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15 Jul 2020 at 01:33
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Bibliography on: Invasive Species


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RJR: Recommended Bibliography 15 Jul 2020 at 01:33 Created: 

Invasive Species

Standard Definition: Invasive species are plants, animals, or pathogens that are non-native (or alien) to the ecosystem under consideration and whose introduction causes or is likely to cause harm. Although that definition allows a logical possibility that some species might be non-native and harmless, most of time it seems that invasive species and really bad critter (or weed) that should be eradicated are seen as equivalent phrases. But, there is a big conceptual problem with that notion: every species in every ecosystem started out in that ecosystem as an invader. If there were no invasive species, all of Hawaii would be nothing but bare volcanic rock. Without an invasion of species onto land, there would be no terrestrial ecosystems at all. For the entire history of life on Earth, the biosphere has responded to perturbation and to opportunity with evolutionary innovation and with physical movement. While one may raise economic or aesthetic arguments against invasive species, it is impossible to make such an argument on scientific grounds. Species movement — the occurrence of invasive species — is the way the biosphere responds to perturbation. One might even argue that species movement is the primary, short-term "healing" mechanism employed by the biosphere to respond to perturbation — to "damage." As with any healing process, the short-term effect may be aesthetically unappealing (who thinks scabs are appealing?), but the long-term effects can be glorious.

Created with PubMed® Query: "invasive species" OR "invasion biology" OR "alien species" OR "introduced species" NOT pmcbook NOT ispreviousversion

Citations The Papers (from PubMed®)


RevDate: 2020-07-13

Sun J, Chen Y, Zhou H, et al (2020)

Carbon isotope ratio of leaf litter correlates with litter production in a mangrove ecosystem in South China.

Marine pollution bulletin, 157:111224.

As an important ecological process, litter production is generally recognized as being directly relevant to net primary productivity and carbon storage of mangrove ecosystems. In the present study, we made continuous, monthly assessment of litter production from 2010 to 2016 for five mangrove sites in Shenzhen Futian Mangrove Nature Reserve. Results showed that all mangrove locations displayed distinct seasonality in litter production, and that the alien species produced significantly more litters than the native species. Carbon isotope analysis revealed an interesting, strongly negative relationship between litter production and δ13C of leaf litter (δ13CLL) among the five studied sites. Although it has long been known that δ13C of plant leaves correlates with water use efficiency and some components of plant productivity, the observed δ13CLL-litter production linkage is novel, justifying future exploration of δ13CLL as an potential indicator of litter production and net primary productivity in mangrove ecosystems.

RevDate: 2020-07-13

Viard F, Riginos C, N Bierne (2020)

Anthropogenic hybridization at sea: three evolutionary questions relevant to invasive species management.

Philosophical transactions of the Royal Society of London. Series B, Biological sciences, 375(1806):20190547.

Species introductions promote secondary contacts between taxa with long histories of allopatric divergence. Anthropogenic contact zones thus offer valuable contrasts to speciation studies in natural systems where past spatial isolations may have been brief or intermittent. Investigations of anthropogenic hybridization are rare for marine animals, which have high fecundity and high dispersal ability, characteristics that contrast to most terrestrial animals. Genomic studies indicate that gene flow can still occur after millions of years of divergence, as illustrated by invasive mussels and tunicates. In this context, we highlight three issues: (i) the effects of high propagule pressure and demographic asymmetries on introgression directionality, (ii) the role of hybridization in preventing introduced species spread, and (iii) the importance of postzygotic barriers in maintaining reproductive isolation. Anthropogenic contact zones offer evolutionary biologists unprecedented large scale hybridization experiments. In addition to breaking the highly effective reproductive isolating barrier of spatial segregation, they allow researchers to explore unusual demographic contexts with strong asymmetries. The outcomes are diverse, from introgression swamping to strong barriers to gene flow, and lead to local containment or widespread invasion. These outcomes should not be neglected in management policies of marine invasive species. This article is part of the theme issue 'Towards the completion of speciation: the evolution of reproductive isolation beyond the first barriers'.

RevDate: 2020-07-13
CmpDate: 2020-07-13

Nagoshi RN, Htain NN, Boughton D, et al (2020)

Southeastern Asia fall armyworms are closely related to populations in Africa and India, consistent with common origin and recent migration.

Scientific reports, 10(1):1421.

The discovery of fall armyworm, a native of the Western Hemisphere, in western Africa in 2016 was rapidly followed by detections throughout sub-Saharan Africa, India, and most recently southeastern Asia. This moth pest has a broad host range that threatens such important crops as corn, rice, millet, and sorghum, creating concern for its potential impact on agriculture in the Eastern Hemisphere. Although genetic data suggest populations sampled in Africa and India originate from a recent common source, it is not known whether this is the case for populations in southeastern Asia, nor whether the subgroup with a preference for rice and millet is present in the region. This study found through comparisons of genetic markers that the fall armyworm from Myanmar and southern China are closely related to those from Africa and India, suggesting a common origin for these geographically distant populations. The results are consistent with a single recent introduction into the Eastern Hemisphere followed by rapid dispersion. The molecular similarities include discrepancies between the genetic markers that brings into question whether the subpopulation most likely to be a threat to rice and millet is present in significant numbers in Asia.

RevDate: 2020-07-11

Zhou L, Ma X, Zhu N, et al (2020)

The role of mab-3 in spermatogenesis and ontogenesis of pinewood nematode, Bursaphelenchus xylophilus.

Pest management science [Epub ahead of print].

BACKGROUND: Bursaphelenchus xylophilus is one of the most destructive invasive species, causing extensive economic losses worldwide. The sex ratio of female to male of B. xylophilus plays an important role in the nematode infestation. However, little is known about the processes of its sex determination. The double sex/mab-3-related family of transcription factors are highly conserved in animals, playing crucial roles in sex determination, spermatogenesis and ontogenesis. We therefore investigated its orthologue, Bxy-mab-3, in B. xylophilus.

RESULTS: Bxy-mab-3 has two typical conserved DM domains. It was observed in J2 (the second-stage of juveniles), J3, J4 and male adults (specifically on the spicules), but not in eggs or female adults via mRNA in situ hybridization. RNA-seq indicated significantly higher expression in males. RNAi showed that the body size and sperm size of male adults were markedly smaller than those of the controls. Meanwhile, almost all the RNAi treated males failed to mate with the normal females, even 26.34% of interfered males did not produce sperm. However, RNAi of Bxy-mab-3 had no effect on the sex ratio of B. xylophilus.

CONCLUSION: Bxy-mab-3 is indispensable for spermatogenesis, ontogenesis and mating behavior. It is a typical sex-determination gene with the differential expression in males and females. However, knocking down Bxy-mab-3 expression could not alter the sex ratio as seen in other species. Our findings contribute towards a better understanding of the molecular events of Bxy-mab-3 in B. xylophilus, which provides promising hints for control of pine wilt disease by blocking ontogenesis and decreasing nematode fecundity. This article is protected by copyright. All rights reserved.

RevDate: 2020-07-11

Tarusikirwa VL, Mutamiswa R, Chidawanyika F, et al (2020)

Cold hardiness of the South American tomato pinworm Tuta absoluta (Lepidoptera: Gelechiidae): both larvae and adults are chill-susceptible.

Pest management science [Epub ahead of print].

BACKGROUND: For many insects, including invasive species, overwintering survival is achieved behaviourally (e.g. through migration) or physiologically by entering diapause, a state of arrested physiological development that may be accompanied with depressed supercooling points (SCPs). Diapause allows in situ adaptation to adverse environmental conditions, providing sufficient parent propagules for insect pest proliferation when optimal conditions resurface. This phenomenon has however not been observed in the invasive South American tomato pinworm Tuta absoluta in its Mediterranean invaded areas. Moreover, no studies have looked at its overwintering survival in sub-Saharan Africa. Here, we thus investigated the cold hardiness of T. absoluta larvae and adults to better explain its local overwintering adaptation strategy.

RESULTS: Larval lower lethal temperatures ranged from -1°C to -17°C for 0.5-4h durations. Adults showed lower temperature activity limits than larvae albeit freeze strategy experiments showed neither survived internal freezing. Fasting and dehydration pre-treatment generally depressed SCPs, although asymmetrically, conferring more negative SCPs for larvae. Ramping rates, synonymic to diurnal temperature changes also significantly affected SCPs while, inoculative freezing significantly compromised freezing temperatures in both larvae and adults.

CONCLUSION: Our results suggest that (1) T. absoluta larvae and adults are chill-susceptible and may successfully overwinter, (2) larvae appear more cold hardy than adults and (3) ecological factors e.g. inoculative freezing, cooling rates, feeding- and hydration -status may affect cold hardiness. These results are important in determining species range limits, population phenology, modelling pest risk status and allows temporal life-stage specific targeting of management strategies. This article is protected by copyright. All rights reserved.

RevDate: 2020-07-11

Tulloch AIT, Hagger V, AC Greenville (2020)

Ecological forecasts to inform near-term management of threats to biodiversity.

Global change biology [Epub ahead of print].

Ecosystems are being altered by rapid and interacting changes in natural processes and anthropogenic threats to biodiversity. Uncertainty in historical, current and future effectiveness of actions hampers decisions about how to mitigate changes to prevent biodiversity loss and species extinctions. Research in resource management, agriculture and health indicates that forecasts predicting the effects of near-term or seasonal environmental conditions on management greatly improve outcomes. Such forecasts help resolve uncertainties about when and how to operationalise management. We reviewed the scientific literature on environmental management to investigate whether near-term forecasts are developed to inform biodiversity decisions in Australia, a nation with one of the highest recent extinction rates across the globe. We found that forecasts focused on economic objectives (e.g. fisheries management) predict on significantly shorter timelines and answer a broader range of management questions than forecasts focused on biodiversity conservation. We then evaluated scientific literature on the effectiveness of 484 actions to manage seven major terrestrial threats in Australia, to identify opportunities for near-term forecasts to inform operational conservation decisions. Depending on the action, between 30 and 80% threat management operations experienced near-term weather impacts on outcomes before, during or after management. Disease control, species translocation/reintroduction and habitat restoration actions were most frequently impacted, and negative impacts such as increased species mortality and reduced recruitment were more likely than positive impacts. Drought or dry conditions, and rainfall, were the most frequently reported weather impacts, indicating that near-term forecasts predicting the effects of low or excessive rainfall on management outcomes are likely to have the greatest benefits. Across the world many regions are, like Australia, becoming warmer and drier, or experiencing more extreme rainfall events. Informing conservation decisions with near-term and seasonal ecological forecasting will be critical to harness uncertainties and lower the risk of threat management failure under global change.

RevDate: 2020-07-11

Cabrera Walsh G, Ávila CJ, Cabrera N, et al (2020)

Biology and Management of Pest Diabrotica Species in South America.

Insects, 11(7): pii:insects11070421.

The genus Diabrotica has over 400 described species, the majority of them neotropical. However, only three species of neotropical Diabrotica are considered agricultural pests: D. speciosa, D. balteata, and D. viridula. D. speciosa and D. balteata are polyphagous both as adults and during the larval stage. D. viridula are stenophagous during the larval stage, feeding essentially on maize roots, and polyphagous as adults. The larvae of the three species are pests on maize, but D. speciosa larvae also feed on potatoes and peanuts, while D. balteata larvae feed on beans and peanuts. None of these species express a winter/dry season egg diapause, displaying instead several continuous, latitude-mediated generations per year. This hinders the use of crop rotation as a management tool, although early planting can help in the temperate regions of the distribution of D. speciosa. The parasitoids of adults, Celatoria bosqi and Centistes gasseni, do not exert much control on Diabrotica populations, or show potential for inundative biocontrol plans. Management options are limited to insecticide applications and Bt genetically modified (GM) maize. Other techniques that show promise are products using Beauveria bassiana and Heterorhabditis bacteriophora, semiochemical attractants for monitoring purposes or as toxic baits, and plant resistance.

RevDate: 2020-07-10

Lanner J, Huchler K, Pachinger B, et al (2020)

Dispersal patterns of an introduced wild bee, Megachile sculpturalis Smith, 1853 (Hymenoptera: Megachilidae) in European alpine countries.

PloS one, 15(7):e0236042 pii:PONE-D-20-05784.

Biodiversity monitoring programs are the baseline of species abundancy studies, which in case of introduced species are especially critical. Megachile sculpturalis Smith, 1853 native to Eastern-Asia, constitutes the first ever recorded wild bee species accidently introduced in Europe. Since its first discovery in 2008, M. sculpturalis has been spreading across the continent. By initiating a citizen science monitoring program, we aimed to investigate the occurrence pattern of M. sculpturalis. Within only two years after starting the project, 111 new reports from Switzerland, Liechtenstein and Austria were recorded. Comparably to other European countries, the population progressed remarkably fast from year to year expanding its area geographically but also ecologically by increasing its altitudinal range. The distribution pattern indicates human assisted jump-dispersal travelling on the major traffic routes of central Europe.

RevDate: 2020-07-10

Wu CH, Dodd AJ, Hauser CE, et al (2020)

Reallocating budgets among ongoing and emerging conservation projects.

Conservation biology : the journal of the Society for Conservation Biology [Epub ahead of print].

Conserving biodiversity and combating ecological hazards require cost-effective allocation of limited resources among potential management projects. Project priorities, however, can be both stochastic and dynamic over time as underlying social-ecological systems progress, novel priorities emerge, and management capabilities evolve. Thus, reallocation of ongoing investments in response to shifting priorities could improve management outcomes and address urgent demands, especially where additional funding is not available immediately. Resource reallocation, however, could incur transaction costs, require additional monitoring and reassessment, and be constrained by ongoing project commitments. Such complexities may prevent managers from considering potentially beneficial reallocation strategies, reducing long-term effectiveness. We propose an iterative project prioritization approach based on marginal return-on-investment estimation and portfolio optimization which guides resource reallocation among ongoing and new projects. Using simulation experiments within two case studies, we explore how this approach can improve efficacy under varying reallocation constraints, frequencies, costs, and rates of project portfolio change. We found that periodic budget reallocation could enhance the management of stochastically emerging invasive weeds in Australia, reducing the overall risk by up to 50% compared to a static budget. Reallocation frequency and the rate of new weed incursion synergistically increase the conservation gains achieved by allowing unconstrained reallocation. Conversely, budget reallocation would not improve the IUCN conservation status of threatened Australian birds due to slow rates of transition among conservation states, and might increase extinction risk if portfolio reassessment is costly. While other project prioritisation studies may recommend periodic reassessment and reallocation, our findings reveal conditions when reallocation is valuable, and demonstrate a structured approach that helps conservation agencies schedule and implement iterative budget allocation decisions cost-effectively. Article Impact Statement: Reallocating funding among conservation projects in response to shifting or emerging priorities may improve outcomes. This article is protected by copyright. All rights reserved.

RevDate: 2020-07-10

Drenth A, McTaggart AR, BD Wingfield (2019)

Fungal clones win the battle, but recombination wins the war.

IMA fungus, 10:18 pii:20.

Clonal reproduction is common in fungi and fungal-like organisms during epidemics and invasion events. The success of clonal fungi shaped systems for their classification and some pathogens are tacitly treated as asexual. We argue that genetic recombination driven by sexual reproduction must be a starting hypothesis when dealing with fungi for two reasons: (1) Clones eventually crash because they lack adaptability; and (2) fungi find a way to exchange genetic material through recombination, whether sexual, parasexual, or hybridisation. Successful clones may prevail over space and time, but they are the product of recombination and the next successful clone will inevitably appear. Fungal pathogen populations are dynamic rather than static, and they need genetic recombination to adapt to a changing environment.

RevDate: 2020-07-10

Lannes LS, Karrer S, Teodoro DAA, et al (2020)

Species richness both impedes and promotes alien plant invasions in the Brazilian Cerrado.

Scientific reports, 10(1):11365 pii:10.1038/s41598-020-68412-5.

Worldwide, alien plant invasions have been intensively studied in the past decades, but mechanisms controlling the invasibility of native communities are not fully understood yet. The stochastic niche hypothesis predicts that species-rich plant communities are less prone to alien plant invasions than species-poor communities, which is supported by some but not all field studies, with some very species-rich communities such as the Brazilian Cerrado becoming heavily invaded. However, species-rich communities potentially contain a greater variety of facilitative interactions in resource exploitation than species-poor communities, from which invasive plants might benefit. This alternative hypothetical mechanism might explain why nutrient-poor, species-rich ecosystems are prone to invasion. Here we show that a high species richness both impedes and promotes invasive plants in the Brazilian Cerrado, using structural equation modelling and data from 38 field sites. We found support for the stochastic niche hypothesis through an observed direct negative influence of species richness on abundance of alien invasive species, but an indirect positive effect of species richness on invasive alien plants through soil phosphatase activity that enhances P availability was also found. These field observations were supported with results from a mesocosm experiment. Root phosphatase activity of plants increased with species richness in the mesocosms, which was associated with greater community P and N uptake. The most prominent alien grass species of the region, Melinis minutiflora, benefited most from the higher N and P availability in the species mixtures. Hence, this study provides a novel explanation of why species-richness may sometimes promote rather than impede invasion, and highlights the need to perform facilitation experiments in multi-species communities.

RevDate: 2020-07-10

Portman SL, Felton GW, Kariyat RR, et al (2020)

Host plant defense produces species specific alterations to flight muscle protein structure and flight-related fitness traits of two armyworms.

The Journal of experimental biology pii:jeb.224907 [Epub ahead of print].

Insects manifest phenotypic plasticity in their development and behavior in response to plant defenses, via molecular mechanisms that produce tissue-specific changes. Phenotypic changes might vary between species that differ in their preferred hosts and these effects could extend beyond larval stages. To test this, we manipulated the diet of southern armyworm (SAW; Spodoptera eridania) and fall armyworm (FAW; Spodoptera frugiperda) using a tomato mutant for jasmonic acid plant defense pathway (def1), and wild type plants, and then quantified gene expression of Troponin t (Tnt) and flight muscle metabolism of the adult insects. Differences in Tnt spliceform ratios in insect flight muscles correlate with changes to flight muscle metabolism and flight muscle output. We found that SAW adults reared on induced def1 plants had higher relative abundances (RA) of the A isoform of Troponin t (Tnt A) in their flight muscles; in contrast, FAW adults reared on induced def1 plants had lower RAs of Tnt A in their flight muscles compared to adults reared on def1 and controls. Although mass-adjusted flight metabolic rates showed no independent host plant effects in either species, higher flight metabolic rates in SAW correlated with increased RAs of Tnt A Flight muscle metabolism also showed an interaction of host plants with Tnt A in both species, suggesting that host plants might be influencing flight muscle metabolic output by altering Tnt This study illustrates how insects respond to variation in host plant's chemical defense by phenotypic modifications to their flight muscle proteins, with possible implications for dispersal.

RevDate: 2020-07-10
CmpDate: 2020-07-10

Fang J, Deng Y, Che R, et al (2020)

Bacterial community composition in soils covered by different vegetation types in the Yancheng tidal marsh.

Environmental science and pollution research international, 27(17):21517-21532.

Coastal wetland vegetation plays an important role in maintaining ecological function and is a key factor affecting the soil bacterial community. Spartina alterniflora was introduced to the Yancheng tidal marsh to stabilize the sediments and gradually replaced the native plants. However, the changes in the soil bacterial community profile caused by S. alterniflora invasion are poorly characterized. Here, we used MiSeq sequencing to compare the composition of the bacterial community in soil at different depths under exotic S. alterniflora (SA), native Phragmites australis (PA), and native Suaeda salsa (SS). The results showed that the pH value was lower, but the salinity, soil organic carbon, total nitrogen, and number of 16S rRNA genes were higher in SA soils than in PA and SS soils. Overall, Proteobacteria was the dominant bacterial phylum, followed by Chloroflexi, Acidobacteria, Planctomycetes, Gemmatimonadetes, and Nitrospirae. Anaerolineae in the Chloroflexi phylum showed the greatest difference based on vegetation, accounting for 14.4% of the overall bacterial community in SA soils but only about 3.8% of those in PA and SS soils. The composition, interaction, and predicted functional profiles of the bacterial community in SA soils were significantly different from those in PA and SS soils, especially for functions related to the sulfur and nitrogen cycles. Salinity was negatively correlated with the Shannon index and accounted for 37.7% of the total variation in the bacterial community, making it the most important environmental factor. Our results showed the differences in bacterial community composition among different vegetation types and soil depths in the Yancheng tidal marsh, which provides a microbial basis for a better understanding of the ecological functions in this ecosystem.

RevDate: 2020-07-10
CmpDate: 2020-07-10

Huang K, Kong DL, Lu XR, et al (2020)

Lesser leaf herbivore damage and structural defense and greater nutrient concentrations for invasive alien plants: Evidence from 47 pairs of invasive and non-invasive plants.

The Science of the total environment, 723:137829.

Empirical evidence of enemy release is still inconsistent for invasive alien plant species, although enemy release is the key assumption for both the enemy release hypothesis (ERH) and the evolution of increased competitive ability hypothesis (EICA). In addition, little effort has been made to test this assumption in terms of defense investment using a multi-species comparative approach. Using a phylogenetically controlled within-study meta-analytical approach, we compared leaf herbivore damage, structural defenses and nutrients between 47 pairs of invasive versus native and/or non-invasive alien plants in China. The invasive relative to the co-occurring native or non-invasive (native and non-invasive alien) plants incurred lesser leaf herbivore damage, had lesser leaf concentrations of cellulose, hemicellulose, lignin and carbon, lesser leaf density and carbon or lignin to nitrogen ratio but greater nutrients, which may facilitate success of the invasive plants. The lesser structural investment did not result in lesser leaf construction costs for the invaders, which may be associated with their greater leaf nitrogen concentration. However, the invasive plants were not significantly different from the non-invasive alien plants in any trait. Our results provide strong evidence for ERH, also are consistent with EICA, and indicate that enemy release may be an important factor in alien plant invasions.

RevDate: 2020-07-10
CmpDate: 2020-07-10

Su Z, Qiu G, Fan H, et al (2020)

Changes in carbon storage and macrobenthic communities in a mangrove-seagrass ecosystem after the invasion of smooth cordgrass in southern China.

Marine pollution bulletin, 152:110887.

The exotic smooth cordgrass (Spartina alterniflora) has invaded intertidal wetlands near the Ronggenshan tidal flats of Beihai, Guangxi, China, where historically seagrasses and mangroves coexisted. We investigated sediment organic carbon (SOC) storage and macrobenthic community structure in the existing mangroves (MG), S. alterniflora (SA), seagrass bed (SG), and unvegetated flat (UnV) habitats following the S. alterniflora invasion. SOC storage increased after S. alternifolia invasion in the SG and UnV habitats. Spartina alterniflora invasion changed the dominant species of the macrobenthos in the original habitats and reduced the diversity of macrobenthos in SG and UnV habitats. Clearly, S. alternifolia invasion can change the ecological functioning of south China's coastal ecosystems by altering carbon sequestration and affecting biodiversity.

RevDate: 2020-07-09

Jeong H, Kim JM, Kim B, et al (2020)

Nutritional Value of the Larvae of the Alien Invasive Wasp Vespa velutina nigrithorax and Amino Acid Composition of the Larval Saliva.

Foods (Basel, Switzerland), 9(7): pii:foods9070885.

The systematic investigations on the value of social wasps as a food resource are deficient, in spite of the long history of the utilization of social wasps as food and pharmaceutical bioresources. Vespa velutina nigrithorax is an invasive alien wasp species that is currently dominating in East Asia and Europe, bringing huge economic damages. As a control over alien species is made when the valuable utilization of the invasive species as a potential resource are discovered, investigations on the potential of V. v. nigrithorax as a useful bioresource are also in demand. Nutritional and heavy metal analyses of the larvae revealed their balanced and rich nutritional value and safety as a food resource. The larval saliva amino acid composition was investigated for further study on amino acid supplementation and exercise enhancement.

RevDate: 2020-07-09
CmpDate: 2020-07-09

van den Hurk P, Edhlund I, Davis R, et al (2020)

Lionfish (Pterois volitans) as biomonitoring species for oil pollution effects in coral reef ecosystems.

Marine environmental research, 156:104915.

With oil spills, and other sources of aromatic hydrocarbons, being a continuous threat to coral reef systems, and most reef fish species being protected or difficult to collect, the use of the invasive lionfish (Pterois volitans) might be a good model species to monitor biomarkers in potentially exposed fish in the Caribbean and western Atlantic. The rapid expansion of lionfish in the Caribbean and western Atlantic, and the unregulated fishing for this species, would make the lionfish a suitable candidate as biomonitoring species for oil pollution effects. However, to date little has been published about the responses of lionfish to environmental pollutants. For this study lionfish were collected in the Florida Keys a few weeks after Hurricane Irma, which sank numerous boats resulting in leaks of oil and fuel, and during the winter and early spring after that. Several biomarkers indicative of exposure to PAHs (bile fluorescence, cytochrome P450-1A induction, glutathione S-transferase activity) were measured. To establish if these biomarkers are inducible in PAH exposed lionfish, dosing experiments with different concentrations of High Energy Water Accommodated Fraction of crude oil were performed. The results revealed no significant effects in the biomarkers in the field collected fish, while the exposure experiments demonstrated that lionfish did show strong effects in the measured biomarkers, even at the lowest concentration tested (0.3% HEWAF, or 25 μg/l ƩPAH50). Based on its widespread distribution, relative ease of collection, and significant biomarker responses in the controlled dosing experiment, it is concluded that lionfish has good potential to be used as a standardized biomonitoring species for oil pollution in its neotropical realm.

RevDate: 2020-07-08

White SA, Bevins SN, Ruder MG, et al (2020)

Surveys for ticks on wildlife hosts and in the environment at Asian longhorned tick (Haemaphysalis longicornis)-positive sites in Virginia and New Jersey, 2018.

Transboundary and emerging diseases [Epub ahead of print].

Haemaphysalis longicornis, the Asian longhorned tick (ALT), is native to eastern Asia, but it has become invasive in several countries, including Australia, New Zealand, and recently in the eastern United States (US). To identify wild mammal and avian host species in the US, we conducted active wildlife surveillance in two states with known ALT infestations (Virginia and New Jersey). In addition, we conducted environmental surveys in both states. These surveillance efforts resulted in detection of 51 ALT-infested individuals from seven wildlife species, including raccoon (Procyon lotor), Virginia opossum (Didelphis virginiana), red fox (Vulpes vulpes), woodchuck (Marmota monax), eastern cottontail (Sylvilagus floridanus), striped skunk (Mephitis mephitis), and white-tailed deer (Odocoileus virginianus). We found ALT in the environment in both states and also collected three native tick species (Amblyomma americanum, Dermacentor variablis, and Ixodes scapularis) that are vectors of pathogens of public health and veterinary importance. This study provides important specific information on the wildlife host range of ALT in the US.

RevDate: 2020-07-08

Egizi A, Bulaga-Seraphin L, Alt E, et al (2020)

First glimpse into the origin and spread of the Asian longhorned tick, Haemaphysalis longicornis, in the United States.

Zoonoses and public health [Epub ahead of print].

Established populations of Asian longhorned ticks (ALT), Haemaphysalis longicornis, were first identified in the United States (US) in 2017 by sequencing the mitochondrial cytochrome c oxidase subunit I (cox1) 'barcoding' locus followed by morphological confirmation. Subsequent investigations detected ALT infestations in 12, mostly eastern, US states. To gain information on the origin and spread of US ALT, we (1) sequenced cox1 from ALT populations across 9 US states and (2) obtained cox1 sequences from potential source populations [China, Japan and Republic of Korea (ROK) as well as Australia, New Zealand and the Kingdom of Tonga (KOT)] both by sequencing and by downloading publicly available sequences in NCBI GenBank. Additionally, we conducted epidemiological investigations of properties near its initial detection locale in Hunterdon County, NJ, as well as a broader risk analysis for importation of ectoparasites into the area. In eastern Asian populations (China/Japan/ROK), we detected 35 cox1 haplotypes that neatly clustered into two clades with known bisexual versus parthenogenetic phenotypes. In Australia/New Zealand/KOT, we detected 10 cox1 haplotypes all falling within the parthenogenetic cluster. In the United States, we detected three differentially distributed cox1 haplotypes from the parthenogenetic cluster, supporting phenotypic evidence that US ALT are parthenogenetic. While none of the source populations examined had all three US cox1 haplotypes, a phylogeographic network analysis supports a northeast Asian source for the US populations. Within the United States, epidemiological investigations indicate ALT can be moved long distances by human transport of animals, such as horses and dogs, with smaller scale movements on wildlife. These results have relevant implications for efforts aimed at minimizing the spread of ALT in the United States and preventing additional exotic tick introductions.

RevDate: 2020-07-08

Duong TY, Tan MH, Lee YP, et al (2020)

Dataset for genome sequencing and de novo assembly of the Vietnamese bighead catfish (Clarias macrocephalus Günther, 1864).

Data in brief, 31:105861 pii:105861.

Freshwater catfish of the genus Clarias, known as the airbreathing catfish, are widespread and important for food security through small scale inland fisheries and aquaculture. Limited genomic data are available for this important group of fishes. The bighead catfish (Clarias macrocephalus) is a commercial aquaculture species in southeast Asia used for aquaculture and threatened in its natural environment through habitat destruction, over-exploitation and competition from other introduced species of Clarias. Despite its commercial importance and threats to natural populations, public databases do not include any genomic data for C. macrocephalus. We present the first genomic data for the bighead catfish from Illumina sequencing. A total of 128 Gb of sequence data in paired-end 150 bp reads were assembled de novo, generating a final assembly of 883 Mbp contained in 27,833 scaffolds (N50 length: 80.8 kbp) with BUSCO completeness assessments of 96.3% and 87.6% based on metazoan and Actinopterygii ortholog datasets, respectively. Annotation of the genome predicted 21,124 gene sequences, which were assigned putative functions based on homology to existing protein sequences in public databases. Raw fastq reads and the final version of the genome assembly have been deposited in the NCBI (BioProject: PRJNA604477, WGS: JAAGKR000000000, SRA: SRR11188453). The complete C. macrocephalus mitochondrial genome was also recovered from the same sequence read dataset and is available on NCBI (accession: MT109097), representing the first mitogenome for this species. Lastly, we find an expansion of the mb and ora1 genes thought to be associated with adaptations to air-breathing and a semi-terrestrial life style in this genus of catfish.

RevDate: 2020-07-07

Wickman J, Dieckmann U, Hui C, et al (2020)

How geographic productivity patterns affect food-web evolution.

Journal of theoretical biology pii:S0022-5193(20)30229-0 [Epub ahead of print].

It is well recognized that spatial heterogeneity and overall productivity have important consequences for the diversity and community structure of food webs. Yet, few, if any, studies have considered the effects of heterogeneous spatial distributions of primary production. Here, we theoretically investigate how the variance and autocorrelation length of primary production affect properties of evolved food webs consisting of one autotroph and several heterotrophs. We report the following findings. (1) Diversity increases with landscape variance and is unimodal in autocorrelation length. (2) Trophic level increases with high landscape variance and is unimodal in autocorrelation length. (3) The extent to which the spatial distribution of heterotrophs differ from that of the autotroph increases with variance and decreases with autocorrelation length. (4) Components of initial disruptive selection experienced by the ancestral heterotroph predict properties of the final evolved communities. Prior to our study reported here, several authors had hypothesized that diversity increases with the variance of productivity. Our results support their hypothesis and contribute new facets by providing quantitative predictions that also account for autocorrelation length and additional properties of the evolved communities.

RevDate: 2020-07-07

Sherwood AR, Huisman JM, Paiano MO, et al (2020)

Taxonomic determination of the cryptogenic red alga, Chondria tumulosa sp. nov., (Rhodomelaceae, Rhodophyta) from Papahānaumokuākea Marine National Monument, Hawai'i, USA: A new species displaying invasive characteristics.

PloS one, 15(7):e0234358 pii:PONE-D-20-06266.

Survey cruises by the National Oceanic and Atmospheric Administration (NOAA) in 2016 and 2019 yielded specimens of an undetermined red alga that rapidly attained alarming levels of benthic coverage at Pearl and Hermes Atoll, Papahānaumokuākea Marine National Monument, Hawai'i. By 2019 the seaweed had covered large expanses on the northeast side of the atoll with mat-like, extensive growth of entangled thalli. Specimens were analyzed using light microscopy and molecular analysis, and were compared to morphological descriptions in the literature for closely related taxa. Light microscopy demonstrated that the specimens likely belonged to the rhodomelacean genus Chondria, yet comparisons to taxonomic literature revealed no morphological match. DNA sequence analyses of the mitochondrial COI barcode marker, the plastidial rbcL gene, and the nuclear SSU gene confirmed its genus-level placement and demonstrated that this alga was unique compared to all other available sequences. Based on these data, this cryptogenic seaweed is here proposed as a new species: Chondria tumulosa A.R.Sherwood & J.M.Huisman sp. nov. Chondria tumulosa is distinct from all other species of Chondria based on its large, robust thalli, a mat-forming tendency, large axial diameter in mature branches (which decreases in diameter with subsequent orders of branching), terete axes, and bluntly rounded apices. Although C. tumulosa does not meet the criteria for the definition of an invasive species given that it has not been confirmed as introduced to Pearl and Hermes Atoll, this seaweed is not closely related to any known Hawaiian native species and is of particular concern given its sudden appearance and rapid increase in abundance in the Papahānaumokuākea Marine National Monument; an uninhabited, remote, and pristine island chain to the northwest of the Main Hawaiian Islands.

RevDate: 2020-07-07

Harms N, J Cronin (2020)

Biological control agent attack timing and population variability, but not density, best explain target weed density across an environmental gradient.

Scientific reports, 10(1):11062 pii:10.1038/s41598-020-68108-w.

Spatial variation in plant-herbivore interactions can be important in pest systems, particularly when insect herbivores are used as biological control agents to manage invasive plants. The geographic ranges of the invasive plant alligatorweed (Alternanthera philoxeroides) and its biological control agent the alligatorweed flea beetle (Agasicles hygrophila) do not completely overlap in the southeastern USA, producing spatial heterogeneity in interaction strength that may be related to latitude-correlated environmental gradients. We studied this system near the range margin of the alligatorweed flea beetle to test whether spatial variation in alligatorweed density was best explained by agent mean or maximum density, variability in agent density, agent attack timing, or a combination of biological control and environmental (i.e., weather) variables. The pattern that emerged was that mean agent and host densities were negatively and positively associated with latitude, respectively. Variability in agent density increased with latitude and was positively correlated with host density. We further discovered that agent first attack timing was negatively correlated with winter and spring temperatures and spring and summer precipitation, and positively correlated with seasonal temperature extremes, which was then directly influential on agent density and variability in density, and indirectly on host density. This study demonstrates that, contrary to common wisdom, weather-related timing of agent activity and population variability, but not agent mean density, contribute to the spatial heterogeneity observed in alligatorweed populations.

RevDate: 2020-07-06

Clusella-Trullas S, M Nielsen (2020)

The evolution of insect body coloration under changing climates.

Current opinion in insect science, 41:25-32 pii:S2214-5745(20)30065-1 [Epub ahead of print].

Insects have been influential models in research on color variation, its evolutionary drivers and the mechanistic basis of such variation. More recently, several studies have indicated that insect color is responding to rapid climate change. However, it remains challenging to ascertain drivers of color variation among populations and species, and across space and time, as multiple biotic and abiotic factors can interact and mediate color change. Here, we describe some of the challenges and recent advances made in this field. First, we outline the main alternative hypotheses that exist for insect color variation in relation to climatic factors. Second, we review the existing evidence for contemporary adaptive evolution of insect color in response to climate change and then discuss factors that can promote or hinder the evolution of color in response to climate change. Finally, we propose future directions and highlight gaps in this research field. Pigments and structures producing insect color can vary concurrently or independently, and may evolve at different rates, with poorly understood effects on gene frequencies and fitness. Disentangling multiple competing hypotheses explaining insect coloration should be key to assign color variation as an evolutionary response to climate change.

RevDate: 2020-07-06

Nania D, Flecks M, D Rödder (2020)

Continuous expansion of the geographic range linked to realized niche expansion in the invasive Mourning gecko Lepidodactylus lugubris (Duméril & Bibron, 1836).

PloS one, 15(7):e0235060 pii:PONE-D-19-32479.

Lepidodactylus lugubris is a parthenogenetic gecko which has been increasingly expanding its range during the last century. This invasive species has been reported from multiple tropical and subtropical countries in five continents, most of which were colonized in recent times. In order to understand how the realized niche of the species was affected by this dramatic geographic range expansion, we reconstructed the history of the geographic range expansion. We built models of the realized niche of the species at different points in time during the invasion process. This was achieved through the implementation of modern hypervolume construction methods, based on the Hutchinson's niche concept. The models were then compared to detect possible realized climatic niche expansion over time. Furthermore, we investigated possible pathways used by the species to spread. A progressive expansion of the realized niche was identified. As the species spread into new areas, we observed a tendency to colonize regions with warmer temperatures and higher precipitation rates. Finally, we found evidence for cargo shipping being the major pathway through which the species expands its range. Further studies on this topic should aim to investigate the role of biological interactions, and how they shape the distribution of L. lugubris on a global scale. A deeper understanding of this kind of processes will help us tackle the issue of invasive species, which has become a major challenge in conservation biology.

RevDate: 2020-07-06

Marques PS, Manna LR, Frauendorf TC, et al (2020)

Urbanization can increase the invasive potential of alien species.

The Journal of animal ecology [Epub ahead of print].

1- Alien species often flourish and become invasive in urban ecosystems. How and why invaders succeed in urban systems is an important, yet poorly understood, question. We investigate whether the success of urban invaders is related to changes in species traits that enhance invasive potential. We also explore whether a trophic mechanism helps explain the success of invaders in urban systems. We use the guppy, Poecilia reticulata, a globally distributed alien species that has invaded both urban and non-urban systems, as our model. 2- We first characterize the effect of urbanization on streams where guppies are present. We measure guppy invasion success using their population density and size-frequency. Then we assess how traits that are related to the potential of guppies to invade (life history and condition) respond to urbanization. Next, we explore how urbanization affects the availability of food for guppies and their diets. We also test if the presence of other fish species grants biological resistance to invasion by dampening guppy invasive potential. 3- We find that urban streams have high concentrations of ammonium and fecal coliforms, indicating contamination from sewage. On average, guppy populations from urban streams have 26x higher density and larger body sizes than non-urban populations. Urban guppies are in better condition and have on average 5 more offspring than non-urban guppies. Urbanization increases the availability and consumption of highly nutritious food (chironomid larvae) by guppies. We find a positive relationship between the consumption of chironomids and both fecundity and condition. The presence of other fish species in urban streams often has a negative but small effect on guppy traits and density. 4- Our data suggest a relaxation of trade-offs that shape life history traits which is related to increased food resources in urban streams. These indicate that urbanization enhances the invasive potential of guppies through a trophic mechanism that simultaneously increases reproduction and somatic investment. Such mechanism is likely widespread because chironomids are often highly abundant in urban systems. Thus, not only guppies but also other invasive species can take advantage of such a resource to invest in traits that enhance invasion success.

RevDate: 2020-07-06

Coughlan NE, Cunningham EM, Potts S, et al (2020)

Steam and Flame Applications as Novel Methods of Population Control for Invasive Asian Clam (Corbicula fluminea) and Zebra Mussel (Dreissena polymorpha).

Environmental management pii:10.1007/s00267-020-01325-1 [Epub ahead of print].

Control strategies for established populations of invasive alien species can be costly and complex endeavours, which are frequently unsuccessful. Therefore, rapid-reaction techniques that are capable of maximising efficacy whilst minimising environmental damage are urgently required. The Asian clam (Corbicula fluminea Müller, 1774), and the zebra mussel (Dreissena polymorpha Pallas, 1771), are invaders capable of adversely affecting the functioning and biodiversity of freshwater ecosystems. Despite efforts to implement substantial population-control measures, both species continue to spread and persist within freshwater environments. As bivalve beds often become exposed during low-water conditions, this study examined the efficacy of steam-spray (≥100 °C, 350 kPa) and open-flame burn treatments (~1000 °C) to kill exposed individuals. Direct steam exposure lasting for 5 min caused 100% mortality of C. fluminea buried at a depth of 3 cm. Further, combined rake and thermal shock treatments, whereby the substrate is disturbed between each application of either a steam or open flame, caused 100% mortality of C. fluminea specimens residing within a 4-cm deep substrate patch, following three consecutive treatment applications. However, deeper 8-cm patches and water-saturated substrate reduced maximum bivalve species mortality rates to 77% and 70%, respectively. Finally, 100% of D. polymorpha specimens were killed following exposure to steam and open-flame treatments lasting for 30 s and 5 s, respectively. Overall, our results confirm the efficacy of thermal shock treatments as a potential tool for substantial control of low-water-exposed bivalves. Although promising, our results require validation through upscaling to field application, with consideration of other substrate types, increased substrate depth, greater bivalve densities, non-target and long-term treatment effects.

RevDate: 2020-07-06

Ivan LN, Mason DM, Zhang H, et al (2020)

Potential establishment and ecological effects of bighead and silver carp in a productive embayment of the Laurentian Great Lakes.

Biological invasions, 22(8):2473-2495.

Bighead carp H. nobilis and silver carp Hypothalmichthys molitrix (collectively bigheaded carps, BHC) are invasive planktivorous fishes that threaten to enter the Laurentian Great Lakes and disrupt food webs. To assess the likelihood of BHC establishment and their likely effects on the food web of Saginaw Bay, Lake Huron, we developed a multi-species individual-based bioenergetics model that tracks individual bighead and silver carp, four key fish species, and seven prey biomass groups over 50 years. The model tracks the daily consumption, mortality and growth of all individuals and the biomass dynamics of interacting prey pools. We ran simulation scenarios to determine the likelihood of BHC establishment under initial introductions from 5 to 1 million yearling and older individuals, and assuming variable age-0 carp survival rates (high, intermediate, and low). We bounded the survival of age-0 BHC as recruitment continues to be one of the biggest unknowns. We also simulated the potential effects of an established population of 1 million bighead carp or silver carp assuming variation in age-0 survival. Results indicated that as few as 10 BHC could establish a population assuming high or intermediate age-0 survival, but at least 100,000 individuals were needed to establish a population assuming low age-0 survival. BHC had negative effects on plankton and planktivorous fish biomass, which increased with BHC density. However, piscivorous walleye Sander vitreus appeared to benefit from BHC establishment. The potential for BHC to establish and affect ecologically and economically important fish species in Saginaw Bay is a cause for concern.

RevDate: 2020-07-06

Mille C, Jourdan H, Cazères S, et al (2020)

New data on the aphid (Hemiptera, Aphididae) fauna of New Caledonia: some new biosecurity threats in a biodiversity hotspot.

ZooKeys, 943:53-89 pii:47785.

Thirty-three species of aphids are now established in New Caledonia. All species appear to have been introduced accidentally by human activity in the last century. Here, 17 aphid species are recorded for the first time: Aphis eugeniae, Aphis glycines, Aphis odinae, Aulacorthum solani, Brachycaudus helichrysi, Cerataphis orchidearum, Greenidea psidii, Hyperomyzus carduellinus, Hysteroneura setariae, Lipaphis pseudobrassicae, Micromyzus katoi, Myzus ornatus, Pentalonia caladii, Rhopalosiphum nymphaeae, Rhopalosiphum rufiabdominale, Schizaphis rotundiventris, and Tetraneura fusiformis. Thirteen more species are also more or less regularly intercepted at the borders through biosecurity surveys, without further establishment. This demonstrates that aphids represent a major biosecurity threat, including a threat as potential plant virus vectors. The reinforcement of biosecurity is a priority for such biodiversity hotspots, from the perspectives of both agriculture and the native environment. Prioritisation and promotion of local development of vegetable and fruit production, rather than their risky importation from abroad, is desirable. Such an approach also should be promoted and extended to other Pacific islands, which all share the lack of native aphid fauna and their associated plant disease vector risks.

RevDate: 2020-07-06
CmpDate: 2020-07-06

Kamiyama MT, Bradford BZ, Groves RL, et al (2020)

Degree day models to forecast the seasonal phenology of Drosophila suzukii in tart cherry orchards in the Midwest U.S.

PloS one, 15(4):e0227726.

Spotted-wing drosophila, Drosophila suzukii (Matsumura) (Diptera: Drosophilidae), is an invasive economic pest of soft-skinned and stone fruit across the globe. Our study establishes both a predictive generalized linear mixed model (GLMM), and a generalized additive mixed model (GAMM) of the dynamic seasonal phenology of D. suzukii based on four years of adult monitoring trap data in Wisconsin tart cherry orchards collected throughout the growing season. The models incorporate year, field site, relative humidity, and degree days (DD); and relate these factors to trap catch. The GLMM estimated a coefficient of 2.21 for DD/1000, meaning for every increment of 1000 DD, trap catch increases by roughly 9 flies. The GAMM generated a curve based on a cubic regression smoothing function of DD which approximates critical DD points of first adult D. suzukii detection at 1276 DD, above average field populations beginning at 2019 DD, and peak activity at 3180 DD. By incorporating four years of comprehensive seasonal phenology data from the same locations, we introduce robust models capable of using DD to forecast changing adult D. suzukii populations in the field leading to the application of more timely and effective management strategies.

RevDate: 2020-07-06
CmpDate: 2020-07-06

Blekhman A, Goryacheva I, Schepetov D, et al (2020)

Variability of the mitochondrial CO1 gene in native and invasive populations of Harmonia axyridis Pall. comparative analysis.

PloS one, 15(4):e0231009.

Our study is focused on original and publicly accessible data on the intraspecific variability of the barcoding DNA fragment in ladybirds Harmonia axyridis Pall analysis. The complete dataset consists of 39 haplotypes, 16 of which we identified for the first time. The intra-population and geographical variability of the barcoding fragment was studied for seven populations of the western and eastern groups of the native range and in six invasive populations, in which 25 of the 39 haplotypes are found. Population structure inferred on base of molecular variability and haplotype frequencies showed a high level of differences between the eastern and western groups of native populations and confirm the hypothesis of the origin of all invasive populations from native populations of the eastern group. A comparative analysis of molecular variation indices testifies to various evolutionary scenarios of the formation of the western and eastern groups of native populations and confirms the hypothesis of the microevolutionary history of the species, previously suggested in morphological character based studies of the geographical variability of H. axyridis. A significant decrease in the molecular diversity of invasive populations confirms the hypothesis of a random nature of the primary invasion of this species in North America.

RevDate: 2020-07-05

Genitoni J, Vassaux D, Delaunay A, et al (2020)

Hypomethylation of the aquatic invasive plant, Ludwigia grandiflora subsp hexapetala mimics the adaptive transition into the terrestrial morphotype.

Physiologia plantarum [Epub ahead of print].

Ongoing global changes affect ecosystems and open up new opportunities for biological invasion. The ability of invasive species to rapidly adapt to new environments represents a relevant model for studying short-term adaptation mechanisms. The aquatic invasive plant, Ludwigia grandiflora subsp hexapetala, is classified as harmful in European rivers. In French wet meadows, this species has shown a rapid transition from aquatic to terrestrial environments with emergence of two distinct morphotypes in five years. To understand the heritable mechanisms involved in adjustment to such a new environment, we investigate both genetic and epigenetic as possible sources of flexibility involved in this fast terrestrial transition. We found a low overall genetic differentiation between the two morphotypes arguing against the possibility that terrestrial morphotype emerged from a new adaptive genetic capacity. Artificial hypomethylation was induced on both morphotypes to assess the epigenetic hypothesis. We analysed global DNA methylation, morphological changes, phytohormones and metabolite profiles of both morphotype responses in both aquatic and terrestrial conditions in shoot and root tissues. Hypomethylation significantly affected morphological variables, phytohormone levels and the amount of some metabolites. The effects of hypomethylation depended on morphotypes, conditions, and plant tissues, which highlighted differences among the morphotypes and their plasticity. Using a correlative integrative approach, we showed that hypomethylation of the aquatic morphotype mimicked the characteristics of the terrestrial morphotype. Our data suggest that DNA methylation rather than a new adaptive genetic capacity is playing a key role in L. grandiflora subsp hexapetala plasticity during its rapid aquatic to terrestrial transition. This article is protected by copyright. All rights reserved.

RevDate: 2020-07-05

Jermacz Ł, Kletkiewicz H, Krzyżyńska K, et al (2020)

Does global warming intensify cost of antipredator reaction? A case study of freshwater amphipods.

The Science of the total environment, 742:140474 pii:S0048-9697(20)33996-6 [Epub ahead of print].

Global warming is a worldwide phenomenon affecting the functioning of diverse ecosystems, including fresh waters. Temperature increase affects physiology and behaviour of ectotherms due to growing energetic demands necessary to sustain increased metabolic rate. Anti-predator responses may resemble temperature-induced changes in organisms, suggesting synergism between these factors. To check how temperature shapes physiological and behavioural responses of ectotherms to predation risk, we exposed amphipods: Dikerogammarus villosus and Gammarus jazdzewskii to fish kairomones at 10, 17 or 24 °C. Animals were placed in tanks where temperature was gradually adjusted to the desired test temperature and acclimated under such conditions for 3 subsequent days. Then they were exposed to the predator cue (the Eurasian perch kairomone) for 35 min to test their acute responses. We measured metabolic rate (as respiration), antioxidant defence (CAT: catalase activity, TAS: total antioxidant status), oxidative molecules (TOS: total oxidative status), oxidative damage (TBARS: thiobarbituric acid reactive substances) and behaviour (locomotor activity). Amphipods increased respiration with raising temperature and when exposed to predation risk (all temperatures). Only G. jazdzewskii exhibited increased TOS when exposed to 24 °C or to predation risk at all temperatures. Antioxidant defence increased with raising temperature (CAT, TAS) and decreased under predation risk (CAT). Cellular damage increased in G. jazdzewskii under predation risk at 10 and 24 °C, but raised temperature itself did not generate any damage. Amphipods reduced locomotor activity at 24 °C. Thus, at elevated temperatures, amphipods minimized their cellular damage at the cost of increased antioxidant defence and lower locomotor activity (potentially disadvantageous under higher energetic demands). Under predation risk, the performance of antioxidant systems was reduced, probably due to energy allocation into anti-predatory mechanisms, leading to increased cellular damage at suboptimum temperatures. Thus, negative consequences of elevated temperature for organisms may be amplified by changes in behaviour (compromising food acquisition) and non-consumptive predator effects.

RevDate: 2020-07-04

Najberek K, Olejniczak P, Berent K, et al (2020)

The ability of seeds to float with water currents contributes to the invasion success of Impatiens balfourii and I. glandulifera.

Journal of plant research pii:10.1007/s10265-020-01212-0 [Epub ahead of print].

Two alien species in Europe, Impatiens glandulifera and I. balfourii, are closely related, have similar growth rates and reproductive capacities, and are very attractive to pollinators. Nevertheless, only I. glandulifera is a highly invasive alien species in Europe, while I. balfourii is non-invasive. We assumed that the varying levels of invasiveness are driven by differences in the floating ability of their seeds, which may determine the invasion success of riparian alien plants, such as the Impatiens species. By mimicking two types of aquatic conditions, we determined seed floating ability for each species from younger and older populations. We also analyzed four seed traits: seed viability, surface, shape and coat structure. Seeds of the non-invasive I. balfourii float less well than seeds of the invasive I. glandulifera. We also found that the seeds of I. balfourii from the younger population have a higher floating ability in comparison with that of the seeds from the older population. The results for I. glandulifera were the opposite, with decreased floating ability in the younger population. These differences were associated with seed surface, shape and coat structure. These results indicate that the floating ability of I. balfourii seeds may increase over time following its introduction into a given area, while in the case of I. glandulifera, this ability may gradually decrease. Therefore, the former species, currently regarded as a poor disperser, has the potential to become invasive in the future, whereas the latter does not seem to benefit from further investments in the floating ability of its seeds.

RevDate: 2020-07-02

Ito HC, Shiraishi H, Nakagawa M, et al (2020)

Combined impact of pesticides and other environmental stressors on animal diversity in irrigation ponds.

PloS one, 15(7):e0229052 pii:PONE-D-20-01257.

Rice paddy irrigation ponds can sustain surprisingly high taxonomic richness and make significant contributions to regional biodiversity. We evaluated the impacts of pesticides and other environmental stressors (including eutrophication, decreased macrophyte coverage, physical habitat destruction, and invasive alien species) on the taxonomic richness of freshwater animals in 21 irrigation ponds in Japan. We sampled a wide range of freshwater animals (reptiles, amphibians, fishes, mollusks, crustaceans, insects, annelids, bryozoans, and sponges) and surveyed environmental variables related to pesticide contamination and other stressors listed above. Statistical analyses comprised contraction of highly correlated environmental variables, best-subset model selection, stepwise model selection, and permutation tests. Results showed that: (i) probenazole (fungicide) was a significant stressor on fish (i.e., contamination with this compound had a significantly negative correlation with fish taxonomic richness), (ii) the interaction of BPMC (insecticide; also known as fenobucarb) and bluegill (invasive alien fish) was a significant stressor on a "large insect" category (Coleoptera, Ephemeroptera, Hemiptera, Lepidoptera, Odonata, and Trichoptera), (iii) the interaction of BPMC and concrete bank protection was a significant stressor on an "invertebrate" category, (iv) the combined impacts of BPMC and the other stressors on the invertebrate and large insect categories resulted in an estimated mean loss of taxonomic richness by 15% and 77%, respectively, in comparison with a hypothetical pond with preferable conditions.

RevDate: 2020-07-02

da Silva Jorge S, T Satir (2020)

Framework and implementation of a fuzzy logic filter-an optimization strategy for the BWMS based on stakeholders' perspectives.

Environmental science and pollution research international pii:10.1007/s11356-020-09807-9 [Epub ahead of print].

The International Convention for the Control and Management of Ships' Ballast Water and Sediments (IMO 2018 Edition) was adopted in 2004 and came into force on 8 September 2017, aiming to introduce global regulations to control the transfer of potentially invasive species. Large efforts have been made by the maritime industry in creating reliable strategies for the installation of systems on board (Register 2014). Environmental considerations (INTERTANKO 2018) and optimization for the management systems (IMO 2017 Report) are factors broadly considered to tackle this matter. A consistent implementation strategy must be stated before the ballast water management system (BWMS) installation project starts-the management of stakeholders (e.g. ship owners, classification societies, administration, shipyards) is an important aspect of this process. This relies on their expertise, which in turn results in a high level of engagement and supports the implementation plan into the organizations. The creation of a framework for the optimization process, considering the implementation project of a BWMS on board of oil tankers, is the first part of this research. The use of fuzzy logic principles in the second part-as an evaluation instrument from a ranking obtained by multicriteria principles-sums up the aim of this paper, where the peculiarities about oil tankers' modelling will be discussed throughout the analysis of 2 optimization cases (Suezmax and Aframax).

RevDate: 2020-07-02

Khdiar MY, Barber PA, Hardy GES, et al (2020)

Association of Phytophthora with Declining Vegetation in an Urban Forest Environment.

Microorganisms, 8(7): pii:microorganisms8070973.

Urban forests consist of various environments from intensely managed spaces to conservation areas and are often reservoirs of a diverse range of invasive pathogens due to their introduction through the nursery trade. Pathogens are likely to persist because the urban forest contains a mixture of native and exotic plant species, and the environmental conditions are often less than ideal for the trees. To test the impact of different land management approaches on the Phytophthora community, 236 discrete soil and root samples were collected from declining trees in 91 parks and nature reserves in Joondalup, Western Australia (WA). Sampling targeted an extensive variety of declining native trees and shrubs, from families known to be susceptible to Phytophthora. A sub-sample was set aside and DNA extracted for metabarcoding using Phytophthora-specific primers; the remaining soil and root sample was baited for the isolation of Phytophthora. We considered the effect on the Phytophthora community of park class and area, soil family, and the change in canopy cover or health as determined through sequential measurements using remote sensing. Of the 236 samples, baiting techniques detected Phytophthora species from 24 samples (18 parks), while metabarcoding detected Phytophthora from 168 samples (64 parks). Overall, forty-four Phytophthora phylotypes were detected. Considering only sampling sites where Phytophthora was detected, species richness averaged 5.82 (range 1-21) for samples and 9.23 (range 2-24) for parks. Phytophthora multivora was the most frequently found species followed by P. arenaria, P. amnicola and P. cinnamomi. While park area and canopy cover had a significant effect on Phytophthora community the R2 values were very low, indicating they have had little effect in shaping the community. Phytophthora cinnamomi and P. multivora, the two most invasive species, often co-occurring (61% of samples); however, the communities with P. multivora were more common than those with P. cinnamomi, reflecting observations over the past decade of the increasing importance of P. multivora as a pathogen in the urban environment.

RevDate: 2020-07-02
CmpDate: 2020-07-02

Vancheva N, Bobeva A, Pehlivanov L, et al (2020)

Alien parasites on an alien fish species: monogeneans from the black bullhead Ameiurus melas (Siluriformes) in the Lake Srebarna Biosphere Reserve, Bulgaria, with the first record of Gyrodactylus nebulosus in the Palaearctic.

Parasitology research, 119(7):2105-2112.

Black bullhead Ameiurus melas (Actinopterygii: Siluriformes) is an alien fish species of North American origin, which has expanded its invasive geographical range in Europe. In 2017-2019, 32 black bullhead specimens from the Lake Srebarna Biosphere Reserve, Bulgaria, were examined for monogenean parasites. Two species of monogeneans were recorded and identified on the basis of morphological and molecular data: Ligictaluridus pricei (Ancyrocephalidae), with prevalence 100% and intensity 2-32 (mean 13.3 ± 6.8), and Gyrodactylus nebulosus (Gyrodactylidae), with prevalence 72.0% and intensity 1-15 (mean 7.4 ± 4.3). Partial 18S rDNA and the ITS1 region of L. pricei were sequenced. For G. nebulosus, sequenced genes included the partial 18S rDNA and the entire ITS1-5.8S rDNA-ITS2 region as well as the mitochondrial COI gene. Both recorded monogenean species are specific parasites of North American ictalurid fishes and alien to Europe. The present study is the first record of L. pricei from Bulgaria and the first record of G. nebulosus from Europe and the Palaearctic Region.

RevDate: 2020-07-01

Lam DK, SYW Sin (2020)

Development and characterization of microsatellite markers in Rosy-faced and other lovebirds (Agapornis spp.) using next-generation sequencing.

Molecular biology reports pii:10.1007/s11033-020-05623-z [Epub ahead of print].

Agapornis are a group of small African parrots that are heavily traded around the world. They are invasive species in many places, but some of them are listed as Vulnerable or Near Threatened. However, the genetic tools for assessing inter-individual relationships, population structure, and genetic diversity of these birds are very limited. Therefore, we developed polymorphic microsatellite markers in A. roseicollis and tested the transferability on 5 lovebird species including A. personatus, A. nigrigenis, A. fischeri, A. pullarius, and A. canus, and two closely related outgroups (i.e. Bolbopsittacus lunulatus and Loriculus galgulus). We first performed whole-genome re-sequencing on five individuals of A. roseicollis to identify potential polymorphic loci. Out of 37 loci tested in 11 A. roseicollis, 27 loci were demonstrated to be polymorphic, with the number of the alleles ranging from 2 to 7 (mean = 3.963). The observed heterozygosity ranged from 0 to 0.875 (mean = 0.481) and expected heterozygosity ranged from 0.233 to 0.842 (mean = 0.642). Five loci (Agro-A13, p < 0.01; Agro-A15, p < 0.05; Agro-A43, p < 0.05, Agro-A65, p < 0.05; Agro-A67, p < 0.05) were detected to deviate from Hardy-Weinberg equilibrium, with the presence of null alleles suggested in locus Agro-A13 and Agro-A77. The exclusion powers for PE1 and PE2 are 0.997 and 0.999, respectively. The 27 novel polymorphic markers developed here will be useful for parentage and kinship assignment and population genetics study in Agapornis, and provide a tool for scientific research, captive breeding industry, and invasion and conservation management of these species.

RevDate: 2020-07-01

Cuthbert RN, Wasserman RJ, Dalu T, et al (2020)

Influence of intra- and interspecific variation in predator-prey body size ratios on trophic interaction strengths.

Ecology and evolution, 10(12):5946-5962 pii:ECE36332.

Predation is a pervasive force that structures food webs and directly influences ecosystem functioning. The relative body sizes of predators and prey may be an important determinant of interaction strengths. However, studies quantifying the combined influence of intra- and interspecific variation in predator-prey body size ratios are lacking.We use a comparative functional response approach to examine interaction strengths between three size classes of invasive bluegill and largemouth bass toward three scaled size classes of their tilapia prey. We then quantify the influence of intra- and interspecific predator-prey body mass ratios on the scaling of attack rates and handling times.Type II functional responses were displayed by both predators across all predator and prey size classes. Largemouth bass consumed more than bluegill at small and intermediate predator size classes, while large predators of both species were more similar. Small prey were most vulnerable overall; however, differential attack rates among prey were emergent across predator sizes. For both bluegill and largemouth bass, small predators exhibited higher attack rates toward small and intermediate prey sizes, while larger predators exhibited greater attack rates toward large prey. Conversely, handling times increased with prey size, with small bluegill exhibiting particularly low feeding rates toward medium-large prey types. Attack rates for both predators peaked unimodally at intermediate predator-prey body mass ratios, while handling times generally shortened across increasing body mass ratios.We thus demonstrate effects of body size ratios on predator-prey interaction strengths between key fish species, with attack rates and handling times dependent on the relative sizes of predator-prey participants.Considerations for intra- and interspecific body size ratio effects are critical for predicting the strengths of interactions within ecosystems and may drive differential ecological impacts among invasive species as size ratios shift.

RevDate: 2020-07-01

Rodrigues NT, Saranholi BH, Angeloni TA, et al (2020)

DNA mini-barcoding of leporids using noninvasive fecal DNA samples and its significance for monitoring an invasive species.

Ecology and evolution, 10(12):5219-5225 pii:ECE35863.

Introduced in South America at the end of the 19th century, the European hare population has expanded dramatically and now represents a risk to native Brazilian forest rabbits. Monitoring the invasive Lepus europaeus and its coexistence with native Sylvilagus brasiliensis is a challenge that can be efficiently addressed by the use of molecular tools. This work describes a set of primers useful for amplifying three mini-barcodes for the molecular identification of both invasive and native leporid species using degraded fecal DNA. In addition, tests in silico indicate that these mini-barcodes can successfully amplify the DNA sequences of a number of leporids. These mini-barcodes constitute a powerful tool for the monitoring and management of the invasive L. europaeus and the conservation of native rabbits.

RevDate: 2020-07-01

Levin SC, Crandall RM, Pokoski T, et al (2020)

Phylogenetic and functional distinctiveness explain alien plant population responses to competition.

Proceedings. Biological sciences, 287(1930):20201070.

Several invasion hypotheses predict a positive association between phylogenetic and functional distinctiveness of aliens and their performance, leading to the idea that distinct aliens compete less with their resident communities. However, synthetic pattern relationships between distinctiveness and alien performance and direct tests of competition as the driving mechanism have not been forthcoming. This is likely because different patterns are observed at different spatial grains, because functional trait and phylogenetic information are often incomplete, and because of the need for competition experiments that measure demographic responses across a variety of alien species that vary in their distinctiveness. We conduct a competitor removal experiment and parameterize matrix population and integral projection models for 14 alien plant species. More novel aliens compete less strongly with co-occurring species in their community, but these results dissipate at a larger spatial grain of investigation. Further, we find that functional traits used in conjunction with phylogeny improve our ability to explain competitive responses. Our investigation shows that competition is an important mechanism underlying the differential success of alien species.

RevDate: 2020-07-01

Liu Y, Beaurepaire A, Rogers CW, et al (2020)

Gene Expression and Functional Analyses of Odorant Receptors in Small Hive Beetles (Aethina tumida).

International journal of molecular sciences, 21(13): pii:ijms21134582.

Olfaction is key to many insects. Odorant receptors (ORs) stand among the key chemosensory receptors mediating the detection of pheromones and kairomones. Small hive beetles (SHBs), Aethina tumida, are parasites of social bee colonies and olfactory cues are especially important for host finding. However, how interactions with their hosts may have shaped the evolution of ORs in the SHB remains poorly understood. Here, for the first time, we analyzed the evolution of SHB ORs through phylogenetic and positive selection analyses. We then tested the expression of selected OR genes in antennae, heads, and abdomens in four groups of adult SHBs: colony odor-experienced/-naive males and females. The results show that SHBs experienced both OR gene losses and duplications, thereby providing a first understanding of the evolution of SHB ORs. Additionally, three candidate ORs potentially involved in host finding and/or chemical communication were identified. Significantly different downregulations of ORs between the abdomens of male and female SHBs exposed to colony odors may reflect that these expression patterns might also reflect other internal events, e.g., oviposition. Altogether, these results provide novel insights into the evolution of SHB ORs and provide a valuable resource for analyzing the function of key genes, e.g., for developing biological control. These results will also help in understanding the chemosensory system in SHBs and other beetles.

RevDate: 2020-07-01
CmpDate: 2020-07-01

Martignoni MM, Hart MM, Tyson RC, et al (2020)

Diversity within mutualist guilds promotes coexistence and reduces the risk of invasion from an alien mutualist.

Proceedings. Biological sciences, 287(1923):20192312.

Biodiversity is an important component of healthy ecosystems, and thus understanding the mechanisms behind species coexistence is critical in ecology and conservation biology. In particular, few studies have focused on the dynamics resulting from the co-occurrence of mutualistic and competitive interactions within a group of species. Here we build a mathematical model to study the dynamics of a guild of competitors who are also engaged in mutualistic interactions with a common partner. We show that coexistence as well as competitive exclusion can occur depending on the competition strength and on strength of the mutualistic interactions, and we formulate concrete criteria for predicting invasion success of an alien mutualist based on propagule pressure, alien traits (such as its resource exchange ability) and composition of the recipient community. We find that intra guild diversity promotes the coexistence of species that would otherwise competitively exclude each other, and makes a guild less vulnerable to invasion. Our results can serve as a useful framework to predict the consequences of species manipulation in mutualistic communities.

RevDate: 2020-06-30

Eble JA, Daly-Engel TS, DiBattista JD, et al (2020)

Marine environmental DNA: Approaches, applications, and opportunities.

Advances in marine biology, 86(1):141-169.

Environmental DNA (eDNA) is increasingly being used to document species distributions and habitat use in marine systems, with much of the recent effort focused on leveraging advances in next-generation DNA sequencing to assess and track biodiversity across taxonomic groups. Environmental DNA offers a number of important advantages over traditional survey techniques, including non-invasive sampling, sampling where traditional approaches are impractical or inefficient (e.g. deep oceans), reduced cost, and increased detection sensitivity. However, eDNA applications are currently limited because of an insufficient understanding of the influence of sample source, analytical approach, and marker type on eDNA detections. Because approaches vary considerably among eDNA studies, we present a summary of the current state of the field and emerging best practices. The impact of observed variation in rates of eDNA production, persistence, and transport are also discussed and future research needs are highlighted with the goal of expanding eDNA applications, including the development of statistical models to improve the predictability of eDNA detection and quantification.

RevDate: 2020-06-29

Sherpa S, Renaud J, Guéguen M, et al (2020)

Landscape does matter: disentangling founder effects from natural and human-aided post-introduction dispersal during an ongoing biological invasion.

The Journal of animal ecology [Epub ahead of print].

Environmental features impacting the spread of invasive species after introduction can be assessed using population genetic structure as a quantitative estimation of effective dispersal at the landscape scale. However, in the case of an ongoing biological invasion, deciphering whether genetic structure represents landscape connectivity or founder effects is particularly challenging. We examined the modes of dispersal (natural and human-aided) and the factors (landscape or founders history) shaping genetic structure in range edge invasive populations of the Asian tiger mosquito, Aedes albopictus, in the region of Grenoble (Southeast France). Based on detailed occupancy-detection data and environmental variables (climatic, topographic, land-cover), we modelled A. albopictus potential suitable area and its expansion history since first introduction. The relative role of dispersal modes was estimated using biological dispersal capabilities and landscape genetics approaches using genome-wide SNP dataset. We demonstrate that both natural and human-aided dispersal have promoted the expansion of populations. Populations in diffuse urban areas, representing highly suitable habitat for A. albopictus, tend to disperse less, while roads facilitate long-distance dispersal. Yet demographic bottlenecks during introduction played a major role in shaping the genetic variability of these range edge populations. The present study is one of the few investigating the role of founder effects and ongoing expansion processes in shaping spatial patterns of genetic variation in an invasive species at the landscape scale. The combination of several dispersal modes and large proportions of continuous suitable habitats for A. albopictus promoted range filling of almost its entire potential distribution in the region of Grenoble only few years after introduction.

RevDate: 2020-06-30

Li J, Yu Z, Choo S, et al (2020)

Chemico-Proteomics Reveal the Enhancement of Salt Tolerance in an Invasive Plant Species via H2S Signaling.

ACS omega, 5(24):14575-14585.

H2S is a small molecule known to have multiple signaling roles in animals. Recently, evidence shows that H2S also has signaling functions in plants; however, the role of H2S in invasive plants is unknown. Spartina alterniflora is a typical invasive species growing along the beaches of southern China. A physiological comparison proves that S. alterniflora is highly tolerant to salinity stress compared with the native species Cyperus malaccensis. To decipher the mechanism that enables S. alterniflora to withstand salinity stress, a chemico-proteomics analysis was performed to examine the salt stress response of the two species; an inhibitor experiment was additionally designed to investigate H2S signaling on salinity tolerance in S. alterniflora. A total of 86 proteins belonging to nine categories were identified and differentially expressed in S. alterniflora exposed to salt stress. Moreover, the expression level of enzymes responsible for the H2S biosynthesis was markedly upregulated, indicating the potential role of H2S signaling in the plant's response to salt stress. The results suggested that salt triggered l-CD enzyme activity and induced the production of H2S, therefore upregulating expression of the antioxidants ascorbate peroxidase, superoxide dismutase, and S-nitrosoglutathione reductase, which mitigates damage from reactive nitrogen species. Additionally, H2S reduced the potassium efflux, thereby sustaining intracellular sodium/potassium ion homeostasis and enhancing S. alterniflora salt tolerance. These findings indicate that H2S plays an important role in the adaptation of S. alterniflora to saline environments, which provides greater insight into the function of H2S signaling in the adaptation of an invasive plant species.

RevDate: 2020-06-30

Sharifdini M, Amin OM, Ashrafi K, et al (2020)

Helminthes in Feral Raccoon (Procyon lotor) as an Alien Species in Iran.

Iranian journal of parasitology, 15(2):240-247.

Background: The raccoon, Procyon lotor Linn. (Procyonidae) is native to North and Central America but has been introduced in several European and Asian countries including Japan, Germany and Iran. Objective of this study was to determine frequency of gastrointestinal and tissue helminthes from feral raccoons in Iran.

Methods: During 2015-2017, 30 feral raccoons including 12 males and 18 females were collected from Guilan Province, northern Iran (the only region in Iran where raccoons are found). The gastrointestinal tracts and tissues such as lung, liver and muscles were examined for presence of helminthes.

Results: Twenty raccoons (66.7%) were found infected with five intestinal helminth species. The prevalence of infection with Strongyloides procyonis Little, 1966 (Nematoda) was 63.3%, Plagiorchis koreanus Ogata, 1938 (Trematoda) (13.3%), Centrorhynchus sp. Lühe, 1911 (Acanthocephala) (10.0%), Camerostrongylus didelphis Wolfgang, 1951 (Nematoda) (3.3%), and Spirocerca lupi Rudolphi, 1809 (Nematoda) (3.3%). No larvae or adult worms were found in other tissues of the examined raccoons.

Conclusion: Most of the raccoons were infected with S. procyonis. The public health importance of zoonotic parasites transmittable through raccoons, the rapid control and decrease of raccoon populations and their distribution in Iran are also discussed.

RevDate: 2020-06-28

Yang QQ, He C, Liu GF, et al (2020)

Introgressive hybridization between two nonnative apple snails in China: widespread hybridization and homogenization in egg morphology.

Pest management science [Epub ahead of print].

BACKGROUND: Apple snails from the genus Pomacea have spread widely in paddy fields and other wetlands of southern China since their introduction in the 1980s. Pomacea spp. are commonly identified using mitochondrial COI sequences. However, sequencing the nuclear EF1α gene revealed genetic introgression between field populations of P. canaliculata and P. maculata, which produce surviving hybrids in laboratory crossbreeding experiments.

RESULTS: In this study, we sequenced 1054 EF1α clones to design specific primers and established a fast and accurate multiplex PCR method for genotyping EF1α. Combined with genotyping P. canaliculata and P. maculata based on COI sequences, we revealed the genetic introgression patterns of 30 Pomacea populations in China. Purebred and hybrid individuals of P. canaliculata were widely distributed, while pure maculata-EF1α type was detected only in a few individuals identified as P. canaliculata based on COI sequences. Each egg clutch had one to three genetic patterns, indicating multiple paternity or segregation in the progeny of hybrids. The higher percentages of hybrids in both wild populations and progeny than the homozygotes indicated a potential heterosis in the apple snail populations. Additionally, egg size and clutch size of the apple snails became homogeneous among the nonnative populations exhibiting introgression hybridization.

CONCLUSION: Our findings emphasize the value of apple snails as a model to study the mechanisms and impacts of introgressive hybridization on fitness traits. This article is protected by copyright. All rights reserved.

RevDate: 2020-06-30
CmpDate: 2020-06-30

Chen L, Fang K, Dong XF, et al (2020)

Characterization of the fungal community in the canopy air of the invasive plant Ageratina adenophora and its potential to cause plant diseases.

PloS one, 15(3):e0230822.

Airborne fungi and their ecological functions have been largely ignored in plant invasions. In this study, high-throughput sequencing technology was used to characterize the airborne fungi in the canopy air of the invasive weed Ageratina adenophora. Then, representative phytopathogenic strains were isolated from A. adenophora leaf spots and their virulence to A.adenophora as well as common native plants in the invaded range was tested. The fungal alpha diversities were not different between the sampling sites or between the high/low part of the canopy air, but fungal co-occurrences were less common in the high than in the low part of the canopy air. Interestingly, we found that the phytopathogenic Didymellaceae fungi co-occurred more frequently with themselves than with other fungi. Disease experiments indicated that all 5 Didymellaceae strains could infect A. adenophora as well as the 16 tested native plants and that there was large variation in the virulence and host range. Our data suggested that the diverse pathogens in the canopy air might be a disease infection source that weakens the competition of invasive weeds, a novel phenomenon that remains to be explored in other invasive plants.

RevDate: 2020-06-30
CmpDate: 2020-06-30

Egan SL, Taylor CL, Austen JM, et al (2020)

Molecular identification of the Trypanosoma (Herpetosoma) lewisi clade in black rats (Rattus rattus) from Australia.

Parasitology research, 119(5):1691-1696.

Invasive rodent species are known hosts for a diverse range of infectious microorganisms and have long been associated with the spread of disease globally. The present study describes molecular evidence for the presence of a Trypanosoma sp. from black rats (Rattus rattus) in northern Sydney, Australia. Sequences of the 18S ribosomal RNA (rRNA) locus were obtained in two out of eleven (18%) blood samples with subsequent phylogenetic analysis confirming the identity within the Trypanosoma lewisi clade.

RevDate: 2020-06-30
CmpDate: 2020-06-30

Wesselmann M, Anton A, Duarte CM, et al (2020)

Tropical seagrass Halophila stipulacea shifts thermal tolerance during Mediterranean invasion.

Proceedings. Biological sciences, 287(1922):20193001.

Exotic species often face new environmental conditions that are different from those that they are adapted to. The tropical seagrass Halophila stipulacea is a Lessepsian migrant that colonized the Mediterranean Sea around 100 years ago, where at present the minimum seawater temperature is cooler than in its native range in the Red Sea. Here, we tested if the temperature range in which H. stipulacea can exist is conserved within the species or if the exotic populations have shifted their thermal breadth and optimum due to the cooler conditions in the Mediterranean. We did so by comparing the thermal niche (e.g. optimal temperatures, and upper and lower thermal limits) of native (Saudi Arabia in the Red Sea) and exotic (Greece and Cyprus in the Mediterranean Sea) populations of H. stipulacea. We exposed plants to 12 temperature treatments ranging from 8 to 40°C for 7 days. At the end of the incubation period, we measured survival, rhizome elongation, shoot recruitment, net population growth and metabolic rates. Upper and lower lethal thermal thresholds (indicated by 50% plant mortality) were conserved across populations, but minimum and optimal temperatures for growth and oxygen production were lower for Mediterranean populations than for the Red Sea one. The displacement of the thermal niche of exotic populations towards the colder Mediterranean Sea regime could have occurred within 175 clonal generations.

RevDate: 2020-06-27

Ferrão-Filho AS, Pereira UJ, Vilar MCP, et al (2020)

Can small-bodied Daphnia control Raphidiopsis raciborskii in eutrophic tropical lakes? A mesocosm experiment.

Environmental science and pollution research international pii:10.1007/s11356-020-09737-6 [Epub ahead of print].

Raphidiopsis raciborskii is being considered an expanding, invasive species all over the world. It is a potentially toxin producer cyanobacterium and form blooms specially in (sub)tropical lakes, causing concern to public health. Thus, controlling such phenomena are of vital importance. To test the hypothesis that a tropical clone of Daphnia laevis is able to reduce the biomass of R. raciborskii, we performed a mesocosm experiment simulating a bloom of this cyanobacterium in field conditions and exposing it to ecologically relevant densities of daphniids. In addition, we tested the hypothesis that omnivorous fish would be able to exert a top-down effect on Daphnia, decreasing the effectiveness of this control. We used treatments with (10 and 20 Daphnia L-1) or without Daphnia and fish (3 per mesocosm). Daphnia was able to significantly reduce the biomass of R. raciborskii only at the highest density tested. Fish had low effect on Daphnia biomass, but it is suggested that nutrient recycling by fish might have contributed to the higher R. raciborskii biomass in fish treatments. This is the first evidence of Daphnia control over saxitoxin-producing cyanobacteria in a tropical ecosystem.

RevDate: 2020-06-26

Pyšek P, Hulme PE, Simberloff D, et al (2020)

Scientists' warning on invasive alien species.

Biological reviews of the Cambridge Philosophical Society [Epub ahead of print].

Biological invasions are a global consequence of an increasingly connected world and the rise in human population size. The numbers of invasive alien species - the subset of alien species that spread widely in areas where they are not native, affecting the environment or human livelihoods - are increasing. Synergies with other global changes are exacerbating current invasions and facilitating new ones, thereby escalating the extent and impacts of invaders. Invasions have complex and often immense long-term direct and indirect impacts. In many cases, such impacts become apparent or problematic only when invaders are well established and have large ranges. Invasive alien species break down biogeographic realms, affect native species richness and abundance, increase the risk of native species extinction, affect the genetic composition of native populations, change native animal behaviour, alter phylogenetic diversity across communities, and modify trophic networks. Many invasive alien species also change ecosystem functioning and the delivery of ecosystem services by altering nutrient and contaminant cycling, hydrology, habitat structure, and disturbance regimes. These biodiversity and ecosystem impacts are accelerating and will increase further in the future. Scientific evidence has identified policy strategies to reduce future invasions, but these strategies are often insufficiently implemented. For some nations, notably Australia and New Zealand, biosecurity has become a national priority. There have been long-term successes, such as eradication of rats and cats on increasingly large islands and biological control of weeds across continental areas. However, in many countries, invasions receive little attention. Improved international cooperation is crucial to reduce the impacts of invasive alien species on biodiversity, ecosystem services, and human livelihoods. Countries can strengthen their biosecurity regulations to implement and enforce more effective management strategies that should also address other global changes that interact with invasions.

RevDate: 2020-06-26
CmpDate: 2020-06-26

Uyan U, Oh CW, Tarkan AS, et al (2020)

Risk screening of the potential invasiveness of non-native marine fishes for South Korean coastal waters.

Marine pollution bulletin, 153:111018.

Risk screening tools are being increasingly used to identify the potential invasiveness and associated risks of non-native species. In this study, the Aquatic Species Invasiveness Screening Kit was used to evaluate the invasiveness risks of extant and horizon non-native marine fish species for the coastal waters of South Korea. In total, 57 marine fish species were screened and the threshold scores for the Basic Risk Assessment (BRA) and the BRA + Climate Change Assessment (BRA+CCA) (5.5 and 1.5, respectively) reliably distinguished those species carrying a high risk of invasiveness from those carrying a low to medium risk. For both the BRA and BRA+CCA, common lionfish Pterois miles was the highest-scoring species, followed by white perch Morone americana, red drum Sciaenops ocellatus, marbled spinefoot Siganus rivulatus and redcoat Sargocentron rubrum. The outcomes of this study will contribute to the management of non-native marine fish species for the conservation of the native ecosystems in the coastal waters of South Korea.

RevDate: 2020-06-26
CmpDate: 2020-06-26

Gleditsch JM, JH Sperry (2019)

Rapid morphological change of nonnative frugivores on the Hawaiian island of O'ahu.

Evolution; international journal of organic evolution, 73(7):1456-1465.

Novel ecosystems have become widespread created, in part, by the global spread of species. The nonnative species in these environments can be under intense evolutionary pressures that cause rapid morphological change, which can then influence species interactions. In Hawaii, much of the native frugivore community is extinct, replaced by nonnative bird species. Here, we determined if the passerine species of the nonnative frugivore community on O'ahu have morphologically diverged from their native ranges. We compared a variety of traits, all important for frugivory, between museum specimens from the species' native ranges to wild individuals from O'ahu. All four species tested exhibited significant divergence ranging in magnitude from 2.3% to 13.0% difference in at least two traits. Using a method developed from quantitative genetics, we found evidence that a mixture of nonadaptive and adaptive processes worked in concert to create the observed patterns of divergence. Our results suggest that rapid morphological change is occurring and, based on the traits measured, that these changes may influence seed dispersal effectiveness. As these species are largely responsible for seed dispersal on the island, the rapid morphological change of these species can influence the stability and maintenance of plant communities on O'ahu.

RevDate: 2020-06-25

Helsen K, Acharya KP, Graae BJ, et al (2020)

Earlier onset of flowering and increased reproductive allocation of an annual invasive plant in the north of its novel range.

Annals of botany pii:5862362 [Epub ahead of print].

BACKGROUND AND AIMS: It remains unclear whether invasive species can maintain both high biomass and reproductive output across their invaded range. Along latitudinal gradients, allocation theory predicts that faster flowering onset at high latitudes results in maturation at smaller size and thus reduced reproductive output. For annual invasive plants, more favourable environmental conditions at low latitudes likely result in stronger competition of co-occurring species, potentially driving selection for higher investment in vegetative biomass, while harsher climatic conditions and associated reproductive uncertainty at higher latitudes could reduce selection for vegetative biomass and increased selection for high reproductive investment (stress-gradient hypothesis). Combined, these drivers could result in increased or constant reproductive allocation with increasing latitude.

METHODS: We quantified life-history traits in the invasive annual plant Impatiens glandulifera along a latitudinal gradient in Europe. By growing two successive greenhouse generations, we assessed genetic differentiation in vegetative growth and reproductive output across six populations, and tested whether onset of flowering drives this divergence.

KEY RESULTS: Trait variation was mainly caused by genetic differentiation. As expected, flowering onset was progressively earlier in populations from higher latitudes. Plant height and vegetative biomass also decreased in populations from higher latitudes, as predicted by the allocation theory, but their variation was independent of the variation in flowering onset. Reproductive output remained constant across latitudes, resulting in increased reproductive allocation towards higher latitudes, supporting the stress-gradient hypothesis. We also observed trait genetic differentiation among populations that was independent of latitude.

CONCLUSIONS: We show that an annual invasive plant evolved several life-history traits across its invaded range in ca. 150 years. The evolution of vegetative and reproductive traits seems unconstrained by evolution of flowering onset. This genetic decoupling between vegetative and reproductive traits possibly contributes to the invasion success of this species.

RevDate: 2020-06-25

Dzido J, Rolbiecki L, Izdebska JN, et al (2020)

Checklist of the parasites of European eel Anguilla anguilla (Linnaeus, 1758) (Anguillidae) in Poland.

Biodiversity data journal, 8:e52346 pii:52346.

The present paper lists all parasite species of the European eel Anguilla anguilla (Linnaeus, 1758), recorded in Poland, in both its saltwater and freshwater habitats. The list has been drawn up, based on data acquired since 1844. The majority of included parasite species are presented with fish infection parameters together with data on their developmental stages and occupied microhabitats, localities and dates of collection of the eels themselves. The database includes 62 parasite taxa (including 50 species, nine identified to the genus level and three to higher taxa), representing at least 47 genera and 39 families. The most frequently-noted parasites of the European eel are the cestode Bothriocephalus claviceps, the nematodes Anguillicoloides crassus, Camallanus lacustris and Raphidascaris acus and the acanthocephalan Acanthocephalus lucii. Four alien species have been noted from this host: A. crassus, the monogeneans Pseudodactylogyrus anguillae and Pseudodactylogyrus bini and the acanthocephalan Paratenuisentis ambiguus. The present list includes both new host records and earlier records not included in previous lists of parasites of eels.

RevDate: 2020-06-25

Vega-Rúa A, Marconcini M, Madec Y, et al (2020)

Vector competence of Aedes albopictus populations for chikungunya virus is shaped by their demographic history.

Communications biology, 3(1):326 pii:10.1038/s42003-020-1046-6.

The mosquito Aedes albopictus is one of the most dangerous invasive species. Its worldwide spread has created health concerns as it is a major vector of arboviruses of public health significance such as chikungunya (CHIKV). Dynamics of different genetic backgrounds and admixture events may have impacted competence for CHIKV in adventive populations. Using microsatellites, we infer the genetic structure of populations across the expansion areas that we then associate with their competence for different CHIKV genotypes. Here we show that the demographic history of Ae. albopictus populations is a consequence of rapid complex patterns of historical lineage diversification and divergence that influenced their competence for CHIKV. The history of adventive populations is associated with CHIKV genotypes in a genotype-by-genotype interaction that impacts their vector competence. Thus, knowledge of the demographic history and vector competence of invasive mosquitoes is pivotal for assessing the risk of arbovirus outbreaks in newly colonized areas.

RevDate: 2020-06-25
CmpDate: 2020-06-25

Cabezas MP, Lasso-Alcalá OM, Xavier R, et al (2020)

First genetic record of the non-native muzzled blenny Omobranchus punctatus (Teleostei: Blenniidae) in the Atlantic Coast of Central and South America.

Journal of fish biology, 96(3):841-846.

In this study we sequenced two mitochondrial (COI and 16S rRNA) and one nuclear (18S rRNA) gene fragment of an introduced muzzled blenny (Omobranchus punctatus) specimen collected from the Orinoco Delta (Gulf of Paria estuary) in Venezuela. This is the first genetic data generated for this species' introduced range in Central and South America, suggesting an introduction from the Indian Ocean.

RevDate: 2020-06-25
CmpDate: 2020-06-25

McLeish J, Briers RA, Dodd JA, et al (2020)

First genetic evidence that invasive bullhead (Cottus L. 1758) in Scotland is of English origin and the difficulty of resolving the European Cottus species taxonomy.

Journal of fish biology, 96(3):617-630.

The European bullhead (Cottus gobio) is widely distributed across Europe, and within the UK is native to England and Wales, where it is protected under the Habitats Directive. In Scotland, however, the species is considered invasive and thriving populations are recorded in the Forth and Clyde river catchments, and the Ale Water in the Scottish Borders. The genetic identity of the Scottish populations has not been established. There is also debate about the status of the European bullhead and its validity as single species, a species complex with several unresolved species, or distinct different species in its European distribution range. There is therefore a need to determine the taxonomy and likely source of the novel Scottish populations. Genetic analyses using cytochrome oxidase 1 (COI) mitochondrial DNA sequences were undertaken on specimens from the Forth and Clyde catchments, and combined with the results of morphological characteristics to provide a comprehensive assessment of the taxonomic classification for Scottish bullheads. There was considerable variation in morphological characteristics between populations within Scotland and a wider range of variability than previously recorded for English populations. Genetically the Scottish populations were very closely related to English specimens, supporting the hypothesis of introduction directly from England to Scotland. In terms of broader relationships, Scottish specimens are genetically more closely related to the ostensible species Chabot fluviatile Cottus perifretum, which has been suggested as one of a complex of species across Europe. Morphologically they exhibit characteristics on the spectrum between C. perifretum and C. gobio. There is an urgent need for the clarification of the taxonomy of Cottus sp(p). to avoid confusion in future publications, legislation and management practices relating to bullheads throughout the UK and Europe.

RevDate: 2020-06-25
CmpDate: 2020-06-25

Kadye WT, AJ Booth (2020)

Environmental niche patterns of native and non-native fishes within an invaded African river system.

Journal of fish biology, 96(5):1269-1277.

To test ecological niche theory, this study investigated the spatial patterns and the environmental niches of native and non-native fishes within the invaded Great Fish River system, South Africa. For the native fishes, there were contrasting environmental niche breadths that varied from being small to being large and overlapped for most species, except minnows that were restricted to headwater tributaries. In addition, there was high niche overlap in habitat association among fishes with similar distribution. It was therefore inferred that habitat filtering-driven spatial organisation was important in explaining native species distribution patterns. In comparison, most non-native fishes were found to have broad environmental niches and these fishes showed high tolerance to environmental conditions, which generally supported the niche opportunity hypothesis. The proliferation of multiple non-native fishes in the mainstem section suggest that they form a functional assemblage that is probably facilitated by the anthropogenic modification of flow regimes through inter-basin water transfer. Based on the distribution patterns observed in the study, it was inferred that there was a likelihood of negative interactions between native and non-native fishes. Such effects are likely to be exacerbated by altered flow regime that was likely to have negative implications for native ichthyofauna.

RevDate: 2020-06-24

Phillips LM, Aitkenhead I, Janion-Scheepers C, et al (2020)

Basal tolerance but not plasticity gives invasive springtails the advantage in an assemblage setting.

Conservation physiology, 8(1):coaa049 pii:coaa049.

As global climates change, alien species are anticipated to have a growing advantage relative to their indigenous counterparts, mediated through consistent trait differences between the groups. These insights have largely been developed based on interspecific comparisons using multiple species examined from different locations. Whether such consistent physiological trait differences are present within assemblages is not well understood, especially for animals. Yet, it is at the assemblage level that interactions play out. Here, we examine whether physiological trait differences observed at the interspecific level are also applicable to assemblages. We focus on the Collembola, an important component of the soil fauna characterized by invasions globally, and five traits related to fitness: critical thermal maximum, minimum and range, desiccation resistance and egg development rate. We test the predictions that the alien component of a local assemblage has greater basal physiological tolerances or higher rates, and more pronounced phenotypic plasticity than the indigenous component. Basal critical thermal maximum, thermal tolerance range, desiccation resistance, optimum temperature for egg development, the rate of development at that optimum and the upper temperature limiting egg hatching success are all significantly higher, on average, for the alien than the indigenous components of the assemblage. Outcomes for critical thermal minimum are variable. No significant differences in phenotypic plasticity exist between the alien and indigenous components of the assemblage. These results are consistent with previous interspecific studies investigating basal thermal tolerance limits and development rates and their phenotypic plasticity, in arthropods, but are inconsistent with results from previous work on desiccation resistance. Thus, for the Collembola, the anticipated advantage of alien over indigenous species under warming and drying is likely to be manifest in local assemblages, globally.

RevDate: 2020-06-24

Luz R, Cordeiro R, Vilaverde J, et al (2020)

Cyanobacteria from freshwater lakes in the Azores archipelago, Portugal: data from long term phytoplankton monitoring.

Biodiversity data journal, 8:e51928 pii:51928.

Background: The Azores are oceanic islands located in the Northern Atlantic Ocean and are particularly rich in aquatic systems, ranging from freshwater, brackish, marine and thermal habitats. Due to the increase in local anthropogenic pressures and global warming, several azorean lakes began to reveal signs of eutrophication that led to the implementation of monitoring programmes and management strategies on the most impacted lakes. Later, the Water Framework Directive (2000/60/EC) demanded the establishment of biomonitoring programmes for European freshwater ecosystems and the limited Azorean monitoring programmes were extended to a larger set of lakes. Since the establishment of the aquatic systems monitoring programme in the Azores archipelago, lakes have been regularly sampled, producing innumerous unpublished records of cyanobacteria that are difficult to access.

New information: Here we present the occurrences of cyanobacteria in Azorean lakes that result from 22 years of phytoplankton monitoring in a total of 1948 cyanobacteria occurrences from 968 phytoplankton sampling events on Azorean lakes done between 1996 and 2018 as part of regional inland aquatic ecosystems monitoring programmes. Forty two cyanobacteria taxa were identified in those events, 28 species and 14 at genus level. This information is crucial for conservation, biodiversity studies and lake management, as some of the cyanobacteria species present are bloom-forming and have the ability to produce toxins. This will also allow for the identification of invasive species and possible targeted control and mitigation programmes, according to the species present in the Azorean lakes.

RevDate: 2020-06-24
CmpDate: 2020-06-24

Collins CL, Burnett NP, Ramsey MJ, et al (2020)

Physiological responses to heat stress in an invasive mussel Mytilus galloprovincialis depend on tidal habitat.

Marine environmental research, 154:104849.

Mussels are ecologically important organisms that can survive in subtidal and intertidal zones where they experience thermal stress. We know little about how mussels from different tidal habitats respond to thermal stress. We used the mussel Mytilus galloprovincialis from separate subtidal and intertidal populations to test whether heart rate and indicators of potential aerobic (citrate synthase activity) and anaerobic (cytosolic malate dehydrogenase activity) metabolic capacity are affected by increased temperatures while exposed to air or submerged in water. Subtidal mussels were affected by warming when submerged in water (decreased heart rate) but showed no effect in air. In contrast, intertidal mussels were affected by exposure to air (increased anaerobic capacity) but not by warming. Overall, physiological responses of mussels to thermal stress were dependent on their tidal habitat. These results highlight the importance of considering the natural habitat of mussels when assessing their responses to environmental challenges.

RevDate: 2020-06-23

Rentería-Solís Z, Meyer-Kayser E, Obiegala A, et al (2020)

Cryptosporidium sp. skunk genotype in wild raccoons (Procyon lotor) naturally infected with Baylisascaris procyonis from Central Germany.

Parasitology international pii:S1383-5769(20)30109-4 [Epub ahead of print].

Cryptosporidium spp. are apicomplexan parasites of public health concern. They are one of the main causes of intestinal diseases in humans and animals. Contaminated water is among the main sources of infection for humans and mammals. Raccoons are an introduced species in Germany. They are anthropogenic adapters with a natural affinity for water bodies. We collected samples from wild raccoons in the Federal States of Saxony and Thuringia, Central Germany. Through molecular genotyping, we found Cryptosporidium sp. skunk genotype in one raccoon from Saxony (1/24) and in one animal from Thuringia (1/27). Both raccoons were also infected with the zoonotic nematode Baylisascaris procyonis. This is the first report of co-infection with these two parasites in raccoons from Germany. Our study highlights the potential of these animals as carriers of zoonotic pathogens. Since raccoons can thrive in human settlements, this study provides data that can be used as a baseline for preventive programs.

RevDate: 2020-06-23

Price CJ, Banks PB, Brown S, et al (2020)

Invasive mammalian predators habituate to and generalize avian prey cues: a mechanism for conserving native prey.

Ecological applications : a publication of the Ecological Society of America [Epub ahead of print].

Invasive mammalian predators can cause the decline and extinction of vulnerable native species. Many invasive mammalian predators are dietary generalists that hunt a variety of prey. These predators often rely upon olfaction when foraging, particularly at night. Little is understood about how prey odor cues are used to inform foraging decisions. Prey cues can vary spatially and temporally in their association with prey and can either reveal the location of prey or lead to unsuccessful foraging. Here we examine how two wild-caught invasive mammalian bird predator species (European hedgehogs Erinaceus europaeus and ferrets Mustela putorius furo) respond to unrewarded bird odors over successive exposures, first demonstrating that the odors are perceptually different using house mice (Mus musculus) as a biological olfactometer. We aim to test if introduced predators categorize odor cues of similar prey together, a tactic that could increase foraging efficiency. We exposed house mice to the odors using a standard habituation/dishabituation test in a laboratory setting, and wild-caught European hedgehogs and ferrets in an outdoor enclosure using a similar procedure. Mice discriminated among all bird odors presented, showing more interest in chicken odor than quail or gull odor. Both predator species showed a decline in interest towards unrewarded prey odor (i.e., habituation), but only ferrets generalized their response from one unrewarded bird odor to another bird odor. Hedgehog responses to unrewarded bird odors were highly variable between individuals. Taken together, our results reveal interspecific and intraspecific differences in response to prey odors, which we argue are a consequence of different diet breadth, life and evolutionary histories, and the conditions in each experiment. Generalization of prey odors may have enabled some species of invasive predators to efficiently hunt a range of intraguild prey species, for example, ground-nesting shorebirds. Olfactory manipulation of predators may be a useful conservation tool for threatened prey if it reduces the conspicuousness of vulnerable prey.

RevDate: 2020-06-23

Rothstein AP, Knapp RA, Bradburd G, et al (2020)

Stepping into the past to conserve the future: archived skin swabs from extant and extirpated populations inform genetic management of an endangered amphibian.

Molecular ecology [Epub ahead of print].

Moving animals on a landscape through translocations and reintroductions is an important management tool used in the recovery of endangered species, particularly for the maintenance of population genetic diversity and structure. Management of imperiled amphibian species rely heavily on translocations and reintroductions, especially for species that have been brought to the brink of extinction by habitat loss, introduced species, and disease. One striking example of amphibian declines and associated management efforts is in California's Sequoia and Kings Canyon National Parks with the mountain yellow-legged frog species complex (Rana sierrae/muscosa). Mountain yellow-legged frogs have been extirpated from more than 93% of their historic range, and limited knowledge of their population genetics has made long-term conservation planning difficult. To address this, we used 598 archived skin swabs from both extant and extirpated populations across 48 lake basins to generate a robust Illumina-based nuclear amplicon dataset. We found that samples grouped into three main genetic clusters, concordant with watershed boundaries. We also found evidence for historical gene flow across watershed boundaries with a north-to-south axis of migration. Finally, our results indicate that genetic diversity is not significantly different between populations with different disease histories. Our study offers specific management recommendations for imperiled mountain yellow-legged frogs and, more broadly, provides a population genetic framework for leveraging minimally invasive samples for the conservation of threatened species.

RevDate: 2020-06-23

Haubrock PJ, Cuthbert RN, Veselý L, et al (2020)

Predatory functional responses under increasing temperatures of two life stages of an invasive gecko.

Scientific reports, 10(1):10119 pii:10.1038/s41598-020-67194-0.

The direct effects of temperature increases and differences among life-history might affect the impacts of native and invasive predators on recipient communities. Comparisons of functional responses can improve our understanding of underlying processes involved in altering species interaction strengths and may predict the effect of species invading new communities. Therefore, we investigated the functional responses of the mourning gecko Lepidodactylus lugubris (Duméril & Bibron, 1836) to explore how temperature, body-size and prey density alter gecko predatory impacts in ecosystems. We quantified the functional responses of juvenile and adult geckos in single-predator experiments at 20, 23 and 26 °C. Both displayed saturating Type-II functional responses, but juvenile functional responses and the novel Functional Response Ratio were positively affected by temperature as juvenile attack rates (a) increased as a function of increased temperature. Handling times (h) tended to shorten at higher temperature for both predator stages. We demonstrate that the effects of temperature on functional responses of geckos differ across ontogeny, perhaps reflecting life-history stages prioritising growth and maturation or body maintenance. This indicates that temperature-dependent gecko predatory impacts will be mediated by population demographics. We advocate further comparisons of functional responses to understand the invasiveness and future predatory impacts of geckos, and other invasive species globally, as temperatures change.

RevDate: 2020-06-23

Schratzberger M, PJ Somerfield (2020)

Effects of widespread human disturbances in the marine environment suggest a new agenda for meiofauna research is needed.

The Science of the total environment, 728:138435.

The response of an ecological community to a disturbance event, and its capacity to recover, are of major interest to ecologists, especially at a time of increasing frequencies and intensities of environmental change brought about by humans. Meiofauna, a group of small-sized organisms, are an abundant and ubiquitous component of seafloor communities that respond rapidly to environmental change. We summarise the available research on the response of metazoan meiofauna to the most widespread anthropogenic disturbances in the marine environment, including bottom fishing, the introduction of invasive species and anthropogenic climate change. We show that disturbance effects on habitats interact critically with effects on resident meiofauna species. Their responses are consistent with competitive replacement, where disparate disturbance effects on competing species drive shifts in dominance and intra- and interspecific interactions. The widespread replacement of habitat-specific ecological specialists by broadly-adapted ecological generalists and opportunists results in biotic and functional homogenisation of once disparate biotas. Anthropogenic disturbances may facilitate novel interactions among meiofauna species, and between meiofauna and other benthic organisms, but the number and breadth of these interactions is likely to be limited. Knowledge about the dependence of meiofauna species on their environment and on other benthic species has been growing. Future studies will be most meaningful if this knowledge is expanded alongside understanding the potential of locally adapted species to respond to shifts in environmental conditions.

RevDate: 2020-06-22

Terblanche JS, AA Hoffmann (2020)

Validating measurements of acclimation for climate change adaptation.

Current opinion in insect science, 41:7-16 pii:S2214-5745(20)30051-1 [Epub ahead of print].

Acclimation and other forms of plasticity that can increase stress resistance feature strongly in discussions surrounding climate change impacts or vulnerability projections of insects and other ectotherms. There is interest in compiling databases for assessing the adequacy of acclimation for dealing with climate change. Here, we argue that the nature of acclimation is context dependent and therefore that estimates summarised across studies, especially those that have assayed stress using diverse methods, are limited in their utility when applied as a standardized metric or to a single general context such as average climate warming. Moreover, the dynamic nature of tolerances and acclimation drives important variation that is quickly obscured through many summary statistics or even in effect size analyses; retaining a strong focus on the temporal-level, population-level and treatment-level variance in forecasting climate change impacts on insects is essential. We summarise recent developments within the context of climate change and propose how future studies might validate the role of acclimation by integration across field studies and mechanistic modelling. Despite arguments to the contrary, to date no studies have convincingly demonstrated an important role for acclimation in recent climate change adaptation of insects. Paramount to these discussions is i) developing a strong conceptual framework for acclimation in the focal trait(s), ii) obtaining novel empirical data dissecting the fitness benefits and consequences of acclimation across diverse contexts and timescales, with iii) better coverage of under-represented geographic regions and taxa.

RevDate: 2020-06-22

Pacífico EC, Efstathion CA, Filadelfo T, et al (2020)

Experimental removal of invasive Africanized honey bees increased breeding population size of the endangered Lear's macaw.

Pest management science [Epub ahead of print].

BACKGROUND: Invasive Africanized honey bees potentially compete with cavity-nesting birds in South America. However, the impacts caused by this competition and its conservation consequences to threatened species are poorly known. We quantified the presence of these bees and assessed its competition for cliff cavities used by nesting Lear's macaws Anodorhynchus leari, a globally endangered parrot endemic to the Caatinga biome of Brazil. We treated bee hives with permethrin by shooting them with a crossbow bolt which distributed the compound upon impact. When feasible, we removed the comb and applied an insecticide (fipronil) to deter bee recolonization. We subsequently surveyed the macaw breeding population to verify whether our treatment allowed for the nest recruitment in cavities previously occupied by bees.

RESULTS: We recorded >100 bee hives in the nesting cliffs. Hives outnumbered the macaw nests tenfold in two areas recently recolonized by the macaws. Cavities occupied by bees were significantly higher than those occupied by macaws, suggesting macaws may be forced to breed in lower cavities. None of the untreated bee-cavities (n = 50) were occupied by nesting macaws, while 15% of treated cavities (n = 52) were occupied within two years post treatment. Treated cavities occupied by macaws were significantly higher than those not occupied. Hive management was responsible for 71% of the macaw breeding population increase.

CONCLUSION: Experimental hive treatments were effective in restoring nesting resources lost due to bee infestation. An intensive and continued eradication program is recommended to enhance macaw's habitat restoration, facilitating its expansion into historical areas. This article is protected by copyright. All rights reserved.

RevDate: 2020-06-22

Infante-Izquierdo MD, Polo-Ávila A, Sanjosé I, et al (2020)

Effects of heavy metal pollution on germination and early seedling growth in native and invasive Spartina cordgrasses.

Marine pollution bulletin, 158:111376 pii:S0025-326X(20)30494-X [Epub ahead of print].

Seed germination and seedling establishment are the stages most sensitive to abiotic stress in the plant life cycle. We analyzed the effects of copper, zinc and nickel on seed germination and early seedling growth of native Spartina maritima and invasive S. densiflora from polluted and non-polluted estuaries. Germination percentages for either species were not affected by any metal at any tested concentration (up to 2000 μM). However, the increase in metal concentration had negative effects on S. densiflora seedlings. The primary effect was on radicle development, representing initial seedling emergence. Spartina densiflora seedlings emerging from seeds from Tinto Estuary, characterized by high bioavailable metal loads, showed higher tolerance to metals than those from less polluted Odiel and Piedras Estuaries. Comparing our results to metal concentrations in the field, we expect S. densiflora seedling development would be negatively impacted in the most metal-polluted areas in Odiel and Tinto Estuaries.

RevDate: 2020-06-22

Curtis AN, ER Larson (2020)

No evidence that crayfish carcasses produce detectable environmental DNA (eDNA) in a stream enclosure experiment.

PeerJ, 8:e9333 pii:9333.

Environmental DNA (eDNA) is an emerging tool for monitoring invasive and imperiled species, particularly at low densities. However, the factors that control eDNA production, transport, and persistence in aquatic systems remain poorly understood. For example, the extent to which carcasses produce detectable eDNA is unknown. If positive detections are associated with dead organisms, this could confound monitoring for imperiled or invasive species. Here, we present results from one of the first studies to examine carcass eDNA in situ by deploying carcasses of the invasive red swamp crayfish (Procambarus clarkii) in a stream enclosure experiment for 28 days. We predicted that carcasses would initially produce eDNA that would decline over time as carcasses decayed. Unsurprisingly, crayfish carcasses lost biomass over time, but at the conclusion of our experiment much of the carapace and chelae remained. However, no eDNA of P. clarkii was detected in any of our samples at the crayfish density (15 P. clarkii carcasses at ∼615 g of biomass initially), stream flow (520-20,319 L/s), or temperature (∼14-25 °C) at our site. Subsequent analyses demonstrated that these results were not the consequence of PCR inhibition in our field samples, poor performance of the eDNA assay for intraspecific genetic diversity within P. clarkii, or due to the preservation and extraction procedure used. Therefore, our results suggest that when crayfish are relatively rare, such as in cases of new invasive populations or endangered species, carcasses may not produce detectable eDNA. In such scenarios, positive detections from field studies may be more confidently attributed to the presence of live organisms. We recommend that future studies should explore how biomass, flow, and differences in system (lentic vs. lotic) influence the ability to detect eDNA from carcasses.

RevDate: 2020-06-22

Nicholson EG, Manzo S, Devereux Z, et al (2020)

Historical museum collections and contemporary population studies implicate roads and introduced predatory bullfrogs in the decline of western pond turtles.

PeerJ, 8:e9248 pii:9248.

The western pond turtle (WPT), recently separated into two paripatrically distributed species (Emys pallida and Emys marmorata), is experiencing significant reductions in its range and population size. In addition to habitat loss, two potential causes of decline are female-biased road mortality and high juvenile mortality from non-native predatory bullfrogs (Rana catesbeiana). However, quantitative analyses of these threats have never been conducted for either species of WPT. We used a combination of historical museum samples and published and unpublished field studies shared with us through personal communications with WPT field researchers (B. Shaffer, P. Scott, R. Fisher, C. Brown, R. Dagit, L. Patterson, T. Engstrom, 2019, personal communications) to quantify the effect of roads and bullfrogs on WPT populations along the west coast of the United States. Both species of WPT shift toward increasingly male biased museum collections over the last century, a trend consistent with increasing, female-biased road mortality. Recent WPT population studies revealed that road density and proximity were significantly associated with increasingly male-biased sex ratios, further suggesting female-biased road mortality. The mean body size of museum collections of E. marmorata, but not E. pallida, has increased over the last 100 years, consistent with reduced recruitment and aging populations that could be driven by invasive predators. Contemporary WPT population sites that co-occur with bullfrogs had significantly greater average body sizes than population sites without bullfrogs, suggesting strong bullfrog predation on small WPT hatchlings and juveniles. Overall, our findings indicate that both species of WPT face demographic challenges which would have been difficult to document without the use of both historical data from natural history collections and contemporary demographic field data. Although correlational, our analyses suggest that female-biased road mortality and predation on small turtles by non-native bullfrogs are occurring, and that conservation strategies reducing both may be important for WPT recovery.

RevDate: 2020-06-20

Pelegrín M, Sáez-Tovar JA, Andreu-Rodríguez J, et al (2018)

Composting of the invasive species Arundo donax with sewage and agri-food sludge: Agronomic, economic and environmental aspects.

Waste management (New York, N.Y.), 78:730-740.

This work evaluates several co-composting scenarios based on the use of Arundo donax biomass (AD) as bulking agent for the co-composting of sewage sludge (MS) and agri-food sludge (AS), to manage these organic wastes and to produce balanced organic fertilizers by optimizing the process. For this, six piles were prepared in commercial composting conditions, using AD in a range of 40%-80% (on a dry weight basis). Physico-chemical and chemical parameters and the thermal behaviour were evaluated during the process, as were the physical and chemical parameters of the final composts. The proportion of AD in the mixtures has a significant effect on the development of the thermophilic stage of composting, showing the piles with higher proportion of AD a quicker organic matter degradation. In addition, the evolution of the thermal indices R1 and R2 was different depending on the origin of the sludge used, indicating an increase in the relative concentration of more recalcitrant materials in the piles prepared with AS. The estimation of the global warming potential showed that the use of higher proportion of AD in the composting mixture may be a strategy to mitigate the emission of greenhouse gases during the composting process. Moreover, the end-products obtained had an additional marketable value, with a balanced nutrient content and a good degree of maturity, which indicates the viability of the composting process as a method for the stabilization of these organic wastes.

RevDate: 2020-06-20

Díaz-Barradas MC, Gallego-Fernández JB, M Zunzunegui (2020)

Plant response to water stress of native and non-native Oenothera drummondii populations.

Plant physiology and biochemistry : PPB, 154:219-228 pii:S0981-9428(20)30276-X [Epub ahead of print].

Invasive plants can spread over climatically diverse areas. We explore the effects of drought on gas exchange and water relations on the invasive dune species Oenothera drummondii, using plants from four populations with different rainfall and temperatures regimes. Plant material was obtained germinating plants from one native and three non-native populations in a greenhouse. Drought stress was induced by withholding water. Responses to drought stressed plants were then compared to well-watered controls. Measurements of gas exchange, chlorophyll fluorescence and leaf traits were taken initially and every 10 days after water was withheld, until day 36 when plants were re-watered and recover capacity was measured. The effect of water stress was more evident in Fv/Fm and gas exchange variables. The results suggest that this species possess a mechanism of thermal dissipation of energy. Leaf relative water content was significant lower in drought stressed than control plants. At the end of withholding water period, stressed plants are separated from control plants along the axis I of the ordination analysis evidencing differences in functional traits. All plants recovered well after re-watering. Our results provide evidence for permanent differences in morphological traits and functional responses to drought stress among native and invasive populations of O. drummondii. Although we have only studied four populations, these results may provide evidence for the role of plasticity in contributing to the invasion success of this species.

RevDate: 2020-06-20

Liu C, Ye J, Lin Y, et al (2020)

Removal of Cadmium (II) using water hyacinth (Eichhornia crassipes) biochar alginate beads in aqueous solutions.

Environmental pollution (Barking, Essex : 1987), 264:114785.

Biochar produced from water hyacinths (Eichhornia crassipes) has been demonstrated to be an effective adsorbent for the removal of certain heavy metals and as a means of control for this highly invasive species. This study involved examined the Cd2+ sorption dynamics of an alginate encapsulated water hyacinth biochar (BAC) generated at different temperatures and modified using ferric/ferrous sulfate (MBAC). The maximum Cd2+ sorption occurred at a pH of 6 and at a solution temperature of 37 °C. Sorption equilibria for the biochar-alginate capsule (BAC) and modified biochar-alginate capsule (MBAC) treatments fit both the Langmuir (R2 = 0.876 to 0.99) and Freundlich (R2 = 0.849 to 0.971) equations. Langmuir isotherms had a better fit than the Freundlich isotherms, with maximum sorption capacities ranging from 24.2 to 45.8 mg Cd2+ g-1. Larger KL values in Freundlich modeling suggest strong bonding of the BAC and MBAC sorbents to Cd2+, with values of KL in the MBAC treatments ranging between 31 and 178% greater than the BAC treatments. Cd2+ sorption followed pseudo first-order kinetics (R2 = 0.926 to 0.991) with greater efficiency of removal using treatments with biochar generated at temperatures >500 °C. Results from this study highlight the potential for biochar-alginate capsules derived from water hyacinth to be effective for the removal of Cd2+ from wastewaters.

RevDate: 2020-06-19

Gong X, Chen Y, Wang T, et al (2020)

Double-edged effects of climate change on plant invasions: Ecological niche modeling global distributions of two invasive alien plants.

The Science of the total environment, 740:139933 pii:S0048-9697(20)33453-7 [Epub ahead of print].

The prediction of the potential distribution of invasive alien species is key for the control of their proliferation. This study developed ensemble niche models to explore the distribution patterns of Cecropia peltata and Ulex europaeus under baseline and future conditions, as well as the factors that regulate them. The models were based on occurrence records as well as climate, land-use and topography datasets. Climatic factors played a stronger role than land-use and topographical factors in their distribution patterns. Additionally, temperature seasonality and temperature annual range were the optimal predictor for the global distributions of C. peltata and U. europaeus, respectively. Under the baseline-RCP 8.5 scenario in 2070, significant increases in habitat suitability for C. peltata were generally detected in tropical regions, while for U. europaeus under the same condition, significant increases in habitat suitability were generally observed in west coast of South America and Europe, suggesting the impacts of climate changes on species distribution may be species specific. The contrast changes of suitable habitat areas for U. europaeus under the baseline-2.6 and 8.5 scenarios may suggest that the scenarios of climate changes may modify its distribution patterns and variations in suitable habitats. The double-edged effects of global warming on plant invasions may be a result of the scenario specific climate change and the species-specific responses to changes in climate. Our findings highlight the importance of climate change scenario specific and species-specific research on the impact of climate change on plant invasions.

RevDate: 2020-06-19

Hardulak LA, Morinière J, Hausmann A, et al (2020)

DNA metabarcoding for biodiversity monitoring in a national park: screening for invasive and pest species.

Molecular ecology resources [Epub ahead of print].

DNA metabarcoding was utilized for a large-scale, multi-year assessment of biodiversity in Malaise trap collections from the Bavarian Forest National Park (Germany, Bavaria). Principal Component Analysis of read count-based biodiversities revealed clustering in concordance with whether collection sites were located inside or outside of the National Park. Jaccard distance matrices of the presences of BINs at collection sites in the two survey years (2016 and 2018) were significantly correlated. Overall similar patterns in the presence of total arthropod BINs, as well as BINs belonging to four major arthropod orders across the study area, were observed in both survey years, and are also comparable with results of a previous study based on DNA barcoding of Sanger-sequenced specimens. A custom reference sequence library was assembled from publicly available data to screen for pest or invasive arthropods among the specimens or from the preservative ethanol. A single 98.6% match to the invasive bark beetle Ips duplicatus was detected in an ethanol sample. This species has not previously been detected in the National Park.

RevDate: 2020-06-19

Clay TA, Joo R, Weimerskirch H, et al (2020)

Sex-specific effects of wind on the flight decisions of a sexually dimorphic soaring bird.

The Journal of animal ecology [Epub ahead of print].

In a highly dynamic airspace, flying animals are predicted to adjust foraging behaviour to variable wind conditions to minimize movement costs. Sexual size dimorphism is widespread in wild animal populations, and for large soaring birds which rely on favourable winds for energy-efficient flight, differences in morphology, wing loading and associated flight capabilities may lead males and females to respond differently to wind. However, the interaction between wind and sex has not been comprehensively tested. We investigated, in a large sexually dimorphic seabird which predominantly uses dynamic soaring flight, whether flight decisions are modulated to variation in winds over extended foraging trips, and whether males and females differ. Using GPS loggers we tracked 385 incubation foraging trips of wandering albatrosses Diomedea exulans, for which males are c. 20% larger than females, from two major populations (Crozet and South Georgia). Hidden Markov models were used to characterize behavioural states-directed flight, area-restricted search (ARS) and resting-and model the probability of transitioning between states in response to wind speed and relative direction, and sex. Wind speed and relative direction were important predictors of state transitioning. Birds were much more likely to take off (i.e. switch from rest to flight) in stronger headwinds, and as wind speeds increased, to be in directed flight rather than ARS. Males from Crozet but not South Georgia experienced stronger winds than females, and males from both populations were more likely to take-off in windier conditions. Albatrosses appear to deploy an energy-saving strategy by modulating taking-off, their most energetically expensive behaviour, to favourable wind conditions. The behaviour of males, which have higher wing loading requiring faster speeds for gliding flight, was influenced to a greater degree by wind than females. As such, our results indicate that variation in flight performance drives sex differences in time-activity budgets and may lead the sexes to exploit regions with different wind regimes.

RevDate: 2020-06-19

Sjodin BMF, Irvine RL, MA Russello (2020)

RapidRat: Development, validation and application of a genotyping-by-sequencing panel for rapid biosecurity and invasive species management.

PloS one, 15(6):e0234694 pii:PONE-D-20-00793.

Invasive alien species (IAS) are among the main causes of global biodiversity loss. Invasive brown (Rattus norvegicus) and black (R. rattus) rats, in particular, are leading drivers of extinction on islands, especially in the case of seabirds where >50% of all extinctions have been attributed to rat predation. Eradication is the primary form of invasive rat management, yet this strategy has resulted in a ~10-38% failure rate on islands globally. Genetic tools can help inform IAS management, but such applications to date have been largely reactive, time-consuming, and costly. Here, we developed a Genotyping-in-Thousands by sequencing (GT-seq) panel for rapid species identification and population assignment of invasive brown and black rats (RapidRat) in Haida Gwaii, an archipelago comprising ~150 islands off the central coast of British Columbia, Canada. We constructed an optimized panel of 443 single nucleotide polymorphisms (SNPs) using previously generated double-digest restriction-site associated DNA (ddRAD) genotypic data (27,686 SNPs) from brown (n = 295) and black rats (n = 241) sampled throughout Haida Gwaii. The informativeness of this panel for identifying individuals to species and island of origin was validated relative to the ddRAD results; in all comparisons, admixture coefficients and population assignments estimated using RapidRat were consistent. To demonstrate application, 20 individuals from novel invasions of three islands (Agglomerate, Hotspring, Ramsay) were genotyped using RapidRat, all of which were confidently assigned (>98.5% probability) to Faraday and Murchison Islands as putative source populations. These results indicated that a previous eradication on Hotspring Island was conducted at an inappropriate geographic scale; future management should expand the eradication unit to include neighboring islands to prevent re-invasion. Overall, we demonstrated that RapidRat is an effective tool for managing invasive rat populations in Haida Gwaii and provided a clear framework for GT-seq panel development for informing biodiversity conservation in other systems.

RevDate: 2020-06-19

Ibabe A, Rayón F, Martinez JL, et al (2020)

Environmental DNA from plastic and textile marine litter detects exotic and nuisance species nearby ports.

PloS one, 15(6):e0228811 pii:PONE-D-19-21907.

Marine debris is currently a significant source of environmental and economic problems. Floating litter can be employed by marine organisms as a surface to attach to and use as spreading vector. Human activities are promoting the expansion of potentially harmful species into novel ecosystems, endangering autochthonous communities. In this project, more than 1,000 litter items were collected and classified from five beaches eastwards the port of Gijon, in Asturias, Spain. Next generation sequencing was employed to study biofouling communities attached to items of different materials. A dominance of DNA from Florideophyceae, Dinophyceae and Arthropoda was found, and four non-indigenous species (NIS) were identified. Results showed a clear preference of Florideophyceae and Bryozoa to attach on textile surfaces versus plastic ones. Considering that these taxa contain several highly invasive species described to date, these data emphasize the potential of textile marine debris as a vector for dispersal of NIS. Moreover, the closest beaches to the port contained a more similar biota profile than the farther ones, confirming that both plastic and textile marine litter can be vectors for species dispersal from ports.

RevDate: 2020-06-19

Siya A, Kalule BJ, Ssentongo B, et al (2020)

Malaria patterns across altitudinal zones of Mount Elgon following intensified control and prevention programs in Uganda.

BMC infectious diseases, 20(1):425 pii:10.1186/s12879-020-05158-5.

BACKGROUND: Malaria remains a major tropical vector-borne disease of immense public health concern owing to its debilitating effects in sub-Saharan Africa. Over the past 30 years, the high altitude areas in Eastern Africa have been reported to experience increased cases of malaria. Governments including that of the Republic of Uganda have responded through intensifying programs that can potentially minimize malaria transmission while reducing associated fatalities. However, malaria patterns following these intensified control and prevention interventions in the changing climate remains widely unexplored in East African highland regions. This study thus analyzed malaria patterns across altitudinal zones of Mount Elgon, Uganda.

METHODS: Times-series data on malaria cases (2011-2017) from five level III local health centers occurring across three altitudinal zones; low, mid and high altitude was utilized. Inverse Distance Weighted (IDW) interpolation regression and Mann Kendall trend test were used to analyze malaria patterns. Vegetation attributes from the three altitudinal zones were analyzed using Normalized Difference Vegetation Index (NDVI) was used to determine the Autoregressive Integrated Moving Average (ARIMA) model was used to project malaria patterns for a 7 year period.

RESULTS: Malaria across the three zones declined over the study period. The hotspots for malaria were highly variable over time in all the three zones. Rainfall played a significant role in influencing malaria burdens across the three zones. Vegetation had a significant influence on malaria in the higher altitudes. Meanwhile, in the lower altitude, human population had a significant positive correlation with malaria cases.

CONCLUSIONS: Despite observed decline in malaria cases across the three altitudinal zones, the high altitude zone became a malaria hotspot as cases variably occurred in the zone. Rainfall played the biggest role in malaria trends. Human population appeared to influence malaria incidences in the low altitude areas partly due to population concentration in this zone. Malaria control interventions ought to be strengthened and strategically designed to achieve no malaria cases across all the altitudinal zones. Integration of climate information within malaria interventions can also strengthen eradication strategies of malaria in such differentiated altitudinal zones.

RevDate: 2020-06-19

Kiswaga SAS, Mbwambo JR, Shirima D, et al (2020)

More widespread alien tree species do not have larger impacts on regeneration of native tree species in a tropical forest reserve.

Ecology and evolution, 10(11):5034-5044 pii:ECE36256.

There is insufficient information regarding the factors affecting the environmental impacts of alien species. In particular, little is known about whether there is any relationship between the invasiveness (establishment and spread) of an introduced species and its per capita impact. We experimentally assessed the relationship between the extent of spread of up to 29 alien plant species and their impact on recruitment of native tree species in Amani Botanical Garden, Tanzania. We also studied the effects of allelochemicals of selected alien on native plant species to assess potential mechanisms of impact. We found no relationship between the extent of spread of an alien tree species and their impact on seed germination, seedling survival, and seedling communities of native trees in their understory, and no indication that allelochemicals consistently explain their effects on recruitment of the studied species. These results suggest that extent of spread cannot be used as a proxy for impact. Hence, managers should continue assessing both the spread and the impact of alien species when prioritizing alien species for management.

RevDate: 2020-06-19

Dong H, Liu T, Liu Z, et al (2020)

Fate of the soil seed bank of giant ragweed and its significance in preventing and controlling its invasion in grasslands.

Ecology and evolution, 10(11):4854-4866 pii:ECE36238.

Giant ragweed (Ambrosia trifida, L. henceforth referred to as GR), an annual non-native invasive weed, may cause health problems and can reduce agricultural productivity. Chemical control of GR in grasslands may have irreversible side effects on herbs and livestock. In an attempt to propose a solution to the harmful effects of GR on grasslands, this study explores the fate of its soil seed bank (SSB) and considers the physical control of its SSB reduction. By studying GR distributed in grasslands of the Yili Valley, Xinjiang, China, we measured the spatial and temporal changes in seed density, seed germination, dormancy, and death. We analyzed seed germination, dormancy, and death following different storage periods. The study analyzed population characteristics over time, including seed fate, and examined physical control methods for reducing the SSB density. The SSB of GR occurs in the upper 0-15 cm of soil in grasslands. Seed density in the SSB decreased by 68.1% to 82.01% from the reproductive growth period to the senescence period. More than 98.7% of the seeds were rotten, eaten, germinated, dispersed, or died within one year after being produced. The seed germination rate of the SSB decreased with the number of years after invasion. When stored for 0.5 or 3.5 years, seed germination rates fell by 40%, during which time seed death rate increased by almost 40%. When GR was completely eradicated for two consecutive years, the SSB and population densities decreased by >99%. The vast majority of GR seeds germinated or died within one year; the germination rate decreased significantly if the seeds were stored dry at room temperature for a long time. Newly produced seeds are the main source of seeds in the SSB. Therefore, thoroughly eradicating GR plants for several years before the seeds can mature provides an effective control method in grasslands.

RevDate: 2020-06-19

McGoey BV, Hodgins KA, JR Stinchcombe (2020)

Parallel flowering time clines in native and introduced ragweed populations are likely due to adaptation.

Ecology and evolution, 10(11):4595-4608 pii:ECE36163.

As introduced species expand their ranges, they often encounter differences in climate which are often correlated with geography. For introduced species, encountering a geographically variable climate sometimes leads to the re-establishment of clines seen in the native range. However, clines can also be caused by neutral processes, and so it is important to gather additional evidence that population differentiation is the result of selection as opposed to nonadaptive processes. Here, we examine phenotypic and genetic differences in ragweed from the native (North America) and introduced (European) ranges. We used a common garden to assess phenotypic differentiation in size and flowering time in ragweed populations. We found significant parallel clines in flowering time in both North America and Europe. Height and branch number had significant clines in North America, and, while not statistically significant, the patterns in Europe were the same. We used SNP data to assess population structure in both ranges and to compare phenotypic differentiation to neutral genetic variation. We failed to detect significant patterns of isolation by distance, geographic patterns in population structure, or correlations between the major axes of SNP variation and phenotypes or latitude of origin. We conclude that the North American clines in size and the parallel clines seen for flowering time are most likely the result of adaptation.

RevDate: 2020-06-19
CmpDate: 2020-06-19

Poursanidis D, Kalogirou S, Azzurro E, et al (2020)

Habitat suitability, niche unfilling and the potential spread of Pterois miles in the Mediterranean Sea.

Marine pollution bulletin, 154:111054.

The common lionfish Pterois miles has rapidly spread across the eastern Mediterranean Sea. We compiled occurrence data from both native and invaded range under the framework of Species Distribution Modelling (SDM). Through a construction of an environmental suitability model and estimation of spread rates we investigated the lionfish climate niche in both its native and invaded domains, this latter represented by the Mediterranean region. Model projections allowed to identify suitable areas for lionfish establishment in the Mediterranean. Spread analysis suggested that a further geographical expansion in this basin could be completed within the next years. Our results did not provide evidence for niche expansion but highlighted a high degree of niche unfilling thus prospecting a likely spread of Mediterranean lionfish invasion beyond the predictions of current SDMs. These findings provide novel inputs to forecast the future geographical evolution of the lionfish in the Mediterranean Sea and asses the related risk of invasion.

RevDate: 2020-06-18

Kelly S, Fletcher RA, JN Barney (2020)

Intraspecific, ecotypic and home climate variation in photosynthetic traits of the widespread invasive grass Johnsongrass.

AoB PLANTS, 12(3):plaa015 pii:plaa015.

Despite their near ubiquity across global ecosystems, the underlying mechanisms contributing to the success of invasive plants remain largely unknown. In particular, ecophysiological traits, which are fundamental to plants' performance and response to their environment, are poorly understood with respect to geographic and climate space. We evaluated photosynthetic trait variation among populations, ecotypes and home climates (i.e. the climates from the locations they were collected) of the widespread and expanding invader Johnsongrass (Sorghum halepense). We found that populations vary in the maximum net photosynthetic flux and the light-saturated net photosynthetic rate, and that agricultural and non-agricultural ecotypes vary in apparent quantum yield and water-use efficiency (WUE). We also found that populations from warmer home climates had lower dark respiration rates, light compensation points and WUEs. As Johnsongrass expands across the USA the abiotic and biotic environments are driving variation in its genetics, phenotypes and its underlying physiology. Our study demonstrates the importance of evaluating physiological traits in invasive plants, especially as they relate to home climates.

RevDate: 2020-06-18

Dick MH, Waeschenbach A, Trott TJ, et al (2020)

Global Distribution and Variation of the Invasive Cheilostome Bryozoan Cribrilina mutabilis.

Zoological science, 37(3):217-231.

Viable populations of the cheilostome bryozoan Cribrilina mutabilis Ito, Onishi & Dick exist in the NW Pacific (Russian Far East and northern Japan), NE Atlantic (Scandinavia and Scotland), and NW Atlantic (Maine, USA). The first NE and NW Atlantic records are from Norway (2008) and Casco Bay, Maine, USA (2018), respectively, indicating a relatively recent introduction to the region. Mitochondrial COI gene sequences from North Atlantic populations (Sweden, Norway, and Maine) showed two haplotypes differing by one substitution, but differed from two haplotypes from Akkeshi, northern Japan, by 6-8 substitutions. North Atlantic populations differed morphologically from the Akkeshi population in that some zooids formed a suboral projection, and frontal zooids were more common. While C. mutabilis in northern Japan has been found only on natural or artificial eelgrass (Zostera marina), across its range it has been found on several species of algae, plastic panels and strips, several species of Zostera, and mollusc shells. Similar frequencies of heteromorphic zooids with differing degree of frontal wall calcification, i.e., R (rib)-, I (intermediate)-, and S (shield)-type zooids, in colonies on eelgrass at comparable times of the season and across populations suggest an innate response to seasonal environmental fluctuations, although zooid frequencies were different on non-eelgrass substrates. The increase in trans-Arctic shipping along the Northern Sea Route in recent decades, and previous documentation of C. mutabilis on ship hulls in the Sea of Japan, indicate a clear mechanism for anthropogenic introduction from the Far East to Europe in recent decades.

RevDate: 2020-06-18
CmpDate: 2020-06-18

Chaves LF, Friberg MD, K Moji (2020)

Synchrony of globally invasive Aedes spp. immature mosquitoes along an urban altitudinal gradient in their native range.

The Science of the total environment, 734:139365.

Mosquito-borne infections often have concerted peaks, or are synchronous, across landscapes. This phenomenon might be driven by vector responses to similar environmental conditions that synchronize their abundance. While adult mosquito populations can be synchronous over spatial scales ranging from a few meters to a few kilometers, little to nothing is known about immature mosquito synchrony, including its relationship with mosquito colonization and persistence in larval habitats. Here, we present results from a 2-yearlong synchrony study in co-occurring populations of Aedes (Stegomyia) albopictus (Skuse), Aedes (Stegomyia) flavopictus Yamada and Aedes (Finlaya) japonicus japonicus (Theobald), three invasive mosquito species, along an urban altitudinal gradient in Japan. We found that Ae. albopictus was asynchronous while Ae. flavopictus and Ae. j. japonicus had synchrony that, respectively, tracked geographic and altitudinal patterns of temperature correlation. Spatially, Ae. albopictus was more persistent at hotter locations near urban land use, while Ae. j. japonicus and Ae. flavopictus increasingly persisted farther away from urban land. Temporally, Ae. albopicus and Ae. flavopictus decreased the proportion of colonized habitats following variable rainfall, while Ae. j. japonicus increased with vegetation growth and leptokurtic temperatures. Our results support the hypothesis that immature mosquito synchrony is autonomous from dispersal and driven by common environmental conditions.

RevDate: 2020-06-18
CmpDate: 2020-06-18

Lattos A, Giantsis IA, Karagiannis D, et al (2020)

First detection of the invasive Haplosporidian and Mycobacteria parasites hosting the endangered bivalve Pinna nobilis in Thermaikos Gulf, North Greece.

Marine environmental research, 155:104889.

Mycobacterium sp. and Haplosporidium pinnae constitute invasive parasite species of bivalves, reported for the first time in the present study in the Aegean Sea and Thermaikos Gulf, respectively. During the last years, the endangered fan mussel (Pinna nobilis) experienced several mortality events in the Mediterranean Sea that caused deaths to 90% or more of their populations and have been attributed to infections by these pathogens. In Greece, two mass mortality events have been recently reported, namely in the Gulf of Kalloni and in Limnos island. In the present study we investigated the presence of both pathogens in P. nobilis from these marine areas as well as from Thermaikos Gulf using both histopathological microscopy and molecular markers. The detected parasite DNA was further quantified in the three populations utilizing a real time qPCR. Histopathological results indicated the presence of a Mycobacterium species alongside with the existence of the Haplosporidian parasite, which was identified in all mortality events in the Mediterranean Sea. The parasite was present in different phases mostly on the digestive gland epithelium. Phylogenetic analysis confirmed the taxonomy of the Haplosporidian parasite as the recently described Haplosporidium pinnae, whereas it failed to identify the Mycobacteria parasite at species level. While Mycobacterium sp. was detected in all examined specimens, H. pinnae was not detected in all diseased fan mussels. Interestingly, monitoring of P. nobilis population from Thermaikos Gulf, an estuary of extremely high importance for bivalve production, revealed the presence of both pathogens in a few specimens in higher quantity but with no symptoms of the disease. Besides, all the specimens from Thermaikos Gulf had inflammatory responses similarly to moribund specimens from mortality events.

RevDate: 2020-06-17

Taitingfong RI (2020)

Islands as Laboratories: Indigenous Knowledge and Gene Drives in the Pacific.

Human biology, 91(3):179-188.

This article argues that the genetic engineering technology known as gene drive must be evaluated in the context of the historic and ongoing impacts of settler colonialism and military experimentation on indigenous lands and peoples. After defining gene drive and previewing some of the key ethical issues related to its use, the author compares the language used to justify Cold War-era nuclear testing in the Pacific with contemporary scholarship framing islands as ideal test sites for gene drive-modified organisms. In both cases, perceptions of islands as remote and isolated are mobilized to warrant their treatment as sites of experimentation for emerging technologies. Though gene drive may offer valuable interventions into issues affecting island communities (e.g., vector-borne disease and invasive species management), proposals to conduct the first open trials of gene drive on islands are complicit in a long history of injustice that has treated islands (and their residents) as dispensable to the risks and unintended consequences associated with experimentation. This article contends that ethical gene drive research cannot be achieved without the inclusion of indigenous peoples as key stakeholders and provides three recommendations to guide community engagement involving indigenous communities: centering indigenous self-determination, replacing the deficit model of engagement with a truly participatory model, and integrating indigenous knowledge and values in the research and decision-making processes related to gene drive.

RevDate: 2020-06-17

Mikami OK, Takamatsu M, R Yarita (2020)

Repurposing a traditional Japanese method of pest control for wintering pine moths, Komo-trap, for use against summer and winter populations of fall webworms.

PeerJ, 8:e9244 pii:9244.

Background: The fall webworm, Hyphantria cunea Drury (Lepidoptera: Erebidae), is a widespread invasive species. It is native to North America, ranging from southern Canada to northern Mexico. During and after the 1940s, this pest was accidentally introduced in many parts of Europe and Asia. It has now spread to more than 30 countries. The larvae feed on leaves of a wide range of tree species, including ones used as street trees in cities, causing an increase in urban management cost. Although several pest management methods have been employed, pest damage continues especially in newly invaded areas. In this study, we examined the effect and cost-effectiveness of the komo-trap, traditionally used in Japan to reduce the population of larvae of the pine moth Dendrolimus spectabilis Butler (Lepidoptera: Lasiocampidae). This trap, which is safe for people and ecosystems, has not yet been applied to trap the fall webworm.

Methods: In two seasons of 2017, we set komo-traps on street trees in Hakodate City, Japan. We counted the numbers of captured fall webworms compared with controls. We also monitored other species to evaluate any nontarget effects of the trap.

Results: One komo, the material cost of which is about 1.10 USD, captured 43.8 fall webworms on average in summer and 27.2 in the fall. The values were significantly larger than those of the controls, which were 0.07 in summer and 0.14 in winter. Bycatch of other species was minimal in summer, whereas in the fall one komo, on average, caught 10.7 woodlice Porcellio sp. or spp. (Isopoda: Porcellionidae).

Discussion: The komo-trap is effective in capturing fall webworm. The cost performance of the trap is very favorable, and the nontarget effects can be reduced by using the trap in summer only. The komo-trap would complement other control methods such as tree pruning. Because its cost is low, we recommend that the komo-trap be introduced as a larger-scale trial.

RevDate: 2020-06-17

Camacho R, Steele S, Challenger S, et al (2020)

Status of coral reefs in Antigua & Barbuda: using data to inform management.

PeerJ, 8:e9236 pii:9236.

The nation of Antigua and Barbuda has experienced major degradation of its coral reef ecosystems over the past 40+ years. The primary drivers of this degradation are multiple and are highly linked to anthropogenic influences, including over-exploitation and poor management of marine resources. The effectiveness of management actions in marine protected areas (MPAs) has often been hampered by a lack of data to inform management recommendations. This was emphasized by The Nature Conservancy's (TNC) Coral Reef Report Card which highlighted not only the lack of data collection in Antigua and Barbuda and other Caribbean nations, but also illustrated how spatially dispersed available datasets are. The government of Antigua and Barbuda recognized the need for a marine data collection program to better inform the designation and management of MPAs as a tool to improve the health of the marine ecosystems. The Atlantic Gulf Rapid Reef Assessment (AGRRA) protocol has been identified as a means to address planning and management for marine areas. Three AGRRA surveys have been conducted in the years following the TNC 2016 report, in previously established managed areas: North East Marine Management Area (NEMMA) in 2017 and Nelson Dockyard National Park (NDNP) in 2019 as well as areas outlined for future management (Redonda in 2018). Our surveys were conducted to provide updated datasets to inform management for the aforementioned areas. While the results of these surveys mirror the underlying poor coral reef-health conditions, which have been shown to exist within the Caribbean region, they also highlight intra-site variation that exists within each survey location. This knowledge can be crucial in guiding management decisions in these marine areas, through zoning and other management prescriptions. Additionally, the marine surveys conducted around Redonda established useful marine baselines to aid in monitoring the island's recovery following removal of terrestrial invasive species. This article provides an overview of data collected using the AGRRA methodology in marine zones across Antigua and Barbuda which have current or future management prescriptions and provides recommendations to demonstrate the data's future utilization for marine conservation and management.

RevDate: 2020-06-17

Ellrich JA, Yorisue T, K Momota (2020)

Limpet disturbance effects on barnacle recruitment are related to recruitment intensity but not recruit size.

PeerJ, 8:e9190 pii:9190.

Intertidal limpets are important grazers along rocky coastlines worldwide that not only control algae but also influence invertebrates such as common barnacles. For instance, grazing limpets ingest settling barnacle cyprid larvae (hereafter cyprids) and push cyprids and barnacle recruits off the substrate. Such limpet disturbance effects (LDEs) can limit barnacle recruitment, a key demographic variable affecting barnacle population establishment and persistence. In this study, we examined limpet (Lottia cassis) disturbance to barnacle (Chthamalus dalli, Balanus glandula) recruitment on the Pacific coast of Hokkaido, Japan, as information on limpet-barnacle interactions from this region is missing. We investigated, for the first time, whether barnacle size and recruitment intensity influence LDEs on barnacle recruitment. Small barnacles may be less susceptible to LDEs than larger barnacles, because small size may reduce the propbability of limpet disturbance. Moreover, recruitment intensity can influence LDEs, as high recruitment can compensate for LDEs on barnacle recruitment density. In Hokkaido, C. dalli cyprids are smaller than B. glandula cyprids, and C. dalli recruitment is higher than B. glandula recruitment. Thus, we hypothesized that LDEs on C. dalli recruitment would be weaker than those on B. glandula recruitment. To test our hypothesis, we conducted a field experiment during which we manipulated limpet presence/absence on the interior surfaces of ring-shaped cages. After four weeks, we measured barnacle recruitment and recruit size on the interior surfaces of the cages and found negative LDEs on C. dalli and B. glandula recruitment and recruit size. As hypothesized, the LDEs on C. dalli recruitment were weaker than the LDEs on B. glandula recruitment. Additionally, C. dalli recruits were smaller than B. glandula recruits. However, the LDEs on C. dalli recruit size were as strong as the LDEs on B. glandula recruit size, indicating that the smaller C. dalli recruits are not less susceptible to LDEs than B. glandula recruits. Since C. dalli recruitment was higher than B. glandula recruitment, we propose that the higher C. dalli recruitment compensated for the LDEs on C. dalli recruitment. Our findings indicate that the detected differences in LDEs on barnacle recruitment are related to barnacle recruitment intensity but not recruit size.

RevDate: 2020-06-17

Kong WL, Rui L, Ni H, et al (2020)

Antifungal Effects of Volatile Organic Compounds Produced by Rahnella aquatilis JZ-GX1 Against Colletotrichum gloeosporioides in Liriodendron chinense × tulipifera.

Frontiers in microbiology, 11:1114.

The use of volatile organic compounds (VOCs) produced by microorganisms for the biological control of plant diseases has attracted much attention in recent years. In this study, the antifungal activity and identity of VOCs produced by Rahnella aquatilis JZ-GX1 isolated from the rhizosphere soil of pine were determined and analyzed. The effect of the VOCs on the mycelial growth of Colletotrichum gloeosporioides, the pathogen of Liriodendron chinense × tulipifera black spot, was determined by a joined-petri dish fumigation method. An in vitro leaf inoculation method was used to determine the fumigation effect of the VOCs on Liriodendron black spot. VOCs with antifungal activity were collected by headspace solid-phase microextraction (SPME), and their components were analyzed by gas chromatography-mass spectrometry (GC-MS). The results showed that the VOCs secreted by JZ-GX1 inhibited the mycelial growth of the tested pathogen. The VOCs destroyed the morphology of the mycelium, significantly increased the permeability of the cell membrane and downregulated the expression of pathogenicity-related genes during mycelial infection, thus inhibiting the expansion of anthracnose disease spots in leaves. In the volatile compound profile, 3-methyl-1-butanol and 2-phenylethyl methyl ether significantly inhibited the mycelial growth and spore germination of C. gloeosporioides. This work provides a new strategy for the research and application of microorganisms and bioactive compounds to control plant anthracnose.

RevDate: 2020-06-17

Spor A, Camargo ARO, Bru D, et al (2020)

Habitat Disturbances Modulate the Barrier Effect of Resident Soil Microbiota on Listeria monocytogenes Invasion Success.

Frontiers in microbiology, 11:927.

Microbial communities are continuously exposed to the arrival of alien species. In complex environments such as soil, the success of invasion depends on the characteristics of the habitat, especially the diversity and structure of the residing bacterial communities. While most data available on microbial invasion relies on experiments run under constant conditions, the fate of invading species when the habitat faces disturbances has not yet been addressed. Here, we designed experiments to assess the consequences of habitat disturbance on the success of ongoing microbial invasion. We investigated (i) if disturbance-induced alterations in resident microbial communities could mitigate or facilitate invasion of Listeria monocytogenes, (ii) if disturbance itself could either improve or reduce the invader's fitness and (iii) if the invading species alters the structure of indigenous microbial communities. Our data show that environmental disturbances affect invasion patterns of L. monocytogenes in soils. Intriguingly, successful invasion was recorded in a regimen of disturbances that triggered small changes in microbial community structure while maintaining high bacterial diversity. On the opposite, dramatic decline of the invader was recorded when disturbance resulted in emergence of specific communities albeit concomitant with a diversity loss. This suggests that community composition is more important than its diversity when it comes to prevent the establishment of an invading species. Finally, shifts in bacterial communities during the disturbance event were strengthened by the presence of the invader indicating a major impact of invasion on microbial diversity when the habitat faces disturbance.

RevDate: 2020-06-17

Skubel SA, Su X, Poulev A, et al (2020)

Metabolomic differences between invasive alien plants from native and invaded habitats.

Scientific reports, 10(1):9749 pii:10.1038/s41598-020-66477-w.

Globalization facilitated the spread of invasive alien species (IAS), undermining the stability of the world's ecosystems. We investigated the metabolomic profiles of three IAS species: Chromolaena odorata (Asteraceae) Datura stramonium (Solanaceae), and Xanthium strumarium (Asteraceae), comparing metabolites of individual plants in their native habitats (USA), to their invasive counterparts growing in and around Kruger National Park (South Africa, ZA). Metabolomic samples were collected using RApid Metabolome Extraction and Storage (RAMES) technology, which immobilizes phytochemicals on glass fiber disks, reducing compound degradation, allowing long-term, storage and simplifying biochemical analysis. Metabolomic differences were analyzed using ultra-performance liquid chromatography-mass spectrometry (UPLC-MS) of samples eluted from RAMES disks. Partial Least Squares-Discriminant Analysis (PLS-DA) of metabolomes of individual plants allowed statistical separation of species, native and invasive populations of each species, and some populations on the same continent. Invasive populations of all species were more phytochemically diverse than their native counterparts, and their metabolomic profiles were statistically distinguishable from their native relatives. These data may elucidate the mechanisms of successful invasion and rapid adaptive evolution of IAS. Moreover, RAMES technology combined with PLS-DA statistical analysis may allow taxonomic identification of species and, possibly, populations within each species.

RevDate: 2020-06-17
CmpDate: 2020-06-17

Lear L, Hesse E, Shea K, et al (2020)

Disentangling the mechanisms underpinning disturbance-mediated invasion.

Proceedings. Biological sciences, 287(1919):20192415.

Disturbances can play a major role in biological invasions: by destroying biomass, they alter habitat and resource abundances. Previous field studies suggest that disturbance-mediated invader success is a consequence of resource influxes, but the importance of other potential covarying causes, notably the opening up of habitats, have yet to be directly tested. Using experimental populations of the bacterium Pseudomonas fluorescens, we determined the relative importance of disturbance-mediated habitat opening and resource influxes, plus any interaction between them, for invader success of two ecologically distinct morphotypes. Resource addition increased invasibility, while habitat opening had little impact and did not interact with resource addition. Both invaders behaved similarly, despite occupying different ecological niches in the microcosms. Treatment also affected the composition of the resident population, which further affected invader success. Our results provide experimental support for the observation that resource input is a key mechanism through which disturbance increases invasibility.


RJR Experience and Expertise


Robbins holds BS, MS, and PhD degrees in the life sciences. He served as a tenured faculty member in the Zoology and Biological Science departments at Michigan State University. He is currently exploring the intersection between genomics, microbial ecology, and biodiversity — an area that promises to transform our understanding of the biosphere.


Robbins has extensive experience in college-level education: At MSU he taught introductory biology, genetics, and population genetics. At JHU, he was an instructor for a special course on biological database design. At FHCRC, he team-taught a graduate-level course on the history of genetics. At Bellevue College he taught medical informatics.


Robbins has been involved in science administration at both the federal and the institutional levels. At NSF he was a program officer for database activities in the life sciences, at DOE he was a program officer for information infrastructure in the human genome project. At the Fred Hutchinson Cancer Research Center, he served as a vice president for fifteen years.


Robbins has been involved with information technology since writing his first Fortran program as a college student. At NSF he was the first program officer for database activities in the life sciences. At JHU he held an appointment in the CS department and served as director of the informatics core for the Genome Data Base. At the FHCRC he was VP for Information Technology.


While still at Michigan State, Robbins started his first publishing venture, founding a small company that addressed the short-run publishing needs of instructors in very large undergraduate classes. For more than 20 years, Robbins has been operating The Electronic Scholarly Publishing Project, a web site dedicated to the digital publishing of critical works in science, especially classical genetics.


Robbins is well-known for his speaking abilities and is often called upon to provide keynote or plenary addresses at international meetings. For example, in July, 2012, he gave a well-received keynote address at the Global Biodiversity Informatics Congress, sponsored by GBIF and held in Copenhagen. The slides from that talk can be seen HERE.


Robbins is a skilled meeting facilitator. He prefers a participatory approach, with part of the meeting involving dynamic breakout groups, created by the participants in real time: (1) individuals propose breakout groups; (2) everyone signs up for one (or more) groups; (3) the groups with the most interested parties then meet, with reports from each group presented and discussed in a subsequent plenary session.


Robbins has been engaged with photography and design since the 1960s, when he worked for a professional photography laboratory. He now prefers digital photography and tools for their precision and reproducibility. He designed his first web site more than 20 years ago and he personally designed and implemented this web site. He engages in graphic design as a hobby.

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This is a must read book for anyone with an interest in invasion biology. The full title of the book lays out the author's premise — The New Wild: Why Invasive Species Will Be Nature's Salvation. Not only is species movement not bad for ecosystems, it is the way that ecosystems respond to perturbation — it is the way ecosystems heal. Even if you are one of those who is absolutely convinced that invasive species are actually "a blight, pollution, an epidemic, or a cancer on nature", you should read this book to clarify your own thinking. True scientific understanding never comes from just interacting with those with whom you already agree. R. Robbins

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Collection of publications by R J Robbins

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Research Gate page for R J Robbins

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Curriculum Vitae for R J Robbins

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