexts.}, journal = {Environmental science and pollution research international}, volume = {25}, number = {28}, pages = {28725-28729}, pmid = {30109688}, issn = {1614-7499}, mesh = {Amphipoda/*chemistry ; Animals ; Dietary Exposure/*analysis ; Ecosystem ; Ecotoxicology/methods ; Environmental Monitoring/methods ; Food Chain ; Gastrointestinal Contents ; Italy ; Plastics/*analysis ; Polyethylene/analysis ; Spectroscopy, Fourier Transform Infrared ; Water Pollutants, Chemical/*analysis ; }, abstract = {Using Fourier transform infrared spectroscopy (FT-IR) measurements and comparing the spectrum peaks (range 4000-600 cm[-1]) with reference spectra database and instrument libraries, we observed new evidence of the ingestion of microplastic particles analyzing the digestive tracts of Talitrus saltator. Specimens, sampled in central Italy, probably ingested the particles with natural detritus. Since worldwide many species of invertebrates and vertebrates (e.g., birds) feed on Amphipoda along coastal ecosystems, we hypothesized that microplastic in these crustaceans can be accumulated along the food chain.}, }
@article {pmid30089131, year = {2018}, author = {Potter, TI and Stannard, HJ and Greenville, AC and Dickman, CR}, title = {Understanding selective predation: Are energy and nutrients important?.}, journal = {PloS one}, volume = {13}, number = {8}, pages = {e0201300}, pmid = {30089131}, issn = {1932-6203}, mesh = {Animals ; Energy Metabolism/*physiology ; *Food Chain ; Marsupialia/*physiology ; *Models, Biological ; *Predatory Behavior ; Spiders ; }, abstract = {For generalist predators, a mixed diet can be advantageous as it allows individuals to exploit a potentially broad range of profitable food types. Despite this, some generalist predators show preferences for certain types of food and may forage selectively in places or at times when these foods are available. One such species is the lesser hairy-footed dunnart (Sminthopsis youngsoni). Usually considered to be a generalist insectivore, in the Simpson Desert, Australia, this small marsupial predator has been found to selectively consume wolf spiders (Family Lycosidae), for reasons yet unknown. Here, we tested whether lycosids have relatively high energy or nutrient contents compared to other invertebrates, and hence whether these aspects of food quality can explain selective predation of lycosids by S. youngsoni. Energy, lipid and protein composition of representatives of 9 arthropod families that are eaten by S. youngsoni in the Simpson Desert were ascertained using microbomb calorimetry, chloroform-methanol extraction and Dumas combustion, respectively. Although lycosids contained a high proportion of energy and nutrients, they were not found to yield statistically greater amounts of these food components than many other available arthropod prey that are not selected by S. youngsoni. Our results therefore suggest that alternative factors may be more influential in shaping dietary selection in this marsupial predator, such as high rates of encounter between lycosids and S. youngsoni.}, }
@article {pmid30082408, year = {2018}, author = {Ni, X and Groffman, PM}, title = {Declines in methane uptake in forest soils.}, journal = {Proceedings of the National Academy of Sciences of the United States of America}, volume = {115}, number = {34}, pages = {8587-8590}, pmid = {30082408}, issn = {1091-6490}, mesh = {*Forests ; Maryland ; Methane/*metabolism ; *Models, Biological ; *Soil ; }, abstract = {Forest soils are a sink for atmospheric methane (CH4) and play an important role in modulating the global CH4 budget. However, whether CH4 uptake by forest soils is affected by global environmental change is unknown. We measured soil to atmosphere net CH4 fluxes in temperate forests at two long-term ecological research sites in the northeastern United States from the late 1990s to the mid-2010s. We found that annual soil CH4 uptake decreased by 62% and 53% in urban and rural forests in Baltimore, Maryland and by 74% and 89% in calcium-fertilized and reference forests at Hubbard Brook, New Hampshire over this period. This decrease occurred despite marked declines in nitrogen deposition and increases in atmospheric CH4 concentration and temperature, which should lead to increases in CH4 uptake. This decrease in soil CH4 uptake appears to be driven by increases in precipitation and soil hydrological flux. Furthermore, an analysis of CH4 uptake around the globe showed that CH4 uptake in forest soils has decreased by an average of 77% from 1988 to 2015, particularly in forests located from 0 to 60 °N latitude where precipitation has been increasing. We conclude that the soil CH4 sink may be declining and overestimated in several regions across the globe.}, }
@article {pmid29996410, year = {2018}, author = {Vuorenmaa, J and Augustaitis, A and Beudert, B and Bochenek, W and Clarke, N and de Wit, HA and Dirnböck, T and Frey, J and Hakola, H and Kleemola, S and Kobler, J and Krám, P and Lindroos, AJ and Lundin, L and Löfgren, S and Marchetto, A and Pecka, T and Schulte-Bisping, H and Skotak, K and Srybny, A and Szpikowski, J and Ukonmaanaho, L and Váňa, M and Åkerblom, S and Forsius, M}, title = {Long-term changes (1990-2015) in the atmospheric deposition and runoff water chemistry of sulphate, inorganic nitrogen and acidity for forested catchments in Europe in relation to changes in emissions and hydrometeorological conditions.}, journal = {The Science of the total environment}, volume = {625}, number = {}, pages = {1129-1145}, doi = {10.1016/j.scitotenv.2017.12.245}, pmid = {29996410}, issn = {1879-1026}, abstract = {The international Long-Term Ecological Research Network (ILTER) encompasses hundreds of long-term research/monitoring sites located in a wide array of ecosystems that can help us understand environmental change across the globe. We evaluated long-term trends (1990-2015) for bulk deposition, throughfall and runoff water chemistry and fluxes, and climatic variables in 25 forested catchments in Europe belonging to the UNECE International Cooperative Programme on Integrated Monitoring of Air Pollution Effects on Ecosystems (ICP IM). Many of the IM sites form part of the monitoring infrastructures of this larger ILTER network. Trends were evaluated for monthly concentrations of non-marine (anthropogenic fraction, denoted as x) sulphate (xSO4) and base cations x(Ca+Mg), hydrogen ion (H[+]), inorganic N (NO3 and NH4) and ANC (Acid Neutralising Capacity) and their respective fluxes into and out of the catchments and for monthly precipitation, runoff and air temperature. A significant decrease of xSO4 deposition resulted in decreases in concentrations and fluxes of xSO4 in runoff, being significant at 90% and 60% of the sites, respectively. Bulk deposition of NO3 and NH4 decreased significantly at 60-80% (concentrations) and 40-60% (fluxes) of the sites. Concentrations and fluxes of NO3 in runoff decreased at 73% and 63% of the sites, respectively, and NO3 concentrations decreased significantly at 50% of the sites. Thus, the LTER/ICP IM network confirms the positive effects of the emission reductions in Europe. Air temperature increased significantly at 61% of the sites, while trends for precipitation and runoff were rarely significant. The site-specific variation of xSO4 concentrations in runoff was most strongly explained by deposition. Climatic variables and deposition explained the variation of inorganic N concentrations in runoff at single sites poorly, and as yet there are no clear signs of a consistent deposition-driven or climate-driven increase in inorganic N exports in the catchments.}, }
@article {pmid29940083, year = {2019}, author = {Mata, VA and Rebelo, H and Amorim, F and McCracken, GF and Jarman, S and Beja, P}, title = {How much is enough? Effects of technical and biological replication on metabarcoding dietary analysis.}, journal = {Molecular ecology}, volume = {28}, number = {2}, pages = {165-175}, pmid = {29940083}, issn = {1365-294X}, support = {//EDP Energias de Portugal/International ; IF/00497/2013//Funda&#xe7;&#xe3;o para Ci&#xea;ncia e Tecnologia/International ; LTER/BIA-BEC/0004/2009//Funda&#xe7;&#xe3;o para Ci&#xea;ncia e Tecnologia/International ; PD/BD/113462/2015//Funda&#xe7;&#xe3;o para Ci&#xea;ncia e Tecnologia/International ; PD/BD/52606/2014//Funda&#xe7;&#xe3;o para Ci&#xea;ncia e Tecnologia/International ; 668981//EU Horizon 2020/International ; }, mesh = {Animals ; Chiroptera/*genetics/physiology ; DNA Barcoding, Taxonomic/*methods ; *Diet ; Feces/chemistry ; *Feeding Behavior ; High-Throughput Nucleotide Sequencing ; Predatory Behavior/physiology ; }, abstract = {DNA metabarcoding is increasingly used in dietary studies to estimate diversity, composition and frequency of occurrence of prey items. However, few studies have assessed how technical and biological replication affect the accuracy of diet estimates. This study addresses these issues using the European free-tailed bat Tadarida teniotis, involving high-throughput sequencing of a small fragment of the COI gene in 15 separate faecal pellets and a 15-pellet pool per each of 20 bats. We investigated how diet descriptors were affected by variability among (a) individuals, (b) pellets of each individual and (c) PCRs of each pellet. In addition, we investigated the impact of (d) analysing separate pellets vs. pellet pools. We found that diet diversity estimates increased steadily with the number of pellets analysed per individual, with seven pellets required to detect ~80% of prey species. Most variation in diet composition was associated with differences among individual bats, followed by pellets per individual and PCRs per pellet. The accuracy of frequency of occurrence estimates increased with the number of pellets analysed per bat, with the highest error rates recorded for prey consumed infrequently by many individuals. Pools provided poor estimates of diet diversity and frequency of occurrence, which were comparable to analysing a single pellet per individual, and consistently missed the less common prey items. Overall, our results stress that maximizing biological replication is critical in dietary metabarcoding studies and emphasize that analysing several samples per individual rather than pooled samples produce more accurate results.}, }
@article {pmid29929254, year = {2018}, author = {Rogora, M and Frate, L and Carranza, ML and Freppaz, M and Stanisci, A and Bertani, I and Bottarin, R and Brambilla, A and Canullo, R and Carbognani, M and Cerrato, C and Chelli, S and Cremonese, E and Cutini, M and Di Musciano, M and Erschbamer, B and Godone, D and Iocchi, M and Isabellon, M and Magnani, A and Mazzola, L and Morra di Cella, U and Pauli, H and Petey, M and Petriccione, B and Porro, F and Psenner, R and Rossetti, G and Scotti, A and Sommaruga, R and Tappeiner, U and Theurillat, JP and Tomaselli, M and Viglietti, D and Viterbi, R and Vittoz, P and Winkler, M and Matteucci, G}, title = {Assessment of climate change effects on mountain ecosystems through a cross-site analysis in the Alps and Apennines.}, journal = {The Science of the total environment}, volume = {624}, number = {}, pages = {1429-1442}, doi = {10.1016/j.scitotenv.2017.12.155}, pmid = {29929254}, issn = {1879-1026}, abstract = {Mountain ecosystems are sensitive and reliable indicators of climate change. Long-term studies may be extremely useful in assessing the responses of high-elevation ecosystems to climate change and other anthropogenic drivers from a broad ecological perspective. Mountain research sites within the LTER (Long-Term Ecological Research) network are representative of various types of ecosystems and span a wide bioclimatic and elevational range. Here, we present a synthesis and a review of the main results from ecological studies in mountain ecosystems at 20 LTER sites in Italy, Switzerland and Austria covering in most cases more than two decades of observations. We analyzed a set of key climate parameters, such as temperature and snow cover duration, in relation to vascular plant species composition, plant traits, abundance patterns, pedoclimate, nutrient dynamics in soils and water, phenology and composition of freshwater biota. The overall results highlight the rapid response of mountain ecosystems to climate change, with site-specific characteristics and rates. As temperatures increased, vegetation cover in alpine and subalpine summits increased as well. Years with limited snow cover duration caused an increase in soil temperature and microbial biomass during the growing season. Effects on freshwater ecosystems were also observed, in terms of increases in solutes, decreases in nitrates and changes in plankton phenology and benthos communities. This work highlights the importance of comparing and integrating long-term ecological data collected in different ecosystems for a more comprehensive overview of the ecological effects of climate change. Nevertheless, there is a need for (i) adopting co-located monitoring site networks to improve our ability to obtain sound results from cross-site analysis, (ii) carrying out further studies, in particular short-term analyses with fine spatial and temporal resolutions to improve our understanding of responses to extreme events, and (iii) increasing comparability and standardizing protocols across networks to distinguish local patterns from global patterns.}, }
@article {pmid29900358, year = {2018}, author = {Cibic, T and Comici, C and Falconi, C and Fornasaro, D and Karuza, A and Lipizer, M}, title = {Phytoplankton community and physical-chemical data measured in the Gulf of Trieste (northern Adriatic Sea) over the period March 2006-February 2007.}, journal = {Data in brief}, volume = {19}, number = {}, pages = {586-593}, pmid = {29900358}, issn = {2352-3409}, abstract = {Biological, hydrological and chemical data were acquired at monthly intervals from March 2006 to February 2007, at the Long-Term Ecological Research site C1 in the Gulf of Trieste, in the northernmost part of the Adriatic Sea. The biological dataset comprises total chl a and phaeopigment concentrations, and the distinction of the total phytoplankton biomass into three photoautotrophic community fractions, i.e. cyanobacteria, nano- and microphytoplankton, collected at discrete depths. Hydrological data encompass the thermohaline properties of the water column (temperature and salinity profiles from CTD casts). Chemical data consist of silicate and phosphate concentrations obtained from discrete seawater samples collected with Niskin bottles at four depths (0.5-5-10-15 m). Data presented here are related to the paper "Structural and functional response of phytoplankton to reduced river inputs and anomalous physical-chemical conditions in the Gulf of Trieste (northern Adriatic Sea) by Cibic et al. (2018) [1].}, }
@article {pmid29898563, year = {2018}, author = {Kogovšek, T and Vodopivec, M and Raicich, F and Uye, SI and Malej, A}, title = {Comparative analysis of the ecosystems in the northern Adriatic Sea and the Inland Sea of Japan: Can anthropogenic pressures disclose jellyfish outbreaks?.}, journal = {The Science of the total environment}, volume = {626}, number = {}, pages = {982-994}, doi = {10.1016/j.scitotenv.2018.01.011}, pmid = {29898563}, issn = {1879-1026}, mesh = {Animals ; *Ecosystem ; Environmental Monitoring/*methods ; Eutrophication ; Italy ; Japan ; Oceans and Seas ; Population Growth ; Scyphozoa/*growth &amp; development ; Seawater/chemistry ; Temperature ; Water Pollution/analysis/statistics &amp; numerical data ; }, abstract = {A prominent increase in the moon jellyfish (genus Aurelia) populations has been observed since 1980 in two semi-enclosed temperate seas: the northern Adriatic Sea and the Inland Sea of Japan. Therefore, we reviewed long-term environmental and biotic data from the two Long-Term Ecological Research (LTER) sites, along with the increase in the moon jellyfish occurrence to elucidate how these coastal seas shifted to the jellyfish-dominated ecosystems. The principal component analysis of atmospheric data revealed a simultaneous occurrence of similar climatic changes in the early 1980s; thereafter, air temperature increased steadily and precipitation decreased but became more extreme. Accordingly, the average seawater temperature from March to October, a period of polyps' asexual reproduction i.e. budding, increased, potentially leading to an increase in the reproductive rates of local polyp populations. Conspicuous eutrophication occurred due to the rise of anthropogenic activities in both areas from the 1960s onwards. This coincided with an increase of the stock size of forage fishes, such as anchovy and sardine, but not the population size of the jellyfish. However, by the end of the 1980s, when the eutrophication lessened due to the regulations of nutrients loads from the land, the productive fishing grounds of both systems turned into a state that may be described as 'jellyfish-permeated,' as manifested by a drastic decrease in fish landings and a prominent increase in the intensity and frequency of medusa blooms. A steady increase in artificial marine structures that provide substrate for newly settled polyps might further contribute to the enhancement of jellyfish population size. Elevated fishing pressure and/or predation by jellyfish on ichthyoplankton and zooplankton might jeopardize the recruitment of anchovy, so that the anchovy catch has never recovered fully. These semi-enclosed seas may represent many temperate coastal waters with increased anthropogenic stressors, which have degraded the ecosystem from fish-dominated to jellyfish-dominated.}, }
@article {pmid29898550, year = {2018}, author = {Mirtl, M and T Borer, E and Djukic, I and Forsius, M and Haubold, H and Hugo, W and Jourdan, J and Lindenmayer, D and McDowell, WH and Muraoka, H and Orenstein, DE and Pauw, JC and Peterseil, J and Shibata, H and Wohner, C and Yu, X and Haase, P}, title = {Genesis, goals and achievements of Long-Term Ecological Research at the global scale: A critical review of ILTER and future directions.}, journal = {The Science of the total environment}, volume = {626}, number = {}, pages = {1439-1462}, doi = {10.1016/j.scitotenv.2017.12.001}, pmid = {29898550}, issn = {1879-1026}, abstract = {Since its founding in 1993 the International Long-term Ecological Research Network (ILTER) has gone through pronounced development phases. The current network comprises 44 active member LTER networks representing 700 LTER Sites and ~80 LTSER Platforms across all continents, active in the fields of ecosystem, critical zone and socio-ecological research. The critical challenges and most important achievements of the initial phase have now become state-of-the-art in networking for excellent science. At the same time increasing integration, accelerating technology, networking of resources and a strong pull for more socially relevant scientific information have been modifying the mission and goals of ILTER. This article provides a critical review of ILTER's mission, goals, development and impacts. Major characteristics, tools, services, partnerships and selected examples of relative strengths relevant for advancing ILTER are presented. We elaborate on the tradeoffs between the needs of the scientific community and stakeholder expectations. The embedding of ILTER in an increasingly collaborative landscape of global environmental observation and ecological research networks and infrastructures is also reflected by developments of pioneering regional and national LTER networks such as SAEON in South Africa, CERN/CEOBEX in China, TERN in Australia or eLTER RI in Europe. The primary role of ILTER is currently seen as a mechanism to investigate ecosystem structure, function, and services in response to a wide range of environmental forcings using long-term, place-based research. We suggest four main fields of activities and advancements for the next decade through development/delivery of a: (1) Global multi-disciplinary community of researchers and research institutes; (2) Strategic global framework and strong partnerships in ecosystem observation and research; (3) Global Research Infrastructure (GRI); and (4) a scientific knowledge factory for societally relevant information on sustainable use of natural resources.}, }
@article {pmid29898505, year = {2018}, author = {Haase, P and Tonkin, JD and Stoll, S and Burkhard, B and Frenzel, M and Geijzendorffer, IR and Häuser, C and Klotz, S and Kühn, I and McDowell, WH and Mirtl, M and Müller, F and Musche, M and Penner, J and Zacharias, S and Schmeller, DS}, title = {The next generation of site-based long-term ecological monitoring: Linking essential biodiversity variables and ecosystem integrity.}, journal = {The Science of the total environment}, volume = {613-614}, number = {}, pages = {1376-1384}, doi = {10.1016/j.scitotenv.2017.08.111}, pmid = {29898505}, issn = {1879-1026}, mesh = {*Biodiversity ; Decision Making ; *Ecosystem ; Environmental Monitoring/*methods/statistics &amp; numerical data ; *Environmental Policy ; }, abstract = {Global change effects on biodiversity and human wellbeing call for improved long-term environmental data as a basis for science, policy and decision making, including increased interoperability, multifunctionality, and harmonization. Based on the example of two global initiatives, the International Long-Term Ecological Research (ILTER) network and the Group on Earth Observations Biodiversity Observation Network (GEO BON), we propose merging the frameworks behind these initiatives, namely ecosystem integrity and essential biodiversity variables, to serve as an improved guideline for future site-based long-term research and monitoring in terrestrial, freshwater and coastal ecosystems. We derive a list of specific recommendations of what and how to measure at a monitoring site and call for an integration of sites into co-located site networks across individual monitoring initiatives, and centered on ecosystems. This facilitates the generation of linked comprehensive ecosystem monitoring data, supports synergies in the use of costly infrastructures, fosters cross-initiative research and provides a template for collaboration beyond the ILTER and GEO BON communities.}, }
@article {pmid29892379, year = {2018}, author = {Potter, TI and Greenville, AC and Dickman, CR}, title = {Assessing the potential for intraguild predation among taxonomically disparate micro-carnivores: marsupials and arthropods.}, journal = {Royal Society open science}, volume = {5}, number = {5}, pages = {171872}, pmid = {29892379}, issn = {2054-5703}, abstract = {Interspecific competition may occur when resources are limited, and is often most intense between animals in the same ecological guild. Intraguild predation (IGP) is a distinctive form of interference competition, where a dominant predator selectively kills subordinate rivals to gain increased access to resources. However, before IGP can be identified, organisms must be confirmed as members of the same guild and occur together in space and time. The lesser hairy-footed dunnart (Sminthopsis youngsoni, Dasyuridae) is a generalist marsupial insectivore in arid Australia, but consumes wolf spiders (Lycosa spp., Lycosidae) disproportionately often relative to their availability. Here, we test the hypothesis that this disproportionate predation is a product of frequent encounter rates between the interactants due to high overlap in their diets and use of space and time. Diet and prey availability were determined using direct observations and invertebrate pitfall trapping, microhabitat use by tracking individuals of both species-groups, and temporal activity using spotlighting and camera traps. Major overlap (greater than 75% similarity) was found in diet and temporal activity, and weaker overlap in microhabitat use. Taken together, these findings suggest reasonable potential, for the first time, for competition and intraguild predation to occur between taxa as disparate as marsupials and spiders.}, }
@article {pmid29890590, year = {2018}, author = {Dick, J and Orenstein, DE and Holzer, JM and Wohner, C and Achard, AL and Andrews, C and Avriel-Avni, N and Beja, P and Blond, N and Cabello, J and Chen, C and Díaz-Delgado, R and Giannakis, GV and Gingrich, S and Izakovicova, Z and Krauze, K and Lamouroux, N and Leca, S and Melecis, V and Miklós, K and Mimikou, M and Niedrist, G and Piscart, C and Postolache, C and Psomas, A and Santos-Reis, M and Tappeiner, U and Vanderbilt, K and Van Ryckegem, G}, title = {What is socio-ecological research delivering? A literature survey across 25 international LTSER platforms.}, journal = {The Science of the total environment}, volume = {622-623}, number = {}, pages = {1225-1240}, doi = {10.1016/j.scitotenv.2017.11.324}, pmid = {29890590}, issn = {1879-1026}, abstract = {With an overarching goal of addressing global and regional sustainability challenges, Long Term Socio-Ecological Research Platforms (LTSER) aim to conduct place-based research, to collect and synthesize both environmental and socio-economic data, and to involve a broader stakeholder pool to set the research agenda. To date there have been few studies examining the output from LTSER platforms. In this study we enquire if the socio-ecological research from 25 self-selected LTSER platforms of the International Long-Term Ecological Research (ILTER) network has produced research products which fulfil the aims and ambitions of the paradigm shift from ecological to socio-ecological research envisaged at the turn of the century. In total we assessed 4983 publically available publications, of which 1112 were deemed relevant to the socio-ecological objectives of the platform. A series of 22 questions were scored for each publication, assessing relevance of responses in terms of the disciplinary focus of research, consideration of human health and well-being, degree of stakeholder engagement, and other relevant variables. The results reflected the diverse origins of the individual platforms and revealed a wide range in foci, temporal periods and quantity of output from participating platforms, supporting the premise that there is a growing trend in socio-ecological research at long-term monitoring platforms. Our review highlights the challenges of realizing the top-down goal to harmonize international network activities and objectives and the need for bottom-up, self-definition for research platforms. This provides support for increasing the consistency of LTSER research while preserving the diversity of regional experiences.}, }
@article {pmid29860010, year = {2018}, author = {Holmberg, M and Aherne, J and Austnes, K and Beloica, J and De Marco, A and Dirnböck, T and Fornasier, MF and Goergen, K and Futter, M and Lindroos, AJ and Krám, P and Neirynck, J and Nieminen, TM and Pecka, T and Posch, M and Pröll, G and Rowe, EC and Scheuschner, T and Schlutow, A and Valinia, S and Forsius, M}, title = {Modelling study of soil C, N and pH response to air pollution and climate change using European LTER site observations.}, journal = {The Science of the total environment}, volume = {640-641}, number = {}, pages = {387-399}, doi = {10.1016/j.scitotenv.2018.05.299}, pmid = {29860010}, issn = {1879-1026}, abstract = {Current climate warming is expected to continue in coming decades, whereas high N deposition may stabilize, in contrast to the clear decrease in S deposition. These pressures have distinctive regional patterns and their resulting impact on soil conditions is modified by local site characteristics. We have applied the VSD+ soil dynamic model to study impacts of deposition and climate change on soil properties, using MetHyd and GrowUp as pre-processors to provide input to VSD+. The single-layer soil model VSD+ accounts for processes of organic C and N turnover, as well as charge and mass balances of elements, cation exchange and base cation weathering. We calibrated VSD+ at 26 ecosystem study sites throughout Europe using observed conditions, and simulated key soil properties: soil solution pH (pH), soil base saturation (BS) and soil organic carbon and nitrogen ratio (C:N) under projected deposition of N and S, and climate warming until 2100. The sites are forested, located in the Mediterranean, forested alpine, Atlantic, continental and boreal regions. They represent the long-term ecological research (LTER) Europe network, including sites of the ICP Forests and ICP Integrated Monitoring (IM) programmes under the UNECE Convention on Long-range Transboundary Air Pollution (LRTAP), providing high quality long-term data on ecosystem response. Simulated future soil conditions improved under projected decrease in deposition and current climate conditions: higher pH, BS and C:N at 21, 16 and 12 of the sites, respectively. When climate change was included in the scenario analysis, the variability of the results increased. Climate warming resulted in higher simulated pH in most cases, and higher BS and C:N in roughly half of the cases. Especially the increase in C:N was more marked with climate warming. The study illustrates the value of LTER sites for applying models to predict soil responses to multiple environmental changes.}, }
@article {pmid29760116, year = {2018}, author = {Schofield, O and Brown, M and Kohut, J and Nardelli, S and Saba, G and Waite, N and Ducklow, H}, title = {Changes in the upper ocean mixed layer and phytoplankton productivity along the West Antarctic Peninsula.}, journal = {Philosophical transactions. Series A, Mathematical, physical, and engineering sciences}, volume = {376}, number = {2122}, pages = {}, pmid = {29760116}, issn = {1471-2962}, abstract = {The West Antarctic Peninsula (WAP) has experienced significant change over the last 50 years. Using a 24 year spatial time series collected by the Palmer Long Term Ecological Research programme, we assessed long-term patterns in the sea ice, upper mixed layer depth (MLD) and phytoplankton productivity. The number of sea ice days steadily declined from the 1980s until a recent reversal that began in 2008. Results show regional differences between the northern and southern regions sampled during regional ship surveys conducted each austral summer. In the southern WAP, upper ocean MLD has shallowed by a factor of 2. Associated with the shallower mixed layer is enhanced phytoplankton carbon fixation. In the north, significant interannual variability resulted in the mixed layer showing no trended change over time and there was no significant increase in the phytoplankton productivity. Associated with the recent increases in sea ice there has been an increase in the photosynthetic efficiency (chlorophyll a-normalized carbon fixation) in the northern and southern regions of the WAP. We hypothesize the increase in sea ice results in increased micronutrient delivery to the continental shelf which in turn leads to enhanced photosynthetic performance.This article is part of the theme issue 'The marine system of the West Antarctic Peninsula: status and strategy for progress in a region of rapid change'.}, }
@article {pmid29758883, year = {2018}, author = {Xia, S and Liu, Y and Yu, X and Fu, B}, title = {Challenges in coupling LTER with environmental assessments: An insight from potential and reality of the Chinese Ecological Research Network in servicing environment assessments.}, journal = {The Science of the total environment}, volume = {633}, number = {}, pages = {1302-1313}, doi = {10.1016/j.scitotenv.2018.03.284}, pmid = {29758883}, issn = {1879-1026}, abstract = {Environmental assessments estimate, evaluate and predict the consequences of natural processes and human activities on the environment. Long-term ecosystem observation and research networks (LTERs) are potentially valuable infrastructure to support environmental assessments. However, very few environmental assessments have successfully incorporated them. In this study, we try to reveal the current status of coupling LTERs with environmental assessments and look at the challenges involved in improving this coupling through exploring the role that Chinese Ecological Research Network (CERN), the LTER of China, currently plays in regional environment assessments. A review of official protocols and standards, regional assessments and CERN researches related to ecosystems and environment shows that there is great potential for coupling CERN with environment assessments. However in practice, CERN does not currently play the expected role. Remote sensing and irregular inventory data are still the main data sources currently used in regional assessments. Several causes led to the present situation: (1) insufficient cross-site research and failure to scale up site-level variables to the regional scale; (2) data barriers resulting from incompatible protocols and low data usability due to lack of data assimilation and scaling; and (3) absence of indicators relevant to human activities in existing monitoring protocols. For these reasons, enhancing cross-site monitoring and research, data assimilation and scaling up are critical steps required to improve coupling of LTER with environmental assessments. Site-focused long-term monitoring should be combined with wide-scale ground surveys and remote sensing to establish an effective connection between different environmental monitoring platforms for regional assessments. It is also necessary to revise the current monitoring protocols to include human activities and their impacts on the ecosystem, or change the LTERs into Long-Term Socio-Ecological Research (LTSER) networks.}, }
@article {pmid29732670, year = {2018}, author = {Carlson, CJ and Getz, WM and Kausrud, KL and Cizauskas, CA and Blackburn, JK and Bustos Carrillo, FA and Colwell, R and Easterday, WR and Ganz, HH and Kamath, PL and Økstad, OA and Turner, WC and Kolstø, AB and Stenseth, NC}, title = {Spores and soil from six sides: interdisciplinarity and the environmental biology of anthrax (Bacillus anthracis).}, journal = {Biological reviews of the Cambridge Philosophical Society}, volume = {93}, number = {4}, pages = {1813-1831}, doi = {10.1111/brv.12420}, pmid = {29732670}, issn = {1469-185X}, mesh = {Animals ; Anthrax/microbiology ; Bacillus anthracis/*genetics/*physiology ; Humans ; *Interdisciplinary Research ; *Soil Microbiology ; *Spores, Bacterial ; }, abstract = {Environmentally transmitted diseases are comparatively poorly understood and managed, and their ecology is particularly understudied. Here we identify challenges of studying environmental transmission and persistence with a six-sided interdisciplinary review of the biology of anthrax (Bacillus anthracis). Anthrax is a zoonotic disease capable of maintaining infectious spore banks in soil for decades (or even potentially centuries), and the mechanisms of its environmental persistence have been the topic of significant research and controversy. Where anthrax is endemic, it plays an important ecological role, shaping the dynamics of entire herbivore communities. The complex eco-epidemiology of anthrax, and the mysterious biology of Bacillus anthracis during its environmental stage, have necessitated an interdisciplinary approach to pathogen research. Here, we illustrate different disciplinary perspectives through key advances made by researchers working in Etosha National Park, a long-term ecological research site in Namibia that has exemplified the complexities of the enzootic process of anthrax over decades of surveillance. In Etosha, the role of scavengers and alternative routes (waterborne transmission and flies) has proved unimportant relative to the long-term persistence of anthrax spores in soil and their infection of herbivore hosts. Carcass deposition facilitates green-ups of vegetation to attract herbivores, potentially facilitated by the role of anthrax spores in the rhizosphere. The underlying seasonal pattern of vegetation, and herbivores' immune and behavioural responses to anthrax risk, interact to produce regular 'anthrax seasons' that appear to be a stable feature of the Etosha ecosystem. Through the lens of microbiologists, geneticists, immunologists, ecologists, epidemiologists, and clinicians, we discuss how anthrax dynamics are shaped at the smallest scale by population genetics and interactions within the bacterial communities up to the broadest scales of ecosystem structure. We illustrate the benefits and challenges of this interdisciplinary approach to disease ecology, and suggest ways anthrax might offer insights into the biology of other important pathogens. Bacillus anthracis, and the more recently emerged Bacillus cereus biovar anthracis, share key features with other environmentally transmitted pathogens, including several zoonoses and panzootics of special interest for global health and conservation efforts. Understanding the dynamics of anthrax, and developing interdisciplinary research programs that explore environmental persistence, is a critical step forward for understanding these emerging threats.}, }
@article {pmid29708645, year = {2018}, author = {Herren, CM and McMahon, KD}, title = {Keystone taxa predict compositional change in microbial communities.}, journal = {Environmental microbiology}, volume = {20}, number = {6}, pages = {2207-2217}, doi = {10.1111/1462-2920.14257}, pmid = {29708645}, issn = {1462-2920}, support = {DGE- 1256259//National Science Foundation/International ; DGE-1256259//United States National Science Foundation (NSF) GRFP award/International ; NTL-LTER DEB-1440297//NSF Long Term Ecological Research program/International ; DEB-1344254//INSPIRE award/International ; Hatch Project 1002996//National Institute of Food and Agriculture, U.S. Department of Agriculture/International ; }, mesh = {*Biodiversity ; *Environment ; *Microbiota ; }, abstract = {The influence of biotic interactions on microbial community assembly is intensely debated. We hypothesized that keystone taxa, which influence community assembly through strong biotic interactions, are important for regulating microbial community composition. While highly connected microbes have been identified, evidence that these taxa act as keystones is lacking, because keystone status requires influence on whole-community dynamics. We address this gap, showing that small subsets of highly connected keystone taxa (generally 1%-5% of richness) can be optimal predictors of whole-community compositional change. In three long-term data sets, greater connectivity due to the presence of keystone taxa corresponded to lower compositional turnover. We further hypothesized that the influence of keystone taxa would be diminished when environmental disturbance was a strong driver of compositional change. We used two case studies of reference and disturbed communities to investigate how biotic and abiotic forces interact to shape community composition. Most of the same taxa were present in both the reference and disturbed communities, but keystone taxa had much greater explanatory power in the reference communities. Our results suggest that greater biotic connectivity arising from the presence of keystone taxa is stabilizing to community composition, and that keystone taxa can be good indicators of pending community shifts.}, }
@article {pmid29635875, year = {2018}, author = {Bowman, JS and Kavanaugh, MT and Doney, SC and Ducklow, HW}, title = {Recurrent seascape units identify key ecological processes along the western Antarctic Peninsula.}, journal = {Global change biology}, volume = {24}, number = {7}, pages = {3065-3078}, doi = {10.1111/gcb.14161}, pmid = {29635875}, issn = {1365-2486}, mesh = {Antarctic Regions ; Biomass ; *Climate Change ; *Ecosystem ; Ice Cover ; Phytoplankton ; Seasons ; Temperature ; }, abstract = {The western Antarctic Peninsula (WAP) is a bellwether of global climate change and natural laboratory for identifying interactions between climate and ecosystems. The Palmer Long-Term Ecological Research (LTER) project has collected data on key ecological and environmental processes along the WAP since 1993. To better understand how key ecological parameters are changing across space and time, we developed a novel seascape classification approach based on in situ temperature, salinity, chlorophyll a, nitrate + nitrite, phosphate, and silicate. We anticipate that this approach will be broadly applicable to other geographical areas. Through the application of self-organizing maps (SOMs), we identified eight recurrent seascape units (SUs) in these data. These SUs have strong fidelity to known regional water masses but with an additional layer of biogeochemical detail, allowing us to identify multiple distinct nutrient profiles in several water masses. To identify the temporal and spatial distribution of these SUs, we mapped them across the Palmer LTER sampling grid via objective mapping of the original parameters. Analysis of the abundance and distribution of SUs since 1993 suggests two year types characterized by the partitioning of chlorophyll a into SUs with different spatial characteristics. By developing generalized linear models for correlated, time-lagged external drivers, we conclude that early spring sea ice conditions exert a strong influence on the distribution of chlorophyll a and nutrients along the WAP, but not necessarily the total chlorophyll a inventory. Because the distribution and density of phytoplankton biomass can have an impact on biomass transfer to the upper trophic levels, these results highlight anticipated links between the WAP marine ecosystem and climate.}, }
@article {pmid29627562, year = {2018}, author = {Greenville, AC and Burns, E and Dickman, CR and Keith, DA and Lindenmayer, DB and Morgan, JW and Heinze, D and Mansergh, I and Gillespie, GR and Einoder, L and Fisher, A and Russell-Smith, J and Metcalfe, DJ and Green, PT and Hoffmann, AA and Wardle, GM}, title = {Biodiversity responds to increasing climatic extremes in a biome-specific manner.}, journal = {The Science of the total environment}, volume = {634}, number = {}, pages = {382-393}, doi = {10.1016/j.scitotenv.2018.03.285}, pmid = {29627562}, issn = {1879-1026}, abstract = {An unprecedented rate of global environmental change is predicted for the next century. The response to this change by ecosystems around the world is highly uncertain. To address this uncertainty, it is critical to understand the potential drivers and mechanisms of change in order to develop more reliable predictions. Australia's Long Term Ecological Research Network (LTERN) has brought together some of the longest running (10-60years) continuous environmental monitoring programs in the southern hemisphere. Here, we compare climatic variables recorded at five LTERN plot network sites during their period of operation and place them into the context of long-term climatic trends. Then, using our unique Australian long-term datasets (total 117 survey years across four biomes), we synthesize results from a series of case studies to test two hypotheses: 1) extreme weather events for each plot network have increased over the last decade, and; 2) trends in biodiversity will be associated with recent climate change, either directly or indirectly through climate-mediated disturbance (wildfire) responses. We examined the biodiversity responses to environmental change for evidence of non-linear behavior. In line with hypothesis 1), an increase in extreme climate events occurred within the last decade for each plot network. For hypothesis 2), climate, wildfire, or both were correlated with biodiversity responses at each plot network, but there was no evidence of non-linear change. However, the influence of climate or fire was context-specific. Biodiversity responded to recent climate change either directly or indirectly as a consequence of changes in fire regimes or climate-mediated fire responses. A national long-term monitoring framework allowed us to find contrasting species abundance or community responses to climate and disturbance across four of the major biomes of Australia, highlighting the need to establish and resource long-term monitoring programs across representative ecosystem types, which are likely to show context-specific responses.}, }
@article {pmid29623101, year = {2018}, author = {Sari, M and Tuna, C}, title = {Prediction of Pathological Subjects Using Genetic Algorithms.}, journal = {Computational and mathematical methods in medicine}, volume = {2018}, number = {}, pages = {6154025}, pmid = {29623101}, issn = {1748-6718}, mesh = {Adolescent ; Adult ; Aged ; *Algorithms ; *Cluster Analysis ; Humans ; Knee Injuries/*diagnosis ; Middle Aged ; Models, Theoretical ; Mutation ; Programming Languages ; Range of Motion, Articular ; Reproducibility of Results ; Rotation ; Tibia/*physiology/*physiopathology ; Young Adult ; }, abstract = {This paper aims at estimating pathological subjects from a population through various physical information using genetic algorithm (GA). For comparison purposes, K-Means (KM) clustering algorithm has also been used for the estimation. Dataset consisting of some physical factors (age, weight, and height) and tibial rotation values was provided from the literature. Tibial rotation types are four groups as RTER, RTIR, LTER, and LTIR. Each tibial rotation group is divided into three types. Narrow (Type 1) and wide (Type 3) angular values were called pathological and normal (Type 2) angular values were called nonpathological. Physical information was used to examine if the tibial rotations of the subjects were pathological. Since the GA starts randomly and walks all solution space, the GA is seen to produce far better results than the KM for clustering and optimizing the tibial rotation data assessments with large number of subjects even though the KM algorithm has similar effect with the GA in clustering with a small number of subjects. These findings are discovered to be very useful for all health workers such as physiotherapists and orthopedists, in which this consequence is expected to help clinicians in organizing proper treatment programs for patients.}, }
@article {pmid29603190, year = {2018}, author = {Prather, CM and Belovsky, GE and Cantrell, SA and González, G}, title = {Tropical herbivorous phasmids, but not litter snails, alter decomposition rates by modifying litter bacteria.}, journal = {Ecology}, volume = {99}, number = {4}, pages = {782-791}, doi = {10.1002/ecy.2169}, pmid = {29603190}, issn = {0012-9658}, mesh = {Animals ; Bacteria ; *Ecosystem ; *Herbivory ; Plant Leaves ; Puerto Rico ; Snails ; Trees ; }, abstract = {Consumers can alter decomposition rates through both feces and selective feeding in many ecosystems, but these combined effects have seldom been examined in tropical ecosystems. Members of the detrital food web (litter-feeders or microbivores) should presumably have greater effects on decomposition than herbivores, members of the green food web. Using litterbag experiments within a field enclosure experiment, we determined the relative effects of common litter snails (Megalomastoma croceum) and herbivorous walking sticks (Lamponius portoricensis) on litter composition, decomposition rates, and microbes in a Puerto Rican rainforest, and whether consumer effects were altered by canopy cover presence. Although canopy presence did not alter consumers' effects, focal organisms had unexpected influences on decomposition. Decomposition was not altered by litter snails, but herbivorous walking sticks reduced leaf decomposition by about 50% through reductions in high quality litter abundance and, consequently, lower bacterial richness and abundance. This relatively unexplored but potentially important link between tropical herbivores, detritus, and litter microbes in this forest demonstrates the need to consider autotrophic influences when examining rainforest ecosystem processes.}, }
@article {pmid29597270, year = {2018}, author = {Sari, M and Tuna, C and Akogul, S}, title = {Prediction of Tibial Rotation Pathologies Using Particle Swarm Optimization and K-Means Algorithms.}, journal = {Journal of clinical medicine}, volume = {7}, number = {4}, pages = {}, pmid = {29597270}, issn = {2077-0383}, abstract = {The aim of this article is to investigate pathological subjects from a population through different physical factors. To achieve this, particle swarm optimization (PSO) and K-means (KM) clustering algorithms have been combined (PSO-KM). Datasets provided by the literature were divided into three clusters based on age and weight parameters and each one of right tibial external rotation (RTER), right tibial internal rotation (RTIR), left tibial external rotation (LTER), and left tibial internal rotation (LTIR) values were divided into three types as Type 1, Type 2 and Type 3 (Type 2 is non-pathological (normal) and the other two types are pathological (abnormal)), respectively. The rotation values of every subject in any cluster were noted. Then the algorithm was run and the produced values were also considered. The values of the produced algorithm, the PSO-KM, have been compared with the real values. The hybrid PSO-KM algorithm has been very successful on the optimal clustering of the tibial rotation types through the physical criteria. In this investigation, Type 2 (pathological subjects) is of especially high predictability and the PSO-KM algorithm has been very successful as an operation system for clustering and optimizing the tibial motion data assessments. These research findings are expected to be very useful for health providers, such as physiotherapists, orthopedists, and so on, in which this consequence may help clinicians to appropriately designing proper treatment schedules for patients.}, }
@article {pmid29528525, year = {2018}, author = {Rowland, JA and Nicholson, E and Murray, NJ and Keith, DA and Lester, RE and Bland, LM}, title = {Selecting and applying indicators of ecosystem collapse for risk assessments.}, journal = {Conservation biology : the journal of the Society for Conservation Biology}, volume = {32}, number = {6}, pages = {1233-1245}, doi = {10.1111/cobi.13107}, pmid = {29528525}, issn = {1523-1739}, mesh = {Biodiversity ; *Conservation of Natural Resources ; Ecology ; *Ecosystem ; Risk Assessment ; }, abstract = {Ongoing ecosystem degradation and transformation are major threats to biodiversity. Measuring ecosystem change toward collapse relies on monitoring indicators that quantify key ecological processes. Yet little guidance is available on selection and use of indicators for ecosystem risk assessment. We reviewed indicator use in ecological studies of ecosystem collapse in marine pelagic and temperate forest ecosystems. We examined indicator-selection methods, indicator types (geographic distribution, abiotic, biotic), methods of assessing multiple indicators, and temporal quality of time series. We compared how these factors were applied in the ecological studies with how they were applied in risk assessments by using the International Union for Conservation of Nature's Red List of Ecosystems (RLE), for which indicators are used to estimate risk of ecosystem collapse. Ecological studies and RLE assessments rarely reported how indicators were selected, particularly in terrestrial ecosystems. Few ecological studies and RLE assessments quantified ecosystem change based on all 3 indicator types, and indicators types used differed between marine and terrestrial ecosystems. Several studies used indices or multivariate analyses to assess multiple indicators simultaneously, but RLE assessments did not because as RLE guidelines advise against them. Most studies and RLE assessments used time-series data that spanned at least 30 years, which increases the probability of reliably detecting change. Limited use of indicator-selection protocols and infrequent use of all 3 indicator types may hamper accurate detection of change. To improve the value of risk assessments for informing policy and management, we recommend using explicit protocols, including conceptual models, to identify and select indicators; a range of indicators spanning distributional, abiotic, and biotic features; indices and multivariate analyses with extreme care until guidelines are developed; time series with sufficient data to increase ability to accurately diagnose directional change; data from multiple sources to support assessments; and explicitly reporting steps in the assessment process.}, }
@article {pmid29503723, year = {2018}, author = {Orwig, DA and Boucher, P and Paynter, I and Saenz, E and Li, Z and Schaaf, C}, title = {The potential to characterize ecological data with terrestrial laser scanning in Harvard Forest, MA.}, journal = {Interface focus}, volume = {8}, number = {2}, pages = {20170044}, pmid = {29503723}, issn = {2042-8898}, abstract = {Contemporary terrestrial laser scanning (TLS) is being used widely in forest ecology applications to examine ecosystem properties at increasing spatial and temporal scales. Harvard Forest (HF) in Petersham, MA, USA, is a long-term ecological research (LTER) site, a National Ecological Observatory Network (NEON) location and contains a 35 ha plot which is part of Smithsonian Institution's Forest Global Earth Observatory (ForestGEO). The combination of long-term field plots, eddy flux towers and the detailed past historical records has made HF very appealing for a variety of remote sensing studies. Terrestrial laser scanners, including three pioneering research instruments: the Echidna Validation Instrument, the Dual-Wavelength Echidna Lidar and the Compact Biomass Lidar, have already been used both independently and in conjunction with airborne laser scanning data and forest census data to characterize forest dynamics. TLS approaches include three-dimensional reconstructions of a plot over time, establishing the impact of ice storm damage on forest canopy structure, and characterizing eastern hemlock (Tsuga canadensis) canopy health affected by an invasive insect, the hemlock woolly adelgid (Adelges tsugae). Efforts such as those deployed at HF are demonstrating the power of TLS as a tool for monitoring ecological dynamics, identifying emerging forest health issues, measuring forest biomass and capturing ecological data relevant to other disciplines. This paper highlights various aspects of the ForestGEO plot that are important to current TLS work, the potential for exchange between forest ecology and TLS, and emphasizes the strength of combining TLS data with long-term ecological field data to create emerging opportunities for scientific study.}, }
@article {pmid29484805, year = {2018}, author = {Thomas Clark, A and Lehman, C and Tilman, D}, title = {Identifying mechanisms that structure ecological communities by snapping model parameters to empirically observed tradeoffs.}, journal = {Ecology letters}, volume = {21}, number = {4}, pages = {494-505}, doi = {10.1111/ele.12910}, pmid = {29484805}, issn = {1461-0248}, mesh = {Biota ; *Ecosystem ; Models, Biological ; Plants ; *Species Specificity ; }, abstract = {Theory predicts that interspecific tradeoffs are primary determinants of coexistence and community composition. Using information from empirically observed tradeoffs to augment the parametrisation of mechanism-based models should therefore improve model predictions, provided that tradeoffs and mechanisms are chosen correctly. We developed and tested such a model for 35 grassland plant species using monoculture measurements of three species characteristics related to nitrogen uptake and retention, which previous experiments indicate as important at our site. Matching classical theoretical expectations, these characteristics defined a distinct tradeoff surface, and models parameterised with these characteristics closely matched observations from experimental multi-species mixtures. Importantly, predictions improved significantly when we incorporated information from tradeoffs by 'snapping' characteristics to the nearest location on the tradeoff surface, suggesting that the tradeoffs and mechanisms we identify are important determinants of local community structure. This 'snapping' method could therefore constitute a broadly applicable test for identifying influential tradeoffs and mechanisms.}, }
@article {pmid29474487, year = {2018}, author = {Lindenmayer, DB and Blanchard, W and Blair, D and McBurney, L and Stein, J and Banks, SC}, title = {Empirical relationships between tree fall and landscape-level amounts of logging and fire.}, journal = {PloS one}, volume = {13}, number = {2}, pages = {e0193132}, pmid = {29474487}, issn = {1932-6203}, mesh = {*Forestry ; *Forests ; *Fraxinus ; *Models, Theoretical ; *Wind ; }, abstract = {Large old trees are critically important keystone structures in forest ecosystems globally. Populations of these trees are also in rapid decline in many forest ecosystems, making it important to quantify the factors that influence their dynamics at different spatial scales. Large old trees often occur in forest landscapes also subject to fire and logging. However, the effects on the risk of collapse of large old trees of the amount of logging and fire in the surrounding landscape are not well understood. Using an 18-year study in the Mountain Ash (Eucalyptus regnans) forests of the Central Highlands of Victoria, we quantify relationships between the probability of collapse of large old hollow-bearing trees at a site and the amount of logging and the amount of fire in the surrounding landscape. We found the probability of collapse increased with an increasing amount of logged forest in the surrounding landscape. It also increased with a greater amount of burned area in the surrounding landscape, particularly for trees in highly advanced stages of decay. The most likely explanation for elevated tree fall with an increasing amount of logged or burned areas in the surrounding landscape is change in wind movement patterns associated with cutblocks or burned areas. Previous studies show that large old hollow-bearing trees are already at high risk of collapse in our study area. New analyses presented here indicate that additional logging operations in the surrounding landscape will further elevate that risk. Current logging prescriptions require the protection of large old hollow-bearing trees on cutblocks. We suggest that efforts to reduce the probability of collapse of large old hollow-bearing trees on unlogged sites will demand careful landscape planning to limit the amount of timber harvesting in the surrounding landscape.}, }
@article {pmid29426160, year = {2018}, author = {Morabito, G and Mazzocchi, MG and Salmaso, N and Zingone, A and Bergami, C and Flaim, G and Accoroni, S and Basset, A and Bastianini, M and Belmonte, G and Bernardi Aubry, F and Bertani, I and Bresciani, M and Buzzi, F and Cabrini, M and Camatti, E and Caroppo, C and Cataletto, B and Castellano, M and Del Negro, P and de Olazabal, A and Di Capua, I and Elia, AC and Fornasaro, D and Giallain, M and Grilli, F and Leoni, B and Lipizer, M and Longobardi, L and Ludovisi, A and Lugliè, A and Manca, M and Margiotta, F and Mariani, MA and Marini, M and Marzocchi, M and Obertegger, U and Oggioni, A and Padedda, BM and Pansera, M and Piscia, R and Povero, P and Pulina, S and Romagnoli, T and Rosati, I and Rossetti, G and Rubino, F and Sarno, D and Satta, CT and Sechi, N and Stanca, E and Tirelli, V and Totti, C and Pugnetti, A}, title = {Plankton dynamics across the freshwater, transitional and marine research sites of the LTER-Italy Network. Patterns, fluctuations, drivers.}, journal = {The Science of the total environment}, volume = {627}, number = {}, pages = {373-387}, doi = {10.1016/j.scitotenv.2018.01.153}, pmid = {29426160}, issn = {1879-1026}, mesh = {Animals ; *Ecosystem ; *Environmental Monitoring ; Italy ; Phytoplankton ; Plankton/*physiology ; Population Dynamics ; Zooplankton ; }, abstract = {A first synoptic and trans-domain overview of plankton dynamics was conducted across the aquatic sites belonging to the Italian Long-Term Ecological Research Network (LTER-Italy). Based on published studies, checked and complemented with unpublished information, we investigated phytoplankton and zooplankton annual dynamics and long-term changes across domains: from the large subalpine lakes to mountain lakes and artificial lakes, from lagoons to marine coastal ecosystems. This study permitted identifying common and unique environmental drivers and ecological functional processes controlling seasonal and long-term temporal course. The most relevant patterns of plankton seasonal succession were revealed, showing that the driving factors were nutrient availability, stratification regime, and freshwater inflow. Phytoplankton and mesozooplankton displayed a wide interannual variability at most sites. Unidirectional or linear long-term trends were rarely detected but all sites were impacted across the years by at least one, but in many case several major stressor(s): nutrient inputs, meteo-climatic variability at the local and regional scale, and direct human activities at specific sites. Different climatic and anthropic forcings frequently co-occurred, whereby the responses of plankton communities were the result of this environmental complexity. Overall, the LTER investigations are providing an unparalleled framework of knowledge to evaluate changes in the aquatic pelagic systems and management options.}, }
@article {pmid29408064, year = {2018}, author = {Dessu, SB and Price, RM and Troxler, TG and Kominoski, JS}, title = {Effects of sea-level rise and freshwater management on long-term water levels and water quality in the Florida Coastal Everglades.}, journal = {Journal of environmental management}, volume = {211}, number = {}, pages = {164-176}, doi = {10.1016/j.jenvman.2018.01.025}, pmid = {29408064}, issn = {1095-8630}, mesh = {*Ecosystem ; Florida ; Fresh Water ; Gulf of Mexico ; Water ; *Water Quality ; Wetlands ; }, abstract = {Since the 1880s, hydrological modification of the Greater Florida Everglades has reduced water levels and flows in Everglades National Park (ENP). The Comprehensive Everglades Restoration Program (CERP) began in 2000 to restore pre-drainage flows and preserve the natural landscape of the Everglades. However, sea-level rise (SLR) was not considered in the development of CERP. We used long-term data (2001-2016) from the Florida Coastal Everglades-Long Term Ecological Research Program to quantify and model the spatial dynamics of water levels, salinity, and nutrients in response to changes in climate, freshwater management and SLR in the Shark River Slough (SRS), ENP. Results indicate that fresh-to-marine head difference (FMHD) was the single most important factor affecting marine-to-freshwater hydrologic connectivity and transport of salinity and phosphorous upstream from the Gulf of Mexico. Sea-level has increasingly exceeded ground surface elevation at the most downstream freshwater site in SRS, thereby reducing the FMHD. We showed a higher impact of SLR in the dry season when there was practically no freshwater inflow to raise FMHD. We also demonstrated effectiveness of inflow depends more on the monthly distribution than the total annual volume. Hence, the impact per unit volume of inflow is significantly higher in the dry season in preventing high salinity and marine-derived nutrient levels. We advocate that FMHD needs to be factored into water management decisions to reduce adverse and likely irreversible effects of SLR throughout the Everglades landscape.}, }
@article {pmid29396346, year = {2018}, author = {Maccherini, S and Bacaro, G and Marignani, M}, title = {Beneficial effects of restoration practices can be thwarted by climate extremes.}, journal = {The Science of the total environment}, volume = {626}, number = {}, pages = {851-859}, doi = {10.1016/j.scitotenv.2018.01.117}, pmid = {29396346}, issn = {1879-1026}, abstract = {The impacts of climate extremes on species, communities and ecosystems have become critical concerns to science and society. Under a changing climate, how restoration outcomes are affected by extreme climate variables is a largely unknown topic. We analyzed the effects of experimental factors (grazing and sowing of native species), extreme climate events (intense precipitation and extreme temperatures indexes) and their combination on the restoration progress of a dry, calcareous grassland in Tuscany (Italy) with a 1 year before/15 years continuous annual monitoring after, control/impact (BACI) experiment. Grazing had a beneficial effect on the diversity of the grassland, while sowing had a limited impact. The climatic index that most affected the entire plant community composition was the number of very heavy precipitation days. The interaction of grazing and extreme climatic indexes had a significant detrimental effect on restoration outcomes, increasing the cover of synanthropic and Cosmopolitan-Subcosmopolitan generalist species and decreasing the cover of more valuable species such endemic species. In the richest grazed plots, species richness showed a lower sensitivity to the average precipitation per wet day but in grazed site, restoration outcomes can be negatively influenced by the intensification of precipitation and temperature extremes. In a context of progressive tropicalization of the Mediterranean area, to assist managers setting achievable restoration goals, restoration practitioners should consider that climate extremes might interfere with the beneficial effects of restoration practices.}, }
@article {pmid29291051, year = {2017}, author = {Greenville, AC and Wardle, GM and Dickman, CR}, title = {Desert mammal populations are limited by introduced predators rather than future climate change.}, journal = {Royal Society open science}, volume = {4}, number = {11}, pages = {170384}, pmid = {29291051}, issn = {2054-5703}, abstract = {Climate change is predicted to place up to one in six species at risk of extinction in coming decades, but extinction probability is likely to be influenced further by biotic interactions such as predation. We use structural equation modelling to integrate results from remote camera trapping and long-term (17-22 years) regional-scale (8000 km[2]) datasets on vegetation and small vertebrates (greater than 38 880 captures) to explore how biotic processes and two key abiotic drivers influence the structure of a diverse assemblage of desert biota in central Australia. We use our models to predict how changes in rainfall and wildfire are likely to influence the cover and productivity of the dominant vegetation and the impacts of predators on their primary rodent prey over a 100-year timeframe. Our results show that, while vegetation cover may decline due to climate change, the strongest negative effect on prey populations in this desert system is top-down suppression from introduced predators.}, }
@article {pmid29275260, year = {2018}, author = {Mollenhauer, H and Kasner, M and Haase, P and Peterseil, J and Wohner, C and Frenzel, M and Mirtl, M and Schima, R and Bumberger, J and Zacharias, S}, title = {Long-term environmental monitoring infrastructures in Europe: observations, measurements, scales, and socio-ecological representativeness.}, journal = {The Science of the total environment}, volume = {624}, number = {}, pages = {968-978}, doi = {10.1016/j.scitotenv.2017.12.095}, pmid = {29275260}, issn = {1879-1026}, mesh = {Climate ; *Ecology ; Ecosystem ; *Environmental Monitoring ; Europe ; *Research ; }, abstract = {The challenges posed by climate and land use change are increasingly complex, with ever-increasing and accelerating impacts on the global environmental system. The establishment of an internationally harmonized, integrated, and long-term operated environmental monitoring infrastructure is one of the major challenges of modern environmental research. Increased efforts are currently being made in Europe to establish such a harmonized pan-European observation infrastructure, and the European network of Long-Term Ecological Research sites - LTER-Europe - is of particular importance. By evaluating 477 formally accredited LTER-Europe sites, this study gives an overview of the current distribution of these infrastructures and the present condition of long-term environmental research in Europe. We compiled information on long-term biotic and abiotic observations and measurements and examined the representativeness in terms of continental biogeographical and socio-ecological gradients. The results were used to identify gaps in both measurements and coverage of the aforementioned gradients. Furthermore, an overview of the current state of the LTER-Europe observation strategies is given. The latter forms the basis for investigating the comparability of existing LTER-Europe monitoring concepts both in terms of observational design as well as in terms of the scope of the environmental compartments, variables and properties covered.}, }
@article {pmid29265568, year = {2018}, author = {Petrie, MD and Peters, DPC and Yao, J and Blair, JM and Burruss, ND and Collins, SL and Derner, JD and Gherardi, LA and Hendrickson, JR and Sala, OE and Starks, PJ and Steiner, JL}, title = {Regional grassland productivity responses to precipitation during multiyear above- and below-average rainfall periods.}, journal = {Global change biology}, volume = {24}, number = {5}, pages = {1935-1951}, doi = {10.1111/gcb.14024}, pmid = {29265568}, issn = {1365-2486}, mesh = {Climate Change ; *Grassland ; Poaceae/physiology ; *Rain ; }, abstract = {There is considerable uncertainty in the magnitude and direction of changes in precipitation associated with climate change, and ecosystem responses are also uncertain. Multiyear periods of above- and below-average rainfall may foretell consequences of changes in rainfall regime. We compiled long-term aboveground net primary productivity (ANPP) and precipitation (PPT) data for eight North American grasslands, and quantified relationships between ANPP and PPT at each site, and in 1-3 year periods of above- and below-average rainfall for mesic, semiarid cool, and semiarid warm grassland types. Our objective was to improve understanding of ANPP dynamics associated with changing climatic conditions by contrasting PPT-ANPP relationships in above- and below-average PPT years to those that occurred during sequences of multiple above- and below-average years. We found differences in PPT-ANPP relationships in above- and below-average years compared to long-term site averages, and variation in ANPP not explained by PPT totals that likely are attributed to legacy effects. The correlation between ANPP and current- and prior-year conditions changed from year to year throughout multiyear periods, with some legacy effects declining, and new responses emerging. Thus, ANPP in a given year was influenced by sequences of conditions that varied across grassland types and climates. Most importantly, the influence of prior-year ANPP often increased with the length of multiyear periods, whereas the influence of the amount of current-year PPT declined. Although the mechanisms by which a directional change in the frequency of above- and below-average years imposes a persistent change in grassland ANPP require further investigation, our results emphasize the importance of legacy effects on productivity for sequences of above- vs. below-average years, and illustrate the utility of long-term data to examine these patterns.}, }
@article {pmid29195206, year = {2018}, author = {Jourdan, J and O'Hara, RB and Bottarin, R and Huttunen, KL and Kuemmerlen, M and Monteith, D and Muotka, T and Ozoliņš, D and Paavola, R and Pilotto, F and Springe, G and Skuja, A and Sundermann, A and Tonkin, JD and Haase, P}, title = {Effects of changing climate on European stream invertebrate communities: A long-term data analysis.}, journal = {The Science of the total environment}, volume = {621}, number = {}, pages = {588-599}, doi = {10.1016/j.scitotenv.2017.11.242}, pmid = {29195206}, issn = {1879-1026}, mesh = {Animals ; *Climate Change ; Conservation of Natural Resources ; *Ecosystem ; Europe ; Introduced Species ; *Invertebrates ; *Rivers ; Temperature ; }, abstract = {Long-term observations on riverine benthic invertebrate communities enable assessments of the potential impacts of global change on stream ecosystems. Besides increasing average temperatures, many studies predict greater temperature extremes and intense precipitation events as a consequence of climate change. In this study we examined long-term observation data (10-32years) of 26 streams and rivers from four ecoregions in the European Long-Term Ecological Research (LTER) network, to investigate invertebrate community responses to changing climatic conditions. We used functional trait and multi-taxonomic analyses and combined examinations of general long-term changes in communities with detailed analyses of the impact of different climatic drivers (i.e., various temperature and precipitation variables) by focusing on the response of communities to climatic conditions of the previous year. Taxa and ecoregions differed substantially in their response to climate change conditions. We did not observe any trend of changes in total taxonomic richness or overall abundance over time or with increasing temperatures, which reflects a compensatory turnover in the composition of communities; sensitive Plecoptera decreased in response to warmer years and Ephemeroptera increased in northern regions. Invasive species increased with an increasing number of extreme days which also caused an apparent upstream community movement. The observed changes in functional feeding group diversity indicate that climate change may be associated with changes in trophic interactions within aquatic food webs. These findings highlight the vulnerability of riverine ecosystems to climate change and emphasize the need to further explore the interactive effects of climate change variables with other local stressors to develop appropriate conservation measures.}, }
@article {pmid29158517, year = {2017}, author = {Cianelli, D and D'Alelio, D and Uttieri, M and Sarno, D and Zingone, A and Zambianchi, E and d'Alcalà, MR}, title = {Disentangling physical and biological drivers of phytoplankton dynamics in a coastal system.}, journal = {Scientific reports}, volume = {7}, number = {1}, pages = {15868}, pmid = {29158517}, issn = {2045-2322}, mesh = {*Ecosystem ; Life Cycle Stages/genetics ; Mediterranean Sea ; Phytoplankton/chemistry/*genetics/metabolism ; Seawater/chemistry ; Species Specificity ; Water/chemistry ; }, abstract = {This proof-of-concept study integrates the surface currents measured by high-frequency coastal radars with plankton time-series data collected at a fixed sampling point from the Mediterranean Sea (MareChiara Long Term Ecological Research site in the Gulf of Naples) to characterize the spatial origin of phytoplankton assemblages and to scrutinize the processes ruling their dynamics. The phytoplankton community generally originated from the coastal waters whereby species succession was mainly regulated by biological factors (life-cycle processes, species-specific physiological performances and inter-specific interactions). Physical factors, e.g. the alternation between coastal and offshore waters and the horizontal mixing, were also important drivers of phytoplankton dynamics promoting diversity maintenance by i) advecting species from offshore and ii) diluting the resident coastal community so as to dampen resource stripping by dominant species and thereby increase the numerical importance of rarer species. Our observations highlight the resilience of coastal communities, which may favour their persistence over time and the prevalence of successional events over small time and space scales. Although coastal systems may act differently from one another, our findings provide a conceptual framework to address physical-biological interactions occurring in coastal basins, which can be generalised to other areas.}, }
@article {pmid29147779, year = {2018}, author = {Wills, BD and Landis, DA}, title = {The role of ants in north temperate grasslands: a review.}, journal = {Oecologia}, volume = {186}, number = {2}, pages = {323-338}, pmid = {29147779}, issn = {1432-1939}, support = {DE-FC02-7ER64494//Office of Science/International ; DE-AC05-76RL01830//Office of Energy Efficiency and Renewable Energy/International ; }, mesh = {Animals ; *Ants ; Biodiversity ; Ecosystem ; Grassland ; Soil ; }, abstract = {Historic and current land-use changes have altered the landscape for grassland biota, with over 90% of grasslands and savannas converted to agriculture or some other use in north temperate regions. Reintegrating grasslands into agricultural landscapes can increase biodiversity while also providing valuable ecosystem services. In contrast to their well-known importance in tropical and subtropical ecosystems, the role of ants in temperate grasslands is often underappreciated. As consumers and ecosystem engineers, ants in temperate grasslands influence invertebrate, plant, and soil microbial diversity and potentially alter grassland productivity. As common and numerically dominant invertebrates in grasslands, ants can also serve as important indicator species to monitor conservation and management practices. Drawing on examples largely from mesic, north temperate studies, and from other temperate regions where necessary, we review the roles of ants as consumers and ecosystem engineers in grasslands. We also identify five avenues for future research to improve our understanding of the roles of ants in grasslands. This includes identifying how grassland fragmentation may influence ant community assembly, quantifying how ant communities impact ecosystem functions and soil processes, and understanding how ant communities and their associated interactions are impacted by climate change. In synthesizing the role of ants in temperate grasslands and identifying knowledge gaps, we hope this and future work will help inform how land managers maximize grassland conservation value while increasing multiple ecosystem services and minimizing disservices.}, }
@article {pmid28931744, year = {2017}, author = {Bland, LM and Regan, TJ and Dinh, MN and Ferrari, R and Keith, DA and Lester, R and Mouillot, D and Murray, NJ and Nguyen, HA and Nicholson, E}, title = {Using multiple lines of evidence to assess the risk of ecosystem collapse.}, journal = {Proceedings. Biological sciences}, volume = {284}, number = {1863}, pages = {}, pmid = {28931744}, issn = {1471-2954}, mesh = {Animals ; Anthozoa ; *Conservation of Natural Resources ; *Coral Reefs ; *Ecosystem ; Forecasting ; *Risk Assessment ; }, abstract = {Effective ecosystem risk assessment relies on a conceptual understanding of ecosystem dynamics and the synthesis of multiple lines of evidence. Risk assessment protocols and ecosystem models integrate limited observational data with threat scenarios, making them valuable tools for monitoring ecosystem status and diagnosing key mechanisms of decline to be addressed by management. We applied the IUCN Red List of Ecosystems criteria to quantify the risk of collapse of the Meso-American Reef, a unique ecosystem containing the second longest barrier reef in the world. We collated a wide array of empirical data (field and remotely sensed), and used a stochastic ecosystem model to backcast past ecosystem dynamics, as well as forecast future ecosystem dynamics under 11 scenarios of threat. The ecosystem is at high risk from mass bleaching in the coming decades, with compounding effects of ocean acidification, hurricanes, pollution and fishing. The overall status of the ecosystem is Critically Endangered (plausibly Vulnerable to Critically Endangered), with notable differences among Red List criteria and data types in detecting the most severe symptoms of risk. Our case study provides a template for assessing risks to coral reefs and for further application of ecosystem models in risk assessment.}, }
@article {pmid28921808, year = {2017}, author = {Schmidt, JE and Weese, DJ and Lau, JA}, title = {Long-term agricultural management does not alter the evolution of a soybean-rhizobium mutualism.}, journal = {Ecological applications : a publication of the Ecological Society of America}, volume = {27}, number = {8}, pages = {2487-2496}, doi = {10.1002/eap.1625}, pmid = {28921808}, issn = {1051-0761}, mesh = {Agriculture/*methods ; *Biological Evolution ; Fertilizers/analysis ; Michigan ; Nitrogen/metabolism ; Rhizobium/*physiology ; Glycine max/*microbiology ; Symbiosis/*physiology ; }, abstract = {Leguminous crops, like soybeans, often rely on biologically fixed nitrogen via their symbiosis with rhizobia rather than synthetic nitrogen inputs. However, agricultural management practices may influence the effectiveness of biological nitrogen fixation (BNF). While the ecological effects of agricultural management on rhizobia have received some attention, the evolutionary effects have been neglected in comparison. Resource mutualism theory predicts that evolutionary effects are likely, however. Both fertilization and tillage are predicted to cause the evolution of rhizobia that provide fewer growth benefits to plant hosts and fix less nitrogen. This study capitalized on a Long-Term Ecological Research experiment that manipulated agricultural management practices in a corn-soybean-wheat row crop system for 24 yr to investigate whether four different management practices (conventional, no-till, low chemical input, and certified organic) cause rhizobia populations to evolve to become more or less cooperative. We found little evidence that 24 yr of varying management practices affect the net growth benefits rhizobia provide to soybeans, although soybean plants inoculated with soils collected from conventional treatments tended to have lower BNF rates than plants inoculated with soils from the no-till, low input, and organic management treatments. These findings suggest that rhizobia will continue to provide adequate growth benefits to leguminous crops in the future, even in intensively managed systems.}, }
@article {pmid28898749, year = {2017}, author = {Alignier, A and Aviron, S}, title = {Time-lagged response of carabid species richness and composition to past management practices and landscape context of semi-natural field margins.}, journal = {Journal of environmental management}, volume = {204}, number = {Pt 1}, pages = {282-290}, doi = {10.1016/j.jenvman.2017.08.054}, pmid = {28898749}, issn = {1095-8630}, mesh = {Agriculture/methods ; Biodiversity ; *Crops, Agricultural ; *Ecosystem ; Forests ; France ; }, abstract = {Field margins are key features for the maintenance of biodiversity and associated ecosystem services in agricultural landscapes. Little is known about the effects of management practices of old semi-natural field margins, and their historical dimension regarding past management practices and landscape context is rarely considered. In this paper, the relative influence of recent and past management practices and landscape context (during the last five years) were assessed on the local biodiversity (species richness and composition) of carabid assemblages of field margins in agricultural landscapes of northwestern France. The results showed that recent patterns of carabid species richness and composition were best explained by management practices and landscape context measured four or five years ago. It suggests the existence of a time lag in the response of carabid assemblages to past environmental conditions of field margins. The relative contribution of past management practices and past landscape context varied depending on the spatial scale at which landscape context was taken into account. Carabid species richness was higher in grazed or sprayed field margins probably due to increased heterogeneity in habitat conditions. Field margins surrounded by grasslands and crops harbored species associated with open habitats whilst forest species dominated field margins surrounded by woodland. Landscape effect was higher at fine spatial scale, within 50 m around field margins. The present study highlights the importance of considering time-lagged responses of biodiversity when managing environment. It also suggests that old semi-natural field margins should not be considered as undisturbed habitats but more as management units being part of farming activities in agricultural landscapes, as for arable fields.}, }
@article {pmid28884803, year = {2017}, author = {Bradford, MA and Leiserowitz, A and Feinberg, G and Rosenthal, SA and Lau, JA}, title = {Long-Term Research in Ecology and Evolution (LTREE): 2015 survey data.}, journal = {Ecology}, volume = {98}, number = {11}, pages = {2980}, doi = {10.1002/ecy.1999}, pmid = {28884803}, issn = {0012-9658}, mesh = {*Biological Evolution ; *Ecology ; Research Design ; Surveys and Questionnaires ; }, abstract = {To systematically assess views on contributions and future activities for long-term research in ecology and evolution (LTREE), we conducted and here provide data responses and associated metadata for a survey of ecological and evolutionary scientists. The survey objectives were to: (1) Identify and prioritize research questions that are important to address through long-term, ecological field experiments; and (2) understand the role that these experiments might play in generating and applying ecological and evolutionary knowledge. The survey was developed adhering to the standards of the American Association for Public Opinion Research. It was administered online using Qualtrics Survey Software. Survey creation was a multi-step process, with questions and format developed and then revised with, for example, input from an external advisory committee comprising senior and junior ecological and evolutionary researchers. The final questionnaire was released to ~100 colleagues to ensure functionality and then fielded 2 d later (January 7[th] , 2015). Two professional societies distributed it to their membership, including the Ecological Society of America, and it was posted to three list serves. The questionnaire was available through February 8th 2015 and completed by 1,179 respondents. The distribution approach targeted practicing ecologists and evolutionary biologists in the U.S. Quantitative (both ordinal and categorical) closed-ended questions used a predefined set of response categories, facilitating direct comparison across all respondents. Qualitative, open-ended questions, provided respondents the opportunity to develop their own answers. We employed quantitative questions to score views on the extent to which long-term experimental research has contributed to understanding in ecology and evolutionary biology; its role compared to other approaches (e.g., short-term experiments); justifications for and caveats to long-term experiments; and the relative importance of incentives for conducting long-term research. Qualitative questions were used to assess community views on the most important topics and questions for long-term research to address, and primary incentives and challenges to realizing this work. Finally, demographic data were collected to determine if views were conditional on such things as years of experience and field of expertise. The final questionnaire and all responses are provided for unrestricted use.}, }
@article {pmid28855365, year = {2017}, author = {Dallas, T and Huang, S and Nunn, C and Park, AW and Drake, JM}, title = {Estimating parasite host range.}, journal = {Proceedings. Biological sciences}, volume = {284}, number = {1861}, pages = {}, pmid = {28855365}, issn = {1471-2954}, mesh = {Animals ; Ecology ; *Host Specificity ; Host-Parasite Interactions ; Mammals/*parasitology ; New Mexico ; Parasites/*classification ; }, abstract = {Estimating the number of host species that a parasite can infect (i.e. host range) provides key insights into the evolution of host specialism and is a central concept in disease ecology. Host range is rarely estimated in real systems, however, because variation in species relative abundance and the detection of rare species makes it challenging to confidently estimate host range. We applied a non-parametric richness indicator to estimate host range in simulated and empirical data, allowing us to assess the influence of sampling heterogeneity and data completeness. After validating our method on simulated data, we estimated parasite host range for a sparsely sampled global parasite occurrence database (Global Mammal Parasite Database) and a repeatedly sampled set of parasites of small mammals from New Mexico (Sevilleta Long Term Ecological Research Program). Estimation accuracy varied strongly with parasite taxonomy, number of parasite occurrence records, and the shape of host species-abundance distribution (i.e. the dominance and rareness of species in the host community). Our findings suggest that between 20% and 40% of parasite host ranges are currently unknown, highlighting a major gap in our understanding of parasite specificity, host-parasite network structure, and parasite burdens.}, }
@article {pmid28851094, year = {2017}, author = {Foster, CN and Barton, PS and Robinson, NM and MacGregor, CI and Lindenmayer, DB}, title = {Effects of a large wildfire on vegetation structure in a variable fire mosaic.}, journal = {Ecological applications : a publication of the Ecological Society of America}, volume = {27}, number = {8}, pages = {2369-2381}, doi = {10.1002/eap.1614}, pmid = {28851094}, issn = {1051-0761}, mesh = {Australian Capital Territory ; *Biodiversity ; *Conservation of Natural Resources ; Ecosystem ; *Forests ; New South Wales ; *Wildfires ; }, abstract = {Management guidelines for many fire-prone ecosystems highlight the importance of maintaining a variable mosaic of fire histories for biodiversity conservation. Managers are encouraged to aim for fire mosaics that are temporally and spatially dynamic, include all successional states of vegetation, and also include variation in the underlying "invisible mosaic" of past fire frequencies, severities, and fire return intervals. However, establishing and maintaining variable mosaics in contemporary landscapes is subject to many challenges, one of which is deciding how the fire mosaic should be managed following the occurrence of large, unplanned wildfires. A key consideration for this decision is the extent to which the effects of previous fire history on vegetation and habitats persist after major wildfires, but this topic has rarely been investigated empirically. In this study, we tested to what extent a large wildfire interacted with previous fire history to affect the structure of forest, woodland, and heath vegetation in Booderee National Park in southeastern Australia. In 2003, a summer wildfire burned 49.5% of the park, increasing the extent of recently burned vegetation (<10 yr post-fire) to more than 72% of the park area. We tracked the recovery of vegetation structure for nine years following the wildfire and found that the strength and persistence of fire effects differed substantially between vegetation types. Vegetation structure was modified by wildfire in forest, woodland, and heath vegetation, but among-site variability in vegetation structure was reduced only by severe fire in woodland vegetation. There also were persistent legacy effects of the previous fire regime on some attributes of vegetation structure including forest ground and understorey cover, and woodland midstorey and overstorey cover. For example, woodland midstorey cover was greater on sites with higher fire frequency, irrespective of the severity of the 2003 wildfire. Our results show that even after a large, severe wildfire, underlying fire histories can contribute substantially to variation in vegetation structure. This highlights the importance of ensuring that efforts to reinstate variation in vegetation fire age after large wildfires do not inadvertently reduce variation in vegetation structure generated by the underlying invisible mosaic.}, }
@article {pmid28830052, year = {2018}, author = {Listopad, CMCS and Köbel, M and Príncipe, A and Gonçalves, P and Branquinho, C}, title = {The effect of grazing exclusion over time on structure, biodiversity, and regeneration of high nature value farmland ecosystems in Europe.}, journal = {The Science of the total environment}, volume = {610-611}, number = {}, pages = {926-936}, doi = {10.1016/j.scitotenv.2017.08.018}, pmid = {28830052}, issn = {1879-1026}, mesh = {Agriculture ; Animals ; *Biodiversity ; Cattle ; *Climate Change ; *Environmental Restoration and Remediation ; *Farms ; Grassland ; Herbivory ; Portugal ; Trees/growth &amp; development ; }, abstract = {Climate change and increasing socio-economic pressure is placing many ecosystems of high ecological and economic value at risk. This is particularly urgent in dryland ecosystems, such as the montado, a multifunctional savannah-like system heavily modeled by grazing. There is still an ongoing debate about the trade-offs between livestock grazing and the potential for ecosystem regeneration. While it is consensual that overgrazing hinders the development of the shrubs and trees in this system, the effects of undergrazing or grazing exclusion are unclear. This study provides the unique opportunity to study the impact of grazing on compositional and structural biodiversity by examining the ecological chronosequence in a long-term ecological research site, located in Portugal, where grazing exclusion was controlled for over 15years. As the threat of intensification persists, even in areas where climate shifts are evident, there is a critical need to understand if and how the montado might recover by removing grazing pressure. We evaluate succession on structural and compositional diversity after grazing pressure is removed from the landscape at 5, 10, and 15years post-cattle exclusion and contrast it with currently grazed plots. A LiDAR-derived structural diversity index (LHDI), a surrogate of ecosystem structure and function first developed for the pine-grassland woodland systems, is used to quantify the impact of grazing exclusion on structure and natural regeneration. The distribution of the vegetation, particularly those of the herbaceous and shrub strata (>10≤150cm), presents statistically significant changes. The LHDI closely mimics the compositional biodiversity of the shrubs, with an increase in diversity with increased years without grazing. Under present climate conditions, both shrub regeneration and the establishment of tree saplings were strongly promoted by grazing exclusion, which has important management implications for the long-term sustainability of montado systems.}, }
@article {pmid28815369, year = {2017}, author = {Abuhelou, F and Mansuy-Huault, L and Lorgeoux, C and Catteloin, D and Collin, V and Bauer, A and Kanbar, HJ and Gley, R and Manceau, L and Thomas, F and Montargès-Pelletier, E}, title = {Suspended particulate matter collection methods influence the quantification of polycyclic aromatic compounds in the river system.}, journal = {Environmental science and pollution research international}, volume = {24}, number = {28}, pages = {22717-22729}, pmid = {28815369}, issn = {1614-7499}, support = {ANR-14-CE01-0019//Agence Nationale de la Recherche/ ; }, mesh = {China ; Environmental Monitoring/*methods ; Geologic Sediments/*chemistry ; Particulate Matter/*analysis ; Polycyclic Aromatic Hydrocarbons/*analysis ; Rivers/*chemistry ; Water Movements ; Water Pollutants, Chemical/*analysis ; }, abstract = {In this study, we compared the influence of two different collection methods, filtration (FT) and continuous flow field centrifugation (CFC), on the concentration and the distribution of polycyclic aromatic compounds (PACs) in suspended particulate matter (SPM) occurring in river waters. SPM samples were collected simultaneously with FT and CFC from a river during six sampling campaigns over 2 years, covering different hydrological contexts. SPM samples were analyzed to determine the concentration of PACs including 16 polycyclic aromatic hydrocarbons (PAHs), 11 oxygenated PACs (O-PACs), and 5 nitrogen PACs (N-PACs). Results showed significant differences between the two separation methods. In half of the sampling campaigns, PAC concentrations differed from a factor 2 to 30 comparing FT and CFC-collected SPMs. The PAC distributions were also affected by the separation method. FT-collected SPM were enriched in 2-3 ring PACs whereas CFC-collected SPM had PAC distributions dominated by medium to high molecular weight compounds typical of combustion processes. This could be explained by distinct cut-off threshold of the two separation methods and strongly suggested the retention of colloidal and/or fine matter on glass-fiber filters particularly enriched in low molecular PACs. These differences between FT and CFC were not systematic but rather enhanced by high water flow rates.}, }
@article {pmid28805959, year = {2017}, author = {Carcaillet, C and Blarquez, O}, title = {Fire ecology of a tree glacial refugium on a nunatak with a view on Alpine glaciers.}, journal = {The New phytologist}, volume = {216}, number = {4}, pages = {1281-1290}, doi = {10.1111/nph.14721}, pmid = {28805959}, issn = {1469-8137}, mesh = {Biomass ; Chronology as Topic ; Climate Change ; *Fires ; *Forests ; France ; *Ice Cover ; *Larix ; Paleontology ; *Pinus ; Trees ; }, abstract = {In paleoecology, the function of biomass as a fire driver has become a focus of attention in cold ecosystems, and concerns have been raised about climate in this context. Little is known about the fire frequency and fire-plant relationships during glaciation when woodlands were limited and the climate was cold. Fire history and tree biomass were reconstructed from sedimentary charcoal and macroremains, respectively, archived in lake sediments from the western Alps. Two nunataks were investigated, both with lacustrine sediments covering the last 21 000 yr at least. During the Last Glacial Maximum (LGM) and the Lateglacial, fires occurred only on the nunatak sheltering woody plants. Cembra pine (Pinus cembra) and larch (Larix decidua) survived above glaciers during the LGM, thus evidencing a biological refugium and supporting the nunatak theory. We highlighted a long-term relationship between fires and dominant trees over the last 21 000 yr, where fire frequencies track the global climate and the local changes in tree biomass. Glacial climate (dry, cold) does not rule out fires. Fuel load and composition were significant fire drivers, with cembra pine dominating during colder periods with rare fires, and larch during the warmer Holocene with frequent fires. These findings increase knowledge of fire ecology in cold environments, and open perspectives in tree population genetics by considering new areas of tree glacial refugia in Europe.}, }
@article {pmid28779184, year = {2017}, author = {Flower, H and Rains, M and Fitz, C}, title = {Visioning the Future: Scenarios Modeling of the Florida Coastal Everglades.}, journal = {Environmental management}, volume = {60}, number = {5}, pages = {989-1009}, pmid = {28779184}, issn = {1432-1009}, support = {Florida Coastal Everglades Long-Term Ecological Research program under Cooperative Agreements No. DEB-1237517, Grant No. DBI-0620409, and Grant No. DEB-9910514//National Science Foundation/International ; }, mesh = {*Climate Change ; Conservation of Natural Resources/*trends ; Florida ; Forecasting ; Fresh Water ; *Models, Theoretical ; Oceans and Seas ; Soil ; *Wetlands ; }, abstract = {In this paper, we provide screening-level analysis of plausible Everglades ecosystem response by 2060 to sea level rise (0.50 m) interacting with macroclimate change (1.5 °C warming, 7% increase in evapotranspiration, and rainfall that either increases or decreases by 10%). We used these climate scenarios as input to the Ecological Landscape Model to simulate changes to seven interactive hydro-ecological metrics. Mangrove forest and other marine influences migrated up to 15 km inland in both scenarios, delineated by the saltwater front. Freshwater habitat area decreased by 25-30% under our two climate change scenarios and was largely replaced by mangroves and, in the increased rainfall scenario, open water as well. Significant mangroves drowned along northern Florida Bay in both climate change scenarios due to sea level rise. Increased rainfall of 10% provided significant benefits to the spatial and temporal salinity regime within the marine-influenced zone, providing a more gradual and natural adjustment for at-risk flora and fauna. However, increased rainfall also increased the risk of open water, due to water depths that inhibited mangrove establishment and reduced peat accumulation rates. We infer that ecological effects related to sea level rise may occur in the extreme front-edge of saltwater intrusion, that topography will control the incursion of this zone as sea level rises, and that differences in freshwater availability will have ecologically significant effects on ecosystem resilience through the temporal and spatial pattern of salinity changes.}, }
@article {pmid28778793, year = {2017}, author = {Pietrelli, L and Di Gennaro, A and Menegoni, P and Lecce, F and Poeta, G and Acosta, ATR and Battisti, C and Iannilli, V}, title = {Pervasive plastisphere: First record of plastics in egagropiles (Posidonia spheroids).}, journal = {Environmental pollution (Barking, Essex : 1987)}, volume = {229}, number = {}, pages = {1032-1036}, doi = {10.1016/j.envpol.2017.07.098}, pmid = {28778793}, issn = {1873-6424}, mesh = {Alismatales/*chemistry ; Ecosystem ; *Environmental Monitoring ; Italy ; Plastics/*analysis ; Polyethylene/analysis ; Polymers/analysis ; Water Pollutants, Chemical/*analysis ; }, abstract = {The ability of Posidonia oceanica spheroids (egagropiles, EG) to incorporate plastics was investigated along the central Italy coast. Plastics were found in the 52.84% of the egagropiles collected (n = 685). The more represented size of plastics has range within 1-1.5 cm, comparable to the size of natural fibres. Comparing plastics occurring both in EG and in surrounding sand, Polyethylene, Polyester and Nylon were the most abundant polymers in EG, while PSE, PE, PP and PET were the most represented in sand. In particular PE and PP were significantly more represented in sand, while PE, Nylon, Polyester and microfibers (as pills) were more represented in EG. Within plastics found in EG, 26.9% were microfibers as small pills (<1 cm), mainly composed of polyamide, polyester, cotton and PET mixing. These microfibers might be produced by discharges from washing machines and currently represents an emerging pollutant with widespread distribution in marine and freshwater ecosystems.}, }
@article {pmid28719191, year = {2017}, author = {Maizel, AC and Li, J and Remucal, CK}, title = {Relationships Between Dissolved Organic Matter Composition and Photochemistry in Lakes of Diverse Trophic Status.}, journal = {Environmental science &amp; technology}, volume = {51}, number = {17}, pages = {9624-9632}, pmid = {28719191}, issn = {1520-5851}, support = {S10 OD018475/OD/NIH HHS/United States ; }, mesh = {*Lakes ; Organic Chemicals ; *Photochemistry ; Water ; Wisconsin ; }, abstract = {The North Temperate Lakes Long-Term Ecological Research site includes seven lakes in northern Wisconsin that vary in hydrology, trophic status, and landscape position. We examine the molecular composition of dissolved organic matter (DOM) within these lakes using Fourier transform-ion cyclotron resonance mass spectrometry (FT-ICR MS) and quantify DOM photochemical activity using probe compounds. Correlations between the relative intensity of individual molecular formulas and reactive species production demonstrate the influence of DOM composition on photochemistry. For example, highly aromatic, tannin-like formulas correlate positively with triplet formation rates, but negatively with triplet quantum yields, as waters enriched in highly aromatic formulas exhibit much higher rates of light absorption, but only slightly higher rates of triplet production. While commonly utilized optical properties also correlate with DOM composition, the ability of FT-ICR MS to characterize DOM subpopulations provides unique insight into the mechanisms through which DOM source and environmental processing determine composition and photochemical activity.}, }
@article {pmid28690791, year = {2017}, author = {Caddy-Retalic, S and Andersen, AN and Aspinwall, MJ and Breed, MF and Byrne, M and Christmas, MJ and Dong, N and Evans, BJ and Fordham, DA and Guerin, GR and Hoffmann, AA and Hughes, AC and van Leeuwen, SJ and McInerney, FA and Prober, SM and Rossetto, M and Rymer, PD and Steane, DA and Wardle, GM and Lowe, AJ}, title = {Bioclimatic transect networks: Powerful observatories of ecological change.}, journal = {Ecology and evolution}, volume = {7}, number = {13}, pages = {4607-4619}, pmid = {28690791}, issn = {2045-7758}, abstract = {Transects that traverse substantial climate gradients are important tools for climate change research and allow questions on the extent to which phenotypic variation associates with climate, the link between climate and species distributions, and variation in sensitivity to climate change among biomes to be addressed. However, the potential limitations of individual transect studies have recently been highlighted. Here, we argue that replicating and networking transects, along with the introduction of experimental treatments, addresses these concerns. Transect networks provide cost-effective and robust insights into ecological and evolutionary adaptation and improve forecasting of ecosystem change. We draw on the experience and research facilitated by the Australian Transect Network to demonstrate our case, with examples, to clarify how population- and community-level studies can be integrated with observations from multiple transects, manipulative experiments, genomics, and ecological modeling to gain novel insights into how species and systems respond to climate change. This integration can provide a spatiotemporal understanding of past and future climate-induced changes, which will inform effective management actions for promoting biodiversity resilience.}, }
@article {pmid28646231, year = {2017}, author = {Engel, A and Piontek, J and Metfies, K and Endres, S and Sprong, P and Peeken, I and Gäbler-Schwarz, S and Nöthig, EM}, title = {Inter-annual variability of transparent exopolymer particles in the Arctic Ocean reveals high sensitivity to ecosystem changes.}, journal = {Scientific reports}, volume = {7}, number = {1}, pages = {4129}, pmid = {28646231}, issn = {2045-2322}, abstract = {Transparent exopolymer particles (TEP) are a class of marine gel particles and important links between surface ocean biology and atmospheric processes. Derived from marine microorganisms, these particles can facilitate the biological pumping of carbon dioxide to the deep sea, or act as cloud condensation and ice nucleation particles in the atmosphere. Yet, environmental controls on TEP abundance in the ocean are poorly known. Here, we investigated some of these controls during the first multiyear time-series on TEP abundance for the Fram Strait, the Atlantic gateway to the Central Arctic Ocean. Data collected at the Long-Term Ecological Research observatory HAUSGARTEN during 2009 to 2014 indicate a strong biological control with highest abundance co-occurring with the prymnesiophyte Phaeocystis pouchetii. Higher occurrence of P. pouchetii in the Arctic Ocean has previously been related to northward advection of warmer Atlantic waters, which is expected to increase in the future. Our study highlights the role of plankton key species in driving climate relevant processes; thus, changes in plankton distribution need to be accounted for when estimating the ocean's biogeochemical response to global change.}, }
@article {pmid28624948, year = {2018}, author = {Maunoury-Danger, F and Felten, V and Bojic, C and Fraysse, F and Cosin Ponce, M and Dedourge-Geffard, O and Geffard, A and Guérold, F and Danger, M}, title = {Metal release from contaminated leaf litter and leachate toxicity for the freshwater crustacean Gammarus fossarum.}, journal = {Environmental science and pollution research international}, volume = {25}, number = {12}, pages = {11281-11294}, pmid = {28624948}, issn = {1614-7499}, support = {TransMet//INSU EC2CO/ ; 1172C0040//ADEME/ ; L01648/PROJET//OTELO/ ; }, mesh = {Amphipoda/chemistry/drug effects ; Animals ; Cadmium/*analysis ; Ecosystem ; Ecotoxicology/*methods ; Fresh Water ; Metals/*analysis/chemistry ; Phosphorus/*analysis ; Plant Leaves/*chemistry ; Toxicity Tests ; Zinc/*analysis ; }, abstract = {Industrialization has left large surfaces of contaminated soils, which may act as a source of pollution for contiguous ecosystems, either terrestrial or aquatic. When polluted sites are recolonized by plants, dispersion of leaf litter might represent a non-negligible source of contaminants, especially metals. To evaluate the risks associated to contaminated leaf litter dispersion in aquatic ecosystems, we first measured the dynamics of metal loss from leaf litter during a 48-h experimental leaching. We used aspen (Populus tremula L.), a common tree species on these polluted sites, and collected leaf litter on three polluted sites (settling pond of a former steel mill) and three control sites situated in the same geographic area. Then, toxicity tests were carried out on individuals of a key detritivore species widely used in ecotoxicology tests, Gammarus fossarum (Crustacea, Amphipoda), with uncontaminated and contaminated leaf litter leachates, using a battery of biomarkers selected for their sensitivity to metallic stress. Leaf litters collected on polluted sites exhibited not only significantly higher cadmium and zinc concentrations but also lower lignin contents. All leaf litters released high amounts of chemical elements during the leaching process, especially potassium and magnesium, and, in a lesser extent, phosphorus, calcium, and trace metals (copper, cadmium, and zinc but not lead). Toxicity tests revealed that the most important toxic effects measured on G. fossarum were due to leaf litter leachates by themselves, whatever the origin of litter (from polluted or control sites), confirming the toxicity of such substances, probably due to their high content in phenolic compounds. Small additional toxic effects of leachates from contaminated leaf litters were only evidenced on gammarid lipid peroxidation, indicating that contaminated leaf litter leachates might be slightly more toxic than uncontaminated ones, but in a very reduced manner. Further studies will be required to verify if these patterns are generalizable to other species and to investigate the effects of contaminated leaf litter ingestion by consumers on aquatic food webs. Nevertheless, our results do not permit to exclude potential chronic effects of an exposure to contaminated leaf litter leachates in aquatic ecosystems.}, }
@article {pmid28624939, year = {2018}, author = {Rollin, M and Coulaud, R and Danger, M and Sohm, B and Flayac, J and Bec, A and Chaumot, A and Geffard, O and Felten, V}, title = {Additive effect of calcium depletion and low resource quality on Gammarus fossarum (Crustacea, Amphipoda) life history traits.}, journal = {Environmental science and pollution research international}, volume = {25}, number = {12}, pages = {11264-11280}, pmid = {28624939}, issn = {1614-7499}, support = {ANR-13-BSV7-0004-01//ANR MULTISTRESS/ ; }, mesh = {Amphipoda/*drug effects ; Animals ; Calcium/chemistry/*pharmacology ; Ecosystem ; Life History Traits ; Plant Leaves/*chemistry ; Rivers ; }, abstract = {Gammarus fossarum is an often-abundant crustacean detritivore that contributes importantly to leaf litter breakdown in oligotrophic, mainly heterotrophic, headwater streams. This species requires large amounts of Ca to moult, thus allowing growth and reproduction. Because resource quality is tightly coupled to the organism's growth and physiological status, we hypothesised that low Ca concentration [Ca] and low food resource quality (low phosphorus [P] and/or reduced highly unsaturated fatty acid [HUFA] contents) would interactively impair molecular responses (gene expression) and reproduction of G. fossarum. To investigate the effects of food resources quality, we experimentally manipulated the P content of sycamore leaves and also used diatoms because they contain high amounts of HUFAs. Three resource quality treatments were tested: low quality (LQ, unmanipulated leaves: low P content), high quality 1 (HQ1; P-manipulated leaves: high P content), and high quality 2 (unmanipulated leaves supplemented with a pellet containing diatoms: high P and HUFA content). Naturally, demineralised stream water was supplemented with CaSO4 to obtain three Ca concentrations (2, 3.5, and 10.5 mg Ca L[-1]). For 21 days, pairs of G. fossarum were individually exposed to one of the nine treatments (3 [Ca] × 3 resource qualities). At the individual level, strong and significant delays in moult stage were observed in gammarids exposed to lower [Ca] and to lower resource quality, with additive effects lengthening the duration of the reproductive cycle. Effects at the molecular level were investigated by measuring expression of 12 genes involved in energy production, translation, or Ca or P homeostasis. Expression of ATP synthase beta (higher in HQ2), calcified cuticle protein (higher in HQ1 and HQ2), and tropomyosin (higher in HQ2 compared to HQ1) was significantly affected by resource quality, and significant additive effects on Ca transporting ATPase expression were induced by [Ca] and resource quality (higher for low [Ca] and higher resource quality). These results highlight the potential drastic deleterious effects of water [Ca] depletion on G. fossarum physiology, populations, and ecosystem functioning, especially in oligotrophic environments.}, }
@article {pmid28616191, year = {2017}, author = {Firbank, LG and Bertora, C and Blankman, D and Delle Vedove, G and Frenzel, M and Grignani, C and Groner, E and Kertész, M and Krab, EJ and Matteucci, G and Menta, C and Mueller, CW and Stadler, J and Kunin, WE}, title = {Towards the co-ordination of terrestrial ecosystem protocols across European research infrastructures.}, journal = {Ecology and evolution}, volume = {7}, number = {11}, pages = {3967-3975}, pmid = {28616191}, issn = {2045-7758}, abstract = {The study of ecosystem processes over multiple scales of space and time is often best achieved using comparable data from multiple sites. Yet, long-term ecological observatories have often developed their own data collection protocols. Here, we address this problem by proposing a set of ecological protocols suitable for widespread adoption by the ecological community. Scientists from the European ecological research community prioritized terrestrial ecosystem parameters that could benefit from a more consistent approach to data collection within the resources available at most long-term ecological observatories. Parameters for which standard methods are in widespread use, or for which methods are evolving rapidly, were not selected. Protocols were developed by domain experts, building on existing methods where possible, and refined through a process of field testing and training. They address above-ground plant biomass; decomposition; land use and management; leaf area index; soil mesofaunal diversity; soil C and N stocks, and greenhouse gas emissions from soils. These complement existing methods to provide a complete assessment of ecological integrity. These protocols offer integrated approaches to ecological data collection that are low cost and are starting to be used across the European Long Term Ecological Research community.}, }
@article {pmid28615350, year = {2017}, author = {Schlaich, AE and Bouten, W and Bretagnolle, V and Heldbjerg, H and Klaassen, RHG and Sørensen, IH and Villers, A and Both, C}, title = {A circannual perspective on daily and total flight distances in a long-distance migratory raptor, the Montagu's harrier, Circus pygargus.}, journal = {Biology letters}, volume = {13}, number = {6}, pages = {}, pmid = {28615350}, issn = {1744-957X}, mesh = {Animal Migration ; Animals ; Denmark ; *Falconiformes ; Female ; France ; Male ; Netherlands ; }, abstract = {Long-distance migrants are particularly recognized for the distances covered on migration, yet little is known about the distances they cover during the rest of the year. GPS-tracks of 29 Montagu's harriers from breeding areas in France, The Netherlands and Denmark showed that harriers fly between 35 653 and 88 049 km yr[-1], of which on average only 28.5% is on migration. Mean daily distances during migration were 296 km d[-1] in autumn and 252 km d[-1] in spring. Surprisingly, males' daily distances during breeding (217 km d[-1]) were close to those during migration, whereas breeding females moved significantly less (101 km d[-1]) than males. In terms of flight distance, the breeding season seemed nearly as demanding as migration periods for males. During the six winter months, both sexes moved less (114 and 128 km d[-1] for females and males, respectively) than during migration. Harriers therefore covered shorter daily distances during winter which might allow birds to compensate for the more demanding phases of migration and breeding.}, }
@article {pmid32665782, year = {2017}, author = {Smith, RM and Kaushal, SS and Beaulieu, JJ and Pennino, MJ and Welty, C}, title = {Influence of infrastructure on water quality and greenhouse gas dynamics in urban streams.}, journal = {Biogeosciences (Online)}, volume = {14}, number = {11}, pages = {}, pmid = {32665782}, issn = {1726-4170}, support = {EPA999999/ImEPA/Intramural EPA/United States ; }, abstract = {Streams and rivers are significant sources of nitrous oxide (N2O), carbon dioxide (CO2), and methane (CH4) globally, and watershed management can alter greenhouse gas (GHG) emissions from streams. We hypothesized that urban infrastructure significantly alters downstream water quality and contributes to variability in GHG saturation and emissions. We measured gas saturation and estimated emission rates in headwaters of two urban stream networks (Red Run and Dead Run) of the Baltimore Ecosystem Study Long-Term Ecological Research project. We identified four combinations of stormwater and sanitary infrastructure present in these watersheds, including: (1) stream burial, (2) inline stormwater wetlands, (3) riparian/floodplain preservation, and (4) septic systems. We selected two first order catchments in each of these categories and measured GHG concentrations, emissions, and dissolved inorganic and organic carbon (DIC and DOC) and nutrient concentrations biweekly for 1 year. From a water quality perspective, the DOC : NO3 [-] ratio of streamwater was significantly different across infrastructure categories. Multiple linear regressions including DOC : NO3 [-] and other variables (dissolved oxygen, DO; total dissolved nitrogen, TDN; and temperature) explained much of the statistical variation in nitrous oxide (N2O, r[2] = 0.78), carbon dioxide (CO2, r[2] = 0.78) and methane (CH4, r 2 = 0.50) saturation in stream water. We measured N2O saturation ratios, which were among the highest reported in the literature for streams, ranging from 1.1 to 47 across all sites and dates. N2O saturation ratios were highest in streams draining watersheds with septic systems and strongly correlated with TDN. The CO2 saturation ratio was highly correlated with the N2O saturation ratio across all sites and dates, and the CO2 saturation ratio ranged from 1.1 to 73. CH4 was always supersaturated, with saturation ratios ranging from 3.0 to 2157. Longitudinal surveys extending form headwaters to third-order outlets of Red Run and Dead Run took place in spring and fall. Linear regressions of these data yielded significant negative relationships between each gas with increasing watershed size as well as consistent relationships between solutes (TDN or DOC, and DOC : TDN ratio) and gas saturation. Despite a decline in gas saturation between the headwaters and stream outlet, streams remained saturated with GHGs throughout the drainage network, suggesting that urban streams are continuous sources of CO2, CH4, and N2O. Our results suggest that infrastructure decisions can have significant effects on downstream water quality and greenhouse gases, and watershed management strategies may need to consider coupled impacts on urban water and air quality.}, }
@article {pmid28596410, year = {2017}, author = {Heinsch, SC and Otto-Hanson, L and Hsu, SY and Kinkel, L and Smanski, MJ}, title = {Genome Sequences for Streptomyces spp. Isolated from Disease-Suppressive Soils and Long-Term Ecological Research Sites.}, journal = {Genome announcements}, volume = {5}, number = {23}, pages = {}, pmid = {28596410}, issn = {2169-8287}, abstract = {We report here the high-quality genome sequences of three Streptomyces spp. isolated as part of a long-term study of microbial soil ecology. Streptomyces sp. strain GS93-23 was isolated from naturally disease-suppressive soil (DSS) in Grand Rapids, MN, and Streptomyces sp. strains S3-4 and 3211-3 were isolated from experimental plots in the Cedar Creek Ecosystem Science Reserve (CCESR).}, }
@article {pmid28589285, year = {2017}, author = {Pietrelli, L and Poeta, G and Battisti, C and Sighicelli, M}, title = {Characterization of plastic beach debris finalized to its removal: a proposal for a recycling scheme.}, journal = {Environmental science and pollution research international}, volume = {24}, number = {19}, pages = {16536-16542}, pmid = {28589285}, issn = {1614-7499}, mesh = {*Bathing Beaches ; *Environmental Monitoring ; Italy ; *Plastics ; Recycling ; Spectroscopy, Fourier Transform Infrared ; }, abstract = {Characterization of beach debris is crucial to assess the strategy to answer questions such as recycling. With the aim to assess its use in a recycling scheme, in this note, we carried out a physical and chemical characterization of plastic litter from a pilot beach in Central Italy, using the FT-IR spectroscopy and thermoanalysis. Fourteen polymers, having mainly thermoplastic origin, were identified; among them, the most represented are polyethylene (41.7%) and polypropylene (36.9%). Chemical and mechanical degradation were clearly observed by an IR spectrum. The thermogravimetric analysis curve of the plastic blend shows the melting point at 120-140 °C, and degradation occurs almost totally in a one-step process within 300-500 °C. The high heating value of the plastic debris is 43.9 MJ kg[-1]. Polymer blends obtained by beach debris show mechanical properties similar to the virgin high-density polyethylene polymer. Following the beach plastic debris characterization, a recycling scheme was suggested.}, }
@article {pmid32995178, year = {2017}, author = {Makaryus, M and Sahni, S and Kumar, A and Shah, RD and Cohen, SL and Mehrishi, S and Talwar, A}, title = {Right Ventricular Perforation and Subsequent Cardiac Tamponade Caused by IVC Filter Strut Fracture Migration.}, journal = {Journal of acute medicine}, volume = {7}, number = {2}, pages = {87-91}, pmid = {32995178}, issn = {2211-5587}, abstract = {Cardiac tamponade, if not recognized and treated immediately, is a life threatening condition with various etiologies. Most common causes of cardiac tamponade encountered in emergency rooms are due to trauma, post myocardial infarction wall rupture, cancer and all other causes of pericardial effusion. Iatrogenic causes of cardiac tamponade include anticoagulation and procedures related. Currently there is a general comfort level amongst physicians that inferior vena cava (IVC) filters are not associated with significant complications. However, one of the feared life-threatening immediate complications of IVC filter placement is complete migration of the filter to the heart, with possible risk for cardiac arrhythmia, cardiac tamponade, and death. IVC filter strut fracture and migration to the heart and pulmonary arteries is another possible cause of cardiac tamponade and needs to be added to the differential diagnosis in the setting of tamponade signs and symptoms in a patient with history of IVC filter placement. We present a case of IVC filter strut fracture and migration to the right ventricle with penetration of the free wall causing cardiac tamponade with subsequent successful percutaneous retrieval. We hope to raise awareness through this case of the rare but potentially fatal complications of IVC filter placement and to advise regarding the judicious use of IVC filters.}, }
@article {pmid28500769, year = {2017}, author = {Kaspari, M and Bujan, J and Weiser, MD and Ning, D and Michaletz, ST and Zhili, H and Enquist, BJ and Waide, RB and Zhou, J and Turner, BL and Wright, SJ}, title = {Biogeochemistry drives diversity in the prokaryotes, fungi, and invertebrates of a Panama forest.}, journal = {Ecology}, volume = {98}, number = {8}, pages = {2019-2028}, doi = {10.1002/ecy.1895}, pmid = {28500769}, issn = {0012-9658}, mesh = {Animals ; *Biodiversity ; Ecosystem ; *Forests ; Fungi/*classification ; Invertebrates/*classification ; Panama ; Soil ; *Soil Microbiology ; }, abstract = {Humans are both fertilizing the world and depleting its soils, decreasing the diversity of aquatic ecosystems and terrestrial plants in the process. We know less about how nutrients shape the abundance and diversity of the prokaryotes, fungi, and invertebrates of Earth's soils. Here we explore this question in the soils of a Panama forest subject to a 13-yr fertilization with factorial combinations of nitrogen (N), phosphorus (P), and potassium (K) and a separate micronutrient cocktail. We contrast three hypotheses linking biogeochemistry to abundance and diversity. Consistent with the Stress Hypothesis, adding N suppressed the abundance of invertebrates and the richness of all three groups of organisms by ca. 1 SD or more below controls. Nitrogen addition plots were 0.8 pH units more acidic with 18% more exchangeable aluminum, which is toxic to both prokaryotes and eukaryotes. These stress effects were frequently reversed, however, when N was added with P (for prokaryotes and invertebrates) and with added K (for fungi). Consistent with the Abundance Hypothesis, adding P generally increased prokaryote and invertebrate diversity, and adding K enhanced invertebrate diversity. Also consistent with the Abundance Hypothesis, increases in invertebrate abundance generated increases in richness. We found little evidence for the Competition Hypothesis: that single nutrients suppressed diversity by favoring a subset of high nutrient specialists, and that nutrient combinations suppressed diversity even more. Instead, combinations of nutrients, and especially the cation/micronutrient treatment, yielded the largest increases in richness in the two eukaryote groups. In sum, changes in soil biogeochemistry revealed a diversity of responses among the three dominant soil groups, positive synergies among nutrients, and-in contrast with terrestrial plants-the frequent enhancement of soil biodiversity.}, }
@article {pmid28494280, year = {2017}, author = {Kanbar, HJ and Montargès-Pelletier, E and Losson, B and Bihannic, I and Gley, R and Bauer, A and Villieras, F and Manceau, L and El Samrani, AG and Kazpard, V and Mansuy-Huault, L}, title = {Iron mineralogy as a fingerprint of former steelmaking activities in river sediments.}, journal = {The Science of the total environment}, volume = {599-600}, number = {}, pages = {540-553}, doi = {10.1016/j.scitotenv.2017.04.156}, pmid = {28494280}, issn = {1879-1026}, abstract = {Submerged sediment cores were collected upstream of a dam in the Orne River, northeastern France. This dam was built in the context of steelmaking to constitute a water reservoir for blast furnace cooling and wet cleaning of furnace smokes. The dam also enhanced sediment deposition in the upstream zone. This study was performed to unravel the contamination status of sediments and to evidence possible contribution sources. The sediment layers were analyzed for water content, grain size, chemical composition, crystalline phases at a bulk scale and poorly crystalline and amorphous phases at a sub-micrometer scale. Visual aspect, texture, color, and chemical and mineralogical analyses showed that the settled sediments were mainly composed of fine black matter, certainly comprising steelmaking by-products. Those materials were highly enriched with Fe, Zn, Pb and other trace metals, except for a relatively thin layer of surficial sediments that had settled more recently. Bulk mineralogy revealed crystalline iron minerals, such as magnetite, goethite, wuestite and pyrite, in the deep layers of the sediment cores. Furthermore, microscopic investigations evidenced the presence of ferrospheres, goethite nanoparticles and newly formed Fe-aluminosilicates; all originating from the former steelmaking facilities. The variation of iron mineralogy, combined with specific chemical profiles and other sediment features, demonstrate the different contributions that constitute the sediment deposit. Furthermore, chemical and mineralogical features of goethite and Fe-aluminosilicates could be used as a fingerprint for such contaminated sediments.}, }
@article {pmid28493884, year = {2017}, author = {Blair, DP and Blanchard, W and Banks, SC and Lindenmayer, DB}, title = {Non-linear growth in tree ferns, Dicksonia antarctica and Cyathea australis.}, journal = {PloS one}, volume = {12}, number = {5}, pages = {e0176908}, pmid = {28493884}, issn = {1932-6203}, mesh = {Ferns/*growth &amp; development ; Fires ; Forests ; Models, Biological ; Nonlinear Dynamics ; South Australia ; Trees/*growth &amp; development ; }, abstract = {Tree ferns are an important structural component of forests in many countries. However, because their regeneration is often unrelated to major disturbances, their age is often difficult to determine. In addition, rates of growth may not be uniform, which further complicates attempts to determine their age. In this study, we measured 5 years of growth of Cyathea australis and Dicksonia antarctica after a large wildfire in 2009 in south-eastern Australia. We found growth rates of these two species were unaffected by aspect and elevation but slope had a minor effect with D. antarctica growing 0.3mm faster for each additional degree of slope. Geographic location influenced growth in both species by up to 12 - 14mm/yr. The most consistent factor influencing growth rate, however, was initial height at the time of the 2009 fire; a finding consistent in both species and all geographic locations. For both tree fern species, individuals that were taller at the commencement of the study had greater overall growth for the duration of the study. This effect did not decrease even among the tallest tree ferns in our study (up to 6 metres tall). Overall, Cyathea australis averaged 73 (± 22)mm/year of growth (± 1SD), with the rate increasing 5mm/yr per metre of additional height. Dicksonia antarctica averaged 33 (± 13)mm/year, increasing by 6mm/yr/m. Growth rates dependent on initial height were unexpected and we discuss possible reasons for this finding. Variable growth rates also suggest that common age estimation methods of dividing height by average growth rate are likely to underestimate the age of short tree ferns, while overestimating the age of tall tree ferns, particularly if they have been subject to a fire.}, }
@article {pmid28441395, year = {2017}, author = {Di Capua, I and Maffucci, F and Pannone, R and Mazzocchi, MG and Biffali, E and Amato, A}, title = {Molecular phylogeny of Oncaeidae (Copepoda) using nuclear ribosomal internal transcribed spacer (ITS rDNA).}, journal = {PloS one}, volume = {12}, number = {4}, pages = {e0175662}, pmid = {28441395}, issn = {1932-6203}, mesh = {Animals ; Arthropod Proteins/genetics ; Base Sequence ; Copepoda/*genetics ; DNA, Ribosomal Spacer/*genetics ; Electron Transport Complex IV/genetics ; *Phylogeny ; }, abstract = {Copepods belonging to the Oncaeidae family are commonly and abundantly found in marine zooplankton. In the Mediterranean Sea, forty-seven oncaeid species occur, of which eleven in the Gulf of Naples. In this Gulf, several Oncaea species were morphologically analysed and described at the end of the XIX century by W. Giesbrecht. In the same area, oncaeids are being investigated over seasonal and inter-annual scales at the long-term coastal station LTER-MC. In the present work, we identified six oncaeid species using the nuclear ribosomal internal transcribed spacers (ITS rDNA) and the mitochondrial cytochrome c oxidase subunit I (mtCOI). Phylogenetic analyses based on these two genomic regions validated the sisterhood of the genera Triconia and the Oncaea sensu stricto. ITS1 and ITS2 phylogenies produced incongruent results about the position of Oncaea curta, calling for further investigations on this species. We also characterised the ITS2 region by secondary structure predictions and found that all the sequences analysed presented the distinct eukaryotic hallmarks. A Compensatory Base Change search corroborated the close relationship between O. venusta and O. curta and between O. media and O. venusta already identified by ITS phylogenies. The present results, which stem from the integration of molecular and morphological taxonomy, represent an encouraging step towards an improved knowledge of copepod biodiversity: The two complementary approaches, when applied to long-term copepod monitoring, will also help to better understanding their genetic variations and ecological niches of co-occurring species.}, }
@article {pmid28435997, year = {2017}, author = {Assaad, A and Pontvianne, S and Pons, MN}, title = {Assessment of organic pollution of an industrial river by synchronous fluorescence and UV-vis spectroscopy: the Fensch River (NE France).}, journal = {Environmental monitoring and assessment}, volume = {189}, number = {5}, pages = {229}, pmid = {28435997}, issn = {1573-2959}, mesh = {Environmental Monitoring/*methods ; Fluorescence ; France ; Industry ; Nitrates/analysis ; Organic Chemicals/*analysis ; Rivers/chemistry ; Spectrometry, Fluorescence/methods ; Water Pollutants, Chemical/*analysis ; }, abstract = {To rapidly monitor the surface water quality in terms of organic pollution of an industrial river undergoing restoration, optical methods (UV-visible spectrometry and fluorescence) were applied in parallel to classical physical-chemical analyses. UV-visible spectra were analyzed using the maximum of the second derivative at 225 nm (related to nitrates), specific absorbance at 254 nm (SUVA254), and the spectral slope between 275 and 295 nm (S 275-295) (related to the aromaticity and molecular weight of dissolved organic carbon). The synchronous fluorescence spectra (wavelength difference = 50 nm) exhibited a high variability in the composition of dissolved organic material between the upstream and downstream sections and also versus time. The principal components analysis of the entire set of synchronous fluorescence spectra helped to define three river sections with different pollution characteristics. Spectral decomposition was applied to the two most upstream sections: five fluorophores, classical in rivers impacted by domestic sewage and related to protein-like (λ ex = 280 nm) and humic-like fluorescence (M-type with λ ex ≈ 305-310 nm and C-type with λ ex ≥ 335 nm), were identified. The irregular shape of the synchronous fluorescence spectra in the most downstream section is likely due to organic pollutants of industrial origin; however, their variability and the complexity of the spectra did not allow the further elucidation of their nature.}, }
@article {pmid28423459, year = {2017}, author = {Browning, DM and Maynard, JJ and Karl, JW and Peters, DC}, title = {Breaks in MODIS time series portend vegetation change: verification using long-term data in an arid grassland ecosystem.}, journal = {Ecological applications : a publication of the Ecological Society of America}, volume = {27}, number = {5}, pages = {1677-1693}, doi = {10.1002/eap.1561}, pmid = {28423459}, issn = {1051-0761}, mesh = {*Biomass ; Biota ; Embryophyta/*physiology ; *Grassland ; New Mexico ; *Satellite Imagery ; Seasons ; }, abstract = {Frequency and severity of extreme climatic events are forecast to increase in the 21st century. Predicting how managed ecosystems may respond to climatic extremes is intensified by uncertainty associated with knowing when, where, and how long effects of extreme events will be manifest in an ecosystem. In water-limited ecosystems with high inter-annual variability in rainfall, it is important to be able to distinguish responses that result from seasonal fluctuations in rainfall from long-term directional increases or decreases in precipitation. A tool that successfully distinguishes seasonal from directional biomass responses would allow land managers to make informed decisions about prioritizing mitigation strategies, allocating human resource monitoring efforts, and mobilizing resources to withstand extreme climatic events. We leveraged long-term observations (2000-2013) of quadrat-level plant biomass at multiple locations across a semiarid landscape in southern New Mexico to verify the use of Normalized Difference Vegetation Index (NDVI) time series derived from 250-m Moderate Resolution Imaging Spectroradiometer (MODIS) data as a proxy for changes in aboveground productivity. This period encompassed years of sustained drought (2000-2003) and record-breaking high rainfall (2006 and 2008) followed by subsequent drought years (2011 through 2013) that resulted in a restructuring of plant community composition in some locations. Our objective was to decompose vegetation patterns derived from MODIS NDVI over this period into contributions from (1) the long-term trend, (2) seasonal cycle, and (3) unexplained variance using the Breaks for Additive Season and Trend (BFAST) model. BFAST breakpoints in NDVI trend and seasonal components were verified with field-estimated biomass at 15 sites that differed in species richness, vegetation cover, and soil properties. We found that 34 of 45 breaks in NDVI trend reflected large changes in mean biomass and 16 of 19 seasonal breaks accompanied changes in the contribution to biomass by perennial and/or annual grasses. The BFAST method using satellite imagery proved useful for detecting previously reported ground-based changes in vegetation in this arid ecosystem. We demonstrate that time series analysis of NDVI data holds potential for monitoring landscape condition in arid ecosystems at the large spatial scales needed to differentiate responses to a changing climate from responses to seasonal variability in rainfall.}, }
@article {pmid28405280, year = {2017}, author = {Helm, N and Essl, F and Mirtl, M and Dirnböck, T}, title = {Multiple environmental changes drive forest floor vegetation in a temperate mountain forest.}, journal = {Ecology and evolution}, volume = {7}, number = {7}, pages = {2155-2168}, pmid = {28405280}, issn = {2045-7758}, abstract = {Human-induced changes of the environment and their possible impacts on temperate forest understory plant communities have been examined in many studies. However, the relative contribution of individual environmental factors to these changes in the herb layer is still unclear. In this study, we used vegetation survey data covering a time period of 21 years and collected from 143 permanent plots in the Northern Limestone Alps, Austria. Data on soil chemistry (49 plots), light condition (51 plots), soil temperature and moisture (four and six plots), disturbance (all plots), climate (one station in a clearing area), and airborne sulfur (S) and nitrogen (N) deposition (two forest stands) were available for analyses. We used these data together with plot mean Ellenberg indicator values in a path analysis to attribute their relative contributions to observed vegetation changes. Our analysis reveals a strong directional shift of the forest understory plant community. We found strong evidence for a recovery of the ground-layer vegetation from acidification as response to decreased S deposition. We did not observe a community response to atmospheric N deposition, but we found a response to altered climatic conditions (thermophilization and drying). The path analysis revealed that changes in the light regime, which were related to small-scale disturbances, had most influence on herb layer community shifts. Thermophilization and drying were identified as drivers of understory community changes independent of disturbance events.}, }
@article {pmid28384186, year = {2017}, author = {Greenville, AC and Dickman, CR and Wardle, GM}, title = {75 years of dryland science: Trends and gaps in arid ecology literature.}, journal = {PloS one}, volume = {12}, number = {4}, pages = {e0175014}, pmid = {28384186}, issn = {1932-6203}, mesh = {Ecology/*trends ; Ecosystem ; }, abstract = {Growth in the publication of scientific articles is occurring at an exponential rate, prompting a growing need to synthesise information in a timely manner to combat urgent environmental problems and guide future research. Here, we undertake a topic analysis of dryland literature over the last 75 years (8218 articles) to identify areas in arid ecology that are well studied and topics that are emerging. Four topics-wetlands, mammal ecology, litter decomposition and spatial modelling, were identified as 'hot topics' that showed higher than average growth in publications from 1940 to 2015. Five topics-remote sensing, climate, habitat and spatial, agriculture and soils-microbes, were identified as 'cold topics', with lower than average growth over the survey period, but higher than average numbers of publications. Topics in arid ecology clustered into seven broad groups on word-based similarity. These groups ranged from mammal ecology and population genetics, broad-scale management and ecosystem modelling, plant ecology, agriculture and ecophysiology, to populations and paleoclimate. These patterns may reflect trends in the field of ecology more broadly. We also identified two broad research gaps in arid ecology: population genetics, and habitat and spatial research. Collaborations between population genetics and ecologists and investigations of ecological processes across spatial scales would contribute profitably to the advancement of arid ecology and to ecology more broadly.}, }
@article {pmid28353113, year = {2017}, author = {Poeta, G and Fanelli, G and Pietrelli, L and Acosta, AT and Battisti, C}, title = {Plastisphere in action: evidence for an interaction between expanded polystyrene and dunal plants.}, journal = {Environmental science and pollution research international}, volume = {24}, number = {12}, pages = {11856-11859}, pmid = {28353113}, issn = {1614-7499}, mesh = {*Ecosystem ; Environmental Pollutants/*analysis ; Italy ; *Poaceae ; Polystyrenes/*analysis ; }, abstract = {Among the many threats that can be recorded on sandy beaches, plastic litter represents a serious problem for these complex and endangered ecosystems. Expanded polystyrene (EPS) is increasingly abundant as a form of plastic litter in natural environments, particularly along shores and waterways. Nevertheless, despite the great number of scientific articles concerning the impact of litter on animal species, there are still no research focusing on the interaction between this type of beach litter and other biodiversity components. In this work, we reported the first evidence of interactions between EPS and living plants along a sandy beach of Tyrrhenian central Italy. We sampled 540 EPS items, mainly deriving from fishery activities (>75%). We obtained evidence for an interaction between EPS and plants: about 5% of items resulted perforated or have roots of three species (Phragmites australis, Spartina versicolor, Anthemis maritima). Apparently, we did not observed a relationship between plants and EPS items size. More research is needed to assess if the plant assemblage growing on EPS is random or if peculiar substrate exerts some sort of selection on the plant community.}, }
@article {pmid28286509, year = {2017}, author = {Ferrero, R and Lima, M and Davis, AS and Gonzalez-Andujar, JL}, title = {Weed Diversity Affects Soybean and Maize Yield in a Long Term Experiment in Michigan, USA.}, journal = {Frontiers in plant science}, volume = {8}, number = {}, pages = {236}, pmid = {28286509}, issn = {1664-462X}, abstract = {Managing production environments in ways that promote weed community diversity may enhance both crop production and the development of a more sustainable agriculture. This study analyzed data of productivity of maize (corn) and soybean in plots in the Main Cropping System Experiment (MCSE) at the W. K. Kellogg Biological Station Long-Term Ecological Research (KBS-LTER) in Michigan, USA, from 1996 to 2011. We used models derived from population ecology to explore how weed diversity, temperature, and precipitation interact with crop yields. Using three types of models that considered internal and external (climate and weeds) factors, with additive or non-linear variants, we found that changes in weed diversity were associated with changes in rates of crop yield increase over time for both maize and soybeans. The intrinsic capacity for soybean yield increase in response to the environment was greater under more diverse weed communities. Soybean production risks were greatest in the least weed diverse systems, in which each weed species lost was associated with progressively greater crop yield losses. Managing for weed community diversity, while suppressing dominant, highly competitive weeds, may be a helpful strategy for supporting long term increases in soybean productivity. In maize, there was a negative and non-additive response of yields to the interaction between weed diversity and minimum air temperatures. When cold temperatures constrained potential maize productivity through limited resources, negative interactions with weed diversity became more pronounced. We suggest that: (1) maize was less competitive in cold years allowing higher weed diversity and the dominance of some weed species; or (2) that cold years resulted in increased weed richness and prevalence of competitive weeds, thus reducing crop yields. Therefore, we propose to control dominant weed species especially in the years of low yield and extreme minimum temperatures to improve maize yields. Results of our study indicate that through the proactive management of weed diversity, it may be possible to promote both high productivity of crops and environmental sustainability.}, }
@article {pmid28286496, year = {2017}, author = {Hoffmann, K and Hassenrück, C and Salman-Carvalho, V and Holtappels, M and Bienhold, C}, title = {Response of Bacterial Communities to Different Detritus Compositions in Arctic Deep-Sea Sediments.}, journal = {Frontiers in microbiology}, volume = {8}, number = {}, pages = {266}, pmid = {28286496}, issn = {1664-302X}, support = {294757/ERC_/European Research Council/International ; }, abstract = {Benthic deep-sea communities are largely dependent on particle flux from surface waters. In the Arctic Ocean, environmental changes occur more rapidly than in other ocean regions, and have major effects on the export of organic matter to the deep sea. Because bacteria constitute the majority of deep-sea benthic biomass and influence global element cycles, it is important to better understand how changes in organic matter input will affect bacterial communities at the Arctic seafloor. In a multidisciplinary ex situ experiment, benthic bacterial deep-sea communities from the Long-Term Ecological Research Observatory HAUSGARTEN were supplemented with different types of habitat-related detritus (chitin, Arctic algae) and incubated for 23 days under in situ conditions. Chitin addition caused strong changes in community activity, while community structure remained similar to unfed control incubations. In contrast, the addition of phytodetritus resulted in strong changes in community composition, accompanied by increased community activity, indicating the need for adaptation in these treatments. High-throughput sequencing of the 16S rRNA gene and 16S rRNA revealed distinct taxonomic groups of potentially fast-growing, opportunistic bacteria in the different detritus treatments. Compared to the unfed control, Colwelliaceae, Psychromonadaceae, and Oceanospirillaceae increased in relative abundance in the chitin treatment, whereas Flavobacteriaceae, Marinilabiaceae, and Pseudoalteromonadaceae increased in the phytodetritus treatments. Hence, these groups may constitute indicator taxa for the different organic matter sources at this study site. In summary, differences in community structure and in the uptake and remineralization of carbon in the different treatments suggest an effect of organic matter quality on bacterial diversity as well as on carbon turnover at the seafloor, an important feedback mechanism to be considered in future climate change scenarios.}, }
@article {pmid28207176, year = {2017}, author = {Mason, TJ and Keith, DA and Letten, AD}, title = {Detecting state changes for ecosystem conservation with long-term monitoring of species composition.}, journal = {Ecological applications : a publication of the Ecological Society of America}, volume = {27}, number = {2}, pages = {458-468}, doi = {10.1002/eap.1449}, pmid = {28207176}, issn = {1051-0761}, mesh = {Biota ; *Conservation of Natural Resources ; *Ecosystem ; New South Wales ; *Plants ; Population Dynamics ; Seasons ; *Wetlands ; }, abstract = {Effective conservation requires an understanding not only of contemporary vegetation distributions in the landscape, but also cognizance of vegetation transitions over time with the goal of maintaining persistence of all states within the landscape. Using a state and transition model framework, we investigated temporal transitions over 31 years in species composition among five upland swamp vegetation communities in southeastern Australia. We applied fuzzy clustering to document transitions across communities; evaluated the resilience and resistance of communities to change; and explored the relationship between ecosystem states and major environmental factors posited to structure the system. We also evaluated the predictive ability of an established vegetation dynamics model. We found that community composition remained stable or underwent reversible or directional transitions depending on the vegetation type. Wetter communities (Ti-tree thicket and Cyperoid heath) were more stable (i.e., resistant) while drier communities showed a greater propensity to transition (i.e., had lower resistance) under the observed disturbance regime (low variance fire intervals). The resilience of drier communities differed under this regime, with Banksia thicket showing reversible compositional change, while Restioid heath and Sedgeland showed directional change. In accord with an established conceptual model, we found that communities were distributed along a hydrological gradient. In addition, vegetation structure, along with light penetration to ground level, differentiated communities. However, internal dynamics of drier communities were complex: differences in fire regime (penultimate fire interval in 2014 and number of fires since 1965) were unable to predict differences in community membership among sites. Aspects of the fire regime are expected to be more important predictors if fire intervals vary more strongly among sites in the future. Fuzzy clustering of compositional data allows managers to track community transitions over time and facilitates planned interventions for conservation purposes.}, }
@article {pmid28174557, year = {2017}, author = {Marti, R and Ribun, S and Aubin, JB and Colinon, C and Petit, S and Marjolet, L and Gourmelon, M and Schmitt, L and Breil, P and Cottet, M and Cournoyer, B}, title = {Human-Driven Microbiological Contamination of Benthic and Hyporheic Sediments of an Intermittent Peri-Urban River Assessed from MST and 16S rRNA Genetic Structure Analyses.}, journal = {Frontiers in microbiology}, volume = {8}, number = {}, pages = {19}, pmid = {28174557}, issn = {1664-302X}, abstract = {Rivers are often challenged by fecal contaminations. The barrier effect of sediments against fecal bacteria was investigated through the use of a microbial source tracking (MST) toolbox, and by Next Generation Sequencing (NGS) of V5-V6 16S rRNA gene (rrs) sequences. Non-metric multi-dimensional scaling analysis of V5-V6 16S rRNA gene sequences differentiated bacteriomes according to their compartment of origin i.e., surface water against benthic and hyporheic sediments. Classification of these reads showed the most prevalent operating taxonomic units (OTU) to be allocated to Flavobacterium and Aquabacterium. Relative numbers of Gaiella, Haliangium, and Thermoleophilum OTU matched the observed differentiation of bacteriomes according to river compartments. OTU patterns were found impacted by combined sewer overflows (CSO) through an observed increase in diversity from the sewer to the hyporheic sediments. These changes appeared driven by direct transfers of bacterial contaminants from wastewaters but also by organic inputs favoring previously undetectable bacterial groups among sediments. These NGS datasets appeared more sensitive at tracking community changes than MST markers. The human-specific MST marker HF183 was strictly detected among CSO-impacted surface waters and not river bed sediments. The ruminant-specific DNA marker was more broadly distributed but intense bovine pollution was required to detect transfers from surface water to benthic and hyporheic sediments. Some OTU showed distribution patterns in line with these MST datasets such as those allocated to the Aeromonas, Acinetobacter, and Pseudomonas. Fecal indicators (Escherichia coli and total thermotolerant coliforms) were detected all over the river course but their concentrations were not correlated with MST ones. Overall, MST and NGS datasets suggested a poor colonization of river sediments by bovine and sewer bacterial contaminants. No environmental outbreak of these bacterial contaminants was detected.}, }
@article {pmid28116549, year = {2017}, author = {Barnett, AA and Silla, JM and de Oliveira, T and Boyle, SA and Bezerra, BM and Spironello, WR and Setz, EZ and da Silva, RF and de Albuquerque Teixeira, S and Todd, LM and Pinto, LP}, title = {Run, hide, or fight: anti-predation strategies in endangered red-nosed cuxiú (Chiropotes albinasus, Pitheciidae) in southeastern Amazonia.}, journal = {Primates; journal of primatology}, volume = {58}, number = {2}, pages = {353-360}, pmid = {28116549}, issn = {1610-7365}, mesh = {Aggression ; Animals ; Brazil ; *Endangered Species ; *Escape Reaction ; Falconiformes/*physiology ; Female ; Food Chain ; Male ; Pitheciidae/*physiology ; *Predatory Behavior ; Running ; }, abstract = {Although primate predation is rarely observed, a series of primate anti-predation strategies have been described. Energetic costs of such strategies can vary from high-cost mobbing, via less costly alarm calling, to low-cost furtive concealment. Here we report the anti-predation strategies of red-nosed cuxiú, Chiropotes albinasus, based on direct observations from four study sites in southeastern Brazilian Amazonia. Over a collective period of 1255 fieldwork hours, we observed nine direct interactions between raptors (all potential predators) and red-nosed cuxiús. Of these, one (11%) resulted in predation. Raptors involved were: Harpia harpyja (four events), Leucopternis sp. (two events), Spizaëtus tyrannus (one event), and unidentified large raptors (two events). Predation attempts occurred in flooded-forest and terra firme rainforest, were directed at both adult and non-adult cuxiús, and involved both adult and juvenile raptors. Anti-predation strategies adopted by the cuxiús included: (1) group defence and mobbing behaviour (two occasions), (2) dropping into dense sub-canopy (seven occasions), (3) alarm calling (eight occasions), and (4) fleeing to, and hiding in, dense vegetation (eight occasions). During each encounter at least two of these behaviours were recorded. These are the first published records of predation, predation attempts, and anti-predator behaviour involving red-nosed cuxiú.}, }
@article {pmid28103631, year = {2017}, author = {Arroyo, B and Mougeot, F and Bretagnolle, V}, title = {Individual variation in behavioural responsiveness to humans leads to differences in breeding success and long-term population phenotypic changes.}, journal = {Ecology letters}, volume = {20}, number = {3}, pages = {317-325}, doi = {10.1111/ele.12729}, pmid = {28103631}, issn = {1461-0248}, mesh = {Animals ; Behavior, Animal ; Falconiformes/*physiology ; Female ; France ; *Nesting Behavior ; Personality ; Reproduction ; Risk-Taking ; *Shyness ; }, abstract = {Whether human disturbance can lead to directional selection and phenotypic change in behaviour in species with limited behavioural plasticity is poorly understood in wild animal populations. Using a 19-year study on Montagu's harrier, we report a long-term increase in boldness towards humans during nest visits. The probability of females fleeing or being passive during nest visits decreased, while defence intensity steadily increased over the study period. These behavioural responses towards humans were significantly repeatable. The phenotypic composition of the breeding population changed throughout the study period (4-5 harrier generations), with a gradual disappearance of shy individuals, leading to a greater proportion of bolder ones and a more behaviourally homogeneous population. We further show that nest visit frequency increased nest failure probability and reduced productivity of shy females, but not of bold ones. Long-term research or conservation programmes needing nest visits can therefore lead to subtle but relevant population compositional changes that require further attention.}, }
@article {pmid28083109, year = {2016}, author = {Hermann, SL and Xue, S and Rowe, L and Davidson-Lowe, E and Myers, A and Eshchanov, B and Bahlai, CA}, title = {Thermally moderated firefly activity is delayed by precipitation extremes.}, journal = {Royal Society open science}, volume = {3}, number = {12}, pages = {160712}, pmid = {28083109}, issn = {2054-5703}, abstract = {The timing of events in the life history of temperate insects is most typically primarily cued by one of two drivers: photoperiod or temperature accumulation over the growing season. However, an insect's phenology can also be moderated by other drivers like rainfall or the phenology of its host plants. When multiple drivers of phenology interact, there is greater potential for phenological asynchronies to arise between an organism and those with which it interacts. We examined the phenological patterns of a highly seasonal group of fireflies (Photinus spp., predominantly P. pyralis) over a 12-year period (2004-2015) across 10 plant communities to determine whether interacting drivers could explain the variability observed in the adult flight activity density (i.e. mating season) of this species. We found that temperature accumulation was the primary driver of phenology, with activity peaks usually occurring at a temperature accumulation of approximately 800 degree days (base 10°C); however, our model found this peak varied by nearly 180 degree-day units among years. This variation could be explained by a quadratic relationship with the accumulation of precipitation in the growing season; in years with either high or low precipitation extremes at our study site, flight activity was delayed. More fireflies were captured in general in herbaceous plant communities with minimal soil disturbance (alfalfa and no-till field crop rotations), but only weak interactions occurred between within-season responses to climatic variables and plant community. The interaction we observed between temperature and precipitation accumulation suggests that, although climate warming has the potential to disrupt phenology of many organisms, changes to regional precipitation patterns can magnify these disruptions.}, }
@article {pmid28070282, year = {2017}, author = {Hudson, LN and Newbold, T and Contu, S and Hill, SL and Lysenko, I and De Palma, A and Phillips, HR and Alhusseini, TI and Bedford, FE and Bennett, DJ and Booth, H and Burton, VJ and Chng, CW and Choimes, A and Correia, DL and Day, J and Echeverría-Londoño, S and Emerson, SR and Gao, D and Garon, M and Harrison, ML and Ingram, DJ and Jung, M and Kemp, V and Kirkpatrick, L and Martin, CD and Pan, Y and Pask-Hale, GD and Pynegar, EL and Robinson, AN and Sanchez-Ortiz, K and Senior, RA and Simmons, BI and White, HJ and Zhang, H and Aben, J and Abrahamczyk, S and Adum, GB and Aguilar-Barquero, V and Aizen, MA and Albertos, B and Alcala, EL and Del Mar Alguacil, M and Alignier, A and Ancrenaz, M and Andersen, AN and Arbeláez-Cortés, E and Armbrecht, I and Arroyo-Rodríguez, V and Aumann, T and Axmacher, JC and Azhar, B and Azpiroz, AB and Baeten, L and Bakayoko, A and Báldi, A and Banks, JE and Baral, SK and Barlow, J and Barratt, BI and Barrico, L and Bartolommei, P and Barton, DM and Basset, Y and Batáry, P and Bates, AJ and Baur, B and Bayne, EM and Beja, P and Benedick, S and Berg, &#xc5; and Bernard, H and Berry, NJ and Bhatt, D and Bicknell, JE and Bihn, JH and Blake, RJ and Bobo, KS and Bóçon, R and Boekhout, T and Böhning-Gaese, K and Bonham, KJ and Borges, PA and Borges, SH and Boutin, C and Bouyer, J and Bragagnolo, C and Brandt, JS and Brearley, FQ and Brito, I and Bros, V and Brunet, J and Buczkowski, G and Buddle, CM and Bugter, R and Buscardo, E and Buse, J and Cabra-García, J and Cáceres, NC and Cagle, NL and Calviño-Cancela, M and Cameron, SA and Cancello, EM and Caparrós, R and Cardoso, P and Carpenter, D and Carrijo, TF and Carvalho, AL and Cassano, CR and Castro, H and Castro-Luna, AA and Rolando, CB and Cerezo, A and Chapman, KA and Chauvat, M and Christensen, M and Clarke, FM and Cleary, DF and Colombo, G and Connop, SP and Craig, MD and Cruz-López, L and Cunningham, SA and D'Aniello, B and D'Cruze, N and da Silva, PG and Dallimer, M and Danquah, E and Darvill, B and Dauber, J and Davis, AL and Dawson, J and de Sassi, C and de Thoisy, B and Deheuvels, O and Dejean, A and Devineau, JL and Diekötter, T and Dolia, JV and Domínguez, E and Dominguez-Haydar, Y and Dorn, S and Draper, I and Dreber, N and Dumont, B and Dures, SG and Dynesius, M and Edenius, L and Eggleton, P and Eigenbrod, F and Elek, Z and Entling, MH and Esler, KJ and de Lima, RF and Faruk, A and Farwig, N and Fayle, TM and Felicioli, A and Felton, AM and Fensham, RJ and Fernandez, IC and Ferreira, CC and Ficetola, GF and Fiera, C and Filgueiras, BK and Fırıncıoğlu, HK and Flaspohler, D and Floren, A and Fonte, SJ and Fournier, A and Fowler, RE and Franzén, M and Fraser, LH and Fredriksson, GM and Freire, GB and Frizzo, TL and Fukuda, D and Furlani, D and Gaigher, R and Ganzhorn, JU and García, KP and Garcia-R, JC and Garden, JG and Garilleti, R and Ge, BM and Gendreau-Berthiaume, B and Gerard, PJ and Gheler-Costa, C and Gilbert, B and Giordani, P and Giordano, S and Golodets, C and Gomes, LG and Gould, RK and Goulson, D and Gove, AD and Granjon, L and Grass, I and Gray, CL and Grogan, J and Gu, W and Guardiola, M and Gunawardene, NR and Gutierrez, AG and Gutiérrez-Lamus, DL and Haarmeyer, DH and Hanley, ME and Hanson, T and Hashim, NR and Hassan, SN and Hatfield, RG and Hawes, JE and Hayward, MW and Hébert, C and Helden, AJ and Henden, JA and Henschel, P and Hernández, L and Herrera, JP and Herrmann, F and Herzog, F and Higuera-Diaz, D and Hilje, B and Höfer, H and Hoffmann, A and Horgan, FG and Hornung, E and Horváth, R and Hylander, K and Isaacs-Cubides, P and Ishida, H and Ishitani, M and Jacobs, CT and Jaramillo, VJ and Jauker, B and Hernández, FJ and Johnson, MF and Jolli, V and Jonsell, M and Juliani, SN and Jung, TS and Kapoor, V and Kappes, H and Kati, V and Katovai, E and Kellner, K and Kessler, M and Kirby, KR and Kittle, AM and Knight, ME and Knop, E and Kohler, F and Koivula, M and Kolb, A and Kone, M and Kőrösi, &#xc1; and Krauss, J and Kumar, A and Kumar, R and Kurz, DJ and Kutt, AS and Lachat, T and Lantschner, V and Lara, F and Lasky, JR and Latta, SC and Laurance, WF and Lavelle, P and Le Féon, V and LeBuhn, G and Légaré, JP and Lehouck, V and Lencinas, MV and Lentini, PE and Letcher, SG and Li, Q and Litchwark, SA and Littlewood, NA and Liu, Y and Lo-Man-Hung, N and López-Quintero, CA and Louhaichi, M and Lövei, GL and Lucas-Borja, ME and Luja, VH and Luskin, MS and MacSwiney G, MC and Maeto, K and Magura, T and Mallari, NA and Malone, LA and Malonza, PK and Malumbres-Olarte, J and Mandujano, S and Måren, IE and Marin-Spiotta, E and Marsh, CJ and Marshall, EJ and Martínez, E and Martínez Pastur, G and Moreno Mateos, D and Mayfield, MM and Mazimpaka, V and McCarthy, JL and McCarthy, KP and McFrederick, QS and McNamara, S and Medina, NG and Medina, R and Mena, JL and Mico, E and Mikusinski, G and Milder, JC and Miller, JR and Miranda-Esquivel, DR and Moir, ML and Morales, CL and Muchane, MN and Muchane, M and Mudri-Stojnic, S and Munira, AN and Muoñz-Alonso, A and Munyekenye, BF and Naidoo, R and Naithani, A and Nakagawa, M and Nakamura, A and Nakashima, Y and Naoe, S and Nates-Parra, G and Navarrete Gutierrez, DA and Navarro-Iriarte, L and Ndang'ang'a, PK and Neuschulz, EL and Ngai, JT and Nicolas, V and Nilsson, SG and Noreika, N and Norfolk, O and Noriega, JA and Norton, DA and Nöske, NM and Nowakowski, AJ and Numa, C and O'Dea, N and O'Farrell, PJ and Oduro, W and Oertli, S and Ofori-Boateng, C and Oke, CO and Oostra, V and Osgathorpe, LM and Otavo, SE and Page, NV and Paritsis, J and Parra-H, A and Parry, L and Pe'er, G and Pearman, PB and Pelegrin, N and Pélissier, R and Peres, CA and Peri, PL and Persson, AS and Petanidou, T and Peters, MK and Pethiyagoda, RS and Phalan, B and Philips, TK and Pillsbury, FC and Pincheira-Ulbrich, J and Pineda, E and Pino, J and Pizarro-Araya, J and Plumptre, AJ and Poggio, SL and Politi, N and Pons, P and Poveda, K and Power, EF and Presley, SJ and Proença, V and Quaranta, M and Quintero, C and Rader, R and Ramesh, BR and Ramirez-Pinilla, MP and Ranganathan, J and Rasmussen, C and Redpath-Downing, NA and Reid, JL and Reis, YT and Rey Benayas, JM and Rey-Velasco, JC and Reynolds, C and Ribeiro, DB and Richards, MH and Richardson, BA and Richardson, MJ and Ríos, RM and Robinson, R and Robles, CA and Römbke, J and Romero-Duque, LP and Rös, M and Rosselli, L and Rossiter, SJ and Roth, DS and Roulston, TH and Rousseau, L and Rubio, AV and Ruel, JC and Sadler, JP and Sáfián, S and Saldaña-Vázquez, RA and Sam, K and Samnegård, U and Santana, J and Santos, X and Savage, J and Schellhorn, NA and Schilthuizen, M and Schmiedel, U and Schmitt, CB and Schon, NL and Schüepp, C and Schumann, K and Schweiger, O and Scott, DM and Scott, KA and Sedlock, JL and Seefeldt, SS and Shahabuddin, G and Shannon, G and Sheil, D and Sheldon, FH and Shochat, E and Siebert, SJ and Silva, FA and Simonetti, JA and Slade, EM and Smith, J and Smith-Pardo, AH and Sodhi, NS and Somarriba, EJ and Sosa, RA and Soto Quiroga, G and St-Laurent, MH and Starzomski, BM and Stefanescu, C and Steffan-Dewenter, I and Stouffer, PC and Stout, JC and Strauch, AM and Struebig, MJ and Su, Z and Suarez-Rubio, M and Sugiura, S and Summerville, KS and Sung, YH and Sutrisno, H and Svenning, JC and Teder, T and Threlfall, CG and Tiitsaar, A and Todd, JH and Tonietto, RK and Torre, I and Tóthmérész, B and Tscharntke, T and Turner, EC and Tylianakis, JM and Uehara-Prado, M and Urbina-Cardona, N and Vallan, D and Vanbergen, AJ and Vasconcelos, HL and Vassilev, K and Verboven, HA and Verdasca, MJ and Verdú, JR and Vergara, CH and Vergara, PM and Verhulst, J and Virgilio, M and Vu, LV and Waite, EM and Walker, TR and Wang, HF and Wang, Y and Watling, JI and Weller, B and Wells, K and Westphal, C and Wiafe, ED and Williams, CD and Willig, MR and Woinarski, JC and Wolf, JH and Wolters, V and Woodcock, BA and Wu, J and Wunderle, JM and Yamaura, Y and Yoshikura, S and Yu, DW and Zaitsev, AS and Zeidler, J and Zou, F and Collen, B and Ewers, RM and Mace, GM and Purves, DW and Scharlemann, JP and Purvis, A}, title = {The database of the PREDICTS (Projecting Responses of Ecological Diversity In Changing Terrestrial Systems) project.}, journal = {Ecology and evolution}, volume = {7}, number = {1}, pages = {145-188}, pmid = {28070282}, issn = {2045-7758}, abstract = {The PREDICTS project-Projecting Responses of Ecological Diversity In Changing Terrestrial Systems (www.predicts.org.uk)-has collated from published studies a large, reasonably representative database of comparable samples of biodiversity from multiple sites that differ in the nature or intensity of human impacts relating to land use. We have used this evidence base to develop global and regional statistical models of how local biodiversity responds to these measures. We describe and make freely available this 2016 release of the database, containing more than 3.2 million records sampled at over 26,000 locations and representing over 47,000 species. We outline how the database can help in answering a range of questions in ecology and conservation biology. To our knowledge, this is the largest and most geographically and taxonomically representative database of spatial comparisons of biodiversity that has been collated to date; it will be useful to researchers and international efforts wishing to model and understand the global status of biodiversity.}, }
@article {pmid28028701, year = {2017}, author = {Four, B and Arce, E and Danger, M and Gaillard, J and Thomas, M and Banas, D}, title = {Catchment land use-dependent effects of barrage fishponds on the functioning of headwater streams.}, journal = {Environmental science and pollution research international}, volume = {24}, number = {6}, pages = {5452-5468}, pmid = {28028701}, issn = {1614-7499}, mesh = {Agriculture ; Animals ; Aquaculture ; Biodegradation, Environmental ; Biomass ; *Ecosystem ; Fishes ; *Forests ; *Fungi ; *Invertebrates ; Plant Leaves ; Rivers ; }, abstract = {Extensive fish production systems in continental areas are often created by damming headwater streams. However, these lentic systems favour autochthonous organic matter production. As headwater stream functioning is essentially based on allochthonous organic matter (OM) supply, the presence of barrage fishponds on headwater streams might change the main food source for benthic communities. The goal of this study was thus to identify the effects of barrage fishponds on the functioning of headwater streams. To this end, we compared leaf litter breakdown (a key ecosystem function in headwater streams), their associated invertebrate communities and fungal biomass at sites upstream and downstream of five barrage fishponds in two dominant land use systems (three in forested catchments and two in agricultural catchments). We observed significant structural and functional differences between headwater stream ecosystems in agricultural catchments and those in forested catchments. Leaf litter decay was more rapid in forest streams, with a moderate, but not significant, increase in breakdown rate downstream from the barrage fishponds. In agricultural catchments, the trend was opposite with a 2-fold lower leaf litter breakdown rate at downstream sites compared to upstream sites. Breakdown rates observed at all sites were closely correlated with fungal biomass and shredder biomass. No effect of barrage fishponds were observed in this study concerning invertebrate community structure or functional feeding groups especially in agricultural landscapes. In forest streams, we observed a decrease in organic pollution (OP)-intolerant taxa at downstream sites that was correlated with an increase in OP-tolerant taxa. These results highlighted that the influence of barrage fishponds on headwater stream functioning is complex and land use dependent. It is therefore necessary to clearly understand the various mechanisms (competition for food resources, complementarities between autochthonous and allochthonous OM) that control ecosystem functioning in different contexts in order to optimize barrage fishpond management.}, }
@article {pmid27870290, year = {2017}, author = {Briske, DD and Bestelmeyer, BT and Brown, JR and Brunson, MW and Thurow, TL and Tanaka, JA}, title = {Assessment of USDA-NRCS rangeland conservation programs: recommendation for an evidence-based conservation platform.}, journal = {Ecological applications : a publication of the Ecological Society of America}, volume = {27}, number = {1}, pages = {94-104}, doi = {10.1002/eap.1414}, pmid = {27870290}, issn = {1051-0761}, mesh = {Agriculture/*methods ; Conservation of Natural Resources/*methods ; United States ; United States Department of Agriculture ; }, abstract = {The Conservation Effects Assessment Project (CEAP) was created in response to a request from the Office of Management and Budget that the U.S. Department of Agriculture, Natural Resource Conservation Service (USDA-NRCS) document the societal benefits anticipated to accrue from a major increase in conservation funding authorized by the 2002 Farm Bill. A comprehensive evaluation of the efficacy of rangeland conservation practices cost-shared with private landowners was unable to evaluate conservation benefits because outcomes were seldom documented. Four interrelated suppositions are presented to examine the causes underlying minimal documentation of conservations outcomes. These suppositions are (1) the benefits of conservation practices are considered a certainty so that documentation in not required, (2) there is minimal knowledge exchange between the USDA-NRCS and research organizations, (3) and a paucity of conservation-relevant science, as well as (4) inadequate technical support for land owners following implementation of conservation practices. We then follow with recommendations to overcome potential barriers to documentation of conservation outcomes identified for each supposition. Collectively, this assessment indicates that the existing conservation practice standards are insufficient to effectively administer large conservation investments on rangelands and that modification of these standards alone will not achieve the goals explicitly stated by CEAP. We recommend that USDA-NRCS modify its conservation programs around a more comprehensive and integrative platform that is capable of implementing evidence-based conservation. Collaborative monitoring organized around landowner-agency-scientist partnerships would represent the focal point of a Conservation Program Assessment Network (CPAN). The primary network objective would be to establish missing information feedback loops between conservation practices and their agricultural and environmental outcomes to promote learning, adaptive management, and innovation. Network information would be archived and made available to guide other, related conservation programs in relevant ecoregions. Restructuring conservation programs as we recommend would (1) provide site specific information, learning, and accountability that has been requested by CEAP and (2) further advance balanced delivery of agricultural production and environmental quality goals.}, }
@article {pmid27859200, year = {2016}, author = {Farjalla, VF and González, AL and Céréghino, R and Dézerald, O and Marino, NA and Piccoli, GC and Richardson, BA and Richardson, MJ and Romero, GQ and Srivastava, DS}, title = {Terrestrial support of aquatic food webs depends on light inputs: a geographically-replicated test using tank bromeliads.}, journal = {Ecology}, volume = {97}, number = {8}, pages = {2147-2156}, doi = {10.1002/ecy.1432}, pmid = {27859200}, issn = {0012-9658}, mesh = {Animals ; Aquatic Organisms/*physiology ; Bromelia ; *Ecosystem ; *Food Chain ; Fresh Water ; Invertebrates/*physiology ; }, abstract = {Food webs of freshwater ecosystems can be subsidized by allochthonous resources. However, it is still unknown which environmental factors regulate the relative consumption of allochthonous resources in relation to autochthonous resources. Here, we evaluated the importance of allochthonous resources (litterfall) for the aquatic food webs in Neotropical tank bromeliads, a naturally replicated aquatic microcosm. Aquatic invertebrates were sampled in more than 100 bromeliads within either open or shaded habitats and within five geographically distinct sites located in four different countries. Using stable isotope analyses, we determined that allochthonous sources comprised 74% (±17%) of the food resources of aquatic invertebrates. However, the allochthonous contribution to aquatic invertebrates strongly decreased from shaded to open habitats, as light incidence increased in the tanks. The density of detritus in the tanks had no impact on the importance of allochthonous sources to aquatic invertebrates. This overall pattern held for all invertebrates, irrespective of the taxonomic or functional group to which they belonged. We concluded that, over a broad geographic range, aquatic food webs of tank bromeliads are mostly allochthonous-based, but the relative importance of allochthonous subsidies decreases when light incidence favors autochthonous primary production. These results suggest that, for other freshwater systems, some of the between-study variation in the importance of allochthonous subsidies may similarly be driven by the relative availability of autochthonous resources.}, }
@article {pmid27859083, year = {2016}, author = {Moreno-de Las Heras, M and Turnbull, L and Wainwright, J}, title = {Seed-bank structure and plant-recruitment conditions regulate the dynamics of a grassland-shrubland Chihuahuan ecotone.}, journal = {Ecology}, volume = {97}, number = {9}, pages = {2303-2318}, doi = {10.1002/ecy.1446}, pmid = {27859083}, issn = {0012-9658}, mesh = {*Conservation of Natural Resources ; Desert Climate ; *Ecosystem ; Grassland ; New Mexico ; *Seeds ; Soil ; Southwestern United States ; }, abstract = {Large areas of desert grasslands in the southwestern United States have shifted to sparse shrublands dominated by drought-tolerant woody species over the last 150 yr, accompanied by accelerated soil erosion. An important step toward the understanding of patterns in species dominance and vegetation change at desert grassland-shrubland transitions is the study of environmental limitations imposed by the shrub-encroachment phenomenon on plant establishment. Here, we analyze the structure of soil seed banks, environmental limitations for seed germination (i.e., soil-water availability and temperature), and simulated seedling emergence and early establishment of dominant species (black grama, Bouteloua eriopoda, and creosotebush, Larrea tridentata) across a Chihuahuan grassland-shrubland ecotone (Sevilleta National Wildlife Refuge, New Mexico, USA). Average viable seed density in soils across the ecotone is generally low (200-400 seeds/m[2]), although is largely concentrated in densely vegetated areas (with peaks up to 800-1,200 seeds/m[2] in vegetated patches). Species composition in the seed bank is strongly affected by shrub encroachment, with seed densities of grass species sharply decreasing in shrub-dominated sites. Environmental conditions for seed germination and seedling emergence are synchronized with the summer monsoon. Soil-moisture conditions for seedling establishment of B. eriopoda take place with a recurrence interval ranging between 5 and 8 yr for grassland and shrubland sites, respectively, and are favored by strong monsoonal precipitation. Limited L. tridentata seed dispersal and a narrow range of rainfall conditions for early seedling establishment (50-100 mm for five to six consecutive weeks) constrain shrub-recruitment pulses to localized and episodic decadal events (9-25 yr recurrence intervals) generally associated with late-summer rainfall. Re-establishment of B. eriopoda in areas now dominated by L. tridentata is strongly limited by the lack of seeds and decreased plant-available soil moisture for seedling establishment.}, }
@article {pmid27859062, year = {2016}, author = {Davies, TJ and Urban, MC and Rayfield, B and Cadotte, MW and Peres-Neto, PR}, title = {Deconstructing the relationships between phylogenetic diversity and ecology: a case study on ecosystem functioning.}, journal = {Ecology}, volume = {97}, number = {9}, pages = {2212-2222}, doi = {10.1002/ecy.1507}, pmid = {27859062}, issn = {0012-9658}, mesh = {*Biodiversity ; Biological Evolution ; Ecology ; *Ecosystem ; *Phylogeny ; }, abstract = {Recent studies have supported a link between phylogenetic diversity and various ecological properties including ecosystem function. However, such studies typically assume that phylogenetic branches of equivalent length are more or less interchangeable. Here we suggest that there is a need to consider not only branch lengths but also their placement on the phylogeny. We demonstrate how two common indices of network centrality can be used to describe the evolutionary distinctiveness of network elements (nodes and branches) on a phylogeny. If phylogenetic diversity enhances ecosystem function via complementarity and the representation of functional diversity, we would predict a correlation between evolutionary distinctiveness of network elements and their contribution to ecosystem process. In contrast, if one or a few evolutionary innovations play key roles in ecosystem function, the relationship between evolutionary distinctiveness and functional contribution may be weak or absent. We illustrate how network elements associated with high functional contribution can be identified from regressions between phylogenetic diversity and productivity using a well-known empirical data set on plant productivity from the Cedar Creek Long-Term Ecological Research. We find no association between evolutionary distinctiveness and ecosystem functioning, but we are able to identify phylogenetic elements associated with species of known high functional contribution within the Fabaceae. Our perspective provides a useful guide in the search for ecological traits linking diversity and ecosystem function, and suggests a more nuanced consideration of phylogenetic diversity is required in the conservation and biodiversity-ecosystem-function literature.}, }
@article {pmid27677681, year = {2017}, author = {Piredda, R and Tomasino, MP and D'Erchia, AM and Manzari, C and Pesole, G and Montresor, M and Kooistra, WH and Sarno, D and Zingone, A}, title = {Diversity and temporal patterns of planktonic protist assemblages at a Mediterranean Long Term Ecological Research site.}, journal = {FEMS microbiology ecology}, volume = {93}, number = {1}, pages = {}, doi = {10.1093/femsec/fiw200}, pmid = {27677681}, issn = {1574-6941}, mesh = {Alveolata/*classification/genetics/isolation &amp; purification ; *Biodiversity ; Chlorophyll/metabolism ; Chlorophyll A ; Ecology ; Mediterranean Sea ; Phylogeny ; Plankton/*classification/genetics/isolation &amp; purification/metabolism ; Rhizaria/*classification/genetics/isolation &amp; purification ; Stramenopiles/*classification/genetics ; }, abstract = {We tracked temporal changes in protist diversity at the Long Term Ecological Research (LTER) station MareChiara in the Gulf of Naples (Mediterranean Sea) on eight dates in 2011 using a metabarcoding approach. Illumina analysis of the V4 and V9 fragments of the 18S rDNA produced 869 522 and 1 410 071 sequences resulting in 6517 and 6519 OTUs, respectively. Marked compositional variations were recorded across the year, with less than 2% of OTUs shared among all samples and similar patterns for the two marker tags. Alveolata, Stramenopiles and Rhizaria were the most represented groups. A comparison with light microscopy data indicated an over-representation of Dinophyta in the sequence dataset, whereas Bacillariophyta showed comparable taxonomic patterns between sequence and light microscopy data. Shannon diversity values were stable from February to September, increasing thereafter with a peak in December. Community variance was mainly explained by seasonality (as temperature), trophic status (as chlorophyll a), and influence of coastal waters (as salinity). Overall, the background knowledge of the system provided a sound context for the result interpretation, showing that LTER sites provide an ideal setting for high-throughput sequencing (HTS) metabarcoding characterisation of protist assemblages and their relationships with environmental variations.}, }
@article {pmid27783349, year = {2016}, author = {Rapinel, S and Hubert-Moy, L and Clément, B and Maltby, E}, title = {Mapping wetland functions using Earth observation data and multi-criteria analysis.}, journal = {Environmental monitoring and assessment}, volume = {188}, number = {11}, pages = {641}, pmid = {27783349}, issn = {1573-2959}, mesh = {Ecosystem ; Environmental Monitoring/*methods ; Geographic Information Systems ; Radar ; *Wetlands ; }, abstract = {Wetland functional assessment is commonly conducted based on field observations, and thus, is generally limited to small areas. However, there is often a need for wetland managers to obtain information on wetland functional performance over larger areas. For this purpose, we are proposing a new field-based functional assessment procedure in which wetland functions are evaluated and classified into hydrogeomorphic units according to a multi-criteria analysis approach. Wetland-related geographic information system layers derived from Earth observation data (LiDAR, multispectral and radar data) are used in this study for a large-scale functional evaluation. These include maps of a hydrogeomorphic units, ditches, vegetation, annual flood duration, biomass, meadows management, and wetland boundaries. To demonstrate the feasibility of this approach, a 132 km[2] international long-term ecological research site located in the west of France was assessed. Four wetland functions were evaluated: flood peak attenuation, low water attenuation, denitrification, and habitat. A spatial distribution map of the individual wetland functions was generated, and the intensity levels of the functions were highlighted. Antagonisms between functions within individual hydrogeomorphic units were also identified. Mapping of hydrological, biogeochemical, and ecological wetland functions over large areas can provide an efficient tool for policy makers and other stakeholders including water authorities, nature conservation agencies, and farmers. Specifically, this tool has the potential to provide a mapping of ecosystem services, conservation management priorities, and possible improvements in water resources management.}, }
@article {pmid27642032, year = {2016}, author = {Schlaich, AE and Klaassen, RH and Bouten, W and Bretagnolle, V and Koks, BJ and Villers, A and Both, C}, title = {How individual Montagu's Harriers cope with Moreau's Paradox during the Sahelian winter.}, journal = {The Journal of animal ecology}, volume = {85}, number = {6}, pages = {1491-1501}, doi = {10.1111/1365-2656.12583}, pmid = {27642032}, issn = {1365-2656}, mesh = {*Animal Migration ; Animals ; *Climate Change ; *Ecosystem ; Falconiformes/*physiology ; Female ; *Food Chain ; Geographic Information Systems ; Grasshoppers/physiology ; Male ; Seasons ; Senegal ; }, abstract = {Hundreds of millions of Afro-Palaearctic migrants winter in the Sahel, a semi-arid belt south of the Sahara desert, where they experience deteriorating ecological conditions during their overwintering stay and have to prepare for spring migration when conditions are worst. This well-known phenomenon was first described by R.E. Moreau and is known ever since as Moreau's Paradox. However, empirical evidence of the deteriorating seasonal ecological conditions is limited and little is known on how birds respond. Montagu's Harriers Circus pygargus spend 6 months of the year in their wintering areas in the Sahel. Within the wintering season, birds move gradually to the south, visiting several distinct sites to which they are site-faithful in consecutive years. At the last wintering site, birds find themselves at the southern edge of the Sahelian zone and have no other options than facing deteriorating conditions. We tracked 36 Montagu's Harriers with GPS trackers to study their habitat use and behaviour during winter and collected data on the abundance of their main prey, grasshoppers, in Senegal. Since grasshopper abundance was positively related to vegetation greenness (measured as normalized difference vegetation index, NDVI), we used NDVI values as a proxy for prey abundance in areas where no field data were collected. Prey abundance (grasshopper counts and vegetation greenness) at wintering sites of Montagu's Harriers decreased during the wintering period. Montagu's Harriers responded to decreasing food availability by increasing their flight time during the second half of the winter. Individuals increased flight time more in areas with stronger declines in NDVI values, suggesting that lower food abundance required more intense foraging to achieve energy requirements. The apparent consequence was that Montagu's Harriers departed later in spring when their final wintering site had lower NDVI values and presumably lower food abundance and consequently arrived later at their breeding site. Our results confirmed the suggestions Moreau made 40 years ago: the late wintering period might be a bottleneck during the annual cycle with possible carry-over effects to the breeding season. Ongoing climate change with less rainfall in the Sahel region paired with increased human pressure on natural and agricultural habitats resulting in degradation and desertification is likely to make this period more demanding, which may negatively impact populations of migratory birds using the Sahel.}, }
@article {pmid27755746, year = {2016}, author = {Pourmokhtarian, A and Driscoll, CT and Campbell, JL and Hayhoe, K and Stoner, AM}, title = {The effects of climate downscaling technique and observational data set on modeled ecological responses.}, journal = {Ecological applications : a publication of the Ecological Society of America}, volume = {26}, number = {5}, pages = {1321-1337}, doi = {10.1890/15-0745}, pmid = {27755746}, issn = {1051-0761}, mesh = {*Climate Change ; *Ecosystem ; Environmental Monitoring/*methods ; Humans ; Hydrology ; *Models, Theoretical ; Rivers/chemistry ; Time Factors ; }, abstract = {Assessments of future climate change impacts on ecosystems typically rely on multiple climate model projections, but often utilize only one downscaling approach trained on one set of observations. Here, we explore the extent to which modeled biogeochemical responses to changing climate are affected by the selection of the climate downscaling method and training observations used at the montane landscape of the Hubbard Brook Experimental Forest, New Hampshire, USA. We evaluated three downscaling methods: the delta method (or the change factor method), monthly quantile mapping (Bias Correction-Spatial Disaggregation, or BCSD), and daily quantile regression (Asynchronous Regional Regression Model, or ARRM). Additionally, we trained outputs from four atmosphere-ocean general circulation models (AOGCMs) (CCSM3, HadCM3, PCM, and GFDL-CM2.1) driven by higher (A1fi) and lower (B1) future emissions scenarios on two sets of observations (1/8º resolution grid vs. individual weather station) to generate the high-resolution climate input for the forest biogeochemical model PnET-BGC (eight ensembles of six runs).The choice of downscaling approach and spatial resolution of the observations used to train the downscaling model impacted modeled soil moisture and streamflow, which in turn affected forest growth, net N mineralization, net soil nitrification, and stream chemistry. All three downscaling methods were highly sensitive to the observations used, resulting in projections that were significantly different between station-based and grid-based observations. The choice of downscaling method also slightly affected the results, however not as much as the choice of observations. Using spatially smoothed gridded observations and/or methods that do not resolve sub-monthly shifts in the distribution of temperature and/or precipitation can produce biased results in model applications run at greater temporal and/or spatial resolutions. These results underscore the importance of carefully considering field observations used for training, as well as the downscaling method used to generate climate change projections, for smaller-scale modeling studies. Different sources of variability including selection of AOGCM, emissions scenario, downscaling technique, and data used for training downscaling models, result in a wide range of projected forest ecosystem responses to future climate change.}, }
@article {pmid27755726, year = {2016}, author = {Lindenmayer, DB and Candy, SG and MacGregor, CI and Banks, SC and Westgate, M and Ikin, K and Pierson, J and Tulloch, A and Barton, P}, title = {Do temporal changes in vegetation structure additional to time since fire predict changes in bird occurrence?.}, journal = {Ecological applications : a publication of the Ecological Society of America}, volume = {26}, number = {7}, pages = {2267-2279}, doi = {10.1002/eap.1367}, pmid = {27755726}, issn = {1051-0761}, mesh = {Animals ; Australia ; *Biodiversity ; Birds/*physiology ; Conservation of Natural Resources/methods ; Cross-Sectional Studies ; Environmental Monitoring ; *Fires ; Plants/*classification ; Population Dynamics ; Time Factors ; }, abstract = {Fire is a major ecological process in ecosystems globally. Its impacts on fauna can be both direct (e.g., mortality) and indirect (e.g., altered habitat), resulting in population recovery being driven by several possible mechanisms. Separating direct from indirect impacts of fire on faunal population recovery can be valuable in guiding management of biodiversity in fire-prone environments. However, resolving the influence of direct and indirect processes remains a key challenge because many processes affecting fauna can change concomitantly with time since fire. We explore the mechanisms influencing bird response to fire by posing the question, can temporal changes in vegetation structure predict changes in bird occurrence on sites, and can these be separated from other temporal changes using the surrogate of time since fire? We conducted a 12-yr study of bird and vegetation responses to fire at 124 sites across six vegetation classes in Booderee National Park, Australia. Approximately half of these sites, established in 2002, were burned by a large (>3000 ha) wildfire in 2003. To disentangle collinear effects of temporal changes in vegetation and direct demographic effects on population recovery that are subsumed by time since fire, we incorporated both longitudinal and cross-sectional vegetation effects in addition to time since fire within logistic structural equation models. We identified temporal changes in vegetation structure and richness of plant and bird species that characterized burned and unburned sites in all vegetation classes. For nine bird species, a significant component of the year trend was driven by temporal trends in one of three vegetation variables (number of understory or midstory plant species, or midstory cover). By contrast, we could not separate temporal effects between time since fire and vegetation attributes for bird species richness, reporting rate, and the occurrence of 11 other bird species. Our findings help identify species for which indirect effects of vegetation dominate recovery and thus may benefit from vegetation management where conservation actions are required and, conversely, those species for which direct effects of time since fire drive recovery, where simply leaving a system to recover following the last disturbance will be sufficient.}, }
@article {pmid27755690, year = {2016}, author = {Manning, DW and Rosemond, AD and Gulis, V and Benstead, JP and Kominoski, JS and Maerz, JC}, title = {Convergence of detrital stoichiometry predicts thresholds of nutrient-stimulated breakdown in streams.}, journal = {Ecological applications : a publication of the Ecological Society of America}, volume = {26}, number = {6}, pages = {1745-1757}, doi = {10.1890/15-1217.1}, pmid = {27755690}, issn = {1051-0761}, mesh = {Animals ; Bacteria/metabolism ; *Biodegradation, Environmental ; Carbon/*metabolism ; *Ecosystem ; Fungi/metabolism ; Invertebrates/metabolism ; Plant Leaves/chemistry/metabolism ; *Rivers ; }, abstract = {Nutrient enrichment of detritus-based streams increases detrital resource quality for consumers and stimulates breakdown rates of particulate organic carbon (C). The relative importance of dissolved inorganic nitrogen (N) vs. phosphorus (P) for detrital quality and their effects on microbial- vs. detritivore-mediated detrital breakdown are poorly understood. We tested effects of experimental N and P additions on detrital stoichiometry (C:N, C:P) and total and microbial breakdown (i.e., with and without detritivorous shredders, respectively) of five detritus types (four leaf litter species and wood) with different initial C : nutrient content. We enriched five headwater streams continuously for two years at different relative availabilities of N and P and compared breakdown rates and detrital stoichiometry to pretreatment conditions. Total breakdown rates increased with nutrient enrichment and were predicted by altered detrital stoichiometry. Streamwater N and P, fungal biomass, and their interactions affected stoichiometry of detritus. Streamwater N and P decreased detrital C:N, whereas streamwater P had stronger negative effects on detrital C:P. Nutrient addition and fungal biomass reduced C:N by 70% and C:P by 83% on average after conditioning, compared to only 26% for C:N and 10% for C:P under pretreatment conditions. Detritus with lowest initial nutrient content changed the most and had greatest increases in total breakdown rates. Detrital stoichiometry was reduced and differences among detritus types were homogenized by nutrient enrichment. With enrichment, detrital nutrient content approached detritivore nutritional requirements and stimulated greater detritivore vs. microbial litter breakdown. We used breakpoint regression to estimate values of detrital stoichiometry that can potentially be used to indicate elevated breakdown rates. Breakpoint ratios for total breakdown were 41 (C:N) and 1518 (C:P), coinciding with total breakdown rates that were ~1.9 times higher when C:N or C:P fell below these breakpoints. Microbial and shredder-mediated breakdown rates both increased when C:N and C:P were reduced, suggesting that detrital stoichiometry is useful for predicting litter breakdown dominated by either microbial or shredder activity. Our results show strong effects of nutrient enrichment on detrital stoichiometry and offer a robust link between a potential holistic nutrient loading metric (decreased and homogenized detrital stoichiometry) and increased C loss from stream ecosystems.}, }
@article {pmid27708022, year = {2016}, author = {Greenville, AC and Emery, NJ}, title = {Gathering lots of data on a small budget.}, journal = {Science (New York, N.Y.)}, volume = {353}, number = {6306}, pages = {1360-1361}, doi = {10.1126/science.aag3057}, pmid = {27708022}, issn = {1095-9203}, mesh = {Animals ; Budgets ; Data Collection/economics/*instrumentation ; Environmental Monitoring/economics/*instrumentation ; Geographic Information Systems/*instrumentation ; Microcomputers/*economics ; Remote Sensing Technology/economics/*instrumentation ; Software ; }, }
@article {pmid27667174, year = {2016}, author = {Poeta, G and Battisti, C and Bazzichetto, M and Acosta, AT}, title = {The cotton buds beach: Marine litter assessment along the Tyrrhenian coast of central Italy following the marine strategy framework directive criteria.}, journal = {Marine pollution bulletin}, volume = {113}, number = {1-2}, pages = {266-270}, doi = {10.1016/j.marpolbul.2016.09.035}, pmid = {27667174}, issn = {1879-3363}, mesh = {Bathing Beaches/*standards ; *Cotton Fiber ; Environmental Monitoring/*methods ; Environmental Pollution/*analysis ; Italy ; Plastics/*analysis ; Polystyrenes/analysis ; Reference Standards ; Seasons ; Specimen Handling ; Waste Products/*analysis ; }, abstract = {We assessed the annual accumulation rates of beach litter on the Tyrrhenian coast of central Italy, providing the characterization of litter following European standardized guidelines. Three different sites of a beach were sampled seasonally from spring 2014 to winter 2015. A total of 31,739 items were removed and classified into 103 categories. Plastic represented the majority (94.4%) of the collected items. We detected temporal and spatial differences in the abundance and composition of litter between seasons and between sites. Furthermore, we found that plastic cotton bud sticks composed >30% of the total amount of litter and, together with plastic and polystyrene pieces, made up >70% of the total items. Finally, our results led us to propose that the most effective strategy to reduce litter pollution is to devise specific management procedures focusing on the most abundant items.}, }
@article {pmid27643637, year = {2017}, author = {Brookfield, AE and Macpherson, GL and Covington, MD}, title = {Effects of Changing Meteoric Precipitation Patterns on Groundwater Temperature in Karst Environments.}, journal = {Ground water}, volume = {55}, number = {2}, pages = {227-236}, doi = {10.1111/gwat.12456}, pmid = {27643637}, issn = {1745-6584}, mesh = {*Groundwater ; Kansas ; Seasons ; *Temperature ; Water Movements ; }, abstract = {Climate predictions indicate that precipitation patterns will change and average air temperatures will increase across much of the planet. These changes will alter surface water and groundwater temperatures which can significantly affect the local and regional environment. Here, we examine the role of precipitation timing in changes to groundwater temperature in carbonate-karst aquifers using measured groundwater level and temperature data from the Konza Prairie Long-Term Ecological Research Site, Kansas. We demonstrate that shifts to increased cool-season precipitation may mitigate the increases in groundwater temperature produced by increases in average annual air temperature. In karst, the solution-enlarged conduits allow faster and focused recharge, and the recharge-event temperature can strongly influence the groundwater temperature in the aquifer. Our field data and analysis show that predictions of future groundwater conditions in karst aquifers need to consider changes in precipitation patterns, in addition to changes to average annual air temperature.}, }
@article {pmid27551382, year = {2016}, author = {Commerford, JL and McLauchlan, KK and Minckley, TA}, title = {High dissimilarity within a multiyear annual record of pollen assemblages from a North American tallgrass prairie.}, journal = {Ecology and evolution}, volume = {6}, number = {15}, pages = {5273-5289}, pmid = {27551382}, issn = {2045-7758}, abstract = {Grassland vegetation varies in composition across North America and has been historically influenced by multiple biotic and abiotic drivers, including fire, herbivory, and topography. Yet, the amount of temporal and spatial variability exhibited among grassland pollen assemblages, and the influence of these biotic and abiotic drivers on pollen assemblage composition and diversity has been relatively understudied. Here, we examine 4 years of modern pollen assemblages collected from a series of 28 traps at the Konza Prairie Long-Term Ecological Research Area in the Flint Hills of Kansas, with the aim of evaluating the influence of these drivers, as well as quantifying the amount of spatial and temporal variability in the pollen signatures of the tallgrass prairie biome. We include all terrestrial pollen taxa in our analyses while calculating four summative metrics of pollen diversity and composition - beta-diversity, Shannon index, nonarboreal pollen percentage, and Ambrosia:Artemisia - and find different roles of fire, herbivory, and topography variables in relation to these pollen metrics. In addition, we find significant annual differences in the means of three of these metrics, particularly the year 2013 which experienced high precipitation relative to the other 3 years of data. To quantify spatial and temporal dissimilarity among the samples over the 4-year study, we calculate pairwise squared-chord distances (SCD). The SCD values indicate higher compositional dissimilarity across the traps (0.38 mean) among all years than within a single trap from year to year (0.31 mean), suggesting that grassland vegetation can have different pollen signatures across finely sampled space and time, and emphasizing the need for additional long-term annual monitoring of grassland pollen.}, }
@article {pmid27453451, year = {2016}, author = {Gaba, S and Gabriel, E and Chadœuf, J and Bonneu, F and Bretagnolle, V}, title = {Herbicides do not ensure for higher wheat yield, but eliminate rare plant species.}, journal = {Scientific reports}, volume = {6}, number = {}, pages = {30112}, pmid = {27453451}, issn = {2045-2322}, mesh = {Agriculture/methods ; Biodiversity ; Crop Production/methods ; Crops, Agricultural/growth &amp; development ; Developed Countries ; Farmers ; France ; Herbicide Resistance/physiology ; Herbicides/*pharmacology ; Plant Weeds/*drug effects ; Poaceae/drug effects ; Seasons ; Triticum/*growth &amp; development ; Weed Control/methods ; }, abstract = {Weed control is generally considered to be essential for crop production and herbicides have become the main method used for weed control in developed countries. However, concerns about harmful environmental consequences have led to strong pressure on farmers to reduce the use of herbicides. As food demand is forecast to increase by 50% over the next century, an in-depth quantitative analysis of crop yields, weeds and herbicides is required to balance economic and environmental issues. This study analysed the relationship between weeds, herbicides and winter wheat yields using data from 150 winter wheat fields in western France. A Bayesian hierarchical model was built to take account of farmers' behaviour, including implicitly their perception of weeds and weed control practices, on the effectiveness of treatment. No relationship was detected between crop yields and herbicide use. Herbicides were found to be more effective at controlling rare plant species than abundant weed species. These results suggest that reducing the use of herbicides by up to 50% could maintain crop production, a result confirmed by previous studies, while encouraging weed biodiversity. Food security and biodiversity conservation may, therefore, be achieved simultaneously in intensive agriculture simply by reducing the use of herbicides.}, }
@article {pmid27441705, year = {2016}, author = {Herbei, R and Rytel, AL and Lyons, WB and McKnight, DM and Jaros, C and Gooseff, MN and Priscu, JC}, title = {Hydrological Controls on Ecosystem Dynamics in Lake Fryxell, Antarctica.}, journal = {PloS one}, volume = {11}, number = {7}, pages = {e0159038}, pmid = {27441705}, issn = {1932-6203}, mesh = {Antarctic Regions ; Chlorophyll/analysis ; Chlorophyll A ; *Ecosystem ; Geography ; *Hydrology ; *Lakes ; Nitrogen/analysis ; Phosphates/analysis ; Regression Analysis ; Rivers ; Solubility ; Time Factors ; }, abstract = {The McMurdo Dry Valleys constitute the largest ice free area of Antarctica. The area is a polar desert with an annual precipitation of ∼ 3 cm water equivalent, but contains several lakes fed by glacial melt water streams that flow from four to twelve weeks of the year. Over the past ∼20 years, data have been collected on the lakes located in Taylor Valley, Antarctica as part of the McMurdo Dry Valley Long-Term Ecological Research program (MCM-LTER). This work aims to understand the impact of climate variations on the biological processes in all the ecosystem types within Taylor Valley, including the lakes. These lakes are stratified, closed-basin systems and are perennially covered with ice. Each lake contains a variety of planktonic and benthic algae that require nutrients for photosynthesis and growth. The work presented here focuses on Lake Fryxell, one of the three main lakes of Taylor Valley; it is fed by thirteen melt-water streams. We use a functional regression approach to link the physical, chemical, and biological processes within the stream-lake system to evaluate the input of water and nutrients on the biological processes in the lakes. The technique has been shown previously to provide important insights into these Antarctic lacustrine systems where data acquisition is not temporally coherent. We use data on primary production (PPR) and chlorophyll-A (CHL)from Lake Fryxell as well as discharge observations from two streams flowing into the lake. Our findings show an association between both PPR, CHL and stream input.}, }
@article {pmid27371928, year = {2016}, author = {Nuttens, A and Chatellier, S and Devin, S and Guignard, C and Lenouvel, A and Gross, EM}, title = {Does nitrate co-pollution affect biological responses of an aquatic plant to two common herbicides?.}, journal = {Aquatic toxicology (Amsterdam, Netherlands)}, volume = {177}, number = {}, pages = {355-364}, doi = {10.1016/j.aquatox.2016.06.006}, pmid = {27371928}, issn = {1879-1514}, mesh = {Aquatic Organisms/drug effects/physiology ; Biomarkers/metabolism ; Herbicides/*toxicity ; Magnoliopsida/*drug effects/physiology ; Nitrates/*toxicity ; Phenylurea Compounds/*toxicity ; Stress, Psychological/physiopathology ; Sulfonylurea Compounds/*toxicity ; Toxicity Tests ; Water Pollutants, Chemical/*toxicity ; }, abstract = {Aquatic systems in agricultural landscapes are subjected to multiple stressors, among them pesticide and nitrate run-off, but effects of both together have rarely been studied. We investigated possible stress-specific and interaction effects using the new OECD test organism, Myriophyllum spicatum, a widespread aquatic plant. In a fully factorial design, we used two widely applied herbicides, isoproturon and mesosulfuron-methyl, in concentration-response curves at two nitrate levels (219.63 and 878.52mg N-NO3). We applied different endpoints reflecting plant performance such as growth, pigment content, content in phenolic compounds, and plant stoichiometry. Relative growth rates based on length (RGR-L) were affected strongly by both herbicides, while effects on relative growth rate based on dry weight (RGR-DW) were apparent for isoproturon but hardly visible for mesosulfuron-methyl due to an increase in dry matter content. The higher nitrate level further reduced growth rates, specifically with mesosulfuron-methyl. Effects were visible between 50 and 500μgL(-1) for isoproturon and 0.5-5μgL(-1) for mesosulfuron-methyl, with some differences between endpoints. The two herbicides had opposite effects on chlorophyll, carotenoid and nitrogen contents in plants, with values increasing with increasing concentrations of isoproturon and decreasing for mesosulfuron-methyl. Herbicides and nitrate level exhibited distinct effects on the content in phenolic compounds, with higher nitrate levels reducing total phenolic compounds in controls and with isoproturon, but not with mesosulfuron-methyl. Increasing concentrations of mesosulfuron-methyl lead to a decline of total phenolic compounds, while isoproturon had little effect. Contents of carbon, nitrogen and phosphorus changed depending on the stressor combination. We observed higher phosphorus levels in plants exposed to certain concentrations of herbicides, potentially indicating a metabolic response. The C:N molar ratio decreased strongly with isoproturon and increased with mesosulfuron-methyl. The C:P and N:P ratios did not vary for most herbicide concentrations, indicating homeostasis. Nitrate level had no effect on the C:N ratio, but the N:P ratio increased in high nitrate level treatments, indicating that the former is more strictly regulated by the plant than the latter. We conclude that the multi-stress impacts caused to aquatic primary producers by herbicides and nitrate enrichment, as often observed in agricultural run-off, not only affected growth and pigment content, but also structural traits (dry matter content) and other physiological traits (elemental stoichiometry, phenolic compounds). Changes in those might have indirect effects on biotic interactions and elemental cycles. We suggest considering some of these endpoints in future studies in environmental risk assessment for agricultural run-off.}, }
@article {pmid27337964, year = {2016}, author = {Greenville, AC and Wardle, GM and Nguyen, V and Dickman, CR}, title = {Spatial and temporal synchrony in reptile population dynamics in variable environments.}, journal = {Oecologia}, volume = {182}, number = {2}, pages = {475-485}, pmid = {27337964}, issn = {1432-1939}, mesh = {Animals ; Australia ; *Environment ; *Population Dynamics ; *Reptiles ; }, abstract = {Resources are seldom distributed equally across space, but many species exhibit spatially synchronous population dynamics. Such synchrony suggests the operation of large-scale external drivers, such as rainfall or wildfire, or the influence of oasis sites that provide water, shelter, or other resources. However, testing the generality of these factors is not easy, especially in variable environments. Using a long-term dataset (13-22 years) from a large (8000 km(2)) study region in arid Central Australia, we tested firstly for regional synchrony in annual rainfall and the dynamics of six reptile species across nine widely separated sites. For species that showed synchronous spatial dynamics, we then used multivariate follow a multivariate auto-regressive state-space (MARSS) models to predict that regional rainfall would be positively associated with their populations. For asynchronous species, we used MARSS models to explore four other possible population structures: (1) populations were asynchronous, (2) differed between oasis and non-oasis sites, (3) differed between burnt and unburnt sites, or (4) differed between three sub-regions with different rainfall gradients. Only one species showed evidence of spatial population synchrony and our results provide little evidence that rainfall synchronizes reptile populations. The oasis or the wildfire hypotheses were the best-fitting models for the other five species. Thus, our six study species appear generally to be structured in space into one or two populations across the study region. Our findings suggest that for arid-dwelling reptile populations, spatial and temporal dynamics are structured by abiotic events, but individual responses to covariates at smaller spatial scales are complex and poorly understood.}, }
@article {pmid27273085, year = {2016}, author = {Chu, C and Kleinhesselink, AR and Havstad, KM and McClaran, MP and Peters, DP and Vermeire, LT and Wei, H and Adler, PB}, title = {Direct effects dominate responses to climate perturbations in grassland plant communities.}, journal = {Nature communications}, volume = {7}, number = {}, pages = {11766}, pmid = {27273085}, issn = {2041-1723}, mesh = {*Climate Change ; *Grassland ; Models, Theoretical ; Plants/*metabolism ; }, abstract = {Theory predicts that strong indirect effects of environmental change will impact communities when niche differences between competitors are small and variation in the direct effects experienced by competitors is large, but empirical tests are lacking. Here we estimate negative frequency dependence, a proxy for niche differences, and quantify the direct and indirect effects of climate change on each species. Consistent with theory, in four of five communities indirect effects are strongest for species showing weak negative frequency dependence. Indirect effects are also stronger in communities where there is greater variation in direct effects. Overall responses to climate perturbations are driven primarily by direct effects, suggesting that single species models may be adequate for forecasting the impacts of climate change in these communities.}, }
@article {pmid27267722, year = {2016}, author = {Karan, M and Liddell, M and Prober, SM and Arndt, S and Beringer, J and Boer, M and Cleverly, J and Eamus, D and Grace, P and Van Gorsel, E and Hero, JM and Hutley, L and Macfarlane, C and Metcalfe, D and Meyer, W and Pendall, E and Sebastian, A and Wardlaw, T}, title = {The Australian SuperSite Network: A continental, long-term terrestrial ecosystem observatory.}, journal = {The Science of the total environment}, volume = {568}, number = {}, pages = {1263-1274}, doi = {10.1016/j.scitotenv.2016.05.170}, pmid = {27267722}, issn = {1879-1026}, mesh = {Australia ; *Ecosystem ; Environmental Monitoring/*methods ; Geography ; }, abstract = {Ecosystem monitoring networks aim to collect data on physical, chemical and biological systems and their interactions that shape the biosphere. Here we introduce the Australian SuperSite Network that, along with complementary facilities of Australia's Terrestrial Ecosystem Research Network (TERN), delivers field infrastructure and diverse, ecosystem-related datasets for use by researchers, educators and policy makers. The SuperSite Network uses infrastructure replicated across research sites in different biomes, to allow comparisons across ecosystems and improve scalability of findings to regional, continental and global scales. This conforms with the approaches of other ecosystem monitoring networks such as Critical Zone Observatories, the U.S. National Ecological Observatory Network; Analysis and Experimentation on Ecosystems, Europe; Chinese Ecosystem Research Network; International Long Term Ecological Research network and the United States Long Term Ecological Research Network. The Australian SuperSite Network currently involves 10 SuperSites across a diverse range of biomes, including tropical rainforest, grassland and savanna; wet and dry sclerophyll forest and woodland; and semi-arid grassland, woodland and savanna. The focus of the SuperSite Network is on using vegetation, faunal and biophysical monitoring to develop a process-based understanding of ecosystem function and change in Australian biomes; and to link this with data streams provided by the series of flux towers across the network. The Australian SuperSite Network is also intended to support a range of auxiliary researchers who contribute to the growing body of knowledge within and across the SuperSite Network, public outreach and education to promote environmental awareness and the role of ecosystem monitoring in the management of Australian environments.}, }
@article {pmid27145612, year = {2016}, author = {Ladwig, LM and Ratajczak, ZR and Ocheltree, TW and Hafich, KA and Churchill, AC and Frey, SJ and Fuss, CB and Kazanski, CE and Muñoz, JD and Petrie, MD and Reinmann, AB and Smith, JG}, title = {Beyond arctic and alpine: the influence of winter climate on temperate ecosystems.}, journal = {Ecology}, volume = {97}, number = {2}, pages = {372-382}, doi = {10.1890/15-0153.1}, pmid = {27145612}, issn = {0012-9658}, mesh = {Animals ; *Climate ; *Ecosystem ; *Seasons ; Temperature ; United States ; *Weather ; }, abstract = {Winter climate is expected to change under future climate scenarios, yet the majority of winter ecology research is focused in cold-climate ecosystems. In many temperate systems, it is unclear how winter climate relates to biotic responses during the growing season. The objective of this study was to examine how winter weather relates to plant and animal communities in a variety of terrestrial ecosystems ranging from warm deserts to alpine tundra. Specifically, we examined the association between winter weather and plant phenology, plant species richness, consumer abundance, and consumer richness in 11 terrestrial ecosystems associated with the U.S. Long-Term Ecological Research (LTER) Network. To varying degrees, winter precipitation and temperature were correlated with all biotic response variables. Bud break was tightly aligned with end of winter temperatures. For half the sites, winter weather was a better predictor of plant species richness than growing season weather. Warmer winters were correlated with lower consumer abundances in both temperate and alpine systems. Our findings suggest winter weather may have a strong influence on biotic activity during the growing season and should be considered in future studies investigating the effects of climate change on both alpine and temperate systems.}, }
@article {pmid27074044, year = {2016}, author = {Chamaillé-Jammes, S and Charbonnel, A and Dray, S and Madzikanda, H and Fritz, H}, title = {Spatial Distribution of a Large Herbivore Community at Waterholes: An Assessment of Its Stability over Years in Hwange National Park, Zimbabwe.}, journal = {PloS one}, volume = {11}, number = {4}, pages = {e0153639}, pmid = {27074044}, issn = {1932-6203}, mesh = {Animal Distribution/*physiology ; Animal Migration/*physiology ; Animals ; Antelopes ; *Ecosystem ; Elephants ; Equidae ; Giraffes ; *Herbivory ; Parks, Recreational ; Water ; Zimbabwe ; }, abstract = {The spatial structuring of populations or communities is an important driver of their functioning and their influence on ecosystems. Identifying the (in)stability of the spatial structure of populations is a first step towards understanding the underlying causes of these structures. Here we studied the relative importance of spatial vs. interannual variability in explaining the patterns of abundance of a large herbivore community (8 species) at waterholes in Hwange National Park (Zimbabwe). We analyzed census data collected over 13 years using multivariate methods. Our results showed that variability in the census data was mostly explained by the spatial structure of the community, as some waterholes had consistently greater herbivore abundance than others. Some temporal variability probably linked to Park-scale migration dependent on annual rainfall was noticeable, however. Once this was accounted for, little temporal variability remained to be explained, suggesting that other factors affecting herbivore abundance over time had a negligible effect at the scale of the study. The extent of spatial and temporal variability in census data was also measured for each species. This study could help in projecting the consequences of surface water management, and more generally presents a methodological framework to simultaneously address the relative importance of spatial vs. temporal effects in driving the distribution of organisms across landscapes.}, }
@article {pmid26952112, year = {2016}, author = {Ferri, V and Battisti, C and Soccini, C}, title = {Bats in a Mediterranean Mountainous Landscape: Does Wind Farm Repowering Induce Changes at Assemblage and Species Level?.}, journal = {Environmental management}, volume = {57}, number = {6}, pages = {1240-1246}, pmid = {26952112}, issn = {1432-1009}, mesh = {Animals ; Chiroptera/classification/*psychology ; *Ecosystem ; Farms ; Italy ; *Power Plants ; Species Specificity ; *Stress, Psychological/etiology ; *Wind ; }, abstract = {We reported data on flying bat assemblages in a Mediterranean mountain landscape of central Italy on a 5-year time span (2005-2010) where a wind farm repowering has been carried out (from 2009, 17 three-blade turbines substituted an a priori set of one-blade turbines). In 4 yearly based surveys, we calculated a set of univariate metrics at species and assemblage level and also performing a diversity/dominance analysis (k-dominance plots) to evaluate temporal changes. Nine species of bats were present (eight classified at species level, one at genus level). Number of detected taxa, Margalef richness, and Shannon-Wiener diversity apparently decreased between 2005-2007 (one-blade turbine period) and 2009-2010 (three-blade turbines period). We showed a weak temporal turnover only between 2007 and 2009. In k-dominance plots, the occurrence curves of the years before the new wind farming activity (2005 and 2007) were lower when compared to the curves related to the 2009 and 2010 years, suggesting an apparent stress at assemblage level in the second period (2009 and 2010). Myotis emarginatus and Pipistrellus pipistrellus significantly changed their relative frequency during the three-blade wind farming activity, supporting the hypothesis that some bats may be sensitive to repowering. Further research is necessary to confirm a possible sensitivity also for locally rare bats (Miniopterus schreibersii and Plecotus sp.).}, }
@article {pmid26868390, year = {2016}, author = {Duhaime, MB and Wichels, A and Sullivan, MB}, title = {Six Pseudoalteromonas Strains Isolated from Surface Waters of Kabeltonne, Offshore Helgoland, North Sea.}, journal = {Genome announcements}, volume = {4}, number = {1}, pages = {}, pmid = {26868390}, issn = {2169-8287}, abstract = {Draft genomes are presented for 6 Pseudoalteromonas sp. strains isolated from surface waters at Kabeltonne, Helgoland, a long-term ecological research station in the North Sea. These strains contribute knowledge of the genomic underpinnings of a developing model system to study phage-host dynamics of a particle-associated ocean copiotroph.}, }
@article {pmid26668721, year = {2015}, author = {Pizzeghello, D and Cocco, S and Francioso, O and Ferrari, E and Cardinali, A and Nardi, S and Agnelli, A and Corti, G}, title = {Snow vole (Chionomys nivalis Martins) affects the redistribution of soil organic matter and hormone-like activity in the alpine ecosystem: ecological implications.}, journal = {Ecology and evolution}, volume = {5}, number = {20}, pages = {4542-4554}, pmid = {26668721}, issn = {2045-7758}, abstract = {In alpine environments, colonies of snow vole (Chionomys nivalis Martins) cause strong pedoturbation, which may affect humification process and soil organic matter (SOM) cycling, with repercussions on the hormone-like activity of organics. We investigated the effect of snow vole pedoturbation on the chemical and spectroscopic features of soil organic fractions, and the potential hormone-like activity of humic and fulvic acids (HA, FA). The study site was located on the high-mountain environment of the Majella massif (central Italy). Pedoturbated and regular soils were morphologically described and characterized for pH and content of total organic carbon, total extractable carbon, HA, and FA. Both HA and FA were extracted and investigated using attenuated total reflectance/Fourier transform infrared (ATR/FTIR), nuclear magnetic resonance with high-resolution magic angle spinning (HRMAS-NMR), and (1)H-(13)C heteronuclear single quantum coherence (HSQC). HA and FA were also tested for their auxin-like and gibberellin-like activities. Results provide evidences that bioturbated and regular soils contain a poorly decomposed SOM, but HA and FA with a well-defined molecular structure. The HA and FA from both bioturbated and regular soils show a hormone-like activity with a different allocation along the soil profile. In the regular soil, the highest auxin-like activity was shown by HA and FA from Oe1 horizon, while gibberellin-like activity was expressed by FA from Oe2 horizon. Burrowing activity determines a redistribution of organics throughout the profile with a relatively high auxin-like activity in the FA from straw tunnel wall (STW) and gibberellin-like activity in the HA from vole feces (VF). The relative high presence of carboxylic acids, amides, proteins, and amino acids in the FA from STW and the aromatic moieties in the HA from VF put evidences for their different behavior. The fact that snow vole activity has modified the chemical and biological properties of SOM in these soils otherwise considered governed only by low temperature has important ecological implications such as the preservation of soil fertility and vegetal biodiversity.}, }
@article {pmid26630453, year = {2015}, author = {Russell-Smith, J and Yates, CP and Edwards, AC and Whitehead, PJ and Murphy, BP and Lawes, MJ}, title = {Deriving Multiple Benefits from Carbon Market-Based Savanna Fire Management: An Australian Example.}, journal = {PloS one}, volume = {10}, number = {12}, pages = {e0143426}, pmid = {26630453}, issn = {1932-6203}, mesh = {Australia ; Biodiversity ; Carbon/*chemistry ; Climate Change ; Conservation of Natural Resources/*methods ; Disasters/*prevention &amp; control ; Ecosystem ; Fires/*prevention &amp; control ; Seasons ; }, abstract = {Carbon markets afford potentially useful opportunities for supporting socially and environmentally sustainable land management programs but, to date, have been little applied in globally significant fire-prone savanna settings. While fire is intrinsic to regulating the composition, structure and dynamics of savanna systems, in north Australian savannas frequent and extensive late dry season wildfires incur significant environmental, production and social impacts. Here we assess the potential of market-based savanna burning greenhouse gas emissions abatement and allied carbon biosequestration projects to deliver compatible environmental and broader socio-economic benefits in a highly biodiverse north Australian setting. Drawing on extensive regional ecological knowledge of fire regime effects on fire-vulnerable taxa and communities, we compare three fire regime metrics (seasonal fire frequency, proportion of long-unburnt vegetation, fire patch-size distribution) over a 15-year period for three national parks with an indigenously (Aboriginal) owned and managed market-based emissions abatement enterprise. Our assessment indicates improved fire management outcomes under the emissions abatement program, and mostly little change or declining outcomes on the parks. We attribute improved outcomes and putative biodiversity benefits under the abatement program to enhanced strategic management made possible by the market-based mitigation arrangement. For these same sites we estimate quanta of carbon credits that could be delivered under realistic enhanced fire management practice, using currently available and developing accredited Australian savanna burning accounting methods. We conclude that, in appropriate situations, market-based savanna burning activities can provide transformative climate change mitigation, ecosystem health, and community benefits in northern Australia, and, despite significant challenges, potentially in other fire-prone savanna settings.}, }
@article {pmid26591465, year = {2015}, author = {Beier, CM and Caputo, J and Groffman, PM}, title = {Measuring ecosystem capacity to provide regulating services: forest removal and recovery at Hubbard Brook (USA).}, journal = {Ecological applications : a publication of the Ecological Society of America}, volume = {25}, number = {7}, pages = {2011-2021}, doi = {10.1890/14-1376.1}, pmid = {26591465}, issn = {1051-0761}, mesh = {Conservation of Natural Resources ; Environmental Monitoring ; Forestry/*methods ; *Forests ; New Hampshire ; Population Dynamics ; Time Factors ; Water Quality ; Water Supply ; }, abstract = {In this study, by coupling long-term ecological data with empirical proxies of societal demand for benefits, we measured the capacity of forest watersheds to provide ecosystem services over variable time periods, to different beneficiaries, and in response to discrete perturbations and drivers of change. We revisited one of the earliest ecosystem experiments in North America: the 1963 de-vegetation of a forested catchment at Hubbard Brook Experimental Forest in New Hampshire, USA. Potential benefits of the regulation of water flow, water quality, greenhouse gases, and forest growth were compared between experimental (WS 2) and reference (WS 6) watersheds over a 30-year period. Both watersheds exhibited similarly high capacity for flow regulation, in part because functional loads remained low (i.e., few major storm events) during the de-vegetation period. Drought mitigation capacity, or the maintenance of flows sufficient to satisfy municipal water consumption, was higher in WS 2 due to reduced evapotranspiration associated with loss of plant cover. We also assessed watershed capacity to regulate flows to satisfy different beneficiaries, including hypothetical flood averse and drought averse types. Capacity to regulate water quality was severely degraded during de-vegetation, as nitrate concentrations exceeded drinking water standards on 40% of measurement days. Once forest regeneration began, WS 2 rapidly recovered the capacity to provide safe drinking water, and subsequently mitigated the eutrophication potential of rainwater at a marginally higher level than WS 6. We estimated this additional pollution removal benefit would have to accrue for approximately 65-70 years to offset the net eutrophication cost incurred during forest removal. Overall, our results affirmed the critical role of forest vegetation in water regulation, but also indicated trade-offs associated with forest removal and recovery that partially depend on larger-scale exogenous changes in climate forcing and pollution inputs. We also provide a starting point for integrating long-term ecological research and modeling data into ecosystem services science.}, }
@article {pmid26582026, year = {2015}, author = {Henry, M and Cerrutti, N and Aupinel, P and Decourtye, A and Gayrard, M and Odoux, JF and Pissard, A and Rüger, C and Bretagnolle, V}, title = {Reconciling laboratory and field assessments of neonicotinoid toxicity to honeybees.}, journal = {Proceedings. Biological sciences}, volume = {282}, number = {1819}, pages = {}, pmid = {26582026}, issn = {1471-2954}, mesh = {Animals ; Bees/*drug effects ; France ; Imidazoles/*toxicity ; Insecticides/*toxicity ; Neonicotinoids ; Nitro Compounds/*toxicity ; Oxazines/*toxicity ; Risk Assessment ; Thiamethoxam ; Thiazoles/*toxicity ; }, abstract = {European governments have banned the use of three common neonicotinoid pesticides due to insufficiently identified risks to bees. This policy decision is controversial given the absence of clear consistency between toxicity assessments of those substances in the laboratory and in the field. Although laboratory trials report deleterious effects in honeybees at trace levels, field surveys reveal no decrease in the performance of honeybee colonies in the vicinity of treated fields. Here we provide the missing link, showing that individual honeybees near thiamethoxam-treated fields do indeed disappear at a faster rate, but the impact of this is buffered by the colonies' demographic regulation response. Although we could ascertain the exposure pathway of thiamethoxam residues from treated flowers to honeybee dietary nectar, we uncovered an unexpected pervasive co-occurrence of similar concentrations of imidacloprid, another neonicotinoid normally restricted to non-entomophilous crops in the study country. Thus, its origin and transfer pathways through the succession of annual crops need be elucidated to conveniently appraise the risks of combined neonicotinoid exposures. This study reconciles the conflicting laboratory and field toxicity assessments of neonicotinoids on honeybees and further highlights the difficulty in actually detecting non-intentional effects on the field through conventional risk assessment methods.}, }
@article {pmid26562919, year = {2015}, author = {Tereshchenko, LV and Anisimov, VN and Shul'govsky, VV and Latanov, AV}, title = {Early Changes in Saccadic Eye Movement in Hemiparkinsonian MPTP-Treated Monkeys.}, journal = {Perception}, volume = {44}, number = {8-9}, pages = {1054-1063}, doi = {10.1177/0301006615596868}, pmid = {26562919}, issn = {0301-0066}, mesh = {1-Methyl-4-phenyl-1,2,3,6-tetrahydropyridine/*pharmacology ; Animals ; Corpus Striatum/drug effects/physiology ; Frontal Lobe/drug effects/physiopathology ; Macaca mulatta ; Male ; Orientation/drug effects/physiology ; Parkinsonian Disorders/*chemically induced/*physiopathology ; Psychomotor Performance/*drug effects/*physiology ; Reaction Time/drug effects/physiology ; Saccades/*drug effects/*physiology ; Thalamus/drug effects/physiopathology ; Visual Fields/drug effects/physiology ; }, abstract = {The saccadic eye movements declining given the development of Parkinson's disease (PD) still deserves thorough analysis. Recent studies confirmed that PD patients show poor saccadic control in visuomotor tasks. The purpose of this study was to investigate the dynamics of saccades parameters at the development of 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP) model of PD. The gradual decline of saccadic control was studied in two monkeys that executed the visuomotor task with low doses of MPTP being injected at a prolonged period of time. The experiment included investigating the horizontal, vertical, oblique visually guided saccades as well as the corrective saccades triggered by stimuli onset in various loci within a two-dimensional visual field in the Gap-Step-Overlap paradigm. Our study revealed that the execution of visually guided saccades with small amplitude and corrective saccades changed dramatically with MPTP-model progressing. These changes are also confirmed statistically at the presymptomatic stage of MPTP syndrome. Not only our study gives a robust report of PD dynamics development and saccadic control but the obtained data could also be helpful in developing methods for the early diagnosis of PD.}, }
@article {pmid26554638, year = {2016}, author = {Foster, CN and Sato, CF and Lindenmayer, DB and Barton, PS}, title = {Integrating theory into disturbance interaction experiments to better inform ecosystem management.}, journal = {Global change biology}, volume = {22}, number = {4}, pages = {1325-1335}, doi = {10.1111/gcb.13155}, pmid = {26554638}, issn = {1365-2486}, mesh = {*Conservation of Natural Resources ; *Ecosystem ; Fires ; Herbivory ; *Models, Theoretical ; }, abstract = {Managing multiple, interacting disturbances is a key challenge to biodiversity conservation, and one that will only increase as global change drivers continue to alter disturbance regimes. Theoretical studies have highlighted the importance of a mechanistic understanding of stressor interactions for improving the prediction and management of interactive effects. However, many conservation studies are not designed or interpreted in the context of theory and instead focus on case-specific management questions. This is a problem as it means that few studies test the relationships highlighted in theoretical models as being important for ecological management. We explore the extent of this problem among studies of interacting disturbances by reviewing recent experimental studies of the interaction between fire and grazing in terrestrial ecosystems. Interactions between fire and grazing can occur via a number of pathways; one disturbance can modify the other's likelihood, intensity or spatial distribution, or one disturbance can alter the other's impacts on individual organisms. The strength of such interactions will vary depending on disturbance attributes (e.g. size or intensity), and this variation is likely to be nonlinear. We show that few experiments testing fire-grazing interactions are able to identify the mechanistic pathway driving an observed interaction, and most are unable to detect nonlinear effects. We demonstrate how these limitations compromise the ability of experimental studies to effectively inform ecological management. We propose a series of adjustments to the design of disturbance interaction experiments that would enable tests of key theoretical pathways and provide the deeper ecological understanding necessary for effective management. Such considerations are relevant to studies of a broad range of ecological interactions and are critical to informing the management of disturbance regimes in the context of accelerating global change.}, }
@article {pmid26439862, year = {2016}, author = {Dirnböck, T and Kobler, J and Kraus, D and Grote, R and Kiese, R}, title = {Impacts of management and climate change on nitrate leaching in a forested karst area.}, journal = {Journal of environmental management}, volume = {165}, number = {}, pages = {243-252}, doi = {10.1016/j.jenvman.2015.09.039}, pmid = {26439862}, issn = {1095-8630}, mesh = {Austria ; Climate ; *Climate Change ; Environmental Monitoring ; Forestry/methods ; *Forests ; Groundwater/*chemistry ; Models, Theoretical ; Nitrates/*analysis/chemistry ; Nitrogen/analysis/chemistry ; Seasons ; Soil ; }, abstract = {Forest management and climate change, directly or indirectly, affect drinking water resources, both in terms of quality and quantity. In this study in the Northern Limestone Alps in Austria we have chosen model calculations (LandscapeDNDC) in order to resolve the complex long-term interactions of management and climate change and their effect on nitrogen dynamics, and the consequences for nitrate leaching from forest soils into the karst groundwater. Our study highlights the dominant role of forest management in controlling nitrate leaching. Both clear-cut and shelterwood-cut disrupt the nitrogen cycle to an extent that causes peak concentrations and high fluxes into the seepage water. While this effect is well known, our modelling approach has revealed additional positive as well as negative impacts of the expected climatic changes on nitrate leaching. First, we show that peak nitrate concentrations during post-cutting periods were elevated under all climate scenarios. The maximal effects of climatic changes on nitrate concentration peaks were 20-24 mg L(-1) in 2090 with shelterwood or clear-cut management. Second, climate change significantly decreased the cumulative nitrate losses over full forest rotation periods (by 10-20%). The stronger the expected temperature increase and precipitation decrease (in summer), the lesser were the observed nitrate losses. However, mean annual seepage water nitrate concentrations and cumulative nitrate leaching were higher under continuous forest cover management than with shelterwood-cut and clear-cut systems. Watershed management can thus be adapted to climate change by either reducing peak concentrations or long-term loads of nitrate in the karst groundwater.}, }
@article {pmid26439435, year = {2015}, author = {Deraison, H and Badenhausser, I and Loeuille, N and Scherber, C and Gross, N}, title = {Functional trait diversity across trophic levels determines herbivore impact on plant community biomass.}, journal = {Ecology letters}, volume = {18}, number = {12}, pages = {1346-1355}, doi = {10.1111/ele.12529}, pmid = {26439435}, issn = {1461-0248}, mesh = {Animals ; *Biodiversity ; *Biomass ; Food Chain ; France ; *Herbivory ; Orthoptera/*physiology ; *Plant Physiological Phenomena ; Seasons ; }, abstract = {Understanding the consequences of trophic interactions for ecosystem functioning is challenging, as contrasting effects of species and functional diversity can be expected across trophic levels. We experimentally manipulated functional identity and diversity of grassland insect herbivores and tested their impact on plant community biomass. Herbivore resource acquisition traits, i.e. mandible strength and the diversity of mandibular traits, had more important effects on plant biomass than body size. Higher herbivore functional diversity increased overall impact on plant biomass due to feeding niche complementarity. Higher plant functional diversity limited biomass pre-emption by herbivores. The functional diversity within and across trophic levels therefore regulates the impact of functionally contrasting consumers on primary producers. By experimentally manipulating the functional diversity across trophic levels, our study illustrates how trait-based approaches constitute a promising way to tackle existing links between trophic interactions and ecosystem functioning.}, }
@article {pmid26290356, year = {2015}, author = {Bleu, J and Herfindal, I and Loison, A and Kwak, AM and Garel, M and Toïgo, C and Rempfler, T and Filli, F and Sæther, BE}, title = {Age-specific survival and annual variation in survival of female chamois differ between populations.}, journal = {Oecologia}, volume = {179}, number = {4}, pages = {1091-1098}, pmid = {26290356}, issn = {1432-1939}, mesh = {Animals ; *Climate Change ; *Environment ; Female ; France ; Life Expectancy ; *Longevity ; Population Dynamics ; Rupicapra/*physiology ; Switzerland ; }, abstract = {In many species, population dynamics are shaped by age-structured demographic parameters, such as survival, which can cause age-specific sensitivity to environmental conditions. Accordingly, we can expect populations with different age-specific survival to be differently affected by environmental variation. However, this hypothesis is rarely tested at the intra-specific level. Using capture-mark-recapture models, we quantified age-specific survival and the extent of annual variations in survival of females of alpine chamois in two sites. In one population, survival was very high (>0.94; Bauges, France) until the onset of senescence at approximately 7 years old, whereas the two other populations (Swiss National Park, SNP) had a later onset (12 years old) and a lower rate of senescence. Senescence patterns are therefore not fixed within species. Annual variation in survival was higher in the Bauges (SD = 0.26) compared to the SNP populations (SD = 0.20). Also, in each population, the age classes with the lowest survival also experienced the largest temporal variation, in accordance with inter-specific comparisons showing a greater impact of environmental variation on these age classes. The large difference between the populations in age-specific survival and variation suggests that environmental variation and climate change will affect these populations differently.}, }
@article {pmid26116927, year = {2015}, author = {Minocha, R and Turlapati, SA and Long, S and McDowell, WH and Minocha, SC}, title = {Long-term trends of changes in pine and oak foliar nitrogen metabolism in response to chronic nitrogen amendments at Harvard Forest, MA.}, journal = {Tree physiology}, volume = {35}, number = {8}, pages = {894-909}, doi = {10.1093/treephys/tpv044}, pmid = {26116927}, issn = {1758-4469}, mesh = {Biomass ; Carbon/metabolism ; Forests ; Massachusetts ; Nitrogen/*metabolism ; Pinus/*metabolism ; Quercus/*metabolism ; Soil ; }, abstract = {We evaluated the long-term (1995-2008) trends in foliar and sapwood metabolism, soil solution chemistry and tree mortality rates in response to chronic nitrogen (N) additions to pine and hardwood stands at the Harvard Forest Long Term Ecological Research (LTER) site. Common stress-related metabolites like polyamines (PAs), free amino acids (AAs) and inorganic elements were analyzed for control, low N (LN, 50 kg NH4NO3 ha(-1) year(-1)) and high N (HN, 150 kg NH4NO3 ha(-1) year(-1)) treatments. In the pine stands, partitioning of excess N into foliar PAs and AAs increased with both N treatments until 2002. By 2005, several of these effects on N metabolites disappeared for HN, and by 2008 they were mostly observed for LN plot. A significant decline in foliar Ca and P was observed mostly with HN for a few years until 2005. However, sapwood data actually showed an increase in Ca, Mg and Mn and no change in PAs in the HN plot for 2008, while AAs data revealed trends that were generally similar to foliage for 2008. Concomitant with these changes, mortality data revealed a large number of dead trees in HN pine plots by 2002; the mortality rate started to decline by 2005. Oak trees in the hardwood plot did not exhibit any major changes in PAs, AAs, nutrients and mortality rate with LN treatment, indicating that oak trees were able to tolerate the yearly doses of 50 kg NH4NO3 ha(-1) year(-1). However, HN trees suffered from physiological and nutritional stress along with increased mortality in 2008. In this case also, foliar data were supported by the sapwood data. Overall, both low and high N applications resulted in greater physiological stress to the pine trees than the oaks. In general, the time course of changes in metabolic data are in agreement with the published reports on changes in soil chemistry and microbial community structure, rates of soil carbon sequestration and production of woody biomass for this chronic N study. This correspondence of selected metabolites with other measures of forest functions suggests that the metabolite analyses are useful for long-term monitoring of the health of forest trees.}, }
@article {pmid26071767, year = {2015}, author = {Petit, S and Munier-Jolain, N and Bretagnolle, V and Bockstaller, C and Gaba, S and Cordeau, S and Lechenet, M and Mézière, D and Colbach, N}, title = {Ecological Intensification Through Pesticide Reduction: Weed Control, Weed Biodiversity and Sustainability in Arable Farming.}, journal = {Environmental management}, volume = {56}, number = {5}, pages = {1078-1090}, pmid = {26071767}, issn = {1432-1009}, mesh = {Agriculture/*methods ; *Biodiversity ; Conservation of Natural Resources ; Crops, Agricultural ; Ecology ; *Herbicides ; Plant Weeds/physiology ; Weed Control/*methods ; }, abstract = {Amongst the biodiversity components of agriculture, weeds are an interesting model for exploring management options relying on the principle of ecological intensification in arable farming. Weeds can cause severe crop yield losses, contribute to farmland functional biodiversity and are strongly associated with the generic issue of pesticide use. In this paper, we address the impacts of herbicide reduction following a causal framework starting with herbicide reduction and triggering changes in (i) the management options required to control weeds, (ii) the weed communities and functions they provide and (iii) the overall performance and sustainability of the implemented land management options. The three components of this framework were analysed in a multidisciplinary project that was conducted on 55 experimental and farmer's fields that included conventional, integrated and organic cropping systems. Our results indicate that the reduction of herbicide use is not antagonistic with crop production, provided that alternative practices are put into place. Herbicide reduction and associated land management modified the composition of in-field weed communities and thus the functions of weeds related to biodiversity and production. Through a long-term simulation of weed communities based on alternative (?) cropping systems, some specific management pathways were identified that delivered high biodiversity gains and limited the negative impacts of weeds on crop production. Finally, the multi-criteria assessment of the environmental, economic and societal sustainability of the 55 systems suggests that integrated weed management systems fared better than their conventional and organic counterparts. These outcomes suggest that sustainable management could possibly be achieved through changes in weed management, along a pathway starting with herbicide reduction.}, }
@article {pmid26039730, year = {2015}, author = {Lindenmayer, DB and Wood, J and MacGregor, C and Buckley, YM and Dexter, N and Fortescue, M and Hobbs, RJ and Catford, JA}, title = {A long-term experimental case study of the ecological effectiveness and cost effectiveness of invasive plant management in achieving conservation goals: bitou bush control in booderee national park in eastern australia.}, journal = {PloS one}, volume = {10}, number = {6}, pages = {e0128482}, pmid = {26039730}, issn = {1932-6203}, mesh = {Animals ; Asteraceae/*physiology ; Australia ; Conservation of Natural Resources/economics/methods ; *Cost-Benefit Analysis ; Decision Trees ; Ecosystem ; *Fires ; *Herbicides ; Humans ; Introduced Species/*economics ; Parks, Recreational ; Weed Control/economics/*methods ; }, abstract = {Invasive plant management is often justified in terms of conservation goals, yet progress is rarely assessed against these broader goals, instead focussing on short-term reductions of the invader as a measure of success. Key questions commonly remain unanswered including whether invader removal reverses invader impacts and whether management itself has negative ecosystem impacts. We addressed these knowledge gaps using a seven year experimental investigation of Bitou Bush, Chrysanthemoides monilifera subsp. rotundata. Our case study took advantage of the realities of applied management interventions for Bitou Bush to assess whether it is a driver or passenger of environmental change, and quantified conservation benefits relative to management costs of different treatment regimes. Among treatments examined, spraying with herbicide followed by burning and subsequent re-spraying (spray-fire-spray) proved the most effective for reducing the number of individuals and cover of Bitou Bush. Other treatment regimes (e.g. fire followed by spraying, or two fires in succession) were less effective or even exacerbated Bitou Bush invasion. The spray-fire-spray regime did not increase susceptibility of treated areas to re-invasion by Bitou Bush or other exotic species. This regime significantly reduced plant species richness and cover, but these effects were short-lived. The spray-fire-spray regime was the most cost-effective approach to controlling a highly invasive species and facilitating restoration of native plant species richness to levels characteristic of uninvaded sites. We provide a decision tree to guide management, where recommended actions depend on the outcome of post-treatment monitoring and performance against objectives. Critical to success is avoiding partial treatments and treatment sequences that may exacerbate invasive species impacts. We also show the value of taking advantage of unplanned events, such as wildfires, to achieve management objectives at reduced cost.}, }
@article {pmid26036846, year = {2015}, author = {Coughlan, MR}, title = {Traditional fire-use, landscape transition, and the legacies of social theory past.}, journal = {Ambio}, volume = {44}, number = {8}, pages = {705-717}, pmid = {26036846}, issn = {1654-7209}, mesh = {Anthropology, Cultural/*history ; *Conservation of Natural Resources ; Ecosystem ; *Fires ; Geography/*history ; History, 19th Century ; History, 20th Century ; History, 21st Century ; Humans ; *Social Theory ; }, abstract = {Fire-use and the scale and character of its effects on landscapes remain hotly debated in the paleo- and historical-fire literature. Since the second half of the nineteenth century, anthropology and geography have played important roles in providing theoretical propositions and testable hypotheses for advancing understandings of the ecological role of human-fire-use in landscape histories. This article reviews some of the most salient and persistent theoretical propositions and hypotheses concerning the role of humans in historical fire ecology. The review discusses this history in light of current research agendas, such as those offered by pyrogeography. The review suggests that a more theoretically cognizant historical fire ecology should strive to operationalize transdisciplinary theory capable of addressing the role of human variability in the evolutionary history of landscapes. To facilitate this process, researchers should focus attention on integrating more current human ecology theory into transdisciplinary research agendas.}, }
@article {pmid26029192, year = {2015}, author = {Beversdorf, LJ and Miller, TR and McMahon, KD}, title = {Long-term monitoring reveals carbon-nitrogen metabolism key to microcystin production in eutrophic lakes.}, journal = {Frontiers in microbiology}, volume = {6}, number = {}, pages = {456}, pmid = {26029192}, issn = {1664-302X}, support = {T32 GM008349/GM/NIGMS NIH HHS/United States ; }, abstract = {The environmental drivers contributing to cyanobacterial dominance in aquatic systems have been extensively studied. However, understanding of toxic vs. non-toxic cyanobacterial population dynamics and the mechanisms regulating cyanotoxin production remain elusive, both physiologically and ecologically. One reason is the disconnect between laboratory and field-based studies. Here, we combined 3 years of temporal data, including microcystin (MC) concentrations, 16 years of long-term ecological research, and 10 years of molecular data to investigate the potential factors leading to the selection of toxic Microcystis and MC production. Our analysis revealed that nitrogen (N) speciation and inorganic carbon (C) availability might be important drivers of Microcystis population dynamics and that an imbalance in cellular C: N ratios may trigger MC production. More specifically, precipitous declines in ammonium concentrations lead to a transitional period of N stress, even in the presence of high nitrate concentrations, that we call the "toxic phase." Following the toxic phase, temperature and cyanobacterial abundance remained elevated but MC concentrations drastically declined. Increases in ammonium due to lake turnover may have led to down regulation of MC synthesis or a shift in the community from toxic to non-toxic species. While total phosphorus (P) to total N ratios were relatively low over the time-series, MC concentrations were highest when total N to total P ratios were also highest. Similarly, high C: N ratios were also strongly correlated to the toxic phase. We propose a metabolic model that corroborates molecular studies and reflects our ecological observations that C and N metabolism may regulate MC production physiologically and ecologically. In particular, we hypothesize that an imbalance between 2-oxoglutarate and ammonium in the cell regulates MC synthesis in the environment.}, }
@article {pmid26019591, year = {2014}, author = {Damyanova, S and Ivanova, I and Ignatova, N}, title = {Water quality assessment of aquatic ecosystems using ecological criteria - case study in Bulgaria.}, journal = {Biotechnology, biotechnological equipment}, volume = {28}, number = {6}, pages = {1050-1056}, pmid = {26019591}, issn = {1310-2818}, abstract = {Four aquatic ecosystems (two rivers and two dams) situated in the western part of Bulgaria were investigated over a three years' period. The River Egulya and Petrohan dam are situated in mountainous regions at about 1000 m altitude, and are not influenced by any anthropogenic sources. Petrohan dam is a site for long-term ecosystem research as a part of Bulgarian long-term ecological research network. The other two systems belong to populated industrial areas. The River Martinovska flows through a region with former long-term mining activity, while Ogosta dam is near a battery production factory. Both the geochemical and geographical ecosystems' conditions are different, and their social usage as well. Ogosta dam water is used for irrigation and Petrohan dam for electric supply. The ecosystem sensitivity to heavy metals was evaluated by a critical load approach. Two criteria were used for risk assessment: critical load exceedance and microbial toxicity test. All studied ecosystems were more sensitive to cadmium than to lead deposition. The potential risk of Cd damage is higher for Petrohan dam and the River Egulya, where critical load exceedance was calculated for two years. Pseudomonas putida growth inhibition test detected a lack of toxicity for all studied ecosystems at the time of investigation with the exception of the low water September sample of the River Martinovska. The fast bacterial test is very suitable for a regular measurement of water toxicity because of its simplicity, lack of sophisticated equipment and clear results.}, }
@article {pmid25994672, year = {2015}, author = {Henckel, L and Börger, L and Meiss, H and Gaba, S and Bretagnolle, V}, title = {Organic fields sustain weed metacommunity dynamics in farmland landscapes.}, journal = {Proceedings. Biological sciences}, volume = {282}, number = {1808}, pages = {20150002}, pmid = {25994672}, issn = {1471-2954}, mesh = {*Biodiversity ; Conservation of Natural Resources ; *Ecosystem ; France ; *Organic Agriculture ; Plant Weeds/*physiology ; Seasons ; Triticum ; }, abstract = {Agro-ecosystems constitute essential habitat for many organisms. Agricultural intensification, however, has caused a strong decline of farmland biodiversity. Organic farming (OF) is often presented as a more biodiversity-friendly practice, but the generality of the beneficial effects of OF is debated as the effects appear often species- and context-dependent, and current research has highlighted the need to quantify the relative effects of local- and landscape-scale management on farmland biodiversity. Yet very few studies have investigated the landscape-level effects of OF; that is to say, how the biodiversity of a field is affected by the presence or density of organically farmed fields in the surrounding landscape. We addressed this issue using the metacommunity framework, with weed species richness in winter wheat within an intensively farmed landscape in France as model system. Controlling for the effects of local and landscape structure, we showed that OF leads to higher local weed diversity and that the presence of OF in the landscape is associated with higher local weed biodiversity also for conventionally farmed fields, and may reach a similar biodiversity level to organic fields in field margins. Based on these results, we derive indications for improving the sustainable management of farming systems.}, }
@article {pmid25957785, year = {2015}, author = {Lynch, AJ and Thackway, R and Specht, A and Beggs, PJ and Brisbane, S and Burns, EL and Byrne, M and Capon, SJ and Casanova, MT and Clarke, PA and Davies, JM and Dovers, S and Dwyer, RG and Ens, E and Fisher, DO and Flanigan, M and Garnier, E and Guru, SM and Kilminster, K and Locke, J and Mac Nally, R and McMahon, KM and Mitchell, PJ and Pierson, JC and Rodgers, EM and Russell-Smith, J and Udy, J and Waycott, M}, title = {Transdisciplinary synthesis for ecosystem science, policy and management: The Australian experience.}, journal = {The Science of the total environment}, volume = {534}, number = {}, pages = {173-184}, doi = {10.1016/j.scitotenv.2015.04.100}, pmid = {25957785}, issn = {1879-1026}, mesh = {Australia ; Conservation of Natural Resources/*methods ; Cooperative Behavior ; *Ecology ; Ecosystem ; Environmental Monitoring ; *Environmental Policy ; Interdisciplinary Communication ; }, abstract = {Mitigating the environmental effects of global population growth, climatic change and increasing socio-ecological complexity is a daunting challenge. To tackle this requires synthesis: the integration of disparate information to generate novel insights from heterogeneous, complex situations where there are diverse perspectives. Since 1995, a structured approach to inter-, multi- and trans-disciplinary(1) collaboration around big science questions has been supported through synthesis centres around the world. These centres are finding an expanding role due to ever-accumulating data and the need for more and better opportunities to develop transdisciplinary and holistic approaches to solve real-world problems. The Australian Centre for Ecological Analysis and Synthesis (ACEAS <http://www.aceas.org.au>) has been the pioneering ecosystem science synthesis centre in the Southern Hemisphere. Such centres provide analysis and synthesis opportunities for time-pressed scientists, policy-makers and managers. They provide the scientific and organisational environs for virtual and face-to-face engagement, impetus for integration, data and methodological support, and innovative ways to deliver synthesis products. We detail the contribution, role and value of synthesis using ACEAS to exemplify the capacity for synthesis centres to facilitate trans-organisational, transdisciplinary synthesis. We compare ACEAS to other international synthesis centres, and describe how it facilitated project teams and its objective of linking natural resource science to policy to management. Scientists and managers were brought together to actively collaborate in multi-institutional, cross-sectoral and transdisciplinary research on contemporary ecological problems. The teams analysed, integrated and synthesised existing data to co-develop solution-oriented publications and management recommendations that might otherwise not have been produced. We identify key outcomes of some ACEAS working groups which used synthesis to tackle important ecosystem challenges. We also examine the barriers and enablers to synthesis, so that risks can be minimised and successful outcomes maximised. We argue that synthesis centres have a crucial role in developing, communicating and using synthetic transdisciplinary research.}, }
@article {pmid25773398, year = {2015}, author = {Gauffre, B and Mallez, S and Chapuis, MP and Leblois, R and Litrico, I and Delaunay, S and Badenhausser, I}, title = {Spatial heterogeneity in landscape structure influences dispersal and genetic structure: empirical evidence from a grasshopper in an agricultural landscape.}, journal = {Molecular ecology}, volume = {24}, number = {8}, pages = {1713-1728}, doi = {10.1111/mec.13152}, pmid = {25773398}, issn = {1365-294X}, mesh = {Agriculture ; *Animal Distribution ; Animals ; Bayes Theorem ; Cluster Analysis ; *Ecosystem ; France ; Gene Frequency ; *Genetics, Population ; Grasshoppers/*genetics ; Grassland ; Spatial Analysis ; }, abstract = {Dispersal may be strongly influenced by landscape and habitat characteristics that could either enhance or restrict movements of organisms. Therefore, spatial heterogeneity in landscape structure could influence gene flow and the spatial structure of populations. In the past decades, agricultural intensification has led to the reduction in grassland surfaces, their fragmentation and intensification. As these changes are not homogeneously distributed in landscapes, they have resulted in spatial heterogeneity with generally less intensified hedged farmland areas remaining alongside streams and rivers. In this study, we assessed spatial pattern of abundance and population genetic structure of a flightless grasshopper species, Pezotettix giornae, based on the surveys of 363 grasslands in a 430-km[2] agricultural landscape of western France. Data were analysed using geostatistics and landscape genetics based on microsatellites markers and computer simulations. Results suggested that small-scale intense dispersal allows this species to survive in intensive agricultural landscapes. A complex spatial genetic structure related to landscape and habitat characteristics was also detected. Two P. giornae genetic clusters bisected by a linear hedged farmland were inferred from clustering analyses. This linear hedged farmland was characterized by high hedgerow and grassland density as well as higher grassland temporal stability that were suspected to slow down dispersal. Computer simulations demonstrated that a linear-shaped landscape feature limiting dispersal could be detected as a barrier to gene flow and generate the observed genetic pattern. This study illustrates the relevance of using computer simulations to test hypotheses in landscape genetics studies.}, }
@article {pmid25762989, year = {2015}, author = {DeAngelis, KM and Pold, G and Topçuoğlu, BD and van Diepen, LT and Varney, RM and Blanchard, JL and Melillo, J and Frey, SD}, title = {Long-term forest soil warming alters microbial communities in temperate forest soils.}, journal = {Frontiers in microbiology}, volume = {6}, number = {}, pages = {104}, pmid = {25762989}, issn = {1664-302X}, abstract = {Soil microbes are major drivers of soil carbon cycling, yet we lack an understanding of how climate warming will affect microbial communities. Three ongoing field studies at the Harvard Forest Long-term Ecological Research (LTER) site (Petersham, MA) have warmed soils 5°C above ambient temperatures for 5, 8, and 20 years. We used this chronosequence to test the hypothesis that soil microbial communities have changed in response to chronic warming. Bacterial community composition was studied using Illumina sequencing of the 16S ribosomal RNA gene, and bacterial and fungal abundance were assessed using quantitative PCR. Only the 20-year warmed site exhibited significant change in bacterial community structure in the organic soil horizon, with no significant changes in the mineral soil. The dominant taxa, abundant at 0.1% or greater, represented 0.3% of the richness but nearly 50% of the observations (sequences). Individual members of the Actinobacteria, Alphaproteobacteria and Acidobacteria showed strong warming responses, with one Actinomycete decreasing from 4.5 to 1% relative abundance with warming. Ribosomal RNA copy number can obfuscate community profiles, but is also correlated with maximum growth rate or trophic strategy among bacteria. Ribosomal RNA copy number correction did not affect community profiles, but rRNA copy number was significantly decreased in warming plots compared to controls. Increased bacterial evenness, shifting beta diversity, decreased fungal abundance and increased abundance of bacteria with low rRNA operon copy number, including Alphaproteobacteria and Acidobacteria, together suggest that more or alternative niche space is being created over the course of long-term warming.}, }
@article {pmid25601856, year = {2014}, author = {Buttigieg, PL and Ramette, A}, title = {Biogeographic patterns of bacterial microdiversity in Arctic deep-sea sediments (HAUSGARTEN, Fram Strait).}, journal = {Frontiers in microbiology}, volume = {5}, number = {}, pages = {660}, pmid = {25601856}, issn = {1664-302X}, abstract = {Marine bacteria colonizing deep-sea sediments beneath the Arctic ocean, a rapidly changing ecosystem, have been shown to exhibit significant biogeographic patterns along transects spanning tens of kilometers and across water depths of several thousand meters (Jacob et al., 2013). Jacob et al. (2013) adopted what has become a classical view of microbial diversity - based on operational taxonomic units clustered at the 97% sequence identity level of the 16S rRNA gene - and observed a very large microbial community replacement at the HAUSGARTEN Long Term Ecological Research station (Eastern Fram Strait). Here, we revisited these data using the oligotyping approach and aimed to obtain new insight into ecological and biogeographic patterns associated with bacterial microdiversity in marine sediments. We also assessed the level of concordance of these insights with previously obtained results. Variation in oligotype dispersal range, relative abundance, co-occurrence, and taxonomic identity were related to environmental parameters such as water depth, biomass, and sedimentary pigment concentration. This study assesses ecological implications of the new microdiversity-based technique using a well-characterized dataset of high relevance for global change biology.}, }
@article {pmid25566348, year = {2014}, author = {Woo, HL and Ballor, NR and Hazen, TC and Fortney, JL and Simmons, B and Davenport, KW and Goodwin, L and Ivanova, N and Kyrpides, NC and Mavromatis, K and Woyke, T and Jansson, J and Kimbrel, J and DeAngelis, KM}, title = {Complete genome sequence of the lignin-degrading bacterium Klebsiella sp. strain BRL6-2.}, journal = {Standards in genomic sciences}, volume = {9}, number = {}, pages = {19}, pmid = {25566348}, issn = {1944-3277}, abstract = {In an effort to discover anaerobic bacteria capable of lignin degradation, we isolated Klebsiella sp. strain BRL6-2 on minimal media with alkali lignin as the sole carbon source. This organism was isolated anaerobically from tropical forest soils collected from the Bisley watershed at the Ridge site in the El Yunque National Forest in Puerto Rico, USA, part of the Luquillo Long-Term Ecological Research Station. At this site, the soils experience strong fluctuations in redox potential and are characterized by cycles of iron oxidation and reduction. Genome sequencing was targeted because of its ability to grow on lignin anaerobically and lignocellulolytic activity via in vitro enzyme assays. The genome of Klebsiella sp. strain BRL6-2 is 5.80 Mbp with no detected plasmids, and includes a relatively small arsenal of genes encoding lignocellulolytic carbohydrate active enzymes. The genome revealed four putative peroxidases including glutathione and DyP-type peroxidases, and a complete protocatechuate pathway encoded in a single gene cluster. Physiological studies revealed Klebsiella sp. strain BRL6-2 to be relatively stress tolerant to high ionic strength conditions. It grows in increasing concentrations of ionic liquid (1-ethyl-3-methyl-imidazolium acetate) up to 73.44 mM and NaCl up to 1.5 M.}, }
@article {pmid25558364, year = {2014}, author = {Hudson, LN and Newbold, T and Contu, S and Hill, SL and Lysenko, I and De Palma, A and Phillips, HR and Senior, RA and Bennett, DJ and Booth, H and Choimes, A and Correia, DL and Day, J and Echeverría-Londoño, S and Garon, M and Harrison, ML and Ingram, DJ and Jung, M and Kemp, V and Kirkpatrick, L and Martin, CD and Pan, Y and White, HJ and Aben, J and Abrahamczyk, S and Adum, GB and Aguilar-Barquero, V and Aizen, MA and Ancrenaz, M and Arbeláez-Cortés, E and Armbrecht, I and Azhar, B and Azpiroz, AB and Baeten, L and Báldi, A and Banks, JE and Barlow, J and Batáry, P and Bates, AJ and Bayne, EM and Beja, P and Berg, &#xc5; and Berry, NJ and Bicknell, JE and Bihn, JH and Böhning-Gaese, K and Boekhout, T and Boutin, C and Bouyer, J and Brearley, FQ and Brito, I and Brunet, J and Buczkowski, G and Buscardo, E and Cabra-García, J and Calviño-Cancela, M and Cameron, SA and Cancello, EM and Carrijo, TF and Carvalho, AL and Castro, H and Castro-Luna, AA and Cerda, R and Cerezo, A and Chauvat, M and Clarke, FM and Cleary, DF and Connop, SP and D'Aniello, B and da Silva, PG and Darvill, B and Dauber, J and Dejean, A and Diekötter, T and Dominguez-Haydar, Y and Dormann, CF and Dumont, B and Dures, SG and Dynesius, M and Edenius, L and Elek, Z and Entling, MH and Farwig, N and Fayle, TM and Felicioli, A and Felton, AM and Ficetola, GF and Filgueiras, BK and Fonte, SJ and Fraser, LH and Fukuda, D and Furlani, D and Ganzhorn, JU and Garden, JG and Gheler-Costa, C and Giordani, P and Giordano, S and Gottschalk, MS and Goulson, D and Gove, AD and Grogan, J and Hanley, ME and Hanson, T and Hashim, NR and Hawes, JE and Hébert, C and Helden, AJ and Henden, JA and Hernández, L and Herzog, F and Higuera-Diaz, D and Hilje, B and Horgan, FG and Horváth, R and Hylander, K and Isaacs-Cubides, P and Ishitani, M and Jacobs, CT and Jaramillo, VJ and Jauker, B and Jonsell, M and Jung, TS and Kapoor, V and Kati, V and Katovai, E and Kessler, M and Knop, E and Kolb, A and Kőrösi, &#xc1; and Lachat, T and Lantschner, V and Le Féon, V and LeBuhn, G and Légaré, JP and Letcher, SG and Littlewood, NA and López-Quintero, CA and Louhaichi, M and Lövei, GL and Lucas-Borja, ME and Luja, VH and Maeto, K and Magura, T and Mallari, NA and Marin-Spiotta, E and Marshall, EJ and Martínez, E and Mayfield, MM and Mikusinski, G and Milder, JC and Miller, JR and Morales, CL and Muchane, MN and Muchane, M and Naidoo, R and Nakamura, A and Naoe, S and Nates-Parra, G and Navarrete Gutierrez, DA and Neuschulz, EL and Noreika, N and Norfolk, O and Noriega, JA and Nöske, NM and O'Dea, N and Oduro, W and Ofori-Boateng, C and Oke, CO and Osgathorpe, LM and Paritsis, J and Parra-H, A and Pelegrin, N and Peres, CA and Persson, AS and Petanidou, T and Phalan, B and Philips, TK and Poveda, K and Power, EF and Presley, SJ and Proença, V and Quaranta, M and Quintero, C and Redpath-Downing, NA and Reid, JL and Reis, YT and Ribeiro, DB and Richardson, BA and Richardson, MJ and Robles, CA and Römbke, J and Romero-Duque, LP and Rosselli, L and Rossiter, SJ and Roulston, TH and Rousseau, L and Sadler, JP and Sáfián, S and Saldaña-Vázquez, RA and Samnegård, U and Schüepp, C and Schweiger, O and Sedlock, JL and Shahabuddin, G and Sheil, D and Silva, FA and Slade, EM and Smith-Pardo, AH and Sodhi, NS and Somarriba, EJ and Sosa, RA and Stout, JC and Struebig, MJ and Sung, YH and Threlfall, CG and Tonietto, R and Tóthmérész, B and Tscharntke, T and Turner, EC and Tylianakis, JM and Vanbergen, AJ and Vassilev, K and Verboven, HA and Vergara, CH and Vergara, PM and Verhulst, J and Walker, TR and Wang, Y and Watling, JI and Wells, K and Williams, CD and Willig, MR and Woinarski, JC and Wolf, JH and Woodcock, BA and Yu, DW and Zaitsev, AS and Collen, B and Ewers, RM and Mace, GM and Purves, DW and Scharlemann, JP and Purvis, A}, title = {The PREDICTS database: a global database of how local terrestrial biodiversity responds to human impacts.}, journal = {Ecology and evolution}, volume = {4}, number = {24}, pages = {4701-4735}, pmid = {25558364}, issn = {2045-7758}, abstract = {Biodiversity continues to decline in the face of increasing anthropogenic pressures such as habitat destruction, exploitation, pollution and introduction of alien species. Existing global databases of species' threat status or population time series are dominated by charismatic species. The collation of datasets with broad taxonomic and biogeographic extents, and that support computation of a range of biodiversity indicators, is necessary to enable better understanding of historical declines and to project - and avert - future declines. We describe and assess a new database of more than 1.6 million samples from 78 countries representing over 28,000 species, collated from existing spatial comparisons of local-scale biodiversity exposed to different intensities and types of anthropogenic pressures, from terrestrial sites around the world. The database contains measurements taken in 208 (of 814) ecoregions, 13 (of 14) biomes, 25 (of 35) biodiversity hotspots and 16 (of 17) megadiverse countries. The database contains more than 1% of the total number of all species described, and more than 1% of the described species within many taxonomic groups - including flowering plants, gymnosperms, birds, mammals, reptiles, amphibians, beetles, lepidopterans and hymenopterans. The dataset, which is still being added to, is therefore already considerably larger and more representative than those used by previous quantitative models of biodiversity trends and responses. The database is being assembled as part of the PREDICTS project (Projecting Responses of Ecological Diversity In Changing Terrestrial Systems - http://www.predicts.org.uk). We make site-level summary data available alongside this article. The full database will be publicly available in 2015.}, }
@article {pmid25553061, year = {2014}, author = {Brodersen, J and Seehausen, O}, title = {Why evolutionary biologists should get seriously involved in ecological monitoring and applied biodiversity assessment programs.}, journal = {Evolutionary applications}, volume = {7}, number = {9}, pages = {968-983}, pmid = {25553061}, issn = {1752-4571}, abstract = {While ecological monitoring and biodiversity assessment programs are widely implemented and relatively well developed to survey and monitor the structure and dynamics of populations and communities in many ecosystems, quantitative assessment and monitoring of genetic and phenotypic diversity that is important to understand evolutionary dynamics is only rarely integrated. As a consequence, monitoring programs often fail to detect changes in these key components of biodiversity until after major loss of diversity has occurred. The extensive efforts in ecological monitoring have generated large data sets of unique value to macro-scale and long-term ecological research, but the insights gained from such data sets could be multiplied by the inclusion of evolutionary biological approaches. We argue that the lack of process-based evolutionary thinking in ecological monitoring means a significant loss of opportunity for research and conservation. Assessment of genetic and phenotypic variation within and between species needs to be fully integrated to safeguard biodiversity and the ecological and evolutionary dynamics in natural ecosystems. We illustrate our case with examples from fishes and conclude with examples of ongoing monitoring programs and provide suggestions on how to improve future quantitative diversity surveys.}, }
@article {pmid25512498, year = {2014}, author = {Green, PT and Harms, KE and Connell, JH}, title = {Nonrandom, diversifying processes are disproportionately strong in the smallest size classes of a tropical forest.}, journal = {Proceedings of the National Academy of Sciences of the United States of America}, volume = {111}, number = {52}, pages = {18649-18654}, pmid = {25512498}, issn = {1091-6490}, mesh = {*Biodiversity ; *Forests ; *Tropical Climate ; }, abstract = {A variety of ecological processes influence diversity and species composition in natural communities. Most of these processes, whether abiotic or biotic, differentially filter individuals from birth to death, thereby altering species' relative abundances. Nonrandom outcomes could accrue throughout ontogeny, or the processes that generate them could be particularly influential at certain stages. One long-standing paradigm in tropical forest ecology holds that patterns of relative abundance among mature trees are largely set by processes operating at the earliest life cycle stages. Several studies confirm filtering processes at some stages, but the longevity of large trees makes a rigorous comparison across size classes impossible without long-term demographic data. Here, we use one of the world's longest-running, plot-based forest dynamics projects to compare nonrandom outcomes across stage classes. We considered a cohort of 7,977 individuals in 186 species that were alive in 1971 and monitored in 13 mortality censuses over 42 y to 2013. Nonrandom mortality with respect to species identity occurred more often in the smaller rather than the larger size classes. Furthermore, observed nonrandom mortality in the smaller size classes had a diversifying influence; species richness of the survivors was up to 30% greater than expected in the two smallest size classes, but not greater than expected in the larger size classes. These results highlight the importance of early life cycle stages in tropical forest community dynamics. More generally, they add to an accumulating body of evidence for the importance of early-stage nonrandom outcomes to community structure in marine and terrestrial environments.}, }
@article {pmid25506926, year = {2014}, author = {Tesson, SV and Montresor, M and Procaccini, G and Kooistra, WH}, title = {Temporal changes in population structure of a marine planktonic diatom.}, journal = {PloS one}, volume = {9}, number = {12}, pages = {e114984}, pmid = {25506926}, issn = {1932-6203}, mesh = {Bayes Theorem ; Diatoms/*genetics ; Genetic Variation ; Genetics, Population ; Microsatellite Repeats ; Plankton/*genetics ; }, abstract = {A prevailing question in phytoplankton research addresses changes of genetic diversity in the face of huge population sizes and apparently unlimited dispersal capabilities. We investigated population genetic structure of the pennate planktonic marine diatom Pseudo-nitzschia multistriata at the LTER station MareChiara in the Gulf of Naples (Italy) over four consecutive years and explored possible changes over seasons and from year to year. A total of 525 strains were genotyped using seven microsatellite markers, for a genotypic diversity of 75.05%, comparable to that found in other Pseudo-nitzschia species. Evidence from Bayesian clustering analysis (BA) identified two genetically distinct clusters, here interpreted as populations, and several strains that could not be assigned with ≥ 90% probability to either population, here interpreted as putative hybrids. Principal Component Analysis (PCA) recovered these two clusters in distinct clouds with most of the putative hybrids located in-between. Relative proportions of the two populations and the putative hybrids remained similar within years, but changed radically between 2008 and 2009 and between 2010 and 2011, when the 2008-population apparently became the dominant one again. Strains from the two populations are inter-fertile, and so is their offspring. Inclusion of genotypes of parental strains and their offspring shows that the majority of the latter could not be assigned to any of the two parental populations. Therefore, field strains classified by BA as the putative hybrids could be biological hybrids. We hypothesize that P. multistriata population dynamics in the Gulf of Naples follows a meta-population-like model, including establishment of populations by cell inocula at the beginning of each growth season and remixing and dispersal governed by moving and mildly turbulent water masses.}, }
@article {pmid25501866, year = {2014}, author = {Hero, JM and Butler, SA and Lollback, GW and Castley, JG}, title = {Determinants of tree assemblage composition at the mesoscale within a subtropical eucalypt forest.}, journal = {PloS one}, volume = {9}, number = {12}, pages = {e114994}, pmid = {25501866}, issn = {1932-6203}, mesh = {*Altitude ; *Biota ; Eucalyptus/*growth &amp; development ; *Forests ; *Geography ; *Models, Biological ; Queensland ; Soil/*chemistry ; Species Specificity ; }, abstract = {A variety of environmental processes, including topography, edaphic and disturbance factors can influence vegetation composition. The relative influence of these patterns has been known to vary with scale, however, few studies have focused on environmental drivers of composition at the mesoscale. This study examined the relative importance of topography, catchment flow and soil in influencing tree assemblages in Karawatha Forest Park; a South-East Queensland subtropical eucalypt forest embedded in an urban matrix that is part of the Terrestrial Ecosystem Research Network South-East Queensland Peri-urban SuperSite. Thirty-three LTER plots were surveyed at the mesoscale (909 ha), where all woody stems ≥1.3 m high rooted within plots were sampled. Vegetation was divided into three cohorts: small (≥1-10 cm DBH), intermediate (≥10-30 cm DBH), and large (≥30 cm DBH). Plot slope, aspect, elevation, catchment area and location and soil chemistry and structure were also measured. Ordinations and smooth surface modelling were used to determine drivers of vegetation assemblage in each cohort. Vegetation composition was highly variable among plots at the mesoscale (plots systematically placed at 500 m intervals). Elevation was strongly related to woody vegetation composition across all cohorts (R2: 0.69-0.75). Other topographic variables that explained a substantial amount of variation in composition were catchment area (R2: 0.43-0.45) and slope (R2: 0.23-0.61). Soil chemistry (R2: 0.09-0.75) was also associated with woody vegetation composition. While species composition differed substantially between cohorts, the environmental variables explaining composition did not. These results demonstrate the overriding importance of elevation and other topographic features in discriminating tree assemblage patterns irrespective of tree size. The importance of soil characteristics to tree assemblages was also influenced by topography, where ridge top sites were typically drier and had lower soil nutrient levels than riparian areas.}, }
@article {pmid25455823, year = {2014}, author = {Poeta, G and Battisti, C and Acosta, ATR}, title = {Marine litter in Mediterranean sandy littorals: Spatial distribution patterns along central Italy coastal dunes.}, journal = {Marine pollution bulletin}, volume = {89}, number = {1-2}, pages = {168-173}, doi = {10.1016/j.marpolbul.2014.10.011}, pmid = {25455823}, issn = {1879-3363}, mesh = {Ecosystem ; Italy ; Mediterranean Sea ; Plastics ; Polystyrenes ; Water Pollutants/*analysis ; }, abstract = {Sandy shores are generally considered important sinks for marine litter and the presence of this litter may represent a serious threat to biotic communities and dune integrity mostly due to cleaning activities carried out through mechanical equipment. In spring (April-May) 2012 we sampled 153 2×2m random plots to assess the spatial distribution patterns of litter on Central Italy sandy shores. We analysed the relationship between the presence of litter and coastal dune habitats along the sea-inland gradient. Our results showed that the most frequent litter items were plastic and polystyrene. Differences of marine litter spatial distribution were found between upper beach and fore dune habitats and fixed dune habitats: embryo dune and mobile dune habitats show the highest frequency of litter, but, surprisingly, marine litter did not impact fixed dune habitats, these possibly acting as a natural barrier protecting the inner part of the coast from marine litter dispersion.}, }
@article {pmid25452078, year = {2014}, author = {Gaba, S and Collas, C and Powolny, T and Bretagnolle, F and Bretagnolle, V}, title = {Skylarks trade size and energy content in weed seeds to maximize total ingested lipid biomass.}, journal = {Behavioural processes}, volume = {108}, number = {}, pages = {142-150}, doi = {10.1016/j.beproc.2014.10.004}, pmid = {25452078}, issn = {1872-8308}, mesh = {Animals ; Feeding Behavior/*physiology ; Female ; *Lipids ; Male ; Passeriformes/*physiology ; *Seeds ; }, abstract = {The trade-off between forage quality and quantity has been particularly studied in herbivore organisms, but much less for seed eating animals, in particular seed-eating birds which constitute the bulk of wintering passerines in European farmlands. The skylark is one of the commonest farmland birds in winter, mainly feeding on seeds. We focus on weed seeds for conservation and management purposes. Weed seeds form the bulk of the diet of skylarks during winter period, and although this is still a matter for discussion, weed seed predation by granivorous has been suggested as an alternative to herbicides used to regulate weed populations in arable crops. Our objectives were to identify whether weed seed traits govern foraging decisions of skylarks, and to characterize key seed traits with respect to size, which is related to searching and handling time, and lipid content, which is essential for migratory birds. We combined a single-offer experiment and a multiple-offer one to test for feeding preferences of the birds by estimating seed intake on weed seed species differing in their seed size and seed lipid content. Our results showed (1) a selective preference for smaller seeds above a threshold of seed size or seed size difference in the pair and, (2) a significant effect of seed lipid biomass suggesting a trade-off between foraging for smaller seeds and selecting seeds rich in lipids. Skylarks foraging decision thus seems to be mainly based on seed size, that is presumably a 'proxy' for weed seed energy content. However, there are clearly many possible combinations of morphological and physiological traits that must play crucial role in the plant-bird interaction such as toxic compound or seed coat.}, }
@article {pmid25377459, year = {2014}, author = {Letten, AD and Keith, DA and Tozer, MG}, title = {Phylogenetic and functional dissimilarity does not increase during temporal heathland succession.}, journal = {Proceedings. Biological sciences}, volume = {281}, number = {1797}, pages = {}, pmid = {25377459}, issn = {1471-2954}, mesh = {Australia ; Linear Models ; Phylogeny ; Plant Physiological Phenomena ; Plants/*classification ; Population Dynamics ; }, abstract = {Succession has been a focal point of ecological research for over a century, but thus far has been poorly explored through the lens of modern phylogenetic and trait-based approaches to community assembly. The vast majority of studies conducted to date have comprised static analyses where communities are observed at a single snapshot in time. Long-term datasets present a vantage point to compare established and emerging theoretical predictions on the phylogenetic and functional trajectory of communities through succession. We investigated within, and between, community measures of phylogenetic and functional diversity in a fire-prone heathland along a 21 year time series. Contrary to widely held expectations that increased competition through succession should inhibit the coexistence of species with high niche overlap, plots became more phylogenetically and functionally clustered with time since fire. There were significant directional shifts in individual traits through time indicating deterministic successional processes associated with changing abiotic and/or biotic conditions. However, relative to the observed temporal rate of taxonomic turnover, both phylogenetic and functional turnover were comparatively low, suggesting a degree of functional redundancy among close relatives. These results contribute to an emerging body of evidence indicating that limits to the similarity of coexisting species are rarely observed at fine spatial scales.}, }
@article {pmid25200993, year = {2014}, author = {Fonseca, BM and de Mendonça-Galvão, L}, title = {Pristine aquatic systems in a Long Term Ecological Research (LTER) site of the Brazilian Cerrado.}, journal = {Environmental monitoring and assessment}, volume = {186}, number = {12}, pages = {8683-8695}, pmid = {25200993}, issn = {1573-2959}, mesh = {Animals ; Brazil ; Conservation of Natural Resources/methods ; Ecology ; *Environmental Monitoring ; Nitrogen/analysis ; Rain ; Research ; Rivers/chemistry ; Seasons ; Water Pollutants/analysis ; Water Quality ; }, abstract = {The maintenance of limnological monitoring programs in the Cerrado Domain is crucial as a provision of useful information about temporal variations in land use and their respective water quality responses, considering its importance as water source for different Brazilian hydrographic basins. The purpose of this research was to describe limnological variables of low-order lotic systems located in the Cerrado Long Term Ecological Research (LTER) site (Environmental Protection Area (APA) Gama and Cabeça de Veado, Federal District of Brazil). Altogether, nine different streams were considered in this study. Samplings were conducted between 2010 and 2012, concentrated in the dry and rainy seasons. The sampling sites were generally characterized by low nutrient concentrations (e.g., medians, TP = 14.8 μg L(-1), TN = 20.0 μg L(-1), NO3 = 13.8 μg L(-1)) and slightly acidic waters (median, pH = 5.3), with quite low electrical conductivity values (median = 6.4 μS cm(-1)). However, water quality degradation as a response to diffuse pollution was reported in some sampling points (e.g., Onça and Gama streams), expressed by relatively higher N and P concentrations, which were probably highlighted by the good water quality of the data set as whole. Although there was a trend to higher values of nitrogen forms during the dry season, significant statistical differences between the seasonal periods were reported only for the variables temperature and dissolved silica, which were higher in the dry and rainy season, respectively. The streams located in the preserved areas inside the ecological stations of APA Gama and Cabeça de Veado can still be considered good examples of reference lotic systems in the Cerrado Domain; notwithstanding, this study reported incipient signs of water quality degradation which cannot be overlooked in future limnological monitoring.}, }
@article {pmid25197446, year = {2014}, author = {Field, D and Sterk, P and Kottmann, R and De Smet, JW and Amaral-Zettler, L and Cochrane, G and Cole, JR and Davies, N and Dawyndt, P and Garrity, GM and Gilbert, JA and Glöckner, FO and Hirschman, L and Klenk, HP and Knight, R and Kyrpides, N and Meyer, F and Karsch-Mizrachi, I and Morrison, N and Robbins, R and San Gil, I and Sansone, S and Schriml, L and Tatusova, T and Ussery, D and Yilmaz, P and White, O and Wooley, J and Caporaso, G}, title = {Genomic standards consortium projects.}, journal = {Standards in genomic sciences}, volume = {9}, number = {3}, pages = {599-601}, pmid = {25197446}, issn = {1944-3277}, abstract = {The Genomic Standards Consortium (GSC) is an open-membership community that was founded in 2005 to work towards the development, implementation and harmonization of standards in the field of genomics. Starting with the defined task of establishing a minimal set of descriptions the GSC has evolved into an active standards-setting body that currently has 18 ongoing projects, with additional projects regularly proposed from within and outside the GSC. Here we describe our recently enacted policy for proposing new activities that are intended to be taken on by the GSC, along with the template for proposing such new activities.}, }
@article {pmid25170894, year = {2014}, author = {Norris, D and Fortin, MJ and Magnusson, WE}, title = {Towards monitoring biodiversity in Amazonian forests: how regular samples capture meso-scale altitudinal variation in 25 km2 plots.}, journal = {PloS one}, volume = {9}, number = {8}, pages = {e106150}, pmid = {25170894}, issn = {1932-6203}, mesh = {*Biodiversity ; Brazil ; *Ecological Parameter Monitoring ; *Models, Biological ; *Rainforest ; }, abstract = {BACKGROUND: Ecological monitoring and sampling optima are context and location specific. Novel applications (e.g. biodiversity monitoring for environmental service payments) call for renewed efforts to establish reliable and robust monitoring in biodiversity rich areas. As there is little information on the distribution of biodiversity across the Amazon basin, we used altitude as a proxy for biological variables to test whether meso-scale variation can be adequately represented by different sample sizes in a standardized, regular-coverage sampling arrangement.<br><br>We used Shuttle-Radar-Topography-Mission digital elevation values to evaluate if the regular sampling arrangement in standard RAPELD (rapid assessments ("RAP") over the long-term (LTER ["PELD" in Portuguese])) grids captured patters in meso-scale spatial variation. The adequacy of different sample sizes (n&#x200a;=&#x200a;4 to 120) were examined within 32,325 km2/3,232,500 ha (1293&#xd7;25 km2 sample areas) distributed across the legal Brazilian Amazon. Kolmogorov-Smirnov-tests, correlation and root-mean-square-error were used to measure sample representativeness, similarity and accuracy respectively. Trends and thresholds of these responses in relation to sample size and standard-deviation were modeled using Generalized-Additive-Models and conditional-inference-trees respectively. We found that a regular arrangement of 30 samples captured the distribution of altitude values within these areas. Sample size was more important than sample standard deviation for representativeness and similarity. In contrast, accuracy was more strongly influenced by sample standard deviation. Additionally, analysis of spatially interpolated data showed that spatial patterns in altitude were also recovered within areas using a regular arrangement of 30 samples.<br><br>CONCLUSIONS/SIGNIFICANCE: Our findings show that the logistically feasible sample used in the RAPELD system successfully recovers meso-scale altitudinal patterns. This suggests that the sample size and regular arrangement may also be generally appropriate for quantifying spatial patterns in biodiversity at similar scales across at least 90% (&#x2248;5 million km2) of the Brazilian Amazon.}, }
@article {pmid25156129, year = {2015}, author = {Morgado, LN and Semenova, TA and Welker, JM and Walker, MD and Smets, E and Geml, J}, title = {Summer temperature increase has distinct effects on the ectomycorrhizal fungal communities of moist tussock and dry tundra in Arctic Alaska.}, journal = {Global change biology}, volume = {21}, number = {2}, pages = {959-972}, pmid = {25156129}, issn = {1365-2486}, mesh = {Alaska ; Arctic Regions ; *Biodiversity ; DNA, Fungal/genetics ; *Global Warming ; Molecular Sequence Data ; Mycorrhizae/genetics/isolation &amp; purification/*physiology ; Polymerase Chain Reaction ; Seasons ; Sequence Analysis, DNA ; *Soil Microbiology ; Temperature ; *Tundra ; }, abstract = {Arctic regions are experiencing the greatest rates of climate warming on the planet and marked changes have already been observed in terrestrial arctic ecosystems. While most studies have focused on the effects of warming on arctic vegetation and nutrient cycling, little is known about how belowground communities, such as fungi root-associated, respond to warming. Here, we investigate how long-term summer warming affects ectomycorrhizal (ECM) fungal communities. We used Ion Torrent sequencing of the rDNA internal transcribed spacer 2 (ITS2) region to compare ECM fungal communities in plots with and without long-term experimental warming in both dry and moist tussock tundra. Cortinarius was the most OTU-rich genus in the moist tundra, while the most diverse genus in the dry tundra was Tomentella. On the diversity level, in the moist tundra we found significant differences in community composition, and a sharp decrease in the richness of ECM fungi due to warming. On the functional level, our results indicate that warming induces shifts in the extramatrical properties of the communities, where the species with medium-distance exploration type seem to be favored with potential implications for the mobilization of different nutrient pools in the soil. In the dry tundra, neither community richness nor community composition was significantly altered by warming, similar to what had been observed in ECM host plants. There was, however, a marginally significant increase in OTUs identified as ECM fungi with the medium-distance exploration type in the warmed plots. Linking our findings of decreasing richness with previous results of increasing ECM fungal biomass suggests that certain ECM species are favored by warming and may become more abundant, while many other species may go locally extinct due to direct or indirect effects of warming. Such compositional shifts in the community might affect nutrient cycling and soil organic C storage.}, }
@article {pmid25000452, year = {2014}, author = {Saba, GK and Fraser, WR and Saba, VS and Iannuzzi, RA and Coleman, KE and Doney, SC and Ducklow, HW and Martinson, DG and Miles, TN and Patterson-Fraser, DL and Stammerjohn, SE and Steinberg, DK and Schofield, OM}, title = {Winter and spring controls on the summer food web of the coastal West Antarctic Peninsula.}, journal = {Nature communications}, volume = {5}, number = {}, pages = {4318}, doi = {10.1038/ncomms5318}, pmid = {25000452}, issn = {2041-1723}, mesh = {Animals ; Antarctic Regions ; Bacteria ; Chlorophyll/analysis ; Euphausiacea ; *Food Chain ; Phytoplankton ; *Seasons ; Spheniscidae ; }, abstract = {Understanding the mechanisms by which climate variability affects multiple trophic levels in food webs is essential for determining ecosystem responses to climate change. Here we use over two decades of data collected by the Palmer Long Term Ecological Research program (PAL-LTER) to determine how large-scale climate and local physical forcing affect phytoplankton, zooplankton and an apex predator along the West Antarctic Peninsula (WAP). We show that positive anomalies in chlorophyll-a (chl-a) at Palmer Station, occurring every 4-6 years, are constrained by physical processes in the preceding winter/spring and a negative phase of the Southern Annular Mode (SAM). Favorable conditions for phytoplankton included increased winter ice extent and duration, reduced spring/summer winds, and increased water column stability via enhanced salinity-driven density gradients. Years of positive chl-a anomalies are associated with the initiation of a robust krill cohort the following summer, which is evident in Adélie penguin diets, thus demonstrating tight trophic coupling. Projected climate change in this region may have a significant, negative impact on phytoplankton biomass, krill recruitment and upper trophic level predators in this coastal Antarctic ecosystem.}, }
@article {pmid24780073, year = {2014}, author = {Newbold, TA and Stapp, P and Levensailor, KE and Derner, JD and Lauenroth, WK}, title = {Community responses of arthropods to a range of traditional and manipulated grazing in shortgrass steppe.}, journal = {Environmental entomology}, volume = {43}, number = {3}, pages = {556-568}, doi = {10.1603/EN12333}, pmid = {24780073}, issn = {1938-2936}, mesh = {Animal Husbandry ; Animals ; Arthropods/*physiology ; *Biota ; Cattle/physiology ; Coleoptera/physiology ; Colorado ; Feeding Behavior ; Food Chain ; Grasshoppers/physiology ; *Grassland ; Sciuridae/physiology ; Seasons ; Spiders/physiology ; }, abstract = {Responses of plants to grazing are better understood, and more predictable, than those of consumers in North American grasslands. In 2003, we began a large-scale, replicated experiment that examined the effects of grazing on three important arthropod groups-beetles, spiders, and grasshoppers-in shortgrass steppe of north-central Colorado. We investigated whether modifications of the intensity and seasonality of livestock grazing alter the structure and diversity of macroarthropod communities compared with traditional grazing practices. Treatments represented a gradient of grazing intensity by cattle and native herbivores: long-term grazing exclosures; moderate summer grazing (the traditional regime); intensive spring grazing; intensive summer grazing; and moderately summer-grazed pastures also inhabited by black-tailed prairie dogs (Cynomys ludovicianus Ord). Beetles and spiders were the most common groups captured, comprising 60% and 21%, respectively, of 4,378 total pitfall captures. Grasshopper counts were generally low, with 3,799 individuals observed and densities <4 m(-2). Two years after treatments were applied, vegetation structure differed among grazing treatments, responding not only to long-term grazing conditions, but also to the short-term, more-intensive grazing manipulations. In response, arthropods were, in general, relatively insensitive to these grazing-induced structural changes. However, species-level analyses of one group (Tenebrionidae) revealed both positive and negative effects of grazing treatments on beetle richness and activity-density. Importantly, these responses to grazing were more pronounced in a year when spring-summer rainfall was low, suggesting that both grazing and precipitation-which together may create the greatest heterogeneity in vegetation structure-are drivers of consumer responses in this system.}, }
@article {pmid32327918, year = {2014}, author = {Coffman, JM and Bestelmeyer, BT and Kelly, JF and Wright, TF and Schooley, RL}, title = {Restoration Practices Have Positive Effects on Breeding Bird Species of Concern in the Chihuahuan Desert.}, journal = {Restoration ecology}, volume = {22}, number = {3}, pages = {336-344}, pmid = {32327918}, issn = {1526-100X}, abstract = {Woody plant encroachment into grasslands is a global concern. Efforts to restore grasslands often assume that removal of woody plants benefits biodiversity but assumptions are rarely tested. In the Chihuahuan Desert of the Southwestern United States, we tested whether abundances of grassland specialist bird species would be greater in plant communities resulting from treatment with herbicides to remove encroaching shrubs compared with untreated shrub-dominated areas that represented pre-treatment conditions. In 2010, we surveyed breeding birds and vegetation at 16 treated-untreated pairs. In 2011, we expanded the survey effort to 21 treated-untreated pairs, seven unpaired treatment areas, and five reference grassland areas. Vegetation in treatment areas had higher perennial grass foliar and basal cover and lower shrub foliar cover compared with untreated areas. Several regionally declining grassland specialists exhibited higher occurrence and relative abundance in treated areas. A shrubland specialist, however, was associated with untreated areas and may be negatively impacted by shrub removal. Bird community composition differed between treated and untreated areas in both years. Our results indicate that shrub removal can have positive effects on grassland specialist bird species, but that a mosaic of treated and untreated areas might be most beneficial for regional biodiversity.}, }
@article {pmid26955069, year = {2014}, author = {Philip Robertson, G and Gross, KL and Hamilton, SK and Landis, DA and Schmidt, TM and Snapp, SS and Swinton, SM}, title = {Farming for Ecosystem Services: An Ecological Approach to Production Agriculture.}, journal = {Bioscience}, volume = {64}, number = {5}, pages = {404-415}, pmid = {26955069}, issn = {0006-3568}, abstract = {A balanced assessment of ecosystem services provided by agriculture requires a systems-level socioecological understanding of related management practices at local to landscape scales. The results from 25 years of observation and experimentation at the Kellogg Biological Station long-term ecological research site reveal services that could be provided by intensive row-crop ecosystems. In addition to high yields, farms could be readily managed to contribute clean water, biocontrol and other biodiversity benefits, climate stabilization, and long-term soil fertility, thereby helping meet society's need for agriculture that is economically and environmentally sustainable. Midwest farmers-especially those with large farms-appear willing to adopt practices that deliver these services in exchange for payments scaled to management complexity and farmstead benefit. Surveyed citizens appear willing to pay farmers for the delivery of specific services, such as cleaner lakes. A new farming for services paradigm in US agriculture seems feasible and could be environmentally significant.}, }
@article {pmid24499870, year = {2014}, author = {Kaplan, S and Myint, SW and Fan, C and Brazel, AJ}, title = {Quantifying outdoor water consumption of urban land use/land cover: sensitivity to drought.}, journal = {Environmental management}, volume = {53}, number = {4}, pages = {855-864}, pmid = {24499870}, issn = {1432-1009}, mesh = {Arizona ; *Cities ; Conservation of Natural Resources/methods/*statistics &amp; numerical data ; *Droughts ; Humans ; *Models, Biological ; Plant Transpiration/physiology ; Satellite Imagery ; *Water Cycle ; Water Supply/*statistics &amp; numerical data ; Weather ; }, abstract = {Outdoor water use is a key component in arid city water systems for achieving sustainable water use and ensuring water security. Using evapotranspiration (ET) calculations as a proxy for outdoor water consumption, the objectives of this research are to quantify outdoor water consumption of different land use and land cover types, and compare the spatio-temporal variation in water consumption between drought and wet years. An energy balance model was applied to Landsat 5 TM time series images to estimate daily and seasonal ET for the Central Arizona Phoenix Long-Term Ecological Research region (CAP-LTER). Modeled ET estimations were correlated with water use data in 49 parks within CAP-LTER and showed good agreement (r[2] = 0.77), indicating model effectiveness to capture the variations across park water consumption. Seasonally, active agriculture shows high ET (>500 mm) for both wet and dry conditions, while the desert and urban land cover types experienced lower ET during drought (<300 mm). Within urban locales of CAP-LTER, xeric neighborhoods show significant differences from year to year, while mesic neighborhoods retain their ET values (400-500 mm) during drought, implying considerable use of irrigation to sustain their greenness. Considering the potentially limiting water availability of this region in the future due to large population increases and the threat of a warming and drying climate, maintaining large water-consuming, irrigated landscapes challenges sustainable practices of water conservation and the need to provide amenities of this desert area for enhancing quality of life.}, }
@article {pmid24331415, year = {2014}, author = {Demeter, Z and Kanalas, P and Máthé, C and Cseke, K and Szőllősi, E and M-Hamvas, M and Jámbrik, K and Kiss, Z and Mészáros, I}, title = {Osmotic stress responses of individual white oak (Quercus section, Quercus subgenus) genotypes cultured in vitro.}, journal = {Journal of plant physiology}, volume = {171}, number = {2}, pages = {16-24}, doi = {10.1016/j.jplph.2013.09.013}, pmid = {24331415}, issn = {1618-1328}, mesh = {Adaptation, Biological ; Culture Techniques ; Droughts ; Genotype ; *Osmotic Pressure ; Polyethylene Glycols ; Quercus/*physiology ; *Stress, Physiological ; Water/*physiology ; }, abstract = {White oaks (Quercus section, Quercus subgenus) are widely distributed in Europe. Quercus petraea (sessile oak), an economically important species is predicted to be affected by climate change. Q. pubescens (pubescent oak) and Q. virgiliana (Italian pubescent oak) are economically less important, drought tolerant species. Frequent hybridization of white oaks was observed and currently the introgression of Q. pubescens and Q. virgiliana in non-mediterranean regions of Europe has been reported. Our goal was to use tissue cultures established from individual trees of the above taxa and their putative hybrids, all present in the forest stand of Síkfőkút LTER Research Area (NE Hungary) as simple experimental model systems for studying drought/osmotic stress tolerance. Tissue cultures are more suitable models for such studies, than seedlings, because they are genetically identical to the parent plants. Polyethylene glycol (PEG6000) treatments were used for this purpose. The identification of taxa was based on leaf morphological traits and microsatellite analysis and showed that Q. petraea is genetically distinct to all other taxa examined. We established six callus lines of Quercus. As expected, in Q. petraea cultures PEG6000 induced severe loss of fresh weight and the ability to recover after removal of the osmoticum, which was not characteristic for Q. pubescens and Q. virgiliana. Putative hybrids exhibited an intermediate response to osmotic stress. Activity gels showed the increase of single-strand preferring (SSP) nuclease and no significant change of guaiacol-peroxidase activities in drought-sensitive genotypes/cultures and no significant increase of SSP nuclease activities accompanied with increases of guaiacol-peroxidase activities in drought-tolerant ones. This indicates that drought/osmotic stress tolerance is associated to increased capacity of scavenging reactive oxygen species and hence less susceptibility to DNA damage. Our results confirm that tissue cultures of oak are suitable model systems for studying drought/osmotic stress responses.}, }
@article {pmid24263235, year = {2014}, author = {Peters, DP and Yao, J and Browning, D and Rango, A}, title = {Mechanisms of grass response in grasslands and shrublands during dry or wet periods.}, journal = {Oecologia}, volume = {174}, number = {4}, pages = {1323-1334}, pmid = {24263235}, issn = {1432-1939}, mesh = {Biomass ; *Climate ; *Droughts ; Models, Theoretical ; New Mexico ; Poaceae/*growth &amp; development ; *Rain ; Seasons ; Seeds/growth &amp; development ; Soil ; Water ; }, abstract = {Multi-year climatic periods are expected to increase with global change, yet long-term data are often insufficient to document factors leading to ecological responses. We used a suite of long-term datasets (1993-2010) to examine the processes underlying different relationships between aboveground net primary production (ANPP) and precipitation in wet and dry rainfall periods in shrublands and grasslands in the Chihuahuan Desert. We hypothesized that trends in ANPP can be explained by different processes associated with their dominant grasses [Bouteloua eriopoda (grasslands); Sporobolus flexuosus (shrublands)] and with ecosystem properties that influence soil water dynamics with feedbacks to ANPP. We compared datasets on recruitment and growth for 7 years with no trend in precipitation followed by a 4-year drought and 5 consecutive wet years. We integrated these data in a simulation model to examine the importance of positive feedbacks. In grasslands, ANPP was linearly related to precipitation regardless of rainfall period, primarily as a result of stolon recruitment by B. eriopoda. A lag in responses suggests the importance of legacies associated with stolon density. In shrublands, ANPP was only related to rainfall in the wet period when it increased nonlinearly as the number of wet years increased. Seed availability increased in the first wet year, and seedling establishment occurred 2-4 years later. Increases in biomass, litter and simulated transpiration beginning in the third year corresponded with increases in ANPP. Understanding the processes underlying ecosystem dynamics in multi-year dry or wet periods is expected to improve predictions under directional increases or decreases in rainfall.}, }
@article {pmid24132996, year = {2014}, author = {Dirnböck, T and Grandin, U and Bernhardt-Römermann, M and Beudert, B and Canullo, R and Forsius, M and Grabner, MT and Holmberg, M and Kleemola, S and Lundin, L and Mirtl, M and Neumann, M and Pompei, E and Salemaa, M and Starlinger, F and Staszewski, T and Uziębło, AK}, title = {Forest floor vegetation response to nitrogen deposition in Europe.}, journal = {Global change biology}, volume = {20}, number = {2}, pages = {429-440}, doi = {10.1111/gcb.12440}, pmid = {24132996}, issn = {1365-2486}, mesh = {*Biodiversity ; *Ecosystem ; Europe ; *Eutrophication ; Nitrogen/*metabolism ; *Plant Physiological Phenomena ; }, abstract = {Chronic nitrogen (N) deposition is a threat to biodiversity that results from the eutrophication of ecosystems. We studied long-term monitoring data from 28 forest sites with a total of 1,335 permanent forest floor vegetation plots from northern Fennoscandia to southern Italy to analyse temporal trends in vascular plant species cover and diversity. We found that the cover of plant species which prefer nutrient-poor soils (oligotrophic species) decreased the more the measured N deposition exceeded the empirical critical load (CL) for eutrophication effects (P = 0.002). Although species preferring nutrient-rich sites (eutrophic species) did not experience a significantly increase in cover (P = 0.440), in comparison to oligotrophic species they had a marginally higher proportion among new occurring species (P = 0.091). The observed gradual replacement of oligotrophic species by eutrophic species as a response to N deposition seems to be a general pattern, as it was consistent on the European scale. Contrary to species cover changes, neither the decrease in species richness nor of homogeneity correlated with nitrogen CL exceedance (ExCLemp N). We assume that the lack of diversity changes resulted from the restricted time period of our observations. Although existing habitat-specific empirical CL still hold some uncertainty, we exemplify that they are useful indicators for the sensitivity of forest floor vegetation to N deposition.}, }
@article {pmid27007318, year = {2013}, author = {Percopo, I and Siano, R and Rossi, R and Soprano, V and Sarno, D and Zingone, A}, title = {A new potentially toxic Azadinium species (Dinophyceae) from the Mediterranean Sea, A. dexteroporum sp. nov.}, journal = {Journal of phycology}, volume = {49}, number = {5}, pages = {950-966}, doi = {10.1111/jpy.12104}, pmid = {27007318}, issn = {0022-3646}, abstract = {A new photosynthetic planktonic marine dinoflagellate, Azadinium dexteroporum sp. nov., is described from the Gulf of Naples (South Tyrrhenian Sea, Mediterranean Sea). The plate formula of the species, Po, cp, X, 4', 3a, 6″, 6C, 5?S, 6‴ and 2″″, is typical for this recently described genus. Azadinium dexteroporum is the smallest rep-resentative of the genus (8.5 μm average length, 6.2 μm average width) and shares the presence of a small antapical spine with the type species A. spinosum and with A. polongum. However, it differs from all other Azadinium species for the markedly asymmetrical Po plate and the position of the ventral pore, which is located at the right posterior end of the Po plate. Another peculiarity of A. dexteroporum is the pronounced concavity of the second intercalary plate (2a), which appears collapsed with respect to the other plates. Phylogenetic analyses based on the large subunit 28S rDNA (D1/D2) and the internal transcribed spacer (ITS rDNA) support the attribution of A. dexteroporum to the genus Azadinium and its separation from the other known species. LC/MS-TOF analysis shows that Azadinium dex-teroporum produces azaspiracids in low amounts. Some of them have the same molecular weight as known compounds such as azaspiracid-3 and -7 and Compound 3 from Amphidoma languida, as well as similar fragmentation patterns in some cases. This is the first finding of a species producing azapiracids in the Mediterranean Sea.}, }
@article {pmid27007316, year = {2013}, author = {Nanjappa, D and Kooistra, WH and Zingone, A}, title = {A reappraisal of the genus Leptocylindrus (Bacillariophyta), with the addition of three species and the erection of Tenuicylindrus gen. nov.}, journal = {Journal of phycology}, volume = {49}, number = {5}, pages = {917-936}, doi = {10.1111/jpy.12102}, pmid = {27007316}, issn = {0022-3646}, abstract = {Centric diatoms of the genus Leptocylindrus are common in the marine plankton worldwide. Only two species, L. danicus Cleve and L. minimus Gran, so far clearly belong to this genus, whose diversity has not been fully investigated. We investigated frustule and spore morphology as well as three nuclear- and three plastid-encoded markers of 85 Leptocylindrus strains from the Gulf of Naples, and one from the Atlantic US. The strains grouped into five molecularly distinct species with different levels of morphological differentiation. Two species matched the description of L. danicus and produced similar spores but differed in morphometric characters and sub-central pore position, supporting the description of L. hargravesii Nanjappa and Zingone as a distinct species. Leptocylindrus danicus var. apora French III and Hargraves, lacking a sub-central pore and not forming spores, was raised to the species level as L. aporus (French III and Hargraves) Nanjappa and Zingone. A fourth species with convex valves was described as L. convexus Nanjappa and Zingone. The fifth species matched the description of L. belgicus Meunier, considered as synonym of L. minimus. However, ultrastructural differences from all other Leptocylindrus supported the erection of the genus Tenuicylindrus Nanjappa and Zingone with T. belgicus (Meunier) Nanjappa and Zingone as type species. None of the sequences matched the L. minimus sequence in GenBank. The species analyzed showed different or partially overlapping seasonal distributions. Despite the addition of the new taxa, the ancient diatom lineage of the Leptocylindraceae shows a relative species poorness and considerable morphological stasis.}, }
@article {pmid24041605, year = {2014}, author = {Jandl, R and Rodeghiero, M and Martinez, C and Cotrufo, MF and Bampa, F and van Wesemael, B and Harrison, RB and Guerrini, IA and Richter, DD and Rustad, L and Lorenz, K and Chabbi, A and Miglietta, F}, title = {Current status, uncertainty and future needs in soil organic carbon monitoring.}, journal = {The Science of the total environment}, volume = {468-469}, number = {}, pages = {376-383}, doi = {10.1016/j.scitotenv.2013.08.026}, pmid = {24041605}, issn = {1879-1026}, mesh = {Carbon/*analysis ; Chemistry Techniques, Analytical ; Conservation of Natural Resources/*statistics &amp; numerical data ; Ecological Parameter Monitoring/*methods ; Soil/*chemistry ; Time Factors ; Uncertainty ; }, abstract = {Increasing human demands on soil-derived ecosystem services requires reliable data on global soil resources for sustainable development. The soil organic carbon (SOC) pool is a key indicator of soil quality as it affects essential biological, chemical and physical soil functions such as nutrient cycling, pesticide and water retention, and soil structure maintenance. However, information on the SOC pool, and its temporal and spatial dynamics is unbalanced. Even in well-studied regions with a pronounced interest in environmental issues information on soil carbon (C) is inconsistent. Several activities for the compilation of global soil C data are under way. However, different approaches for soil sampling and chemical analyses make even regional comparisons highly uncertain. Often, the procedures used so far have not allowed the reliable estimation of the total SOC pool, partly because the available knowledge is focused on not clearly defined upper soil horizons and the contribution of subsoil to SOC stocks has been less considered. Even more difficult is quantifying SOC pool changes over time. SOC consists of variable amounts of labile and recalcitrant molecules of plant, and microbial and animal origin that are often operationally defined. A comprehensively active soil expert community needs to agree on protocols of soil surveying and lab procedures towards reliable SOC pool estimates. Already established long-term ecological research sites, where SOC changes are quantified and the underlying mechanisms are investigated, are potentially the backbones for regional, national, and international SOC monitoring programs.}, }
@article {pmid24023770, year = {2013}, author = {Jacob, M and Soltwedel, T and Boetius, A and Ramette, A}, title = {Biogeography of Deep-sea benthic bacteria at regional scale (LTER HAUSGARTEN, Fram Strait, Arctic).}, journal = {PloS one}, volume = {8}, number = {9}, pages = {e72779}, pmid = {24023770}, issn = {1932-6203}, mesh = {Arctic Regions ; *Bacteria ; Biodiversity ; Ecosystem ; Geologic Sediments/microbiology ; Oceans and Seas ; Water Microbiology ; }, abstract = {Knowledge on spatial scales of the distribution of deep-sea life is still sparse, but highly relevant to the understanding of dispersal, habitat ranges and ecological processes. We examined regional spatial distribution patterns of the benthic bacterial community and covarying environmental parameters such as water depth, biomass and energy availability at the Arctic Long-Term Ecological Research (LTER) site HAUSGARTEN (Eastern Fram Strait). Samples from 13 stations were retrieved from a bathymetric (1,284-3,535 m water depth, 54 km in length) and a latitudinal transect (∼ 2,500 m water depth; 123 km in length). 454 massively parallel tag sequencing (MPTS) and automated ribosomal intergenic spacer analysis (ARISA) were combined to describe both abundant and rare types shaping the bacterial community. This spatial sampling scheme allowed detection of up to 99% of the estimated richness on phylum and class levels. At the resolution of operational taxonomic units (97% sequence identity; OTU3%) only 36% of the Chao1 estimated richness was recovered, indicating a high diversity, mostly due to rare types (62% of all OTU3%). Accordingly, a high turnover of the bacterial community was also observed between any two sampling stations (average replacement of 79% of OTU3%), yet no direct correlation with spatial distance was observed within the region. Bacterial community composition and structure differed significantly with increasing water depth along the bathymetric transect. The relative sequence abundance of Verrucomicrobia and Planctomycetes decreased significantly with water depth, and that of Deferribacteres increased. Energy availability, estimated from phytodetrital pigment concentrations in the sediments, partly explained the variation in community structure. Overall, this study indicates a high proportion of unique bacterial types on relatively small spatial scales (tens of kilometers), and supports the sampling design of the LTER site HAUSGARTEN to study bacterial community shifts in this rapidly changing area of the world's oceans.}, }
@article {pmid23734484, year = {2013}, author = {Burke, IC and Bontti, EE and Barrett, JE and Lowe, PN and Lauenroth, WK and Riggle, R}, title = {Impact of labile and recalcitrant carbon treatments on available nitrogen and plant communities in a semiarid ecosystem.}, journal = {Ecological applications : a publication of the Ecological Society of America}, volume = {23}, number = {3}, pages = {537-545}, doi = {10.1890/12-0015.1}, pmid = {23734484}, issn = {1051-0761}, mesh = {Carbon/*pharmacology ; Colorado ; *Ecosystem ; Nitrogen/*chemistry/metabolism ; Plants/classification/*drug effects ; Species Specificity ; Time Factors ; }, abstract = {In a 10-year study, we assessed the influence of five carbon (C) treatments on the labile C and nitrogen (N) pools of historically N-enriched plots on the Shortgrass Steppe Long Term Ecological Research site located in northeastern Colorado. For eight years, we applied sawdust, sugar, industrial lignin, sawdust + sugar, and lignin + sugar to plots that had received N and water additions in the early 1970s. Previous work showed that past water and N additions altered plant species composition and enhanced rates of nutrient cycling; these effects were still apparent 25 years later. We hypothesized that labile C amendments would stimulate microbial activity and suppress rates of N mineralization, whereas complex forms of carbon (sawdust and lignin) could enhance humification and lead to longer-term reductions in N availability. Results indicated that, of the five carbon treatments, sugar, sawdust, and sawdust + sugar suppressed N availability, with sawdust + sugar being the most effective treatment to reduce N availability. The year after treatments stopped, N availability remained less in the sawdust + sugar treatment plots than in the high-N control plots. Three years after treatments ended, reductions in N availability were smaller (40-60%). Our results suggest that highly labile forms of carbon generate strong short-term N sinks, but these effects dissipate within one year of application, and that more recalcitrant forms reduce N longer. Sawdust + sugar was the most effective treatment to decrease exotic species canopy cover and increase native species density over the long term. Labile carbon had neither short- nor long-term effects on exotic species. Even though the organic amendments did not contribute to recovery of the dominant native species Bouteloua gracilis, they were effective in increasing another native species, Carex eleocharis. These results indicate that organic amendments may be a useful tool for restoring some native species in the shortgrass steppe, though not all.}, }
@article {pmid23594357, year = {2013}, author = {Zhang, L and Dickhut, R and DeMaster, D and Pohl, K and Lohmann, R}, title = {Organochlorine pollutants in Western Antarctic Peninsula sediments and benthic deposit feeders.}, journal = {Environmental science &amp; technology}, volume = {47}, number = {11}, pages = {5643-5651}, doi = {10.1021/es303553h}, pmid = {23594357}, issn = {1520-5851}, mesh = {Animals ; Antarctic Regions ; Environmental Monitoring/methods ; Euphausiacea ; *Food Chain ; Geologic Sediments/*analysis ; Holothuria/physiology ; Hydrocarbons, Chlorinated/*analysis ; Pesticides/analysis ; Polychlorinated Biphenyls/analysis ; Soot ; Water Pollutants, Chemical/*analysis ; }, abstract = {Sediments and benthic deposit feeding holothurians were collected near the Palmer Long Term Ecological Research grid during the austral winter of 2008. Polychlorinated biphenyls (PCBs) and organochlorine pesticides (OCPs) were measured in Western Antarctic Peninsula continental shelf sediments, porewater, and benthic biota. Concentrations and fluxes in sediments decreased sharply away from the tip of the peninsula toward its interior. Sedimentary PCB fluxes were an order of magnitude lower than reported elsewhere, supporting the notion of a pristiner Antarctic environment. Hexa-chlorinated biphenyls dominated (40-100%) the PCB profiles in the sediments, while trichlorinated biphenyl 28 was the most abundant PCB congener in the porewater. PCB and OCP concentrations in holothurians were comparable to concentrations in other low trophic level biota in the Antarctic food web (i.e., krill). The partitioning of PCBs and OCPs between the sediments and porewater can be explained by a dual-mode model, which included both organic carbon and black carbon as partitioning media. Alternatively, a simpler one-parameter prediction assuming coal tar-like organic carbon performed equally well in explaining porewater concentrations The majorities of PCBs (63-94%) in the Western Antarctic Peninsula sediments were bound to black carbon or recalcitrant tar-like organic carbon, thereby lowering porewater concentrations. PCBs and OCPs in the holothurians were in equilibrium with those in the porewater.}, }
@article {pmid23342531, year = {2012}, author = {Simões, NR and Lansac-Tôha, FA and Velho, LF and Bonecker, CC}, title = {Intra and inter-annual structure of zooplankton communities in floodplain lakes: a long-term ecological research study.}, journal = {Revista de biologia tropical}, volume = {60}, number = {4}, pages = {1819-1836}, doi = {10.15517/rbt.v60i4.2183}, pmid = {23342531}, issn = {0034-7744}, mesh = {Animals ; Bayes Theorem ; Brazil ; *Ecosystem ; *Lakes ; Population Density ; Population Dynamics ; Seasons ; Water Movements ; Zooplankton/*physiology ; }, abstract = {Water flow management has significantly changed the natural dynamic of floods, which are responsible for the structure and dynamic of aquatic communities in river-floodplain systems. With the aim to elaborate a conceptual framework that describes the main ecological factors associated with zooplankton community structure in the Upper Paraná River, we investigated the mechanisms that regulate the communities structure and their response to inter-annual and hydro-sedimentological variations in the floodplain and the biological factors associated with species abundance in those communities. For this we conducted samplings every six months (potamophase in March and limnophase in September) to characterize intra and inter-annual variations in community structure between 2000 and 2008. The intra-annual differences on the species richness, abundance, Shannon diversity index, and evenness, were conducted using Bayesian procedures to show probabilistic predictions of the data fit to main variation sources. Non-metric multi-dimensional scaling (NMDS), multi-response permutation procedure (MRPP), and indicator species analysis (IndVal) were run to assess and characterize the seasonality of the community structure. During high water (potamophase), hydrologic connectivity favoured exchange and dispersal of species in some lakes, increasing local diversity; during low water (limnophase), higher local productivity favoured opportunistic taxa, increasing species dominance and decreasing local diversity. Food resources and density of small-size fish were biological factors associated with the seasonal dynamic of the zooplankton community; these factors were dependent on hydrosedimentological phase (potamophase or limnophase). Water levels and limnological modifications related to water flow management have promoted replacement and impoverishment of aquatic biota in affected lakes and have indicated the ecological importance of a natural dynamic flood, which displays regular flood pulses. The conceptual model presented encompassed interactions between diverse environmental variables to more understandable mechanisms of the main sources of community variation.}, }
@article {pmid23216915, year = {2013}, author = {Bestelmeyer, BT and Duniway, MC and James, DK and Burkett, LM and Havstad, KM}, title = {A test of critical thresholds and their indicators in a desertification-prone ecosystem: more resilience than we thought.}, journal = {Ecology letters}, volume = {16}, number = {3}, pages = {339-345}, doi = {10.1111/ele.12045}, pmid = {23216915}, issn = {1461-0248}, mesh = {Animals ; Conservation of Natural Resources ; *Desert Climate ; *Ecosystem ; *Herbivory ; Models, Biological ; Poaceae/*growth &amp; development ; Prosopis/*growth &amp; development ; }, abstract = {Theoretical models predict that drylands can cross critical thresholds, but experimental manipulations to evaluate them are non-existent. We used a long-term (13-year) pulse-perturbation experiment featuring heavy grazing and shrub removal to determine if critical thresholds and their determinants can be demonstrated in Chihuahuan Desert grasslands. We asked if cover values or patch-size metrics could predict vegetation recovery, supporting their use as early-warning indicators. We found that season of grazing, but not the presence of competing shrubs, mediated the severity of grazing impacts on dominant grasses. Recovery occurred at the same rate irrespective of grazing history, suggesting that critical thresholds were not crossed, even at low cover levels. Grass cover, but not patch size metrics, predicted variation in recovery rates. Some transition-prone ecosystems are surprisingly resilient; management of grazing impacts and simple cover measurements can be used to avert undesired transitions and initiate restoration.}, }
@article {pmid23185605, year = {2012}, author = {Ward, DF}, title = {More than just records: analysing natural history collections for biodiversity planning.}, journal = {PloS one}, volume = {7}, number = {11}, pages = {e50346}, pmid = {23185605}, issn = {1932-6203}, mesh = {Animals ; *Biodiversity ; Biological Specimen Banks/*standards/statistics &amp; numerical data ; Climate ; Conservation of Natural Resources ; Ecosystem ; Hymenoptera/*classification ; Natural History ; New Zealand ; Phylogeography ; Records/*standards/statistics &amp; numerical data ; Time Factors ; }, abstract = {Natural History Collections (NHCs) play a central role as sources of data for biodiversity and conservation. Yet, few NHCs have examined whether the data they contain is adequately representative of local biodiversity. I examined over 15,000 databased records of Hymenoptera from 1435 locations across New Zealand collected over the past 90 years. These records are assessed in terms of their geographical, temporal, and environmental coverage across New Zealand. Results showed that the spatial coverage of records was significantly biased, with the top four areas contributing over 51% of all records. Temporal biases were also evident, with a large proportion (40%) of records collected within a short time period. The lack of repeat visits to specific locations indicated that the current set of NHC records would be of limited use for long-term ecological research. Consequently, analyses and interpretation of historical data, for example, shifts in community composition, would be limited. However, in general, NHC records provided good coverage of the diversity of New Zealand habitats and climatic environments, although fewer NHC records were represented at cooler temperatures (<5°C) and the highest rainfalls (>5000 mm/yr). Analyses of NHCs can be greatly enhanced by using simple techniques that examine collection records in terms of environmental and geographical space. NHCs that initiate a systematic sampling strategy will provide higher quality data for biodiversity research than ad hoc or point samples, as is currently the norm. Although NHCs provide a rich source of information they could be far better utilised in a range of large-scale ecological and conservation studies.}, }
@article {pmid22990818, year = {2012}, author = {Brandão, LP and Fajardo, T and Eskinazi-Sant'anna, E and Brito, S and Maia-Barbosa, P}, title = {Fluctuations of the population of Daphnia laevis Birge 1878: a six-year study in a tropical lake.}, journal = {Brazilian journal of biology = Revista brasleira de biologia}, volume = {72}, number = {3}, pages = {479-487}, doi = {10.1590/s1519-69842012000300010}, pmid = {22990818}, issn = {1678-4375}, mesh = {Animals ; Brazil ; Daphnia/*physiology ; Environmental Monitoring/*methods ; Lakes/*analysis ; Population Density ; Population Dynamics ; Seasons ; Tropical Climate ; }, abstract = {The fluctuation of the population of Daphnia laevis in Lake Jacaré (Middle River Doce, Minas Gerais) was monitored monthly (at one point in the limnetic region) for six years (2002-2007) as part of the Program of Long-Term Ecological Research (LTER/UFMG). The following parameters were also monitored: water temperature, pH, electrical conductivity, dissolved oxygen, chlorophyll a, total phosphorus, phosphate, total nitrogen, nitrate, nitrite, ammonia, and densities of Chaoborus and ephippia of Daphnia laevis in the sediment. A seasonal pattern was observed in the fluctuation of D. laevis, with higher densities recorded during periods of circulation (May-August). A significant correlation was found between the density of D. laevis and temperature (r = -0.47, p = 0.0001), chlorophyll-a (r = -0.32, p = 0.016) and indicators of the lake's trophic status (total phosphorus, r = 0.32, p = 0.007 and trophic state, r = 0.36, p = 0.003), as well as Chaoborus density (r = 0.43 and p = 0.002). These results indicate that changes in the physical and chemical characteristics of the water related with stratification and circulation of the lake may have a direct (temperature, total phosphorous) or an indirect (food availability, presence of predators, ephippia eclosion) influence on the fluctuation of the D. laevis population.}, }
@article {pmid22611866, year = {2012}, author = {Metson, GS and Hale, RL and Iwaniec, DM and Cook, EM and Corman, JR and Galletti, CS and Childers, DL}, title = {Phosphorus in Phoenix: a budget and spatial representation of phosphorus in an urban ecosystem.}, journal = {Ecological applications : a publication of the Ecological Society of America}, volume = {22}, number = {2}, pages = {705-721}, doi = {10.1890/11-0865.1}, pmid = {22611866}, issn = {1051-0761}, mesh = {Arizona ; Cities ; Computer Simulation ; *Ecosystem ; Environmental Pollutants/*chemistry ; Models, Theoretical ; Phosphorus/*chemistry ; }, abstract = {As urban environments dominate the landscape, we need to examine how limiting nutrients such as phosphorus (P) cycle in these novel ecosystems. Sustainable management of P resources is necessary to ensure global food security and to minimize freshwater pollution. We used a spatially explicit budget to quantify the pools and fluxes of P in the Greater Phoenix Area in Arizona, USA, using the boundaries of the Central Arizona-Phoenix Long-Term Ecological Research site. Inputs were dominated by direct imports of food and fertilizer for local agriculture, while most outputs were small, including water, crops, and material destined for recycling. Internally, fluxes were dominated by transfers of food and feed from local agriculture and the recycling of human and animal excretion. Spatial correction of P dynamics across the city showed that human density and associated infrastructure, especially asphalt, dominated the distribution of P pools across the landscape. Phosphorus fluxes were dominated by agricultural production, with agricultural soils accumulating P. Human features (infrastructure, technology, and waste management decisions) and biophysical characteristics (soil properties, water fluxes, and storage) mediated P dynamics in Phoenix. P cycling was most notably affected by water management practices that conserve and recycle water, preventing the loss of waterborne P from the ecosystem. P is not intentionally managed, and as a result, changes in land use and demographics, particularly increased urbanization and declining agriculture, may lead to increased losses of P from this system. We suggest that city managers should minimize cross-boundary fluxes of P to the city. Reduced P fluxes may be accomplished through more efficient recycling of waste, therefore decreasing dependence on external nonrenewable P resources and minimizing aquatic pollution. Our spatial approach and consideration of both pools and fluxes across a heterogeneous urban ecosystem increases the utility of nutrient budgets for city managers. Our budget explicitly links processes that affect P cycling across space with the management of other resources (e.g., water). A holistic management strategy that deliberately couples the management of P and other resources should be a priority for cities in achieving urban sustainability.}, }
@article {pmid22534409, year = {2012}, author = {Liu, PJ and Meng, PJ and Liu, LL and Wang, JT and Leu, MY}, title = {Impacts of human activities on coral reef ecosystems of southern Taiwan: a long-term study.}, journal = {Marine pollution bulletin}, volume = {64}, number = {6}, pages = {1129-1135}, doi = {10.1016/j.marpolbul.2012.03.031}, pmid = {22534409}, issn = {1879-3363}, mesh = {Animals ; Anthozoa/*drug effects/growth &amp; development ; Bays/chemistry ; Conservation of Natural Resources ; *Coral Reefs ; Environmental Monitoring ; Humans ; Seawater/chemistry ; Seaweed/growth &amp; development ; Sewage/analysis ; Taiwan ; Water Pollutants/*analysis ; Water Pollution/statistics &amp; numerical data ; }, abstract = {In July 2001, the National Museum of Marine Biology and Aquarium, co-sponsored by the Kenting National Park Headquarters and Taiwan's National Science Council, launched a Long-Term Ecological Research (LTER) program to monitor anthropogenic impacts on the ecosystems of southern Taiwan, specifically the coral reefs of Kenting National Park (KNP), which are facing an increasing amount of anthropogenic pressure. We found that the seawater of the reef flats along Nanwan Bay, Taiwan's southernmost embayment, was polluted by sewage discharge at certain monitoring stations. Furthermore, the consequently higher nutrient and suspended sediment levels had led to algal blooms and sediment smothering of shallow water corals at some sampling sites. Finally, our results show that, in addition to this influx of anthropogenically-derived sewage, increasing tourist numbers are correlated with decreasing shallow water coral cover, highlighting the urgency of a more proactive management plan for KNP's coral reefs.}, }
@article {pmid22531931, year = {2012}, author = {Silaghi, D and Badea, O}, title = {Monitoring of ozone in selected forest ecosystems in Southern Carpathian and Romanian Intensive Monitoring Network (level II).}, journal = {Journal of environmental monitoring : JEM}, volume = {14}, number = {6}, pages = {1710-1717}, doi = {10.1039/c2em30022b}, pmid = {22531931}, issn = {1464-0333}, mesh = {Air Pollutants/*analysis ; Air Pollution/statistics &amp; numerical data ; Ammonia/analysis ; Ecosystem ; Environmental Monitoring ; Nitrogen Oxides/analysis ; Ozone/*analysis ; Romania ; Seasons ; Sulfur Dioxide/analysis ; *Trees ; }, abstract = {In the Romanian forest ecosystems, the first measurements of ambient ozone (O(3)) concentrations started in 1997 in 6 of 26 locations established in a trans-Carpathian Network. Furthermore, three additional ozone and other phytotoxic pollutant (NO(x), SO(2) and NH(3)) monitoring networks were installed in 2000 in Retezat (11 locations) and during 2006-2009 in Bucegi-Piatra Craiului (22 locations) LTER Sites. Since 2007, in four Intensive Forest Monitoring plots (level II), measurements of ozone concentrations were developed. Measurements were made using the Ogawa® passive sampler system during the growing season (April to October). In the Bucegi LTER Site, the seasonal means of 42.5-47.2 ppb in 2006 and 2008 were higher than those determined in the Carpathian Network in the 1997-1999 period (39.0-42.0 ppb), while the 2009 mean of 40.0 ppb was in the range of these values. The O(3) levels were slightly higher than those measured in Retezat LTER Site. In the Intensive Forest Monitoring Network (level II), no significant differences in ozone concentrations between individual core plots were noticed. The seasonal means for each plot range between 36.8 and 49.8 ppb in 2008. An influence of ozone concentrations on crown condition and tree volume growth was not determined.}, }
@article {pmid22234644, year = {2012}, author = {Badea, O and Bytnerowicz, A and Silaghi, D and Neagu, S and Barbu, I and Iacoban, C and Iacob, C and Guiman, G and Preda, E and Seceleanu, I and Oneata, M and Dumitru, I and Huber, V and Iuncu, H and Dinca, L and Leca, S and Taut, I}, title = {Status of the Southern Carpathian forests in the long-term ecological research network.}, journal = {Environmental monitoring and assessment}, volume = {184}, number = {12}, pages = {7491-7515}, pmid = {22234644}, issn = {1573-2959}, mesh = {Acid Rain/analysis ; Air Pollution/*analysis/statistics &amp; numerical data ; Biodiversity ; Ecology ; *Ecosystem ; *Environmental Monitoring ; Nitrogen/analysis ; Ozone/analysis ; Phosphorus/analysis ; Romania ; Trees/classification/*growth &amp; development ; }, abstract = {Air pollution, bulk precipitation, throughfall, soil condition, foliar nutrients, as well as forest health and growth were studied in 2006-2009 in a long-term ecological research (LTER) network in the Bucegi Mountains, Romania. Ozone (O(3)) was high indicating a potential for phytotoxicity. Ammonia (NH(3)) concentrations rose to levels that could contribute to deposition of nutritional nitrogen (N) and could affect biodiversity changes. Higher that 50% contribution of acidic rain (pH < 5.5) contributed to increased acidity of forest soils. Foliar N concentrations for Norway spruce (Picea abies), Silver fir (Abies alba), Scots pine (Pinus sylvestris), and European beech (Fagus sylvatica) were normal, phosphorus (P) was high, while those of potassium (K), magnesium (Mg), and especially of manganese (Mn) were significantly below the typical European or Carpathian region levels. The observed nutritional imbalance could have negative effects on forest trees. Health of forests was moderately affected, with damaged trees (crown defoliation >25%) higher than 30%. The observed crown damage was accompanied by the annual volume losses for the entire research forest area up to 25.4%. High diversity and evenness specific to the stand type's structures and local climate conditions were observed within the herbaceous layer, indicating that biodiversity of the vascular plant communities was not compromised.}, }
@article {pmid22180812, year = {2011}, author = {Deangelis, KM and D'Haeseleer, P and Chivian, D and Fortney, JL and Khudyakov, J and Simmons, B and Woo, H and Arkin, AP and Davenport, KW and Goodwin, L and Chen, A and Ivanova, N and Kyrpides, NC and Mavromatis, K and Woyke, T and Hazen, TC}, title = {Complete genome sequence of "Enterobacter lignolyticus" SCF1.}, journal = {Standards in genomic sciences}, volume = {5}, number = {1}, pages = {69-85}, pmid = {22180812}, issn = {1944-3277}, abstract = {In an effort to discover anaerobic bacteria capable of lignin degradation, we isolated "Enterobacter lignolyticus" SCF1 on minimal media with alkali lignin as the sole source of carbon. This organism was isolated anaerobically from tropical forest soils collected from the Short Cloud Forest site in the El Yunque National Forest in Puerto Rico, USA, part of the Luquillo Long-Term Ecological Research Station. At this site, the soils experience strong fluctuations in redox potential and are net methane producers. Because of its ability to grow on lignin anaerobically, we sequenced the genome. The genome of "E. lignolyticus" SCF1 is 4.81 Mbp with no detected plasmids, and includes a relatively small arsenal of lignocellulolytic carbohydrate active enzymes. Lignin degradation was observed in culture, and the genome revealed two putative laccases, a putative peroxidase, and a complete 4-hydroxyphenylacetate degradation pathway encoded in a single gene cluster.}, }
@article {pmid22123520, year = {2012}, author = {Zhang, M and Duan, H and Shi, X and Yu, Y and Kong, F}, title = {Contributions of meteorology to the phenology of cyanobacterial blooms: implications for future climate change.}, journal = {Water research}, volume = {46}, number = {2}, pages = {442-452}, doi = {10.1016/j.watres.2011.11.013}, pmid = {22123520}, issn = {1879-2448}, mesh = {China ; *Climate Change ; Cyanobacteria/growth &amp; development/*physiology ; Environmental Monitoring/*methods ; *Eutrophication ; Lakes/microbiology ; Meteorology ; Regression Analysis ; Seasons ; Spacecraft ; Time Factors ; }, abstract = {Cyanobacterial blooms are often a result of eutrophication. Recently, however, their expansion has also been found to be associated with changes in climate. To elucidate the effects of climatic variables on the expansion of cyanobacterial blooms in Taihu, China, we analyzed the relationships between climatic variables and bloom events which were retrieved by satellite images. We then assessed the contribution of each climate variable to the phenology of blooms using multiple regression models. Our study demonstrates that retrieving ecological information from satellite images is meritorious for large-scale and long-term ecological research in freshwater ecosystems. Our results show that the phenological changes of blooms at an inter-annual scale are strongly linked to climate in Taihu during the past 23 yr. Cyanobacterial blooms occur earlier and last longer with the increase of temperature, sunshine hours, and global radiation and the decrease of wind speed. Furthermore, the duration increases when the daily averages of maximum, mean, and minimum temperature each exceed 20.3 °C, 16.7 °C, and 13.7 °C, respectively. Among these factors, sunshine hours and wind speed are the primary contributors to the onset of the blooms, explaining 84.6% of their variability over the past 23 yr. These factors are also good predictors of the variability in the duration of annual blooms and determined 58.9% of the variability in this parameter. Our results indicate that when nutrients are in sufficiently high quantities to sustain the formation of cyanobacterial blooms, climatic variables become crucial in predicting cyanobacterial bloom events. Climate changes should be considered when we evaluate how much the amount of nutrients should be reduced in Taihu for lake management.}, }
@article {pmid21941767, year = {2011}, author = {Zhu, GR and Porter, JH and Xu, XG}, title = {[Thirty years of US long-term ecological research: characteristics, results, and lessons learned of--taking the Virginia Coast Reserve as an example].}, journal = {Ying yong sheng tai xue bao = The journal of applied ecology}, volume = {22}, number = {6}, pages = {1615-1622}, pmid = {21941767}, issn = {1001-9332}, mesh = {Data Collection/methods ; Ecology/*methods/*trends ; *Ecosystem ; Environmental Exposure/prevention &amp; control ; Environmental Health ; Environmental Monitoring ; Research Design ; Time Factors ; United States ; }, abstract = {In order to observe and understand long-term and large-scale ecological changes, the US National Science Foundation initiated a Long-Term Ecological Research (LTER) program in 1980. Over the past 30 years, the US LTER program has achieved advances in ecological and social science research, and in the development of site-based research infrastructure. This paper attributed the success of the program to five characteristics, i.e., 1) consistency of research topics and data across the network, 2) long-term time scale of both the research and the program, 3) flexibility in research content and funding procedures, 4) growth of LTER to include international partners, new disciplines such as social science, advanced research methods, and cooperation among sites, and 5) sharing of data and educational resources. The Virginia Coast Reserve LTER site was taken as an example to illustrate how the US LTER works at site level. Some suggestions were made on the China long-term ecological research, including strengthening institution construction, improving network and inter-site cooperation, emphasizing data quality, management, and sharing, reinforcing multidisciplinary cooperation, and expanding public influence.}, }
@article {pmid21900967, year = {2012}, author = {McCliment, EA and Nelson, CE and Carlson, CA and Alldredge, AL and Witting, J and Amaral-Zettler, LA}, title = {An all-taxon microbial inventory of the Moorea coral reef ecosystem.}, journal = {The ISME journal}, volume = {6}, number = {2}, pages = {309-319}, pmid = {21900967}, issn = {1751-7370}, mesh = {Archaea/classification/genetics/*physiology ; Bacteria/classification/genetics ; *Bacterial Physiological Phenomena ; Biodiversity ; *Coral Reefs ; DNA, Ribosomal/genetics ; *Ecosystem ; Eukaryota/classification/genetics/*physiology ; Oceans and Seas ; Polynesia ; RNA, Ribosomal, 16S/genetics ; Seasons ; }, abstract = {The Moorea Coral Reef Long Term Ecological Research (LTER) Site (17.50°S, 149.83°W) comprises the fringe of coral reefs and lagoons surrounding the volcanic island of Moorea in the Society Islands of French Polynesia. As part of our Microbial Inventory Research Across Diverse Aquatic LTERS biodiversity inventory project, we characterized microbial community composition across all three domains of life using amplicon pyrosequencing of the V6 (bacterial and archaeal) and V9 (eukaryotic) hypervariable regions of small-subunit ribosomal RNA genes. Our survey spanned eight locations along a 130-km transect from the reef lagoon to the open ocean to examine changes in communities along inshore to offshore gradients. Our results illustrate consistent community differentiation between inshore and offshore ecosystems across all three domains, with greater richness in all domains in the reef-associated habitats. Bacterial communities were more homogenous among open ocean sites spanning >100 km than among inshore sites separated by <1 km, whereas eukaryotic communities varied more offshore than inshore, and archaea showed more equal levels of dissimilarity among subhabitats. We identified signature communities representative of specific geographic and geochemical milieu, and characterized co-occurrence patterns of specific microbial taxa within the inshore ecosystem including several bacterial groups that persist in geographical niches across time. Bacterial and archaeal communities were dominated by few abundant taxa but spatial patterning was consistent through time and space in both rare and abundant communities. This is the first in-depth inventory analysis of biogeographic variation of all three microbial domains within a coral reef ecosystem.}, }
@article {pmid21830824, year = {2011}, author = {Kaushal, SS and Groffman, PM and Band, LE and Elliott, EM and Shields, CA and Kendall, C}, title = {Tracking nonpoint source nitrogen pollution in human-impacted watersheds.}, journal = {Environmental science &amp; technology}, volume = {45}, number = {19}, pages = {8225-8232}, doi = {10.1021/es200779e}, pmid = {21830824}, issn = {1520-5851}, mesh = {Agriculture ; Atmosphere/chemistry ; Baltimore ; Cities ; Cyclonic Storms ; Ecosystem ; Humans ; Models, Chemical ; Nitrates/analysis ; Nitrogen/*analysis ; Rural Population ; Water/*chemistry ; Water Pollutants, Chemical/*analysis ; Water Pollution/*analysis ; }, abstract = {Nonpoint source nitrogen (N) pollution is a leading contributor to U.S. water quality impairments. We combined watershed N mass balances and stable isotopes to investigate fate and transport of nonpoint N in forest, agricultural, and urbanized watersheds at the Baltimore Long-Term Ecological Research site. Annual N retention was 55%, 68%, and 82% for agricultural, suburban, and forest watersheds, respectively. Analysis of δ(15)N-NO(3)(-), and δ(18)O-NO(3)(-) indicated wastewater was an important nitrate source in urbanized streams during baseflow. Negative correlations between δ(15)N-NO(3)(-) and δ(18)O-NO(3)(-) in urban watersheds indicated mixing between atmospheric deposition and wastewater, and N source contributions changed with storm magnitude (atmospheric sources contributed ∼50% at peak storm N loads). Positive correlations between δ(15)N-NO(3)(-) and δ(18)O-NO(3)(-) in watersheds suggested denitrification was removing septic system and agriculturally derived N, but N from belowground leaking sewers was less susceptible to denitrification. N transformations were also observed in a storm drain (no natural drainage network) potentially due to organic carbon inputs. Overall, nonpoint sources such as atmospheric deposition, wastewater, and fertilizer showed different susceptibility to watershed N export. There were large changes in nitrate sources as a function of runoff, and anticipating source changes in response to climate and storms will be critical for managing nonpoint N pollution.}, }
@article {pmid21779347, year = {2011}, author = {Hanson, PC and Hamilton, DP and Stanley, EH and Preston, N and Langman, OC and Kara, EL}, title = {Fate of allochthonous dissolved organic carbon in lakes: a quantitative approach.}, journal = {PloS one}, volume = {6}, number = {7}, pages = {e21884}, pmid = {21779347}, issn = {1932-6203}, mesh = {Carbon/*analysis ; Fresh Water/*analysis ; }, abstract = {Inputs of dissolved organic carbon (DOC) to lakes derived from the surrounding landscape can be stored, mineralized or passed to downstream ecosystems. The balance among these OC fates depends on a suite of physical, chemical, and biological processes within the lake, as well as the degree of recalcintrance of the allochthonous DOC load. The relative importance of these processes has not been well quantified due to the complex nature of lakes, as well as challenges in scaling DOC degradation experiments under controlled conditions to the whole lake scale. We used a coupled hydrodynamic-water quality model to simulate broad ranges in lake area and DOC, two characteristics important to processing allochthonous carbon through their influences on lake temperature, mixing depth and hydrology. We calibrated the model to four lakes from the North Temperate Lakes Long Term Ecological Research site, and simulated an additional 12 'hypothetical' lakes to fill the gradients in lake size and DOC concentration. For each lake, we tested several mineralization rates (range: 0.001 d(-1) to 0.010 d(-1)) representative of the range found in the literature. We found that mineralization rates at the ecosystem scale were roughly half the values from laboratory experiments, due to relatively cool water temperatures and other lake-specific factors that influence water temperature and hydrologic residence time. Results from simulations indicated that the fate of allochthonous DOC was controlled primarily by the mineralization rate and the hydrologic residence time. Lakes with residence times <1 year exported approximately 60% of the DOC, whereas lakes with residence times >6 years mineralized approximately 60% of the DOC. DOC fate in lakes can be determined with a few relatively easily measured factors, such as lake morphometry, residence time, and temperature, assuming we know the recalcitrance of the DOC.}, }
@article {pmid21774433, year = {2011}, author = {Lerman, SB and Warren, PS}, title = {The conservation value of residential yards: linking birds and people.}, journal = {Ecological applications : a publication of the Ecological Society of America}, volume = {21}, number = {4}, pages = {1327-1339}, doi = {10.1890/10-0423.1}, pmid = {21774433}, issn = {1051-0761}, mesh = {Animals ; Birds/classification/*physiology ; Cities ; Conservation of Natural Resources/*methods ; Demography ; *Ecosystem ; Humans ; Plants ; }, abstract = {Urbanization is recognized as one of the greatest threats to biodiversity throughout the world. However, the vegetation within an urbanized landscape is diverse and includes a variety of native and exotic plant species. This variation allows for testing whether certain landscape designs outperform others in the support of native biodiversity. Residential yards represent a large component of an urban landscape and, if managed collectively for birds and other wildlife, could offset some of the negative effects of urbanization. In addition, many urbanites have their primary interaction with the natural world in their front and back yards. Therefore, ensuring positive wildlife experiences for them is essential in promoting urban biodiversity. At the Central Arizona-Phoenix Long-Term Ecological Research site we tested the efficacy of native landscaping in residential yards in attracting native birds. We also explored the links between socioeconomic factors, landscape designs, and urban gradient measurements with the urban bird communities. A redundancy analysis suggested that native desert bird species increased in abundance in neighborhoods with desert landscaping designs, neighborhoods closer to large desert tracts, and higher-income neighborhoods. Variance partitioning showed that collectively these three sets of environmental variables explained almost 50% of the variation in the urban bird community. Results suggested racial and economic inequities in access to biodiversity, whereby predominantly Hispanic and lower-income neighborhoods had fewer native birds. We also found that residents' satisfaction with bird diversity was positively correlated with actual bird diversity. Our study provides new insights into the relative importance of socioeconomic variables and common urban ecological measurements in explaining urban bird communities. Urban planners can use this information to develop residential landscapes that support the well-being of both birds and people.}, }
@article {pmid21558258, year = {2010}, author = {Kahl, LA and Schofield, O and Fraser, WR}, title = {Autonomous gliders reveal features of the water column associated with foraging by adelie penguins.}, journal = {Integrative and comparative biology}, volume = {50}, number = {6}, pages = {1041-1050}, doi = {10.1093/icb/icq098}, pmid = {21558258}, issn = {1557-7023}, mesh = {Animals ; Antarctic Regions ; Ecosystem ; Environmental Monitoring/instrumentation/*methods ; Oceanography/instrumentation/*methods ; Oceans and Seas ; Population Dynamics ; Seasons ; Spheniscidae/*physiology ; }, abstract = {Despite their strong dependence on the pelagic environment, seabirds and other top predators in polar marine ecosystems are generally studied during their reproductive phases in terrestrial environments. As a result, a significant portion of their life history is understudied which in turn has led to limited understanding. Recent advances in autonomous underwater vehicle (AUV) technologies have allowed satellite-tagged Adélie penguins to guide AUV surveys of the marine environment at the Palmer Long-Term Ecological Research (LTER) site on the western Antarctic Peninsula. Near real-time data sent via Iridium satellites from the AUVs to a centralized control center thousands of miles away allowed scientists to adapt AUV sampling strategies to meet the changing conditions of the subsurface. Such AUV data revealed the water masses and fine-scale features associated with Adélie penguin foraging trips. During this study, the maximum concentration of chlorophyll was between 30 and 50 m deep. Encompassing this peak in the chlorophyll concentration, within the water-column, was a mixture of nutrient-laden Upper Circumpolar Deep (UCDW) and western Antarctic Peninsula winter water (WW). Together, data from the AUV survey and penguin dives reveal that 54% of foraging by Adélie penguins occurs immediately below the chlorophyll maximum. These data demonstrate how bringing together emerging technologies, such as AUVs, with established methods such as the radio-tagging of penguins can provide powerful tools for monitoring and hypothesis testing of previously inaccessible ecological processes. Ocean and atmosphere temperatures are expected to continue increasing along the western Antarctic Peninsula, which will undoubtedly affect regional marine ecosystems. New and emerging technologies such as unmanned underwater vehicles and individually mounted satellite tracking devices will provide the tools critical to documenting and understanding the widespread ecological change expected in polar regions.}, }
@article {pmid21310487, year = {2011}, author = {Nelson, MP and Vucetich, JA and Peterson, RO and Vucetich, LM}, title = {The Isle Royale Wolf-Moose Project (1958-present) and the wonder of long-term ecological research.}, journal = {Endeavour}, volume = {35}, number = {1}, pages = {31-39}, doi = {10.1016/j.endeavour.2010.09.002}, pmid = {21310487}, issn = {1873-1929}, mesh = {Animals ; *Deer ; Ecology/*organization &amp; administration ; *Ecosystem ; Environmental Monitoring ; North America ; Predatory Behavior ; *Wilderness ; *Wolves ; }, }
@article {pmid21302816, year = {2010}, author = {Ramirez, KS and Lauber, CL and Knight, R and Bradford, MA and Fierer, N}, title = {Consistent effects of nitrogen fertilization on soil bacterial communities in contrasting systems.}, journal = {Ecology}, volume = {91}, number = {12}, pages = {3463-70; discussion 3503-14}, doi = {10.1890/10-0426.1}, pmid = {21302816}, issn = {0012-9658}, mesh = {Bacteria/*isolation &amp; purification/metabolism ; Ecosystem ; *Fertilizers ; Michigan ; Minnesota ; Nitrogen/*metabolism ; Phylogeny ; RNA, Bacterial/genetics ; RNA, Ribosomal, 16S/genetics ; *Soil Microbiology ; }, abstract = {Ecosystems worldwide are receiving increasing amounts of reactive nitrogen (N) through anthropogenic activities. Although the effects of increased N inputs on plant communities have been reasonably well studied, few comparable studies have examined impacts on whole soil bacterial communities, though they play critical roles in ecosystem functioning. We sampled soils from two long-term ecological research (LTER) experimental N gradients, both of which have been amended with NH4NO3; a grassland at Cedar Creek (27 years of N additions) and an agricultural field at Kellogg Biological Station (8 years of N additions). By examining shifts in bacterial communities across these contrasting ecosystem types, we could test competing hypotheses about the direct and indirect factors that might drive bacterial responses to elevated N inputs. Bacterial community structure was highly responsive to N additions. We observed predictable and consistent changes in the structure of the bacterial communities across both ecosystem types. Our results suggest that bacterial communities across these gradients are more structured by N and/or soil carbon availability than by shifts in the plant community or soil pH associated with the elevated nitrogen inputs. In contrast to the pronounced shifts in bacterial community composition and in direct contrast to the patterns often observed in plant communities, increases in N availability did not have consistent effects on the richness and diversity of soil bacterial communities.}, }
@article {pmid21255862, year = {2011}, author = {Lister, AM and , }, title = {Natural history collections as sources of long-term datasets.}, journal = {Trends in ecology &amp; evolution}, volume = {26}, number = {4}, pages = {153-154}, doi = {10.1016/j.tree.2010.12.009}, pmid = {21255862}, issn = {0169-5347}, mesh = {Animals ; Biota ; *Conservation of Natural Resources ; *Museums ; Natural History ; Plants ; }, abstract = {In the otherwise excellent special issue of Trends in Ecology and Evolution on long-term ecological research (TREE 25(10), 2010), none of the contributors mentioned the importance of natural history collections (NHCs) as sources of data that can strongly complement past and ongoing survey data. Whereas very few field surveys have operated for more than a few decades, NHCs, conserved in museums and other institutions, comprise samples of the Earth's biota typically extending back well into the nineteenth century and, in some cases, before this time. They therefore span the period of accelerated anthropogenic habitat destruction, climate warming and ocean acidification, in many cases reflecting baseline conditions before the major impact of these factors.}, }
@article {pmid21111419, year = {2011}, author = {Furuäng, L and Siennicki-Lantz, A and Elmståhl, S}, title = {Reduced cerebral perfusion in elderly men with silent myocardial ischaemia and nocturnal blood pressure dipping.}, journal = {Atherosclerosis}, volume = {214}, number = {1}, pages = {231-236}, doi = {10.1016/j.atherosclerosis.2010.10.043}, pmid = {21111419}, issn = {1879-1484}, mesh = {Aged ; Aged, 80 and over ; *Blood Pressure ; Blood Pressure Monitoring, Ambulatory/methods ; Brain/pathology ; Cerebrovascular Circulation ; Circadian Rhythm ; Cohort Studies ; Cross-Sectional Studies ; Electrocardiography/methods ; Humans ; Male ; Monitoring, Ambulatory/methods ; Myocardial Ischemia/diagnosis/*pathology ; Perfusion ; Tomography, Emission-Computed, Single-Photon/methods ; }, abstract = {OBJECTIVE: Knowledge about the impact of cardiovascular disease on cerebral autoregulation and cognition in aging is sparse. The aim of our study is to examine the association between cerebral blood flow (CBF), silent ST segment depression (STDE) on ambulatory ECG (LTER) and nocturnal blood pressure variations in elderly men.<br><br>METHODS: In a cross-sectional cohort study "Men born in 1914", eighty 83-year-old men were examined by CBF, LTER and ambulatory blood pressure monitoring (ABPM). The presence and the degree of STDE were analyzed in relation to regional CBF in nocturnal blood pressure dippers/non-dippers.<br><br>RESULTS: Fourty-five (56%) study subjects had STDE, 25 at both day and night and 20 only daytime. Subjects with STDE expressed lower CBF in left frontal, temporal, inferior parietal regions and bilateral superior parietal regions compared to men without STDE. Low regional CBF was most frequent in subjects with daytime STDE. Subjects with nocturnal diastolic blood pressure dip and STDE (22 subjects; 35%) had lower mean CBF in the parietal lobe and also correlation between STDE and CBF (r=0.31-0.44, p=0.056-0.006) compared to non-dippers with STDE. The lowest CBF in nocturnal dippers was observed in subjects with maximal STDE daytime.<br><br>CONCLUSION: Silent myocardial ischemia may contribute to cerebrovascular disease in non-demented elderly men. Cerebral perfusion seems to be most vulnerable to myocardial ischemia in elderly with nocturnal blood pressure dipping.}, }
@article {pmid20943500, year = {2010}, author = {Rollins, AW and Landolt, JC and Stephenson, SL}, title = {Dictyostelid cellular slime molds associated with grasslands of the central and western United States.}, journal = {Mycologia}, volume = {102}, number = {5}, pages = {996-1003}, doi = {10.3852/09-099}, pmid = {20943500}, issn = {0027-5514}, mesh = {Animals ; Dictyostelium/classification/isolation &amp; purification/*physiology ; Ecology ; Ecosystem ; Fires ; Geography ; Poaceae/*parasitology ; United States ; }, abstract = {Dictyostelid cellular slime molds (dictyostelids) associated with grassland ecosystems of the central and western United States were investigated at nine sites that included examples of the three major ecological types of grasslands (tall grass, mixed grass and short grass) generally recognized for the region. Samples of soil/humus collected from each site were examined with the Cavender method of isolating dictyostelids. For each of those six sites with well developed gallery forests present, an additional set of forest soil/humus samples was collected. A more intensive sampling effort was carried out at one site (Konza LTER) to assess the possible effects of burning and grazing on dictyostelid diversity and density. Twelve species of dictyostelids were recovered from grassland sites, whereas gallery forest sites yielded only nine species. Four cosmopolitan species (Dictyostelium giganteum, D. mucoroides, D. sphaerocephalum and Polysphondylium pallidum) were represented by the greatest densities of clones, with D. sphaerocephalum particularly common. The general pattern across all sites was that both species richness and density of dictyostelids decreased with decreasing precipitation. Samples collected from ungrazed grassland plots yielded higher numbers of both species and clones as compared to grazed plots, and the general pattern was for both values to increase as the interval between fires increased. For numbers of clones this correlation was statistically significant.}, }
@article {pmid20853742, year = {2010}, author = {Krugner-Higby, L and Haak, D and Johnson, PT and Shields, JD and Jones, WM and Reece, KS and Meinke, T and Gendron, A and Rusak, JA}, title = {Ulcerative disease outbreak in crayfish Orconectes propinquus linked to Saprolegnia australis in big Muskellunge Lake, Wisconsin.}, journal = {Diseases of aquatic organisms}, volume = {91}, number = {1}, pages = {57-66}, doi = {10.3354/dao02237}, pmid = {20853742}, issn = {0177-5103}, mesh = {Animals ; Astacoidea/*parasitology ; Disease Outbreaks ; Fresh Water ; Host-Parasite Interactions ; Integumentary System/parasitology/pathology ; Phylogeny ; Saprolegnia/genetics/*isolation &amp; purification ; Wisconsin ; }, abstract = {Crayfish populations in the area of the North Temperate Lakes Long Term Ecological Research (LTER) project, Wisconsin, USA, have been monitored for >25 yr. In 2005, native crayfish Orconectes propinquus from Big Muskellunge Lake were found with ulcerated lesions in the cuticle. In 2006, lesions occurred in 9.5% of sampled crayfish from the lake (n=3146). Ulcers generally occurred on the appendages of affected individuals but varied in location and severity. The prevalence of ulcers varied widely among sites, sample depths, and sampling dates, ranging from < 2% to >20%. The prevalence of ulcers in crayfish increased from a minimum in early June to a maximum in late July and August. In aquarium trials, healthy crayfish representing either O. propinquus or O. rusticus co-housed with ulcerated crayfish did not develop ulcers within 4 wk of exposure. Gross and histopathologic analyses of ulcerated crayfish revealed the presence of filamentous hyphae in the lesions while hemocytic infiltrates, melanotic reactions and silver-stained sections indicated that the ulcers had an oomycete etiology. Excised samples of ulcerated crayfish cuticle grown in culture developed an oomycete that was identified as Saprolegnia australis by PCR amplification and sequence analysis of 2 different DNA fragments. This is the first report of the occurrence of ulcers in wild crayfish associated with S. australis infection in the U.S.A. The advent of the outbreak and its underlying ecological causes are still under investigation.}, }
@article {pmid20735464, year = {2010}, author = {Dovciak, M and Halpern, CB}, title = {Positive diversity-stability relationships in forest herb populations during four decades of community assembly.}, journal = {Ecology letters}, volume = {13}, number = {10}, pages = {1300-1309}, doi = {10.1111/j.1461-0248.2010.01524.x}, pmid = {20735464}, issn = {1461-0248}, mesh = {*Biodiversity ; Models, Biological ; Oregon ; *Plant Development ; Population Dynamics ; Time Factors ; *Trees ; }, abstract = {It is suggested that diversity destabilizes individual populations within communities; however, generalizations are problematic because effects of diversity can be confounded by variation attributable to community type, life history or successional stage. We examined these complexities using a 40-year record of reassembly in forest herb communities in two clearcut watersheds in the Andrews Long-term Ecological Research Site (Oregon, USA). Population stability was higher among forest than colonizing species and increased with successional stage. Thus, life history and successional stage may explain some of the variability in diversity-stability relationships found previously. However, population stability was positively related to diversity and this relationship held for different forest communities, for species with contrasting life histories, and for different successional stages. Positive relationships between diversity and population stability can arise if diversity has facilitative effects, or if stability is a precursor, rather than a response, to diversity.}, }
@article {pmid20711610, year = {2010}, author = {Zehnder, CB and Stodola, KW and Cooper, RJ and Hunter, MD}, title = {Spatial heterogeneity in the relative impacts of foliar quality and predation pressure on red oak, Quercus rubra, arthropod communities.}, journal = {Oecologia}, volume = {164}, number = {4}, pages = {1017-1027}, pmid = {20711610}, issn = {1432-1939}, mesh = {Animals ; Arthropods/*physiology ; *Food Chain ; Nitrogen/metabolism ; Plant Leaves/growth &amp; development/metabolism ; Population Density ; Quercus/growth &amp; development/*metabolism ; }, abstract = {Predation pressure and resource availability often interact in structuring herbivore communities, with their relative influence varying in space and time. The operation of multiple ecological pressures and guild-specific herbivore responses may combine to override simple predictions of how the roles of plant quality and predation pressure vary in space. For 2 years at the Coweeta LTER in the Southern Appalachian Mountains, we conducted a bird exclosure experiment on red oak (Quercus rubra) saplings to investigate the effects of bird predation on red oak arthropod communities. We established bird exclosures at six sites along an elevational gradient and estimated variation in foliar nitrogen and bird predation pressure along this gradient. Foliar nitrogen concentrations increased with elevation while our index of bird predation pressure was variable across sites. Greater arthropod densities were detected inside exclosures; however, this result was mainly driven by the response of phloem feeders which were much more prevalent inside exclosures than on control trees. There was little evidence for an effect of bird predation on the other arthropod guilds. Consequently, there was no evidence of a trophic cascade either in terms of leaf damage or tree growth. Finally, we found more variation in arthropod density among trees within sites than variation in arthropod density among sites, indicating the importance of micro-site variation in structuring arthropod communities.}, }
@article {pmid20583705, year = {2010}, author = {Warne, RW and Pershall, AD and Wolf, BO}, title = {Linking precipitation and C3-C4 plant production to resource dynamics in higher-trophic-level consumers.}, journal = {Ecology}, volume = {91}, number = {6}, pages = {1628-1638}, doi = {10.1890/08-1471.1}, pmid = {20583705}, issn = {0012-9658}, mesh = {Animals ; Arthropods/*physiology ; Biomass ; *Ecosystem ; Food Chain ; Lizards/physiology ; *Plant Development ; Plants/*metabolism ; *Rain ; }, abstract = {In many ecosystems, seasonal shifts in temperature and precipitation induce pulses of primary productivity that vary in phenology, abundance, and nutritional quality. Variation in these resource pulses could strongly influence community composition and ecosystem function, because these pervasive bottom-up forces play a primary role in determining the biomass, life cycles, and interactions of organisms across trophic levels. The focus of this research is to understand how consumers across trophic levels alter resource use and assimilation over seasonal and interannual timescales in response to climatically driven changes in pulses of primary productivity. We measured the carbon isotope ratios (delta(13)C) of plant, arthropod, and lizard tissues in the northern Chihuahuan Desert to quantify the relative importance of primary production from plants using C3 and C4 photosynthesis for consumers. Summer monsoonal rains on the Sevilleta Long Term Ecological Research (LTER) site in New Mexico support a pulse of C4 plant production that has tissue delta(13)C values distinct from C3 plants. During a year when precipitation patterns were relatively normal, delta(13)C measurements showed that consumers used and assimilated significantly more C4-derived carbon over the course of a summer, tracking the seasonal increase in abundance of C4 plants. In the following spring, after a failure in winter precipitation and the associated failure of spring C3 plant growth, consumers showed elevated assimilation of C4-derived carbon relative to a normal rainfall regime. These findings provide insight into how climate, pulsed resources, and temporal trophic dynamics may interact to shape semiarid grasslands such as the Chihuahuan Desert in the present and future.}, }
@article {pmid20207473, year = {2010}, author = {Metzger, MJ and Bunce, RG and van Eupen, M and Mirtl, M}, title = {An assessment of long term ecosystem research activities across European socio-ecological gradients.}, journal = {Journal of environmental management}, volume = {91}, number = {6}, pages = {1357-1365}, doi = {10.1016/j.jenvman.2010.02.017}, pmid = {20207473}, issn = {1095-8630}, mesh = {*Ecology ; *Ecosystem ; Europe ; Research ; }, abstract = {Integration of European long term ecosystem research (LTER) would provide important support for the management of the pan-European environment and ecosystems, as well as international policy commitments. This does require appropriate coverage of Europe and standardised frameworks and research methods between countries. Emerging interest in socio-ecological systems prompted the present assessment of the distribution of LTER activities across European socio-ecological gradients. This paper presents a European stratification with a 1 km(2) resolution, delineating 48 broad socio-ecological regions. The dataset is based on an existing biogeophysical stratification constructed using multivariate clustering of mainly climatic variables and a newly developed socio-economic stratification based on an economic density indicator. The coverage of European LTER facilities across the socio-ecological gradients is tested using this dataset. The analysis shows two strong biases in the present LTER effort. Firstly, urban and disturbed regions are consistently under-represented, illustrating a bias for traditional ecological research away from human activity. Secondly, the Mediterranean, for which some of the most extreme global change impacts are projected, is receiving comparatively little attention. Both findings can help guide future investment in the European LTER network - and especially in a Long Term Socio-Ecological Research (LTSER) component- to provide a more balanced coverage. This will provide better scientific understanding of pan-European environmental concerns and support the management of natural resources and international policy commitments in the European Union.}, }
@article {pmid20182521, year = {2010}, author = {Morales, SE and Cosart, T and Holben, WE}, title = {Bacterial gene abundances as indicators of greenhouse gas emission in soils.}, journal = {The ISME journal}, volume = {4}, number = {6}, pages = {799-808}, doi = {10.1038/ismej.2010.8}, pmid = {20182521}, issn = {1751-7370}, mesh = {Agriculture ; Bacteria/classification/*genetics ; DNA, Bacterial/genetics ; *Genes, Bacterial ; Genes, rRNA ; *Greenhouse Effect ; Nitrous Oxide/*analysis ; Polymerase Chain Reaction ; Principal Component Analysis ; Regression Analysis ; Ribotyping ; Soil/*analysis ; *Soil Microbiology ; }, abstract = {Nitrogen fixing and denitrifying bacteria, respectively, control bulk inputs and outputs of nitrogen in soils, thereby mediating nitrogen-based greenhouse gas emissions in an ecosystem. Molecular techniques were used to evaluate the relative abundances of nitrogen fixing, denitrifying and two numerically dominant ribotypes (based on the > or =97% sequence similarity at the 16S rRNA gene) of bacteria in plots representing 10 agricultural and other land-use practices at the Kellogg biological station long-term ecological research site. Quantification of nitrogen-related functional genes (nitrite reductase, nirS; nitrous oxide reductase, nosZ; and nitrogenase, nifH) as well as two dominant 16S ribotypes (belonging to the phyla Acidobacteria, Thermomicrobia) allowed us to evaluate the hypothesis that microbial community differences are linked to greenhouse gas emissions under different land management practices. Our results suggest that the successional stages of the ecosystem are strongly linked to bacterial functional group abundance, and that the legacy of agricultural practices can be sustained over decades. We also link greenhouse gas emissions with specific compositional responses in the soil bacterial community and assess the use of denitrifying gene abundances as proxies for determining nitrous oxide emissions from soils.}, }
@article {pmid20033070, year = {2010}, author = {Angel, R and Soares, MI and Ungar, ED and Gillor, O}, title = {Biogeography of soil archaea and bacteria along a steep precipitation gradient.}, journal = {The ISME journal}, volume = {4}, number = {4}, pages = {553-563}, doi = {10.1038/ismej.2009.136}, pmid = {20033070}, issn = {1751-7370}, mesh = {Archaea/*classification/*isolation &amp; purification ; Bacteria/*classification/*isolation &amp; purification ; *Biodiversity ; Cluster Analysis ; DNA Fingerprinting ; DNA, Archaeal/genetics ; DNA, Bacterial/genetics ; DNA, Ribosomal/genetics ; Geography ; Israel ; Polymorphism, Restriction Fragment Length ; RNA, Ribosomal, 16S/genetics ; *Soil Microbiology ; }, abstract = {For centuries, biodiversity has spellbound biologists focusing mainly on macroorganism's diversity and almost neglecting the geographic mediated dynamics of microbial communities. We surveyed the diversity of soil bacteria and archaea along a steep precipitation gradient ranging from the Negev Desert in the south of Israel (<100 mm annual rain) to the Mediterranean forests in the north (>900 mm annual rain). Soil samples were retrieved from triplicate plots at five long-term ecological research stations, collected from two types of patches: plant interspaces and underneath the predominant perennial at each site. The molecular fingerprint of each soil sample was taken using terminal restriction length polymorphism of the 16S rRNA gene to evaluate the bacterial and archaeal community composition and diversity within and across sites. The difference in community compositions was not statistically significant within sites (P=0.33 and 0.77 for bacteria and archaea, respectively), but it differed profoundly by ecosystem type. These differences could largely be explained by the precipitation gradient combined with the vegetation cover: the archaeal and bacterial operational taxonomic units were unique to each climatic region, that is, arid, semiarid and Mediterranean (P=0.0001, for both domains), as well as patch type (P=0.009 and 0.02 for bacteria and archaea, respectively). Our results suggest that unlike macroorganisms that are more diverse in the Mediterranean ecosystems compared with the desert sites, archaeal and bacterial diversities are not constrained by precipitation. However, the community composition is unique to the climate and vegetation cover that delineates each ecosystem.}, }
@article {pmid19738980, year = {2009}, author = {Mendonça, LB and Lopes, EV and Anjos, L}, title = {On the possible extinction of bird species in the Upper Paraná River floodplain, Brazil.}, journal = {Brazilian journal of biology = Revista brasleira de biologia}, volume = {69}, number = {2 Suppl}, pages = {747-755}, doi = {10.1590/s1519-69842009000300028}, pmid = {19738980}, issn = {1678-4375}, mesh = {Animals ; Birds/classification/*physiology ; Brazil ; *Ecosystem ; *Extinction, Biological ; Power Plants ; Rivers ; }, abstract = {The Upper Paraná River floodplain (UPR) represents the last stretch of the Paraná River in Brazilian territory where a river-floodplain ecosystem still exists. However, the region had been subjected to intense deforestation in previous decades, and more than half of the original floodplain has been lost due to the construction of the Porto Primavera dam, which may have resulted in the local extinction of species. In the present study, we compared the list of bird species recorded before the construction of Porto Primavera dam (1926-1996) to that gotten afterwards (1999-2007) under the Long-Term Ecological Research program (LTER-site 6). We aim to investigate biogeographical and ecological traits of species potentially lost in the UPR. Endemism, proximity to the edge of species' geographic range, low tolerance to human-altered habitats and habitat specificity were associated to the potential extinction of birds in the UPR. The region represents an important opportunity for conservation, and should be target of conservation efforts to avoid further loss of species and ecological processes.}, }
@article {pmid19738979, year = {2009}, author = {Souza, MC and Kawakita, K and Slusarski, SR and Pereira, GF}, title = {Vascular flora of the Upper Paraná River floodplain.}, journal = {Brazilian journal of biology = Revista brasleira de biologia}, volume = {69}, number = {2 Suppl}, pages = {735-745}, doi = {10.1590/s1519-69842009000300027}, pmid = {19738979}, issn = {1678-4375}, mesh = {*Biodiversity ; Brazil ; Plants/*classification ; *Rivers ; }, abstract = {The purpose of this study was to update the floristic inventory found in the Upper Paraná River floodplain. Floristic surveys were performed from February 2000 through March 2008, as part of the Brazilian Long-Term Ecological Research Program (PELD/CNPq-Site 6). The material collected was identified from 774 species, 442 genera, and 116 families. The ten families with high species richness were Leguminosae, Poaceae, Rubiaceae, Asteraceae, Euphorbiaceae, Myrtaceae, Cyperaceae, Solanaceae, Sapindaceae, and Orchidaceae, which contributed to 46.1% of the total number of species. Genera with high richness were Solanum, Cyperus, Panicum, Eugenia, Tillandsia, Serjania, Casearia, and Polygonum, which together contributed to 10.2% of the total number of species. These data, combined with information published in 1997, recorded 955 species, 575 genera, and 128 families. These organisms were from several riparian environments and were distributed as herbs, shrubs, trees, climbers and epiphytes. Panicum maximum, Pennisetum purpureum, Ricinus communis, and Urochloa decumbens are considered weeds due to the wide distributions determined for these species. The results presented herein suggest the need to further investigate the control of these potential weed species.}, }
@article {pmid19689895, year = {2009}, author = {Zehnder, CB and Stodola, KW and Joyce, BL and Egetter, D and Cooper, RJ and Hunter, MD}, title = {Elevational and seasonal variation in the foliar quality and arthropod community of Acer pensylvanicum.}, journal = {Environmental entomology}, volume = {38}, number = {4}, pages = {1161-1167}, doi = {10.1603/022.038.0424}, pmid = {19689895}, issn = {0046-225X}, mesh = {Acer/*metabolism ; *Altitude ; Animals ; *Arthropods ; Cellulose/metabolism ; *Ecosystem ; Lignin/metabolism ; Nitrogen/metabolism ; North Carolina ; Phenols/metabolism ; Plant Leaves/*metabolism ; }, abstract = {Elevational gradients provide natural experiments for examining how variation in abiotic forces such as nutrient mineralization rates, risk of photodamge, temperature, and precipitation influence plant-insect interactions. At the Coweeta LTER site in the Southern Appalachian Mountains, we examined spatial and temporal variation in striped maple, Acer pensylvanicum, foliar quality and associated patterns in the arthropod community. Variation in herbivore densities was associated more strongly with seasonal variation in plant quality than with spatial variation in quality among three sampling sites. Leaf chewer, but not phloem feeder or arthropod predator, densities increased with elevation. Foliar quality, by our measures, decreased throughout the growing season, with decreases in nitrogen concentrations and increases in lignin concentrations. Foliar quality varied among the three sites but not systematically along the elevational gradient. We conclude that, in this system, temporal heterogeneity in plant quality is likely to be more important to insect herbivores than is spatial heterogeneity and that other factors, such as the abiotic environment and natural enemies, likely have substantial effects on herbivore density.}, }
@article {pmid19633714, year = {2009}, author = {Amaral-Zettler, LA and McCliment, EA and Ducklow, HW and Huse, SM}, title = {A method for studying protistan diversity using massively parallel sequencing of V9 hypervariable regions of small-subunit ribosomal RNA genes.}, journal = {PloS one}, volume = {4}, number = {7}, pages = {e6372}, pmid = {19633714}, issn = {1932-6203}, support = {P50 ES012742/ES/NIEHS NIH HHS/United States ; 1 P50 ES012742-01/ES/NIEHS NIH HHS/United States ; }, mesh = {Base Sequence ; Biodiversity ; DNA Primers ; Polymerase Chain Reaction ; RNA, Ribosomal/*genetics ; }, abstract = {BACKGROUND: Massively parallel pyrosequencing of amplicons from the V6 hypervariable regions of small-subunit (SSU) ribosomal RNA (rRNA) genes is commonly used to assess diversity and richness in bacterial and archaeal populations. Recent advances in pyrosequencing technology provide read lengths of up to 240 nucleotides. Amplicon pyrosequencing can now be applied to longer variable regions of the SSU rRNA gene including the V9 region in eukaryotes.<br><br>We present a protocol for the amplicon pyrosequencing of V9 regions for eukaryotic environmental samples for biodiversity inventories and species richness estimation. The International Census of Marine Microbes (ICoMM) and the Microbial Inventory Research Across Diverse Aquatic Long Term Ecological Research Sites (MIRADA-LTERs) projects are already employing this protocol for tag sequencing of eukaryotic samples in a wide diversity of both marine and freshwater environments.<br><br>CONCLUSIONS/SIGNIFICANCE: Massively parallel pyrosequencing of eukaryotic V9 hypervariable regions of SSU rRNA genes provides a means of estimating species richness from deeply-sampled populations and for discovering novel species from the environment.}, }
@article {pmid18959324, year = {2008}, author = {Johnson, NC and Rowland, DL and Corkidi, L and Allen, EB}, title = {Plant winners and losers during grassland N-eutrophication differ in biomass allocation and mycorrhizas.}, journal = {Ecology}, volume = {89}, number = {10}, pages = {2868-2878}, doi = {10.1890/07-1394.1}, pmid = {18959324}, issn = {0012-9658}, mesh = {*Biodiversity ; Biomass ; Ecosystem ; *Eutrophication ; *Fertilizers ; Mycorrhizae/*growth &amp; development/metabolism ; Nitrogen/*metabolism ; Poaceae/classification/*growth &amp; development/metabolism/microbiology ; Soil/analysis/standards ; Soil Microbiology ; Species Specificity ; }, abstract = {Human activities release tremendous amounts of nitrogenous compounds into the atmosphere. Wet and dry deposition distributes this airborne nitrogen (N) on otherwise pristine ecosystems. This eutrophication process significantly alters the species composition of native grasslands; generally a few nitrophilic plant species become dominant while many other species disappear. The functional equilibrium model predicts that, compared to species that decline in response to N enrichment, nitrophilic grass species should respond to N enrichment with greater biomass allocation aboveground and reduced allocation to roots and mycorrhizas. The mycorrhizal feedback hypothesis states that the composition of mycorrhizal fungal communities may influence the composition of plant communities, and it predicts that N enrichment may generate reciprocal shifts in the species composition of mycorrhizal fungi and plants. We tested these hypotheses with experiments that compared biomass allocation and mycorrhizal function of four grass ecotypes (three species), two that gained and two that lost biomass and cover in response to long-term N enrichment experiments at Cedar Creek and Konza Long-Term Ecological Research grasslands. Local grass ecotypes were grown in soil from their respective sites and inoculated with whole-soil inoculum collected from either fertilized (FERT) or unfertilized (UNFERT) plots. Our results strongly support the functional equilibrium model. In both grassland systems the nitrophilic grass species grew taller, allocated more biomass to shoots than to roots, and formed fewer mycorrhizas compared to the grass species that it replaced. Our results did not fully support the hypothesis that N-induced changes in the mycorrhizal fungal community were drivers of the plant community shifts that accompany N eutrophication. The FERT and UNFERT soil inoculum influenced the growth of the grasses differently, but this varied with site and grass ecotype in both expected and unexpected ways suggesting that ambient soil fertility or other factors may be interacting with mycorrhizal feedbacks.}, }
@article {pmid18831387, year = {2008}, author = {Balog, A and Marko, V and Adam, L}, title = {Rove beetles (Coleoptera: Staphylinidae) collected during the long term ecological research in a Hungarian oak forest.}, journal = {Journal of environmental biology}, volume = {29}, number = {2}, pages = {263-266}, pmid = {18831387}, issn = {0254-8704}, mesh = {Animals ; Biodiversity ; Coleoptera/*growth &amp; development ; *Ecology ; *Environmental Monitoring ; Population Dynamics ; *Quercus ; Research ; Time Factors ; *Trees ; }, abstract = {Along term ecological research was carried out in a Hungarian oak forest, in "Bükk" National Park starting with 1972. During the faunistical studies 3,602 insect species and more than 200,000 individuals were collected. The dominant orders were Coleoptera (1,051 species), Lepidoptera (803 species), Hymenoptera (470 species) and Diptera (400 species). The relative species abundance (RSA) for all insects collected in all years of sampling period suggests a rather J shape curve than a not clear scaling property. This means that we were able to identify almost three quarters of the insect species from one ha European oak forest during the survey (from 1987 to 2003), and two third of the staphylinides expected. Considering the staphylinid fauna a total number of 160 species and 4,022 individuals were collected. The most widely occurring species in dominance order were: Ocypus biharicus, Pseudocypus mus, Atheta gagatina, Philonthus quisquiliarius, Oxypoda acuminate, Platydracus chalcocephalus, Atheta crassicomis, Latrimaeum atrocephalum, Haploglossa puncticollis, Philonthus succicola and Anotylus mutator. The pooled value of alpha diversity was 1.51. The Shannon-Weiner Index (H') was relatively high (3.29) in comparison with other studies.}, }
@article {pmid18764871, year = {2008}, author = {Nemergut, DR and Townsend, AR and Sattin, SR and Freeman, KR and Fierer, N and Neff, JC and Bowman, WD and Schadt, CW and Weintraub, MN and Schmidt, SK}, title = {The effects of chronic nitrogen fertilization on alpine tundra soil microbial communities: implications for carbon and nitrogen cycling.}, journal = {Environmental microbiology}, volume = {10}, number = {11}, pages = {3093-3105}, doi = {10.1111/j.1462-2920.2008.01735.x}, pmid = {18764871}, issn = {1462-2920}, mesh = {Archaea/*classification/isolation &amp; purification ; Bacteria/*classification/isolation &amp; purification ; *Biodiversity ; Carbon/*metabolism ; *Fertilizers ; Fungi/*classification/isolation &amp; purification ; Molecular Sequence Data ; Nitrogen/*metabolism ; Organic Chemicals/analysis ; Phylogeny ; Sequence Analysis, DNA ; Soil/analysis ; *Soil Microbiology ; }, abstract = {Many studies have shown that changes in nitrogen (N) availability affect primary productivity in a variety of terrestrial systems, but less is known about the effects of the changing N cycle on soil organic matter (SOM) decomposition. We used a variety of techniques to examine the effects of chronic N amendments on SOM chemistry and microbial community structure and function in an alpine tundra soil. We collected surface soil (0-5 cm) samples from five control and five long-term N-amended plots established and maintained at the Niwot Ridge Long-term Ecological Research (LTER) site. Samples were bulked by treatment and all analyses were conducted on composite samples. The fungal community shifted in response to N amendments, with a decrease in the relative abundance of basidiomycetes. Bacterial community composition also shifted in the fertilized soil, with increases in the relative abundance of sequences related to the Bacteroidetes and Gemmatimonadetes, and decreases in the relative abundance of the Verrucomicrobia. We did not uncover any bacterial sequences that were closely related to known nitrifiers in either soil, but sequences related to archaeal nitrifiers were found in control soils. The ratio of fungi to bacteria did not change in the N-amended soils, but the ratio of archaea to bacteria dropped from 20% to less than 1% in the N-amended plots. Comparisons of aliphatic and aromatic carbon compounds, two broad categories of soil carbon compounds, revealed no between treatment differences. However, G-lignins were found in higher relative abundance in the fertilized soils, while proteins were detected in lower relative abundance. Finally, the activities of two soil enzymes involved in N cycling changed in response to chronic N amendments. These results suggest that chronic N fertilization induces significant shifts in soil carbon dynamics that correspond to shifts in microbial community structure and function.}, }
@article {pmid18622750, year = {2008}, author = {Guo, H and Wang, B and Ma, X and Zhao, G and Li, S}, title = {Evaluation of ecosystem services of Chinese pine forests in China.}, journal = {Science in China. Series C, Life sciences}, volume = {51}, number = {7}, pages = {662-670}, doi = {10.1007/s11427-008-0083-z}, pmid = {18622750}, issn = {1006-9305}, mesh = {China ; *Ecosystem ; Pinus/*physiology ; Time Factors ; Trees/*physiology ; }, abstract = {Evaluation of forest ecosystem services is a hot topic, both in China and at abroad, but it has not yet obtained a consistency of evaluation indicator systems and evaluation methods. Under the framework of evaluation criteria to be implemented for forest ecosystem services, years of consecutive observation data from Long Term Ecological Research Stations affiliated to Chinese Forest Ecosystem Research Network (CFERN), forest resource inventory and public data were applied to carry out a detailed and dynamic evaluation on the physical quantity and value of ecosystem services of Chinese pine forests in China. The results showed that the above services had the total value and unit value of 1144.9640 billion (1.1449640x10(12)) RMB and 52.074 thousand RMB per hectare per year, respectively during the 9th Five-year Plan (1996-2000), and of 1190.5461 billion RMB and 52.101 thousand RMB per hectare per year, respectively, during the 10th Five-year Plan (2001-2005). For Chinese pine forests, water conservation was 40.40 hundred million cubic meters annually, soil conservation was 67 million tons and C fixation 9 million tons annually, production of healthful negative ions was 1.96x10(20), absorption of SO(2) was 5.02 hundred million kilograms and dust-catching was 759.10 hundred million kilograms. Among the 15 provinces of China with Chinese pine forests, the biggest beneficiary from ecosystem services was Liaoning Province; while Hunan Province was the smallest beneficiary between the 9th Five-year Plan.}, }
@article {pmid18550152, year = {2008}, author = {Lohse, KA and Hope, D and Sponseller, R and Allen, JO and Grimm, NB}, title = {Atmospheric deposition of carbon and nutrients across an arid metropolitan area.}, journal = {The Science of the total environment}, volume = {402}, number = {1}, pages = {95-105}, doi = {10.1016/j.scitotenv.2008.04.044}, pmid = {18550152}, issn = {0048-9697}, mesh = {Air Pollutants/*analysis ; Ammonia/analysis ; Arizona ; Atmosphere/*analysis ; Carbon/*analysis ; Cities ; Ecosystem ; *Environmental Monitoring ; Geography ; Nitrates/analysis ; Nitrogen/*analysis ; Phosphorus/*analysis ; Sulfates/analysis ; Time Factors ; Wind ; }, abstract = {Urbanization is increasing rapidly in semi-arid environments and is predicted to alter atmospheric deposition of nutrients and pollutants to cities as well as to ecosystems downwind. We examined patterns of wet and coarse dry deposition chemistry over a five-year period at 7 sites across the Central Arizona-Phoenix (CAP) study area, one of two urban sites within the National Science Foundation's Long-Term Ecological Research (LTER) program. Wet and dry deposition of organic carbon (oC) were significantly elevated in the urban core; in contrast, mean annual wet and dry fluxes of nitrogen (N) were low (<6 kg ha(-1) yr(-1)) compared to previous estimates and did not differ significantly among sites. Wet deposition of sulfate (SO(4)2-) was high across CAP (mean 1.39 kg ha(-1) yr(-1) as S) and represented the dominant anion in rainfall. Dry deposition rates did not show strong seasonal trends with the exception of oC, which was 3-fold higher in winter than in summer; ammonium (NH4+) deposition was high but more variable. Dry deposition of NO3- and oC was strongly correlated with particulate base cations and dust-derived soluble reactive phosphorus (SRP), suggesting that urban-derived dust is scrubbing the atmosphere of acidic gases and entrained particles and increasing local deposition. Differences between measured and predicted rates of dry N deposition to the urban core may be explained by incomplete collection of gas phase N on surrogate deposition surfaces in this hot and arid environment. The extent of urban enhancement of cations and oC inputs to desert ecosystems appears to be restricted to the urbanized metropolitan area rather than extending far downwind, although a low number of sites make it difficult to resolve this spatial pattern. Nevertheless, wet and dry inputs may be important for biogeochemical cycles in nutrient and carbon-poor desert ecosystems within and near arid cities.}, }
@article {pmid18407745, year = {2008}, author = {Gil, IS and Sheldon, W and Schmidt, T and Servilla, M and Aguilar, R and Gries, C and Gray, T and Field, D and Cole, J and Pan, JY and Palanisamy, G and Henshaw, D and O'Brien, M and Kinkel, L and McMahon, K and Kottmann, R and Amaral-Zettler, L and Hobbie, J and Goldstein, P and Guralnick, RP and Brunt, J and Michener, WK}, title = {Defining linkages between the GSC and NSF's LTER program: how the Ecological Metadata Language (EML) relates to GCDML and other outcomes.}, journal = {Omics : a journal of integrative biology}, volume = {12}, number = {2}, pages = {151-156}, doi = {10.1089/omi.2008.0015}, pmid = {18407745}, issn = {1536-2310}, mesh = {*Databases, Genetic ; Genome ; *Programming Languages ; }, abstract = {The Genomic Standards Consortium (GSC) invited a representative of the Long-Term Ecological Research (LTER) to its fifth workshop to present the Ecological Metadata Language (EML) metadata standard and its relationship to the Minimum Information about a Genome/Metagenome Sequence (MIGS/MIMS) and its implementation, the Genomic Contextual Data Markup Language (GCDML). The LTER is one of the top National Science Foundation (NSF) programs in biology since 1980, representing diverse ecosystems and creating long-term, interdisciplinary research, synthesis of information, and theory. The adoption of EML as the LTER network standard has been key to build network synthesis architectures based on high-quality standardized metadata. EML is the NSF-recognized metadata standard for LTER, and EML is a criteria used to review the LTER program progress. At the workshop, a potential crosswalk between the GCDML and EML was explored. Also, collaboration between the LTER and GSC developers was proposed to join efforts toward a common metadata cataloging designer's tool. The community adoption success of a metadata standard depends, among other factors, on the tools and trainings developed to use the standard. LTER's experience in embracing EML may help GSC to achieve similar success. A possible collaboration between LTER and GSC to provide training opportunities for GCDML and the associated tools is being explored. Finally, LTER is investigating EML enhancements to better accommodate genomics data, possibly integrating the GCDML schema into EML. All these action items have been accepted by the LTER contingent, and further collaboration between the GSC and LTER is expected.}, }
@article {pmid27879784, year = {2008}, author = {Zhou, W and Troy, A and Grove, M}, title = {Object-based Land Cover Classification and Change Analysis in the Baltimore Metropolitan Area Using Multitemporal High Resolution Remote Sensing Data.}, journal = {Sensors (Basel, Switzerland)}, volume = {8}, number = {3}, pages = {1613-1636}, doi = {10.3390/s8031613}, pmid = {27879784}, issn = {1424-8220}, abstract = {Accurate and timely information about land cover pattern and change in urbanareas is crucial for urban land management decision-making, ecosystem monitoring andurban planning. This paper presents the methods and results of an object-basedclassification and post-classification change detection of multitemporal high-spatialresolution Emerge aerial imagery in the Gwynns Falls watershed from 1999 to 2004. TheGwynns Falls watershed includes portions of Baltimore City and Baltimore County,Maryland, USA. An object-based approach was first applied to implement the land coverclassification separately for each of the two years. The overall accuracies of theclassification maps of 1999 and 2004 were 92.3% and 93.7%, respectively. Following theclassification, we conducted a comparison of two different land cover change detectionmethods: traditional (i.e., pixel-based) post-classification comparison and object-basedpost-classification comparison. The results from our analyses indicated that an objectbasedapproach provides a better means for change detection than a pixel based methodbecause it provides an effective way to incorporate spatial information and expertknowledge into the change detection process. The overall accuracy of the change mapproduced by the object-based method was 90.0%, with Kappa statistic of 0.854, whereasthe overall accuracy and Kappa statistic of that by the pixel-based method were 81.3% and0.712, respectively.}, }
@article {pmid18274779, year = {2008}, author = {Boschilia, SM and Oliveira, EF and Thomaz, SM}, title = {Do aquatic macrophytes co-occur randomly? An analysis of null models in a tropical floodplain.}, journal = {Oecologia}, volume = {156}, number = {1}, pages = {203-214}, pmid = {18274779}, issn = {0029-8549}, mesh = {Biodiversity ; Brazil ; Ecosystem ; *Magnoliopsida ; *Models, Statistical ; *Rivers ; Tropical Climate ; }, abstract = {One of the main issues in community ecology is the detection of structure and the identification of its related causes. In this study, co-occurrence null models were used to identify possible spatio-temporal patterns in the assemblage of aquatic macrophytes in the Upper Paraná River floodplain. The samples were obtained through the Long Term Ecological Research (LTER) Program at two different grains: (1) a coarser spatial grain in January and August 2001 (entire floodplain lagoons); (2) and a finer spatial grain in November 2006 (1 m(2) quadrats). The study was conducted in 36 lagoons, both connected and disconnected to the main river channel, located in the sub-basins of the Baía, Ivinheima and Paraná rivers. Two null models of species co-occurrence, the C-Score and Checkerboard indices, were used to test the null hypothesis of random structure of the aquatic macrophyte assemblages. The null models showed that the aquatic macrophyte assemblages were spatially structured in the distinct spatial grains. However, despite this general pattern, macrophyte assemblages are organized differently depending on the degree of connectivity, seasonal period and, at a finer grain, depth. Species co-occurrences were random in the disconnected lagoons during flood periods, in deep zones of the lagoons of the Baía River and in the shallow littoral zone in the lagoons of the Paraná River. Analysis of the patterns of co-occurrence indicated that competition and/or habitat preferences are probably important influences on the nonrandom structure of assemblages. However, we suppose that at least three important factors (disturbances by water level fluctuation, dispersion and facilitation) counteract potential effects of competition in specific situations, leading macrophyte assemblages to assume random structure.}, }
@article {pmid17895905, year = {2008}, author = {Woolbright, SA and Difazio, SP and Yin, T and Martinsen, GD and Zhang, X and Allan, GJ and Whitham, TG and Keim, P}, title = {A dense linkage map of hybrid cottonwood (Populus fremontii x P. angustifolia) contributes to long-term ecological research and comparison mapping in a model forest tree.}, journal = {Heredity}, volume = {100}, number = {1}, pages = {59-70}, doi = {10.1038/sj.hdy.6801063}, pmid = {17895905}, issn = {1365-2540}, mesh = {Chimera ; *Chromosome Mapping ; Ecology ; *Genetic Linkage ; Genetic Markers/genetics ; Genetics, Population ; Genome, Plant ; Linkage Disequilibrium ; Models, Biological ; Polymorphism, Restriction Fragment Length/genetics ; Populus/*classification/*genetics ; Trees/classification/genetics ; }, abstract = {Cottonwoods are foundation riparian species, and hybridization among species is known to produce ecological effects at levels higher than the population, including effects on dependent species, communities and ecosystems. Because these patterns result from increased genetic variation in key cottonwood traits, novel applications of genetic tools (for example, QTL mapping) could be used to place broad-scale ecological research into a genomic perspective. In addition, linkage maps have been produced for numerous species within the genus, and, coupled with the recent publication of the Populus genome sequence, these maps present a unique opportunity for genome comparisons in a model system. Here, we conducted linkage analyses in order to (1) create a platform for QTL and candidate gene studies of ecologically important traits, (2) create a framework for chromosomal-scale perspectives of introgression in a natural population, and (3) enhance genome-wide comparisons using two previously unmapped species. We produced 246 backcross mapping (BC(1)) progeny by crossing a naturally occurring F(1) hybrid (Populus fremontii x P. angustifolia) to a pure P. angustifolia from the same population. Linkage analysis resulted in a dense linkage map of 541 AFLP and 111 SSR markers distributed across 19 linkage groups. These results compared favorably with other Populus linkage studies, and addition of SSR loci from the poplar genome project provided coarse alignment with the genome sequence. Preliminary applications of the data suggest that our map represents a useful framework for applying genomic research to ecological questions in a well-studied system, and has enhanced genome-wide comparisons in a model tree.}, }
@article {pmid17878554, year = {2007}, author = {Belt, KT and Hohn, C and Gbakima, A and Higgins, JA}, title = {Identification of culturable stream water bacteria from urban, agricultural, and forested watersheds using 16S rRNA gene sequencing.}, journal = {Journal of water and health}, volume = {5}, number = {3}, pages = {395-406}, doi = {10.2166/wh.2007.035}, pmid = {17878554}, issn = {1477-8920}, mesh = {Agriculture ; Bacteria/*classification/*genetics/isolation &amp; purification ; Cities ; Colony Count, Microbial ; DNA, Bacterial/genetics ; Environmental Monitoring ; Genetic Variation ; Maryland ; Polymerase Chain Reaction ; RNA, Bacterial/genetics ; RNA, Ribosomal, 16S/genetics ; Rivers/*microbiology ; Sequence Analysis, RNA ; Trees ; *Water Microbiology ; Water Pollutants/*classification/isolation &amp; purification ; Water Supply ; }, abstract = {Bacteria present in water samples taken on a weekly basis, from June 2004 through June 2005, from three streams, were cultured on Coliscan Easygel agar plates. Colonies representative of a variety of colors and morphologies were subjected to amplification and sequencing of a 1000-1100 nt portion of the 16S rRNA gene. A total of 528 colonies were sequenced; these categorized into 26 genera and 78 species. Of 175 dark blue/purple colonies presumed to be E. coli, sequence analysis indicated that 45 (25%) were actually other genera. For the urban stream Gwynns Falls Gwynns Run, E. coli was the most common genus/species encountered, followed by Klebsiella and Aeromonas. For Pond Branch, a stream located in a forested watershed, it was Serratia, followed by Yersinia and Aeromonas. For McDonogh (MCDN), a stream associated with Zea mays (corn) row crop agriculture, E. coli was the most frequently isolated genus/species, followed by Aeromonas and Enterobacter. ERIC-PCR genotyping of isolates from the most prevalent genera/species, indicated a high degree of diversity within-stream for E. coli and K. pneumoniae. Conversely, genotyping of Y. enterocolitica isolates indicated that some were shared between different streams.}, }
@article {pmid17293520, year = {2007}, author = {Eichorst, SA and Breznak, JA and Schmidt, TM}, title = {Isolation and characterization of soil bacteria that define Terriglobus gen. nov., in the phylum Acidobacteria.}, journal = {Applied and environmental microbiology}, volume = {73}, number = {8}, pages = {2708-2717}, pmid = {17293520}, issn = {0099-2240}, mesh = {Bacterial Typing Techniques ; Blotting, Southern ; Carbon/metabolism ; Carotenoids/biosynthesis ; DNA, Bacterial/chemistry/genetics ; DNA, Ribosomal/chemistry/genetics ; Extracellular Matrix ; Fatty Acids/analysis/chemistry ; Genes, rRNA/genetics ; Gram-Negative Aerobic Rods and Cocci/*classification/cytology/*isolation &amp; purification/physiology ; Molecular Sequence Data ; Movement ; Phylogeny ; Pigments, Biological/biosynthesis ; RNA, Bacterial/genetics ; RNA, Ribosomal, 16S/genetics ; Sequence Analysis, DNA ; Sequence Homology, Nucleic Acid ; *Soil Microbiology ; }, abstract = {Bacteria in the phylum Acidobacteria are widely distributed and abundant in soils, but their ecological roles are poorly understood, owing in part to a paucity of cultured representatives. In a molecular survey of acidobacterial diversity at the Michigan State University Kellogg Biological Station Long-Term Ecological Research site, 27% of acidobacterial 16S rRNA gene clones in a never-tilled, successional plant community belonged to subdivision 1, whose relative abundance varied inversely with soil pH. Strains of subdivision 1 were isolated from these never-tilled soils using low-nutrient medium incubated for 3 to 4 weeks under elevated levels of carbon dioxide, which resulted in a slightly acidified medium that matched the pH optima of the strains (between 5 and 6). Colonies were approximately 1 mm in diameter and either white or pink, the latter due to a carotenoid(s) that was synthesized preferentially under 20% instead of 2% oxygen. Strains were gram-negative, aerobic, chemo-organotrophic, nonmotile rods that produced an extracellular matrix. All strains contained either one or two copies of the 16S rRNA encoding gene, which along with a relatively slow doubling time (10 to 15 h at ca. 23 degrees C) is suggestive of an oligotrophic lifestyle. Six of the strains are sufficiently similar to one another, but distinct from previously named Acidobacteria, to warrant creation of a new genus, Terriglobus, with Terriglobus roseus defined as the type species. The physiological and nutritional characteristics of Terriglobus are consistent with its potential widespread distribution in soil.}, }
@article {pmid16964466, year = {2006}, author = {Tereshchenko, LV and Molchanov, SA and Kolesnikova, OV and Latanov, AV and Shul'govskii, VV}, title = {Asymmetry of the amplitude-time properties of directed saccades in monkeys depending on the complexity of the spatial scheme of visual stimulation.}, journal = {Neuroscience and behavioral physiology}, volume = {36}, number = {8}, pages = {863-869}, pmid = {16964466}, issn = {0097-0549}, mesh = {Animals ; Evoked Potentials, Visual/physiology ; Macaca mulatta ; Photic Stimulation/methods ; Reaction Time/physiology ; Saccades/*physiology ; Time Factors ; Visual Fields/*physiology ; Visual Perception/*physiology ; }, abstract = {Three Macaca rhesus monkeys were used for studies of the performance of visually evoked saccades in single-step changes in the position of a stimulus using standard schemes for presentation of GAP-OVERLAP stimuli. Two spatial schemes were used: presentation of stimuli along the horizontal meridian (one-dimensional) and presentation of stimuli within a rectangular area of the visual field (two-dimensional). Asymmetrical foci of short-and long-latency saccades were found in the visual field. Dispersion factor analysis demonstrated that the dimensionality factor (one-dimensional versus two-dimensional stimulation schemes) had greater effects on the latent period of saccades than the lateralization factor (presentation on the left or right sides of the gaze point). The precision of the performance of visually evoked saccades decreased with increases in its eccentricity in both spatial stimulation schemes.}, }
@article {pmid16950900, year = {2006}, author = {Lynch, MD and Thorn, RG}, title = {Diversity of basidiomycetes in michigan agricultural soils.}, journal = {Applied and environmental microbiology}, volume = {72}, number = {11}, pages = {7050-7056}, pmid = {16950900}, issn = {0099-2240}, mesh = {*Agriculture ; Basidiomycota/*classification/genetics ; DNA, Fungal/analysis/isolation &amp; purification ; Genetic Variation ; Michigan ; Molecular Sequence Data ; Phylogeny ; Polymerase Chain Reaction/methods ; Sequence Analysis, DNA ; *Soil Microbiology ; Species Specificity ; }, abstract = {We analyzed the communities of soil basidiomycetes in agroecosystems that differ in tillage history at the Kellogg Biological Station Long-Term Ecological Research site near Battle Creek, Michigan. The approach combined soil DNA extraction through a bead-beating method modified to increase recovery of fungal DNA, PCR amplification with basidiomycete-specific primers, cloning and restriction fragment length polymorphism screening of mixed PCR products, and sequencing of unique clones. Much greater diversity was detected than was anticipated in this habitat on the basis of culture-based methods or surveys of fruiting bodies. With "species" defined as organisms yielding PCR products with > or =99% identity in the 5' 650 bases of the nuclear large-subunit ribosomal DNA, 241 "species" were detected among 409 unique basidiomycete sequences recovered. Almost all major clades of basidiomycetes from basidiomycetous yeasts and other heterobasidiomycetes through polypores and euagarics (gilled mushrooms and relatives) were represented, with a majority from the latter clade. Only 24 of 241 "species" had 99% or greater sequence similarity to named reference sequences in GenBank, and several clades with multiple "species" could not be identified at the genus level by phylogenetic comparisons with named sequences. The total estimated "species" richness for this 11.2-ha site was 367 "species" of basidiomycetes. Since >99% of the study area has not been sampled, the accuracy of our diversity estimate is uncertain. Replication in time and space is required to detect additional diversity and the underlying community structure.}, }
@article {pmid16937822, year = {2006}, author = {Costamagna, AC and Landis, DA}, title = {Predators exert top-down control of soybean aphid across a gradient of agricultural management systems.}, journal = {Ecological applications : a publication of the Ecological Society of America}, volume = {16}, number = {4}, pages = {1619-1628}, doi = {10.1890/1051-0761(2006)016[1619:petcos]2.0.co;2}, pmid = {16937822}, issn = {1051-0761}, mesh = {*Agriculture ; Animals ; Aphids/*physiology ; Coleoptera/physiology ; Heteroptera/physiology ; Insect Control/*methods ; Larva/physiology ; Population Growth ; Predatory Behavior/*physiology ; Seasons ; Glycine max/*parasitology ; Time Factors ; }, abstract = {The discovery of soybean aphid, Aphis glycines Matusumura, in North America in 2000 provided the opportunity to investigate the relative strength of top-down and bottom-up forces in regulating populations of this new invasive herbivore. At the Kellogg Biological Station Long Term Ecological Research site in agroecology, we contrasted A. glycines establishment and population growth under three agricultural production systems that differed markedly in disturbance and fertility regimes. Agricultural treatments consisted of a conventional-tillage high-input system, a no-tillage high-input system, and a zero-chemical-input system under conventional tillage. By selectively restricting or allowing predator access we simultaneously determined aphid response to top-down and bottom-up influences. Irrespective of predator exclusion, our agricultural manipulations did not result in bottom-up control of A. glycines intrinsic rate of increase or realized population growth. In contrast, we observed strong evidence for top-down control of A. glycines establishment and overall population growth in all production systems. Abundant predators, including Harmonia axyridis, Coccinella septempunctata, Orius insidiosus, and various predaceous fly larvae, significantly reduced A. glycines establishment and population increase in all trials. In contrast to other systems in which bottom-up forces control herbivore populations, we conclude that A. glycines is primarily controlled via top-down influences of generalist predators under a wide range of agricultural management systems. Understanding the role of top-down and bottom-up forces in this context allows agricultural managers to focus on effective strategies for control of this invasive pest.}, }
@article {pmid16869431, year = {2006}, author = {Cross, WF and Wallace, JB and Rosemond, AD and Eggert, SL}, title = {Whole-system nutrient enrichment increases secondary production in a detritus-based ecosystem.}, journal = {Ecology}, volume = {87}, number = {6}, pages = {1556-1565}, doi = {10.1890/0012-9658(2006)87[1556:wneisp]2.0.co;2}, pmid = {16869431}, issn = {0012-9658}, mesh = {Animals ; *Food Chain ; Insecta/*growth &amp; development ; Phosphates/*metabolism/*pharmacology ; *Plant Development ; *Rivers ; Time Factors ; }, abstract = {Although the effects of nutrient enrichment on consumer-resource dynamics are relatively well studied in ecosystems based on living plants, little is known about the manner in which enrichment influences the dynamics and productivity of consumers and resources in detritus-based ecosystems. Because nutrients can stimulate loss of carbon at the base of detrital food webs, effects on higher consumers may be fundamentally different than what is expected for living-plant-based food webs in which nutrients typically increase basal carbon. We experimentally enriched a detritus-based headwater stream for two years to examine the effects of nutrient-induced changes at the base of the food web on higher metazoan (predominantly invertebrate) consumers. Our paired-catchment design was aimed at quantifying organic matter and invertebrate dynamics in the enriched stream and an adjacent reference stream for two years prior to enrichment and two years during enrichment. Enrichment had a strong negative effect on standing crop of leaf litter, but no apparent effect on that of fine benthic organic matter. Despite large nutrient-induced reductions in the quantity of leaf litter, invertebrate secondary production during the enrichment was the highest ever reported for headwater streams at this Long Term Ecological Research site and was 1.2-3.3 times higher than predicted based on 15 years of data from these streams. Abundance, biomass, and secondary production of invertebrate consumers increased significantly in response to enrichment, and the response was greater among taxa with larval life spans < or = 1 yr than among those with larval life spans >1 yr. Production of invertebrate predators closely tracked the increased production of their prey. The response of invertebrates was largely habitat-specific with little effect of enrichment on food webs inhabiting bedrock outcrops. Our results demonstrate that positive nutrient-induced changes to food quality likely override negative changes to food quantity for consumers during the initial years of enrichment of detritus-based stream ecosystems. Longer-term enrichment may impact consumers through eventual reductions in the quantity of detritus.}, }
@article {pmid16783449, year = {2006}, author = {Yang, SS and Tsai, SH and Fan, HY and Yang, CK and Hung, WL and Cho, ST}, title = {Seasonal variation of microbial ecology in hemlock soil of Tatachia Mountain, Taiwan.}, journal = {Journal of microbiology, immunology, and infection = Wei mian yu gan ran za zhi}, volume = {39}, number = {3}, pages = {195-205}, pmid = {16783449}, issn = {1684-1182}, mesh = {Actinobacteria/isolation &amp; purification ; Biomass ; Carbon/analysis ; Carboxylic Acids/analysis ; *Ecology ; Fungi/isolation &amp; purification ; *Hemlock ; Hydrogen-Ion Concentration ; Nitrogen/analysis ; Phosphates/analysis ; Seasons ; Soil/*analysis ; *Soil Microbiology ; Taiwan ; Temperature ; Trees ; }, abstract = {BACKGROUND AND PURPOSE: Forest soil microorganisms and fauna decompose the organic materials, and thus strongly influence the nutrient cycling of the ecosystem. Soil microorganisms also contribute to soil structure and soil fertility. In Taiwan, the microbial distributions of soils have only been determined in acidic soil, inorganic acidic soil, upland soil, alkaline soil and power plant areas. There are few data on the microbial populations of forest soils. Tatachia Mountain is located in the central part of Taiwan and is a typical high altitude protected ecosystem area, designated as a National Park. This study investigated the role of microorganisms in the ecology and nutrient transformation of forest soil in Taiwan.<br><br>METHODS: As part of long-term ecological research in Taiwan, the environmental conditions, seasons, microbial populations, biomass and organic acid contents of hemlock soil were investigated. We also studied the effect of depth on microbial populations and biomass.<br><br>RESULTS: The soil temperatures were between 5.5 and 15.6 degrees C and the soil pH ranged from 3.3 to 4.4. Total organic carbon and total nitrogen contents ranged from 2.3 to 37.1% and from 0.3 to 1.7%, respectively. The carbon/nitrogen ratio was between 8.2 and 24.4. In topsoil, each gram of soil contained 10(5)-10(7) colony-forming units (CFU) culturable bacteria, 10(2)-10(5) CFU actinomycetes, 10(3)-10(5) CFU fungi, 10(4)-10(6) CFU cellulolytic microbes, 10(4)-10(6) CFU phosphate-solubilizing microbes, and 10(3)-10(6) CFU nitrogen-fixing microbes. Microbial populations were higher in topsoil compared with subsoil, but lower in topsoil than in organic layer. Microbial populations also decreased with the depth of soil. Microbial populations at 1E horizon were 0.6% to 9.4% of those at O horizon. The microbial biomass evaluated contained carbon 391-1013 mug, nitrogen 51-146 mug, malic acid 76-557 nM and succinic acid 37-527 nM per gram of soil. Summer season had higher microbial populations, biomass and organic content than winter season, but the differences were not significant.<br><br>CONCLUSION: Heavy coverage of organic matter was found in hemlock and spruce soils and was associated with acidic pH. Microbial populations decreased with increasing soil depth. Microbes play a very important role in organic matter decomposition and nutrition transformation in hemlock soil.}, }
@article {pmid16676540, year = {2006}, author = {Bestelmeyer, BT and Ward, JP and Havstad, KM}, title = {Soil-geomorphic heterogeneity governs patchy vegetation dynamics at an arid ecotone.}, journal = {Ecology}, volume = {87}, number = {4}, pages = {963-973}, doi = {10.1890/0012-9658(2006)87[963:shgpvd]2.0.co;2}, pmid = {16676540}, issn = {0012-9658}, mesh = {*Ecosystem ; *Plants ; Rain ; *Soil ; }, abstract = {Soil properties are well known to affect vegetation, but the role of soil heterogeneity in the patterning of vegetation dynamics is poorly documented. We asked whether the location of an ecotone separating grass-dominated and sparsely vegetated areas reflected only historical variation in degradation or was related to variation in inherent soil properties. We then asked whether changes in the cover and spatial organization of vegetated and bare patches assessed using repeat aerial photography reflected self-organizing dynamics unrelated to soil variation or the stable patterning of soil variation. We found that the present-day ecotone was related to a shift from more weakly to more strongly developed soils. Parts of the ecotone were stable over a 60-year period, but shifts between bare and vegetated states, as well as persistently vegetated and bare states, occurred largely in small (<40 m2) patches throughout the study area. The probability that patches were presently vegetated or bare, as well as the probability that vegetation persisted and/or established over the 60-year period, was negatively related to surface calcium carbonate and positively related to subsurface clay content. Thus, only a fraction of the landscape was susceptible to vegetation change, and the sparsely vegetated area probably featured a higher frequency of susceptible soil patches. Patch dynamics and self-organizing processes can be constrained by subtle (and often unrecognized) soil heterogeneity.}, }
@article {pmid15922566, year = {2005}, author = {Nemergut, DR and Costello, EK and Meyer, AF and Pescador, MY and Weintraub, MN and Schmidt, SK}, title = {Structure and function of alpine and arctic soil microbial communities.}, journal = {Research in microbiology}, volume = {156}, number = {7}, pages = {775-784}, doi = {10.1016/j.resmic.2005.03.004}, pmid = {15922566}, issn = {0923-2508}, mesh = {Archaea/*classification/genetics/isolation &amp; purification ; Arctic Regions ; Bacteria/*classification/genetics/isolation &amp; purification ; Biodiversity ; *Cold Climate ; *Ecosystem ; Eukaryotic Cells/*classification ; Fungi/*classification/genetics/isolation &amp; purification ; Genes, rRNA ; *Soil Microbiology ; }, abstract = {Cultivation-independent molecular phylogenetic techniques are now widely employed to examine environmental microbial diversity; however, the relationship between microbial community structure and ecosystem function is unclear. This review synthesizes cultivation-independent views of microbiological diversity with our current understanding of nutrient dynamics in alpine and arctic soils. Recently, we have begun to explore connections between microbial community structure and function in soils from the alpine Niwot Ridge LTER site in Colorado, USA, whose ecology has been extensively investigated for over 50 years. We examined the diversity of bacterial, eucaryal, and archaeal small subunit rRNA genes in tundra and talus soils across seasons in the alpine. This work has provided support for spatial and seasonal shifts in specific microbial groups, which correlate well with previously documented transitions in microbial processes. In addition, these preliminary results suggest that the physiologies of certain groups of organisms may scale up to the ecosystem level, providing the basis for testable hypotheses about the function of specific microbes in this system. These studies have also expanded on the known diversity of life, as these soils harbor bacterial and eucaryotic lineages that are distantly related to other known organisms. In contrast to the alpine, microbial diversity in the arctic has been little explored; only three published studies have used molecular techniques to examine these soils. Because of the importance of these systems, particularly to the global C cycle, and their vulnerability to current and impending climate change, the microbial diversity of these soils needs to be further investigated.}, }
@article {pmid15887368, year = {2004}, author = {Barbosa, FA and Scarano, FR and Sabará, MG and Esteves, FA}, title = {Brazilian LTER: ecosystem and biodiversity information in support of decision-making.}, journal = {Environmental monitoring and assessment}, volume = {90}, number = {1-3}, pages = {121-133}, pmid = {15887368}, issn = {0167-6369}, mesh = {*Biodiversity ; Brazil ; Cost-Benefit Analysis ; *Decision Making ; *Ecosystem ; Environmental Exposure/prevention &amp; control ; Environmental Health ; *Environmental Monitoring ; Geography ; Humans ; *Public Policy ; Risk Management ; }, abstract = {Brazil officially joined the International Long Term Ecological Research (ILTER) network in January 2000, when nine research sites were created and funded by the Brazilian Council for Science and Technology (CNPq). Two-years later some positive signs already emerge of the scientific, social and political achievements of the Brazilian LTER program. We discuss examples of how ecosystem and biodiversity information gathered within a long-term research approach are currently subsidizing decision-making as regards biodiversity conservation and watershed management at local and regional scales. Success in this respect has often been related to satisfactory communication between scientists, private companies, government and local citizens. Environmental education programs in the LTER sites are playing an important role in social and political integration. Most examples of integration of ecological research to decision-making in Brazil derive from case studies at local or regional scale. Despite the predominance of a bottom-up integrative pathway (from case studies to models; from local to national scale), some top-down initiatives are also in order, such as the construction of a model to estimate the inpact of different macroeconomic policies and growth trajectories on land use. We believe science and society in Brazil will benefit of the coexistence of bottom-up and top-down integrative approaches.}, }
@article {pmid15812655, year = {2005}, author = {Boelman, NT and Stieglitz, M and Griffin, KL and Shaver, GR}, title = {Inter-annual variability of NDVI in response to long-term warming and fertilization in wet sedge and tussock tundra.}, journal = {Oecologia}, volume = {143}, number = {4}, pages = {588-597}, pmid = {15812655}, issn = {0029-8549}, mesh = {Alaska ; Analysis of Variance ; Biomass ; *Ecosystem ; *Environment ; Longitudinal Studies ; Nitrogen ; Phosphorus ; *Plant Physiological Phenomena ; *Temperature ; }, abstract = {This study explores the relationship between the normalized difference vegetation index (NDVI) and aboveground plant biomass for tussock tundra vegetation and compares it to a previously established NDVI-biomass relationship for wet sedge tundra vegetation. In addition, we explore inter-annual variation in NDVI in both these contrasting vegetation communities. All measurements were taken across long-term experimental treatments in wet sedge and tussock tundra communities at the Toolik Lake Long Term Ecological Research (LTER) site, in northern Alaska. Over 15 years (for wet sedge tundra) and 14 years (for tussock tundra), N and P were applied in factorial experiments (N, P and N+P), air temperature was increased using greenhouses with and without N+P fertilizer, and light intensity was reduced by 50% using shade cloth. during the peak growing seasons of 2001, 2002, and 2003, NDVI measurements were made in both the wet sedge and tussock tundra experimental treatment plots, creating a 3-year time series of inter-annual variation in NDVI. We found that: (1) across all tussock experimental tundra treatments, NDVI is correlated with aboveground plant biomass (r2 = 0.59); (2) NDVI-biomass relationships for tussock and wet sedge tundra communities are community specific, and; (3) NDVI values for tussock tundra communities are typically, but not always, greater than for wet sedge tundra communities across all experimental treatments. We suggest that differences between the response of wet sedge and tussock tundra communities in the same experimental treatments result from the contrasting degree of heterogeneity in species and functional types that characterize each of these Arctic tundra vegetation communities.}, }
@article {pmid15696386, year = {2004}, author = {Graham, JM and Kent, AD and Lauster, GH and Yannarell, AC and Graham, LE and Triplett, EW}, title = {Seasonal dynamics of phytoplankton and planktonic protozoan communities in a northern temperate humic lake: diversity in a dinoflagellate dominated system.}, journal = {Microbial ecology}, volume = {48}, number = {4}, pages = {528-540}, pmid = {15696386}, issn = {0095-3628}, mesh = {Animals ; Bacterial Physiological Phenomena ; Biodiversity ; Dinoflagellida/*physiology ; Ecosystem ; Eukaryota/*physiology ; Fresh Water/microbiology/*parasitology ; Hydrogen-Ion Concentration ; Phytoplankton/*physiology ; Population Dynamics ; Seasons ; Wisconsin ; }, abstract = {Species diversity and richness, and seasonal population dynamics of phytoplankton, planktonic protozoa, and bacterioplankton sampled from the epilimnion of Crystal Bog in 2000, were examined in order to test the hypothesis that these groups' diversity and abundance patterns might be linked. Crystal Bog, a humic lake in Vilas County, Wisconsin, is part of the North Temperate Lakes Long-Term Ecological Research Site. Phytoplankton and planktonic protozoa were identified and enumerated in a settling chamber with an inverted microscope. Bacterial cells were enumerated with the use of fluorescence 4', 6'-diamidino-2-phenylindole (DAPI)-staining procedures, and automated ribosomal intergenic spacer analysis (ARISA) was used to assess bacterioplankton diversity. Bacterial cell counts showed little seasonal variation and averaged 2.6 x 10(6) cells/mL over the ice-free season. Phytoplankton and planktonic protozoan numbers varied by up to two orders of magnitude and were most numerous in late spring and summer. Dinoflagellates largely dominated Crystal Bog throughout the ice-free period, specifically Peridiniopsis quadridens in the spring, Peridinium limbatum in summer, and Gymnodinium fuscum and P. quadridens in fall. Brief blooms of Cryptomonas, Dinobryon, and Synura occurred between periods of dinoflagellate domination. The dominant dinoflagellate, Peridinium limbatum, was calculated to have a growth rate of 0.065 day(-1) and a doubling time of 10.7 days. Heterotrophic nanoflagellates (HNFs) were a consistent component of the planktonic protozoa; seasonal patterns were determined for three genera of HNFs (Monosiga, Bicosoeca, and Desmarella moniliformis). Three genera of ciliates (Coleps, Strobilidium, and Strombidium) comprised the greater part of the planktonic protozoa in Crystal Bog. The number of species of planktonic protozoa was too low to calculate a diversity index. Shannon-Weaver diversity indices for phytoplankton and bacterioplankton in the epilimnion followed very similar seasonal patterns in this lake, supporting the hypothesis that in freshwaters, diversity patterns of these groups are linked.}, }
@article {pmid15623324, year = {2004}, author = {Heisler, GM and Grant, RH and Gao, W and Slusser, JR}, title = {Solar ultraviolet-B radiation in urban environments: the case of Baltimore, Maryland.}, journal = {Photochemistry and photobiology}, volume = {80}, number = {3}, pages = {422-428}, doi = {10.1562/0031-8655(2004)080&lt;0422:SURIUE&gt;2.0.CO;2}, pmid = {15623324}, issn = {0031-8655}, mesh = {Baltimore ; *Environment ; Ozone/analysis ; Time Factors ; *Ultraviolet Rays ; }, abstract = {Ultraviolet-B radiation (UV-B, 280-320 nm) has important effects in urban areas, including those on human health. Broadband UV-B radiation is monitored in Baltimore, MD, as part of the Baltimore Ecosystem Study, a long-term ecological research program. We compare broadband UV-B irradiance in Baltimore with UV-B at two nearby locations: a more rural station 64 km southeast and a suburban station 42 km southwest. The monitoring station in Baltimore is on the roof of a 33-m-tall building; there are no significant obstructions to sky view. The U.S. Department of Agriculture UV-B Monitoring and Research Program provided all sensors, which were calibrated at the National Oceanic and Atmospheric Administration Central UV Calibration Facility. UV-B irradiances at the three sites generally were similar. Over all conditions, Baltimore and the suburban site measured 3.4% less irradiance than the rural site. This difference is within the anticipated +/-3% calibration uncertainty of the pyranometers. On 59 days with cloud-free conditions at all three sites, average differences in measured UV-B among the three sites were even smaller; Baltimore measured 1.2% less irradiance than the rural site. High aerosol optical thickness strongly reduced daily UV-B dose, whereas [SO2] had no influence. Surface O3 increased with increasing UV-B dose when [NO2] exceeded 10 ppb.}, }
@article {pmid15296304, year = {2004}, author = {Chiuchiolo, AL and Dickhut, RM and Cochran, MA and Ducklow, HW}, title = {Persistent organic pollutants at the base of the Antarctic marine food web.}, journal = {Environmental science &amp; technology}, volume = {38}, number = {13}, pages = {3551-3557}, doi = {10.1021/es0351793}, pmid = {15296304}, issn = {0013-936X}, mesh = {Animals ; Antarctic Regions ; Environmental Pollutants/*analysis/pharmacokinetics ; Eukaryota/*metabolism ; Euphausiacea/*metabolism ; *Food Chain ; Gas Chromatography-Mass Spectrometry ; Geography ; Hydrocarbons, Brominated/analysis/pharmacokinetics ; Ice ; Insecticides/analysis/pharmacokinetics ; Oceans and Seas ; Organic Chemicals/*analysis/pharmacokinetics ; Phenyl Ethers/analysis/pharmacokinetics ; Plankton/*metabolism ; Seasons ; }, abstract = {Various organochlorine pesticides and brominated diphenyl ethers (BDE-47, -99, and -100) were measured in sea ice algae, water column plankton, and juvenile and adult krill collected in the Palmer Long-Term Ecological Research (LTER) region west of the Antarctic Peninsula during late austral winter and midsummer, 2001-2002. BDEs were 100-1000 times higher in ice algae and 2-10 times higher in phytoplankton than the most abundant organochlorine pesticide, hexachlorobenzene (HCB), reflecting the current production and use of BDEs versus organochlorine pesticides. However, concentrations of HCB and BDEs were significantly lower in summer plankton than in ice algae indicating lower atmospheric inputs, removal from the water column, and/or biodilution of persistent organic pollutants at the base of the food web during summer. Concentrations of HCB (juvenile and adult krill) and BDEs (juvenile krill) were not significantly different from their primary food source (ice algae, phytoplankton), and BDEs were significantly lower in adult krill versus phytoplankton, indicating no biomagnification of HCB or BDEs during transfer from plankton to krill. The high concentrations of BDEs and HCB in ice algae and associated juvenile krill illustrate the importance of sea ice as a vector for entry of POPs into the Antarctic marine ecosystem.}, }
@article {pmid21653470, year = {2004}, author = {Forbis, TA and Doak, DF}, title = {Seedling establishment and life history trade-offs in alpine plants.}, journal = {American journal of botany}, volume = {91}, number = {7}, pages = {1147-1153}, doi = {10.3732/ajb.91.7.1147}, pmid = {21653470}, issn = {0002-9122}, abstract = {Seedling establishment is central to population maintenance for nonclonal plant species. Plants with low recruitment rates are expected to have high survival rates, and life history theory indicates there should be a single curve for the trade-off between recruitment and mortality that applies to most or all plant species. Alpine perennials are thought to have extraordinarily low recruitment rates because of the harsh environment, but the importance of recruitment in the life history of these plants is unknown. Two alpine cushion plant species, Minuartia obtusiloba and Paronychia pulvinata, were used to (1) determine the role of recruitment in population maintenance and (2) determine whether the fecundity/mortality trade-off for these alpine plants falls on or off of the curve for other perennial plant species. Using size-based population projection matrices, we determined that the life history of Minuartia and Paronychia emphasizes recruitment less than that of any other nonclonal species in a literature survey. Estimated maximum life spans of these two species are 200 and 324 yr, respectively, and a regression with other perennial species from the literature indicated that the relationship between fecundity and mortality in these alpine species is consistent with the predicted trade-off curve for perennial species from other environments.}, }
@article {pmid15005542, year = {2003}, author = {McCluskey, BJ and Beaty, BJ and Salman, MD}, title = {Climatic factors and the occurrence of vesicular stomatitis in New Mexico, United States of America.}, journal = {Revue scientifique et technique (International Office of Epizootics)}, volume = {22}, number = {3}, pages = {849-856}, doi = {10.20506/rst.22.3.1438}, pmid = {15005542}, issn = {0253-1933}, mesh = {Animals ; Animals, Domestic ; *Climate ; Discriminant Analysis ; Humidity ; Multivariate Analysis ; New Mexico/epidemiology ; Rain ; Rhabdoviridae Infections/epidemiology/*veterinary ; Seasons ; Stomatitis/epidemiology/*veterinary ; Temperature ; *Vesicular stomatitis Indiana virus ; }, abstract = {Vesicular stomatitis (VS) outbreaks occurred in the southwestern United States of America in 1995, 1997 and 1998. The epidemiology of VS is not understood completely and some of the epidemiologic aspects of this disease are currently under investigation. In this study, daily maximum temperature, daily minimum temperature, daily mean temperature, daily mean relative humidity and daily total precipitation were collected at the Sevilleta Long Term Ecological Research site in central New Mexico. Discriminant analysis was used to identify the climatic variables best able to classify in which months VS would occur. The study found that the amounts of precipitation occurring two, ten, eleven and twelve months prior to the month in which cases were diagnosed, were the climatic variables that best described the occurrence of VS cases. The association of VS cases and precipitation suggests that, like numerous other arthropod-borne diseases, transmission of the disease-causing pathogen is linked to variations in climate.}, }
@article {pmid14602639, year = {2003}, author = {Kent, AD and Smith, DJ and Benson, BJ and Triplett, EW}, title = {Web-based phylogenetic assignment tool for analysis of terminal restriction fragment length polymorphism profiles of microbial communities.}, journal = {Applied and environmental microbiology}, volume = {69}, number = {11}, pages = {6768-6776}, pmid = {14602639}, issn = {0099-2240}, mesh = {Bacteria/*classification/genetics ; Computational Biology/methods ; DNA, Bacterial/analysis/genetics/isolation &amp; purification ; *Ecosystem ; Fresh Water/*microbiology ; Gene Library ; *Internet ; *Phylogeny ; *Polymorphism, Restriction Fragment Length ; RNA, Ribosomal, 16S/genetics ; }, abstract = {Culture-independent DNA fingerprints are commonly used to assess the diversity of a microbial community. However, relating species composition to community profiles produced by community fingerprint methods is not straightforward. Terminal restriction fragment length polymorphism (T-RFLP) is a community fingerprint method in which phylogenetic assignments may be inferred from the terminal restriction fragment (T-RF) sizes through the use of web-based resources that predict T-RF sizes for known bacteria. The process quickly becomes computationally intensive due to the need to analyze profiles produced by multiple restriction digests and the complexity of profiles generated by natural microbial communities. A web-based tool is described here that rapidly generates phylogenetic assignments from submitted community T-RFLP profiles based on a database of fragments produced by known 16S rRNA gene sequences. Users have the option of submitting a customized database generated from unpublished sequences or from a gene other than the 16S rRNA gene. This phylogenetic assignment tool allows users to employ T-RFLP to simultaneously analyze microbial community diversity and species composition. An analysis of the variability of bacterial species composition throughout the water column in a humic lake was carried out to demonstrate the functionality of the phylogenetic assignment tool. This method was validated by comparing the results generated by this program with results from a 16S rRNA gene clone library.}, }
@article {pmid14559272, year = {2004}, author = {Chiang, PN and Wang, MK and Chiu, CY and King, HB and Hwong, JL}, title = {Changes in the grassland-forest boundary at Ta-Ta-Chia long term ecological research (LTER) site detected by stable isotope ratios of soil organic matter.}, journal = {Chemosphere}, volume = {54}, number = {2}, pages = {217-224}, doi = {10.1016/j.chemosphere.2003.07.005}, pmid = {14559272}, issn = {0045-6535}, mesh = {Carbon Isotopes/chemistry ; *Ecosystem ; Fires ; Poaceae/*chemistry ; Population Dynamics ; Soil/*analysis ; Taiwan ; Trees/*chemistry ; }, abstract = {The carbon isotope analysis [delta13C values] of organic samples can be a useful research in ecological studies because delta13C values are indicative of the plant source. This study investigated the changes in plant communities along the grassland-forest boundary in the alpine forest at Ta-Ta-Chia long term ecological research (LTER) site in central Taiwan using carbon isotope data. The aim of this study was focused on the forest fire affected the change of vegetation community. Four pedons from grassland dominated by Miscanthus transmorrisonensis (pedons 1 and 2), transition zone by Tsuga and Yushania nittakeyamensis (pedon 3), and forest zone by Tsuga and nittakeyamensis (pedon 4) were examined. Soil organic matter (SOM) delta13C values in the upper soil horizon were similar to delta13C values of the overlaying vegetation types. This indicates that the boundary between these plant communities remained the same in the past decades. The delta13C values of the grassland SOM ranged from -19.4 per thousand to -24.1 per thousand, showing decrease with soil depth. This suggests that C4 plants (transmorrisonensis) have replaced C3 plants of Tsuga and nittakeyamensis. The delta13C values of the Tsuga forest area (pedon 4) range from -27.0 per thousand to -23.5 per thousand and showed only slight change with soil depth, implying that C3 plants have remained the major species in the forest.}, }
@article {pmid14557865, year = {2004}, author = {Forbis, TA and Larmore, J and Addis, E}, title = {Temporal patterns in seedling establishment on pocket gopher disturbances.}, journal = {Oecologia}, volume = {138}, number = {1}, pages = {112-121}, pmid = {14557865}, issn = {0029-8549}, mesh = {Animals ; Ecosystem ; Germination ; *Plant Development ; Population Dynamics ; *Rodentia ; Seedlings ; Seeds ; Survival Analysis ; }, abstract = {Disturbances often facilitate seedling establishment, and can change the species composition of a community by increasing recruitment of disturbance-adapted species. To understand the effects of pocket gopher disturbances on alpine seedling dynamics, we examined the gopher disturbances' effects on seedling emergence and survival on gopher disturbances 0 to 5 years old. In contrast to results from most other ecosystems, these recently created gopher mounds had lower seedling emergence and survival rates than undisturbed areas. A lack of correlation between species' abundances on gopher mounds and undisturbed sites in one of the two communities studied suggested that a suite of disturbance-adapted species recruited onto the mounds. To explain low seedling emergence on recent gopher mounds, we quantified gopher mound seed banks and studied recruitment in a site with mounds that ranged from 0 to >20 years old. Seed numbers in first-year gopher mound soils were extremely low relative to undisturbed soils, and this pattern was mirrored in seedling establishment patterns over the long term. Gopher disturbance depressed seedling emergence density for the first 5 years. Subsequently, emergence density increased until at least 20 years following the disturbance. Emergence on disturbances more than 20 years old was higher than on undisturbed sites. Therefore, gopher disturbances probably facilitate seedling establishment in alpine dry and moist meadow; however, this process takes place over decades.}, }
@article {pmid21659220, year = {2003}, author = {Forbis, TA}, title = {Seedling demography in an alpine ecosystem.}, journal = {American journal of botany}, volume = {90}, number = {8}, pages = {1197-1206}, doi = {10.3732/ajb.90.8.1197}, pmid = {21659220}, issn = {0002-9122}, abstract = {Seedling establishment has long been believed to be rare on alpine tundra because of predicted life history trade-offs, the clonality of alpine species, and the harshness of the alpine climate. Contrary to the idea that seedlings are rare on alpine tundra, a 4-yr demographic study of seedlings at Niwot Ridge, Colorado, USA, found seedlings at high densities, particularly in wetter plant communities. Higher germination densities were associated with higher soil moistures both across communities and across time. Mortality of seedlings was highest in the first year and decreased in subsequent years. Species' abundances differed between seedling and adult populations. Many forbs that lacked vegetative reproduction were significantly more abundant among seedling populations, and many monocots and clonal forbs were more abundant among adult populations. In a comparison with published demographic rates, seedling recruitment and mortality rates of Niwot Ridge species fell above or within rates for a wide range of perennial species. Therefore, germination and seedling establishment stages are no more limiting to sexual reproduction in alpine plants than in other perennial plants.}, }
@article {pmid12750992, year = {2003}, author = {Tyler, AC and Mastronicola, TA and McGlathery, KJ}, title = {Nitrogen fixation and nitrogen limitation of primary production along a natural marsh chronosequence.}, journal = {Oecologia}, volume = {136}, number = {3}, pages = {431-438}, pmid = {12750992}, issn = {0029-8549}, mesh = {Biomass ; Ecosystem ; Eukaryota ; Nitrogen/analysis/*metabolism ; Nitrogen Fixation/*physiology ; Poaceae/*physiology ; Population Dynamics ; Seasons ; }, abstract = {Nitrogen (N) limitation of primary production is common in temperate salt marshes, even though conservative N recycling can fulfill a large proportion of plant N demand. In nutrient poor young marshes, N limitation may be more severe and new N sources, such as N fixation, more important for plant growth. We measured N fixation and the response of salt marsh primary producers (Spartina alterniflora and benthic microalgae) to N fertilization in one mature (>150 year) and two young (7 and 15 year) naturally developing marshes at the Virginia Coast Reserve LTER site. S. alterniflora aboveground biomass in the mature marsh (1,700+/-273 g m(-2)) was 1.8 and 2.8 times higher than in the 15 year and 7 year old marshes, respectively. Fertilization significantly increased S. alterniflora biomass in the two young marshes (160-175%) and areal aboveground tissue N in the youngest marsh (260%). Microalgal chlorophyll a (Chl a) in the mature marsh was nearly 2-fold lower than in the 7-year-old marsh, and there was no evidence that this was due to light limitation. However, Chl a in fertilized plots was 30% higher than control plots at the youngest site. Daily N fixation decreased with increasing marsh age in summer, when rates were highest at all sites. Autotrophic N fixation (difference between rates in the light and dark) was most important in the summer, but we saw no indication of a shift in dominance between autotrophic and heterotrophic N fixers during marsh development. Estimated annual N fixation was 2- to 3-fold higher in the young marsh (18.3+/-1.5 g N m(-2) year(-1)), than in the intermediate-aged (9.0+/-0.7) or mature marsh (6.1+/-0.5). In the young marshes, N fixation was sufficient to provide a substantial proportion of aboveground S. alterniflora N demand. Our results suggest that both benthic microalgae and S. alterniflora in young salt marshes are N limited, and that this limitation decreases as the marsh matures. The high rates of N fixation by autotrophic and heterotrophic bacteria in the sediment could provide an important source of N for primary producers during marsh development.}, }
@article {pmid12721832, year = {2003}, author = {Boelman, NT and Stieglitz, M and Rueth, HM and Sommerkorn, M and Griffin, KL and Shaver, GR and Gamon, JA}, title = {Response of NDVI, biomass, and ecosystem gas exchange to long-term warming and fertilization in wet sedge tundra.}, journal = {Oecologia}, volume = {135}, number = {3}, pages = {414-421}, pmid = {12721832}, issn = {0029-8549}, mesh = {Biomass ; Carbon Dioxide/*analysis/*metabolism ; Ecosystem ; Environmental Monitoring ; Gases ; Nitrogen/metabolism ; Phosphorus/metabolism ; *Photosynthesis ; Plant Physiological Phenomena ; Spacecraft ; }, abstract = {This study explores the relationship between the normalized difference vegetation index (NDVI), aboveground plant biomass, and ecosystem C fluxes including gross ecosystem production (GEP), ecosystem respiration (ER) and net ecosystem production. We measured NDVI across long-term experimental treatments in wet sedge tundra at the Toolik Lake LTER site, in northern Alaska. Over 13 years, N and P were applied in factorial experiments (N, P and N + P), air temperature was increased using greenhouses with and without N + P fertilizer, and light intensity (photosynthetically active photon flux density) was reduced by 50% using shade cloth. Within each treatment plot, NDVI, aboveground biomass and whole-system CO(2) flux measurements were made at the same sampling points during the peak-growing season of 2001. We found that across all treatments, NDVI is correlated with aboveground biomass (r(2)=0.84), GEP (r(2)=0.75) and ER (r(2)=0.71), providing a basis for linking remotely sensed NDVI to aboveground biomass and ecosystem carbon flux.}, }
@article {pmid12676229, year = {2003}, author = {Bytnerowicz, A and Badea, O and Barbu, I and Fleischer, P and Fraczek, W and Gancz, V and Godzik, B and Grodzińska, K and Grodzki, W and Karnosky, D and Koren, M and Krywult, M and Krzan, Z and Longauer, R and Mankovska, B and Manning, WJ and McManus, M and Musselman, RC and Novotny, J and Popescu, F and Postelnicu, D and Prus-Głowacki, W and Skawiński, P and Skiba, S and Szaro, R and Tamas, S and Vasile, C}, title = {New international long-term ecological research on air pollution effects on the Carpathian Mountain forests, Central Europe.}, journal = {Environment international}, volume = {29}, number = {2-3}, pages = {367-376}, doi = {10.1016/S0160-4120(02)00172-1}, pmid = {12676229}, issn = {0160-4120}, mesh = {Air Pollutants/*adverse effects ; *Ecology ; Europe ; *International Cooperation ; Nitrogen/adverse effects ; Population Dynamics ; Research/trends ; Sulfur/adverse effects ; Trees ; }, abstract = {An international cooperative project on distribution of ozone in the Carpathian Mountains, Central Europe was conducted from 1997 to 1999. Results of that project indicated that in large parts of the Carpathian Mountains, concentrations of ozone were elevated and potentially phytotoxic to forest vegetation. That study led to the establishment of new long-term studies on ecological changes in forests and other ecosystems caused by air pollution in the Retezat Mountains, Southern Carpathians, Romania and in the Tatra Mountains, Western Carpathians on the Polish-Slovak border. Both of these important mountain ranges have the status of national parks and are Man &amp; the Biosphere Reserves. In the Retezat Mountains, the primary research objective was to evaluate how air pollution may affect forest health and biodiversity. The main research objective in the Tatra Mountains was to evaluate responses of natural and managed Norway spruce forests to air pollution and other stresses. Ambient concentrations of ozone (O(3)), sulfur dioxide (SO(2)), nitrogen oxides (NO(x)) as well as forest health and biodiversity changes were monitored on densely distributed research sites. Initial monitoring of pollutants indicated low levels of O(3), SO(2), and NO(x) in the Retezat Mountains, while elevated levels of O(3) and high deposition of atmospheric sulfur (S) and nitrogen (N) have characterized the Tatra Mountains. In the Retezat Mountains, air pollution seems to have little effect on forest health; however, there was concern that over a long time, even low levels of pollution may affect biodiversity of this important ecosystem. In contrast, severe decline of Norway spruce has been observed in the Tatra Mountains. Although bark beetle seems to be the immediate cause of that decline, long-term elevated levels of atmospheric N and S depositions and elevated O(3) could predispose trees to insect attacks and other stresses. European and US scientists studied pollution deposition, soil and plant chemistry, O(3)-sensitive plant species, forest insects, and genetic changes in the Retezat and Tatra Mountains. Results of these investigations are presented in a GIS format to allow for a better understanding of the changes and the recommendations for effective management in these two areas.}, }
@article {pmid12487343, year = {2002}, author = {Forbis, TA and Floyd, SK and de Queiroz, A}, title = {The evolution of embryo size in angiosperms and other seed plants: implications for the evolution of seed dormancy.}, journal = {Evolution; international journal of organic evolution}, volume = {56}, number = {11}, pages = {2112-2125}, doi = {10.1111/j.0014-3820.2002.tb00137.x}, pmid = {12487343}, issn = {0014-3820}, mesh = {*Biological Evolution ; Magnoliopsida/classification/*embryology/physiology ; Models, Biological ; Phylogeny ; Seeds/cytology/*physiology ; }, abstract = {Seed dormancy plays an important role in germination ecology and seed plant evolution. Morphological seed dormancy is caused by an underdeveloped embryo that must mature prior to germination. It has been suggested that the presence of an underdeveloped embryo is plesiomorphic among seed plants and that parallel directional change in embryo morphology has occurred separately in gymnosperms and in angiosperms. We test these hypotheses using original data on embryo morphology of key basal taxa, a published dataset, and the generalized least squares (GLS) method of ancestral character state reconstruction. Reconstructions for embryo to seed ratio (E:S) using family means for 179 families showed that E:S has increased between the ancestral angiosperm and almost all extant angiosperm taxa. Species in the rosid clade have particularly large embryos relative to the angiosperm ancestor. Results for the gymnosperms show a similar but smaller increase. There were no statistically significant differences in E:S between basal taxa and any derived group due to extremely large standard errors produced by GLS models. However, differences between reconstructed values for the angiosperm ancestor and more highly nested nodes are large and these results are robust to topological and branch-length manipulations. Our analysis supports the idea that the underdeveloped embryo is primitive among seed plants and that there has been a directional change in E:S within both angiosperms and gymnosperms. Our analysis suggests that dormancy enforced by an underdeveloped embryo is plesiomorphic among angiosperms and that nondormancy and other dormancy types probably evolved within the angiosperms. The shift in E:S was likely a heterochronic change, and has important implications for the life history of seed plants.}, }
@article {pmid12428290, year = {2002}, author = {Tereshchenko, LV and Yudin, AG and Kuznetsov, Y and Latanov, AV and Shul'govskii, VV}, title = {Disturbances of saccadic eye movements in monkeys during development of MPTP-induced syndrome.}, journal = {Bulletin of experimental biology and medicine}, volume = {133}, number = {2}, pages = {182-184}, doi = {10.1023/a:1015563225510}, pmid = {12428290}, issn = {0007-4888}, mesh = {1-Methyl-4-phenyl-1,2,3,6-tetrahydropyridine/administration &amp; dosage ; Animals ; Macaca ; *Parkinsonian Disorders ; Reaction Time ; Saccades/*physiology ; }, abstract = {Changes in the amplitude and dynamic parameters of purposive saccades were studied in monkeys with MPTP-induced Parkinson-like syndrome. Lengthening of saccade latency, decreased maximum velocity of eye movements, and impaired saccade accuracy were observed at the early stages MPTP-syndrome. Different disturbances of large- and small-scale saccades were found.}, }
@article {pmid12222058, year = {2002}, author = {Fu, B and Liu, S}, title = {[Problems and trends of long-term ecological research].}, journal = {Ying yong sheng tai xue bao = The journal of applied ecology}, volume = {13}, number = {4}, pages = {476-480}, pmid = {12222058}, issn = {1001-9332}, mesh = {*Bias ; *Ecology ; Ecosystem ; Environmental Monitoring ; Research/*trends ; }, abstract = {Long-Term Ecological Research (LTER) has been focused on the monitoring and controlling the factors that influence the ecological process in a long period. The results are also the basis for the ecological assessment and management. Referring to the experiences of long-term research in international perspectives, this paper attempts to elucidate the problems, research contents, research trends and solutions of LTER with the expansion of temporal and spatial scales. It also has an instructive role in the long-term research, the construction of ecological research network and the terrestrial assessment in China.}, }
@article {pmid12035077, year = {2001}, author = {Buckley, DH and Schmidt, TM}, title = {The Structure of Microbial Communities in Soil and the Lasting Impact of Cultivation.}, journal = {Microbial ecology}, volume = {42}, number = {1}, pages = {11-21}, pmid = {12035077}, issn = {1432-184X}, abstract = {The structure of microbial communities was examined as a function of community composition and the relative abundance of specific microbial groups to examine the effects that plant community composition and land-use history have on microbial communities in the soil. The sites sampled were part of the Long Term Ecological Research (LTER) project in agricultural ecology at the W.K. Kellogg Biological Station of Michigan State University (Hickory Corners, MI) and included both active and abandoned agricultural fields as well as nearby fields that had never been cultivated. Microbial community structure was assessed by extracting total RNA from soil samples and using 16S rRNA-targeted oligonucleotide probes to quantify the abundance of rRNA from the alpha, beta, and gamma Proteobacteria, the Actinobacteria (Gram positive bacteria with a high mol % G+C genome), the Bacteria, and the Eukarya. In addition, soil microbial communities were characterized by examining fluorescently tagged terminal restriction fragment length polymorphisms (T-RFLP) in PCR amplified 16S rDNA. Microbial community structure was observed to be remarkably similar among plots that shared a long-term history of agricultural management despite differences in plant community composition and land management that have been maintained on the plots in recent years. In contrast, microbial community structure differed significantly between fields that had never been cultivated and those having a long-term history of cultivation.}, }
@article {pmid11830636, year = {2002}, author = {Dierssen, HM and Smith, RC and Vernet, M}, title = {Glacial meltwater dynamics in coastal waters west of the Antarctic peninsula.}, journal = {Proceedings of the National Academy of Sciences of the United States of America}, volume = {99}, number = {4}, pages = {1790-1795}, pmid = {11830636}, issn = {0027-8424}, mesh = {Air ; Antarctic Regions ; Chlorophyll/chemistry ; *Ecosystem ; Oceans and Seas ; Phytoplankton/physiology ; Seasons ; Temperature ; Time Factors ; Water ; *Weather ; }, abstract = {The annual advance and retreat of sea ice has been considered a major physical determinant of spatial and temporal changes in the structure of the Antarctic coastal marine ecosystem. However, the role of glacial meltwater on the hydrography of the Antarctic Peninsula ecosystem has been largely ignored, and the resulting biological effects have only been considered within a few kilometers from shore. Through several lines of evidence collected in conjunction with the Palmer Station Long-Term Ecological Research Project, we show that the freshening and warming of the coastal surface water over the summer months is influenced not solely by sea ice melt, as suggested by the literature, but largely by the influx of glacial meltwater. Moreover, the seasonal variability in the amount and extent of the glacial meltwater plume plays a critical role in the functioning of the biota by influencing the physical dynamics of the water (e.g., water column stratification, nearshore turbidity). From nearly a decade of observations (1991-1999), the presence of surface meltwater is correlated not only to phytoplankton blooms nearshore, but spatially over 100 km offshore. The amount of meltwater will also have important secondary effects on the ecosystem by influencing the timing of sea ice formation. Because air temperatures are statistically increasing along the Antarctic Peninsula region, the presence of glacial meltwater is likely to become more prevalent in these surface waters and continue to play an ever-increasing role in driving this fragile ecosystem.}, }
@article {pmid11572952, year = {2001}, author = {Tilman, D}, title = {An evolutionary approach to ecosystem functioning.}, journal = {Proceedings of the National Academy of Sciences of the United States of America}, volume = {98}, number = {20}, pages = {10979-10980}, pmid = {11572952}, issn = {0027-8424}, mesh = {*Biological Evolution ; Ecology ; *Ecosystem ; Environment ; Genetic Variation ; }, }
@article {pmid11344290, year = {2001}, author = {Tilman, D and Lehman, C}, title = {Human-caused environmental change: impacts on plant diversity and evolution.}, journal = {Proceedings of the National Academy of Sciences of the United States of America}, volume = {98}, number = {10}, pages = {5433-5440}, pmid = {11344290}, issn = {0027-8424}, mesh = {*Biological Evolution ; *Environmental Health ; Humans ; Plants/*genetics ; Species Specificity ; }, abstract = {Human-caused environmental changes are creating regional combinations of environmental conditions that, within the next 50 to 100 years, may fall outside the envelope within which many of the terrestrial plants of a region evolved. These environmental modifications might become a greater cause of global species extinction than direct habitat destruction. The environmental constraints undergoing human modification include levels of soil nitrogen, phosphorus, calcium and pH, atmospheric CO(2), herbivore, pathogen, and predator densities, disturbance regimes, and climate. Extinction would occur because the physiologies, morphologies, and life histories of plants limit each species to being a superior competitor for a particular combination of environmental constraints. Changes in these constraints would favor a few species that would competitively displace many other species from a region. In the long-term, the "weedy" taxa that became the dominants of the novel conditions imposed by global change should become the progenitors of a series of new species that are progressively less weedy and better adapted to the new conditions. The relative importance of evolutionary versus community ecology responses to global environmental change would depend on the extent of regional and local recruitment limitation, and on whether the suite of human-imposed constraints were novel just regionally or on continental or global scales.}, }
@article {pmid11318559, year = {2001}, author = {Decker, KH and Duszynski, DW and Patrick, MJ}, title = {Biotic and abiotic effects on endoparasites infecting Dipodomys and Perognathus species.}, journal = {The Journal of parasitology}, volume = {87}, number = {2}, pages = {300-307}, doi = {10.1645/0022-3395(2001)087[0300:BAAEOE]2.0.CO;2}, pmid = {11318559}, issn = {0022-3395}, mesh = {Animals ; Body Composition ; Cestoda/isolation &amp; purification ; Dipodomys/*parasitology ; Eimeria/isolation &amp; purification ; Female ; Logistic Models ; Male ; Nematoda/isolation &amp; purification ; New Mexico ; Parasitic Diseases, Animal/*epidemiology/parasitology ; Prevalence ; Rodent Diseases/*epidemiology/parasitology ; Rodentia ; Seasons ; }, abstract = {Between 1989 and 1998, 3,504 rodents of the genera Dipodomys and Perognathus were collected from 4 permanent collecting sites on the University of New Mexico's Long Term Ecological Research station, located on the Sevilleta National Wildlife Refuge (SNWR), Socorro County. New Mexico. All animals were killed and examined for endoparasites (acanthocephalans, cestodes, coccidia, and nematodes). The present report focuses on 3 endoparasite groups, cestodes, coccidia, and nematodes. Specific analyses address how prevalence changes were related to abiotic factors such as habitat, season, or precipitation, and how prevalence of each parasite species in each host species differed in relation to host age, host sex, host reproductive status, host body mass, host density, parasite-parasite interactions, and host specificity. A logistic regression was used to determine which host characters and which abiotic factors are correlated with a parasite infection. Significant variables for at least half of the parasites include season, site, and winter precipitation. However, no parasite prevalences were correlated, and significant variables were not identical between parasites, indicating that each parasite species varied independently and that no generalizations can be drawn. The parasite prevalences in these rodents on the SNWR vary in independent and complex ways.}, }
@article {pmid11303102, year = {2001}, author = {Tilman, D and Fargione, J and Wolff, B and D'Antonio, C and Dobson, A and Howarth, R and Schindler, D and Schlesinger, WH and Simberloff, D and Swackhamer, D}, title = {Forecasting agriculturally driven global environmental change.}, journal = {Science (New York, N.Y.)}, volume = {292}, number = {5515}, pages = {281-284}, doi = {10.1126/science.1057544}, pmid = {11303102}, issn = {0036-8075}, mesh = {*Agriculture ; *Ecosystem ; *Environment ; Eutrophication ; Fertilizers ; Forecasting ; Fresh Water ; Nitrogen ; Pesticides ; Phosphorus ; Regression Analysis ; }, abstract = {During the next 50 years, which is likely to be the final period of rapid agricultural expansion, demand for food by a wealthier and 50% larger global population will be a major driver of global environmental change. Should past dependences of the global environmental impacts of agriculture on human population and consumption continue, 10(9) hectares of natural ecosystems would be converted to agriculture by 2050. This would be accompanied by 2.4- to 2.7-fold increases in nitrogen- and phosphorus-driven eutrophication of terrestrial, freshwater, and near-shore marine ecosystems, and comparable increases in pesticide use. This eutrophication and habitat destruction would cause unprecedented ecosystem simplification, loss of ecosystem services, and species extinctions. Significant scientific advances and regulatory, technological, and policy changes are needed to control the environmental impacts of agricultural expansion.}, }
@article {pmid11161201, year = {2001}, author = {Knapp, AK and Smith, MD}, title = {Variation among biomes in temporal dynamics of aboveground primary production.}, journal = {Science (New York, N.Y.)}, volume = {291}, number = {5503}, pages = {481-484}, doi = {10.1126/science.291.5503.481}, pmid = {11161201}, issn = {0036-8075}, mesh = {Arctic Regions ; *Climate ; Cold Climate ; Desert Climate ; *Ecosystem ; North America ; *Plant Development ; *Rain ; Snow ; Trees/*growth &amp; development ; }, abstract = {Interannual variability in aboveground net primary production (ANPP) was assessed with long-term (mean = 12 years) data from 11 Long Term Ecological Research sites across North America. The greatest interannual variability in ANPP occurred in grasslands and old fields, with forests the least variable. At a continental scale, ANPP was strongly correlated with annual precipitation. However, interannual variability in ANPP was not related to variability in precipitation. Instead, maximum variability in ANPP occurred in biomes where high potential growth rates of herbaceous vegetation were combined with moderate variability in precipitation. In the most dynamic biomes, ANPP responded more strongly to wet than to dry years. Recognition of the fourfold range in ANPP dynamics across biomes and of the factors that constrain this variability is critical for detecting the biotic impacts of global change phenomena.}, }
@article {pmid10821284, year = {2000}, author = {Chapin, FS and Zavaleta, ES and Eviner, VT and Naylor, RL and Vitousek, PM and Reynolds, HL and Hooper, DU and Lavorel, S and Sala, OE and Hobbie, SE and Mack, MC and Díaz, S}, title = {Consequences of changing biodiversity.}, journal = {Nature}, volume = {405}, number = {6783}, pages = {234-242}, doi = {10.1038/35012241}, pmid = {10821284}, issn = {0028-0836}, mesh = {Animals ; *Ecosystem ; Humans ; Sociology ; }, abstract = {Human alteration of the global environment has triggered the sixth major extinction event in the history of life and caused widespread changes in the global distribution of organisms. These changes in biodiversity alter ecosystem processes and change the resilience of ecosystems to environmental change. This has profound consequences for services that humans derive from ecosystems. The large ecological and societal consequences of changing biodiversity should be minimized to preserve options for future solutions to global environmental problems.}, }
@article {pmid10821280, year = {2000}, author = {Tilman, D}, title = {Causes, consequences and ethics of biodiversity.}, journal = {Nature}, volume = {405}, number = {6783}, pages = {208-211}, doi = {10.1038/35012217}, pmid = {10821280}, issn = {0028-0836}, mesh = {Animals ; *Bioethics ; *Ecosystem ; Humans ; Sociology ; }, abstract = {The existence of so great a diversity of species on Earth remains a mystery, the solution to which may also explain why and how biodiversity influences the functioning of ecosystems. The answer may lie in quantifying the trade-offs that organisms face in dealing with the constraints of their environment. Societal responses to the loss of biodiversity also involve trade-offs, and the elaboration of these will be essential in developing wiser environmental ethics and policy.}, }
@article {pmid10718728, year = {2000}, author = {Collins, SL}, title = {Disturbance Frequency and Community Stability in Native Tallgrass Prairie.}, journal = {The American naturalist}, volume = {155}, number = {3}, pages = {311-325}, doi = {10.1086/303326}, pmid = {10718728}, issn = {1537-5323}, abstract = {Ecological communities are spatially and temporally variable in response to a variety of biotic and abiotic forces. It is not always clear, however, if spatial and temporal variability leads to instability in communities. Instability may result from strong biotic interactions or from stochastic processes acting on small populations. I used 10-15 yr of annual data from the Konza Prairie Long-Term Ecological Research site to examine whether plant, breeding bird, grasshopper, and small mammal communities in tallgrass prairie exhibit stability or directional change in response to different experimentally induced fire frequencies. Based on ordination and ANOVA, plant and grasshopper communities on annually burned sites differed significantly from plant and grasshopper communities on less frequently burned sites. Breeding birds and small mammals differed among sites as well, but these differences were not clearly related to disturbance frequency. A modified time series analysis indicated that plant communities were undergoing directional change (unstable) on all watersheds, regardless of fire frequency. Contrary to expectations, directional change was greatest on the annually burned sites and lowest on the infrequently burned sites. Unlike the plant communities, breeding bird, grasshopper, and small mammal communities were temporally stable, despite high-compositional variability from 1 yr to the next. Stability among the consumer communities within these dynamic plant communities occurs because three-dimensional vegetation structure does not change over time, despite changes in plant species composition. Evidence suggests that instability in the plant community results from strong biotic interactions among temporally persistent core species and stochastic dynamics among infrequent satellite species. Overall, community stability cannot be assessed if the pattern of temporal dynamics is unknown. Long-term empirical studies of different taxa under different disturbance regimes are needed to determine over what time frames and spatial scales communities may be stable. Such studies are essential for the development of generalities regarding the relationship between disturbance frequency and community stability in terrestrial and aquatic systems.}, }
@article {pmid10388694, year = {1999}, author = {Bruns, MA and Stephen, JR and Kowalchuk, GA and Prosser, JI and Paul, EA}, title = {Comparative diversity of ammonia oxidizer 16S rRNA gene sequences in native, tilled, and successional soils.}, journal = {Applied and environmental microbiology}, volume = {65}, number = {7}, pages = {2994-3000}, pmid = {10388694}, issn = {0099-2240}, mesh = {Ammonia/*metabolism ; Cloning, Molecular ; Colony Count, Microbial ; DNA, Bacterial/genetics/isolation &amp; purification ; DNA, Ribosomal/analysis ; Ecosystem ; Electrophoresis/methods ; *Genes, rRNA ; *Genetic Variation ; Gram-Negative Chemolithotrophic Bacteria/*genetics/*isolation &amp; purification ; Molecular Sequence Data ; Nitrosomonas/genetics/isolation &amp; purification ; Oxidation-Reduction ; Phylogeny ; RNA, Ribosomal, 16S/*genetics ; Sequence Analysis, DNA ; *Soil Microbiology ; }, abstract = {Autotrophic ammonia oxidizer (AAO) populations in soils from native, tilled, and successional treatments at the Kellogg Biological Station Long-Term Ecological Research site in southwestern Michigan were compared to assess effects of disturbance on these bacteria. N fertilization effects on AAO populations were also evaluated with soils from fertilized microplots within the successional treatments. Population structures were characterized by PCR amplification of microbial community DNA with group-specific 16S rRNA gene (rDNA) primers, cloning of PCR products and clone hybridizations with group-specific probes, phylogenetic analysis of partial 16S rDNA sequences, and denaturing gradient gel electrophoresis (DGGE) analysis. Population sizes were estimated by using most-probable-number (MPN) media containing varied concentrations of ammonium sulfate. Tilled soils contained higher numbers than did native soils of culturable AAOs that were less sensitive to different ammonium concentrations in MPN media. Compared to sequences from native soils, partial 16S rDNA sequences from tilled soils were less diverse and grouped exclusively within Nitrosospira cluster 3. Native soils yielded sequences representing three different AAO clusters. Probes for Nitrosospira cluster 3 hybridized with DGGE blots from tilled and fertilized successional soils but not with blots from native or unfertilized successional soils. Hybridization results thus suggested a positive association between the Nitrosospira cluster 3 subgroup and soils amended with inorganic N. DGGE patterns for soils sampled from replicated plots of each treatment were nearly identical for tilled and native soils in both sampling years, indicating spatial and temporal reproducibility based on treatment.}, }
@article {pmid9797286, year = {1998}, author = {Buckley, DH and Graber, JR and Schmidt, TM}, title = {Phylogenetic analysis of nonthermophilic members of the kingdom crenarchaeota and their diversity and abundance in soils.}, journal = {Applied and environmental microbiology}, volume = {64}, number = {11}, pages = {4333-4339}, pmid = {9797286}, issn = {1098-5336}, abstract = {Within the last several years, molecular techniques have uncovered numerous 16S rRNA gene (rDNA) sequences which represent a unique and globally distributed lineage of the kingdom Crenarchaeota that is phylogenetically distinct from currently characterized crenarchaeotal species. rDNA sequences of members of this novel crenarchaeotal group have been recovered from low- to moderate-temperature environments (-1.5 to 32 degreesC), in contrast to the high-temperature environments (temperature, >80 degreesC) required for growth of the currently recognized crenarchaeotal species. We determined the diversity and abundance of the nonthermophilic members of the Crenarchaeota in soil samples taken from cultivated and uncultivated fields located at the Kellogg Biological Station's Long-Term Ecological Research site (Hickory Corners, Mich.). Clones were generated from 16S rDNA that was amplified by using broad-specificity archaeal PCR primers. Twelve crenarchaeotal sequences were identified, and the phylogenetic relationships between these sequences and previously described crenarchaeotal 16S rDNA sequences were determined. Phylogenetic analyses included nonthermophilic crenarchaeotal sequences found in public databases and revealed that the nonthermophilic Crenarchaeota group is composed of at least four distinct phylogenetic clusters. A 16S rRNA-targeted oligonucleotide probe specific for all known nonthermophilic crenarchaeotal sequences was designed and used to determine their abundance in soil samples. The nonthermophilic Crenarchaeota accounted for as much as 1.42% +/- 0.42% of the 16S rRNA in the soils analyzed.}, }
@article {pmid28565615, year = {1996}, author = {Cabin, RJ}, title = {GENETIC COMPARISONS OF SEED BANK AND SEEDLING POPULATIONS OF A PERENNIAL DESERT MUSTARD, LESQUERELLA FENDLERI.}, journal = {Evolution; international journal of organic evolution}, volume = {50}, number = {5}, pages = {1830-1841}, doi = {10.1111/j.1558-5646.1996.tb03569.x}, pmid = {28565615}, issn = {1558-5646}, abstract = {Soil seed banks may accumulate and store seed genotypes produced over many seasons. If germination and establishment of these soil seeds are influenced by seed genotypes, then seed bank and seedling populations may differ genetically. I compared the genetic structure of dormant but viable soil seeds of the desert mustard Lesquerella fendleri with the genetic structure of Lesquerella seedlings at the Sevilleta Long-Term Ecological Research Site. In 1991 and 1992, soil seeds and seedlings were mapped and genetically analyzed using starch gel electrophoresis. When data from all loci were lumped, there were highly significant differences in allele frequencies between soil seeds and seedlings at the population level (all plots) in both years, in all subpopulation (adjacent plots) comparisons in 1991, and three of five subpopulations in 1992. Differences at some individual loci were also detected in one or both years. Analysis of data pooled across both years revealed highly significant differences in the distribution of multilocus soil seed and seedling heterozygosity, but no significant differences in mean heterozygosity. Fst values showed small but statistically significant genetic differentiation within soil seeds and seedlings in both years. Fst values also showed significant genetic differentiation between these two groups at three of seven loci in 1991, and at one locus in 1992. Soil seeds and seedlings showed a general pattern of decreasing genetic relationship with distance, as estimated by the coefficient of coancestry analyses. In 1991, seedlings were roughly twice as genetically related to each other than were soil seeds at fine spatial scales (0-0.25 and 0.25-0.50 m). This study suggests that Lesquerella seedlings in this system represent a nonrandom genetic subset of the underlying Lesquerella seed bank. Such temporal genetic change may be an important yet frequently overlooked mechanism for generating population genetic structure.}, }
@article {pmid21237914, year = {1996}, author = {Gosz, JR}, title = {International long-term ecological research: priorities and opportunities.}, journal = {Trends in ecology &amp; evolution}, volume = {11}, number = {10}, pages = {444}, doi = {10.1016/0169-5347(96)20090-4}, pmid = {21237914}, issn = {0169-5347}, }
@article {pmid7588450, year = {1995}, author = {Saykin, AJ and Stafiniak, P and Robinson, LJ and Flannery, KA and Gur, RC and O'Connor, MJ and Sperling, MR}, title = {Language before and after temporal lobectomy: specificity of acute changes and relation to early risk factors.}, journal = {Epilepsia}, volume = {36}, number = {11}, pages = {1071-1077}, doi = {10.1111/j.1528-1157.1995.tb00464.x}, pmid = {7588450}, issn = {0013-9580}, support = {MH-00586/MH/NIMH NIH HHS/United States ; MH-43880/MH/NIMH NIH HHS/United States ; R01-NS-28813/NS/NINDS NIH HHS/United States ; }, mesh = {Aphasia/diagnosis/etiology ; Epilepsy, Temporal Lobe/physiopathology/*surgery ; Functional Laterality/physiology ; Humans ; *Language ; Language Tests ; Neuropsychological Tests ; Postoperative Complications/diagnosis ; Risk Factors ; Temporal Lobe/*physiology/surgery ; }, abstract = {We evaluated language functions in 154 patients with left hemisphere speech dominance undergoing anterior temporal lobectomy (ATL). Measures of phonemic and semantic fluency, confrontation naming, repetition, comprehension, and reading were administered before and 3 weeks postoperatively. Patients were grouped by focus (left, LT; right, RT) and presence of early risk factors for development of seizures (ER, early risk, < or = 5 years; NER, no early risk): (LT-ER, n = 45; RT-ER, n = 49; LT-NER, n = 27; RT-NER, n = 33). Preoperatively, the LT group showed a selective naming deficit as compared with the RT group. Postoperatively only the LT-NER group showed significant overall decline in language. For this group, the change was attributable to a selective decline in naming as compared with other functions. These data indicate that there is a specific risk to naming after dominant ATL for adult temporal lobe epilepsy (TLE) patients with a left hemisphere focus and the absence of an early risk factor for the development of seizures.}, }
@article {pmid24220828, year = {1993}, author = {Stafford, SG}, title = {Data, data everywhere but not a byte to read: Managing monitoring information.}, journal = {Environmental monitoring and assessment}, volume = {26}, number = {2-3}, pages = {125-141}, doi = {10.1007/BF00547491}, pmid = {24220828}, issn = {0167-6369}, abstract = {The problem of managing scientific information for widespread availability and use can be overwhelming. At Oregon State University, the Quantitative Sciences Group has found a workable solution. The group has developed a Forest Science Data Bank (FSDB) to house data generated by scientists and collaborating researchers in the Andrews Long-Term Ecological Research program. Today the FSDB houses some 2400 data sets from over 350 existing ecological studies and adds about 20 new studies yearly. This paper describes what we have learned in setting up the FSDB as a facility that can be used by researchers who both deposit information in and retrieve information from the FSDB.}, }
@article {pmid1865166, year = {1991}, author = {Juul-Möller, S and Hedblad, B and Janzon, L and Johansson, BW}, title = {Increased occurrence of arrhythmias in men with ischaemic type ST-segment depression during long-term ECG recording. Prognostic impact on ischaemic heart disease: results from the prospective population study 'Men born in 1914', Malmö, Sweden.}, journal = {Journal of internal medicine}, volume = {230}, number = {2}, pages = {143-149}, doi = {10.1111/j.1365-2796.1991.tb00422.x}, pmid = {1865166}, issn = {0954-6820}, mesh = {Aged ; Analysis of Variance ; Arrhythmias, Cardiac/complications/*epidemiology/mortality ; Coronary Disease/complications/*mortality/physiopathology ; *Electrocardiography, Ambulatory ; Humans ; Incidence ; Male ; Prevalence ; Prognosis ; Proportional Hazards Models ; Prospective Studies ; Sweden/epidemiology ; }, abstract = {The objective of this long-term ECG (LTER) study in 394 68-year-old men, selected at random from the general population of Malmö, Sweden, was to determine the prevalence and occurrence of cardiac arrhythmias and their impact on morbidity and mortality from IHD. According to Lown classification, 29.4% (116 men) had ventricular arrhythmia (VA) group 4-5. Serious ventricular arrhythmia (Lown group 4-5) was more common in men with asymptomatic ischaemic type ST-segment depression (STD) than in those without it (37.8% vs. 26.7%: P less than 0.05). During the mean follow-up period of 53.1 months there were seven IHD deaths (6%) among the 116 patients with VA, Lown 4-5, and nine IHD deaths (3.2%) among the 278 patients without serious VA, Lown 0-3, (P = 0.26). Six and three of these deaths, respectively, were considered to be sudden (P = 0.022). The increased cardiac event rate (fatal or non-fatal MI or deaths due to chronic IHD) associated with a serious ventricular arrhythmia disappeared when history of IHD at baseline and occurrence of STD during LTER were taken into account. The study did not provide any evidence to suggest that ventricular arrhythmia was triggered by myocardial ischaemia. Five of 9 (56%) deaths due to IHD in men with STD occurred among the 38% (37/98) of patients who belonged to Lown class 4-5. It is concluded that the prognostic information derived from LTER can be improved by combined monitoring of STD and ventricular arrhythmias.}, }
@article {pmid2800989, year = {1989}, author = {Jakobsson, J and Rehnqvist, N and Davidson, S}, title = {Computerised evaluation of the electrocardiogram during and for a short period after gall bladder surgery.}, journal = {Acta anaesthesiologica Scandinavica}, volume = {33}, number = {6}, pages = {474-477}, doi = {10.1111/j.1399-6576.1989.tb02948.x}, pmid = {2800989}, issn = {0001-5172}, mesh = {Aged ; Blood Pressure ; *Cholecystectomy ; *Computers ; Coronary Disease/*diagnosis ; *Electrocardiography ; Evaluation Studies as Topic ; Female ; Humans ; Intraoperative Care ; Male ; Middle Aged ; Postoperative Care ; Pulse ; Respiration ; }, abstract = {Long-term ECG recording on tape (LTER) was performed in 32 consecutive patients undergoing cholecystectomy. Twenty-two of the patients recorded showed ST-segment changes during the per- and early post-operative period. ST-segment depression was the most common change seen in 17 patients; however, 12 patients showed ST-segment elevation. In only nine patients were the ST-segment changes seen to be associated with major changes in pulse or blood pressure. ST-segment changes were seen as frequently in patients with, as without, known cardiovascular disease. All patients had an uncomplicated postoperative course and no case of myocardial infarction was seen. ST-segment changes during elective surgery seem to be a common phenomenon. The etiology of the observed changes is not clear and its value in the detection of per- or postoperative myocardial ischemia needs to be further evaluated.}, }
@article {pmid2706915, year = {1989}, author = {Ringqvist, I and Jonason, T and Nilsson, G and Khan, AR}, title = {Diagnostic value of longterm ambulatory ECG in patients with syncope, dizziness or palpitations.}, journal = {Clinical physiology (Oxford, England)}, volume = {9}, number = {1}, pages = {47-55}, doi = {10.1111/j.1475-097x.1989.tb00955.x}, pmid = {2706915}, issn = {0144-5979}, mesh = {Aged ; Arrhythmias, Cardiac/*diagnosis ; Dizziness/*diagnosis ; Electrocardiography/*instrumentation ; Female ; Humans ; Male ; Middle Aged ; Monitoring, Physiologic ; Syncope/*diagnosis ; }, abstract = {The diagnostic value of longterm ambulatory ECG recording (LTER) was determined in 63 patients referred for investigation of syncope, in 32 with dizziness and in 89 with palpitations. Among patients referred for syncope, dizziness or palpitations 8, 13 and 54%, respectively, had typical symptoms during the recording with concomitant arrhythmia explaining the symptom, and 6, 50 and 11% had a typical symptom without concomitant arrhythmia. In 12 and 3% of the patients referred for syncope or dizziness, respectively, arrhythmia was observed and probably explained their previous complaint, but no symptoms occurred during LTER. LTER was found to be of diagnostic value in 24% of the patients with syncope, in 66% of those with dizziness and in 65% of those with palpitations. In the latter two groups the presence of symptoms the week before the start of these recordings predicted the occurrence of symptoms during LTER. Only occasionally was there a higher yield of typical symptoms beyond 48 h of recording.}, }
@article {pmid3234409, year = {1988}, author = {Juul-Möller, S and Lilja, B and Johansson, BW}, title = {Ventricular arrhythmias and left ventricular function: one-year follow-up after myocardial infarction.}, journal = {European heart journal}, volume = {9}, number = {11}, pages = {1181-1187}, doi = {10.1093/oxfordjournals.eurheartj.a062427}, pmid = {3234409}, issn = {0195-668X}, mesh = {Adult ; Aged ; Arrhythmias, Cardiac/*complications ; Electrocardiography ; Exercise Test ; Female ; Follow-Up Studies ; Heart Function Tests ; Heart Ventricles/*physiopathology ; Humans ; Male ; Middle Aged ; Myocardial Infarction/*complications ; Prognosis ; Radionuclide Angiography ; }, abstract = {One hundred and one consecutive post-myocardial infarction (MI) patients were investigated with 24-h long-term ECG registration (LTER), exercise test and radionuclide angiocardiography (RNA) within one month of the MI and after six and 12 months. Patients with low left ventricular ejection fraction (LVEF) or a high value in a quantified phase analysis (Phase SD) were found to have frequent ventricular arrhythmia and high Lown class. Significant correlations between LVEF or phase SD and the number of ventricular arrhythmias or Lown class were found (P less than 0.05). Frequent ventricular arrhythmias and high Lown class were also found in patients with inverse left ventricular wall movement at RNA. Prolonged QTc was found in patients with frequent ventricular arrhythmias. These connections were found at all three investigations during the follow-up year. A significant correlation was not observed between ventricular arrhythmias and exercise capacity, NYHA grouping, ST depression in an exercise test or symptoms of angina pectoris. More than 300 ventricular premature complexes (VPC) per 24 h was found to predict death during the follow-up year as was LVEF less than 30%; complex arrhythmia (i.e., the patient being in Lown classes 3-5) being the only factor to predict repeat-MI during the follow-up year. It is concluded, that ventricular arrhythmias in the post-MI patient reflect the left ventricular performance. Both LVEF and arrhythmias contribute univariately to the risk of death during the first year after an MI. Whether they both carry independent prognostic information for death must be studied in future larger trials.}, }
@article {pmid3453293, year = {1987}, author = {De Pedis, G and Hedner, K and Johansson, BW and Steen, B}, title = {Cardiac arrhythmia in geriatric patients with organic dementia.}, journal = {Comprehensive gerontology. Section A, Clinical and laboratory sciences}, volume = {1}, number = {3}, pages = {115-117}, pmid = {3453293}, issn = {0902-0071}, mesh = {Aged ; Aged, 80 and over ; Alzheimer Disease/complications ; Arrhythmias, Cardiac/*complications/diagnosis ; Atrial Fibrillation/complications/diagnosis ; Dementia/*complications ; Electrocardiography ; Female ; Heart Rate ; Humans ; Male ; Tachycardia/complications/diagnosis ; }, abstract = {Cardiac arrhythmia and ST segment depression was analyzed with long-term ECG registration (LTER) in 36 patients with organic dementia aged 69-96 (mean 84) years and 27 patients without dementia or current heart disease aged 68-93 (mean 83) years. In the dementia group we found a higher prevalence of atrial fibrillation (p = 0.0131), ventricular tachycardia (p = 0.0156) and gaps (p = 0.0347) in comparison with the reference group. Ventricular and supraventricular extrasystoles were frequent in both groups. There was no difference in the prevalence of ST segment depression between the two groups. In conclusion we found an increased prevalence of atrial fibrillation, ventricular tachycardia and gaps in the dementia group in comparison with the reference group.}, }
@article {pmid7147300, year = {1982}, author = {Abdon, NJ and Zettervall, O and Carlson, J and Berglund, S and Sterner, G and Tejler, L and Turesson, I}, title = {Is occult atrial disorder a frequent cause of non-hemorrhagic stroke? Long-term ECG in 86 patients.}, journal = {Stroke}, volume = {13}, number = {6}, pages = {832-837}, doi = {10.1161/01.str.13.6.832}, pmid = {7147300}, issn = {0039-2499}, mesh = {Aged ; Arrhythmias, Cardiac/*complications/diagnosis ; Atrial Fibrillation/complications ; Electrocardiography/methods ; Female ; Heart Atria ; Humans ; Intracranial Embolism and Thrombosis/*etiology ; Ischemic Attack, Transient/*etiology ; Male ; Middle Aged ; Risk ; Sick Sinus Syndrome/complications ; }, abstract = {To assess the importance of occult atrial disorder with possible embolization as a cause of non-hemorrhagic stroke, 68 patients with neurologic symptoms lasting 24 hours or more and 18 patients with transient ischemic attacks were examined by long-term electrocardiographic recording (LTER). Lacking matched controls we used a reference population of 103 elderly subjects selected at random from the general population for a previous LTER study. Permanent or episodic atrial arrhythmias of types known to cause cerebral embolization were detected by LTER in 32 (47%) of the 68 patients with a clinical diagnosis of cerebral embolization or thrombosis and in 6 (33%) of the 18 patients with transient ischemic attacks. Of the 38 patients with atrial arrhythmia during LTER 17 had such arrhythmias in their standard ECGs. This frequency of atrial arrhythmias during LTER differs from that of the reference population (p less than 0.025). Thirteen of 16 patients with multiple cerebral lesions had signs of atrial arrhythmia during LTER. Patients having occult atrial disorder with episodic atrial arrhythmia may be an important and common risk group for non-hemorrhagic stroke in addition to the previously recognized group of patients with atrial arrhythmia detectable in the standard ECG. LTER may be important in the evaluation of patients with unexplained stroke.}, }
@article {pmid7223511, year = {1981}, author = {Abdon, NJ}, title = {Frequency and distribution of long-term ECG-recorded cardiac arrhythmias in an elderly population. With special reference to neurological symptoms.}, journal = {Acta medica Scandinavica}, volume = {209}, number = {3}, pages = {175-183}, doi = {10.1111/j.0954-6820.1981.tb11573.x}, pmid = {7223511}, issn = {0001-6101}, mesh = {Aged ; Arrhythmias, Cardiac/*complications ; Bradycardia/physiopathology ; Dizziness/etiology ; *Electrocardiography ; Heart Block/physiopathology ; Humans ; Middle Aged ; Nervous System Diseases/*etiology ; Pacemaker, Artificial ; Sick Sinus Syndrome/physiopathology ; Syncope/etiology ; Time Factors ; }, abstract = {The prevalence of serious episodic cardiac arrhythmias known to correlate with cerebral symptoms was investigated in 103 elderly, randomly selected persons with the aid of 22 hours of long-term ECG recording (LTER). Twelve of 26 subjects with dizziness/syncope had serious episodic arrhythmias compared with 5 of 77 subjects without these symptoms. This difference is significant (p less than 0.001). Five patients fulfilled strict criteria for pacemaker treatment of symptomatic bradycardias. Three had the sick sinus syndrome and two had third degree atrioventricular block. In 4 subjects, drugs were withdrawn due to bradycardia; and 4 were treated for tachyarrhythmias. Despite the finding of minor arrhythmnias in almost all asymptomatic subjects, it is concluded that serious episodic arrhythmias in the elderly are related to cerebral symptoms. It is also concluded that these arrhythmias are more common than previously believed and that LTER should be widely used.}, }
@article {pmid75190, year = {1978}, author = {Haas, M}, title = {Genetic analysis of in vitro leukemogenesis induced by thymus epithelial reticulum cells transmitting murine leukemia viruses.}, journal = {International journal of cancer}, volume = {21}, number = {1}, pages = {115-120}, doi = {10.1002/ijc.2910210119}, pmid = {75190}, issn = {0020-7136}, mesh = {Animals ; *Antigens ; *Cell Transformation, Neoplastic ; Cells, Cultured ; Epithelial Cells ; Epitopes ; Female ; Fluorescent Antibody Technique ; Leukemia Virus, Murine ; Leukemia, Experimental/*etiology/immunology ; Lymphocyte Activation ; Mice ; Mice, Inbred C57BL ; T-Lymphocytes/*immunology ; }, abstract = {Lymphatic leukemia developed in C57BL/6 mice following inoculation of normal thymocytes that and been co-cultured on leukemic thymus epithelial reticulum monolayer cells. Using thymocytes genetically marked in Ly membrane antigens, we showed that the thymomas which developed were produced by the co-cultured thymocytes rather than by leukemic cells derived from the monolayer. Thus, leukemogenic conversion of normal thymocytes took place in vitro. Inoculation of cultured leukemic thymus epithelial reticulum monolayer cells (LTER) gave rise mainly to reticulum cell sarcomas and myeloid leukemias, rather than to lymphatic leukemias (which developed following inoculation of thymocytes that had been cultured on the LTER monolayers). Thus LTER cells may themselves be tumor cells capable of producing RCNA (reticulum cell neoplasm type A) or myeloid tumors in addition to their ability to convert normal thymocytes into leukemic cells.}, }