Search

Wetlands, one of the most biodiverse ecosystems in the world, are increasingly subjected to area loss and degradation due to land-use and climate changes. These factors impact their unique biodiversity, including numerous invertebrates that depend on them. Here we investigated the current and future habitat suitability of the aquatic spiders Argyroneta aquatica and Dolomedes plantarius. We evaluated future trends in their geographic range, aiming at assessing their extinction risk according to the International Union for Conservation of Nature (IUCN) Red List criteria, at both global and regional levels. We investigated present and future distribution ranges using species distribution models for two integrated emission scenarios (SSP1-2.6 and SSP5-8.5) and combining three general circulation models. These were combined with knowledge on species' dispersal limitation to account for the possibility that these species will not be able to move beyond the current range in the next decades. We found a significant future northern shift in the geographic range and a global reduction in habitat suitability for both species, corresponding to a loss of 28.9 % for A. aquatica and 38.1 % for D. plantarius in the next 10 years. The application of the IUCN criteria qualifies A. aquatica as Near Threatened and D. plantarius as Vulnerable. Regional assessments provided similar patterns of range reductions and population vulnerability across all European regions, particularly for Central-Eastern and Western Europe. Conversely, Northern Europe is expected to become a climatic refugium for both species. This work goes beyond the available studies on the conservation of these species by taking account their dispersal abilities in quantifying future trends in their habitat suitability using the most up to date knowledge. Conservation strategies should be directed towards limiting the impact of climatic and non-climatic stressors on wetlands, and towards implementing management plans and restoration programmes to increase habitat suitability and connectivity among wetland patches. [Display omitted] • Argyroneta aquatica and Dolomedes plantarius are charismatic species of wetlands subjected to habitat loss and degradation. • A future northern shift in geographic range and a global reduction in habitat suitability is forecasted for both species. • The predicted loss is 28.9 % for A. aquatica and 38.1 % for D. plantarius in the next 10 years. • The application of the IUCN criteria qualifies A. aquatica as Near Threatened and D. plantarius as Vulnerable. • Regional assessments provided similar patterns of range reductions and population vulnerability across all European regions. [ABSTRACT FROM AUTHOR]

Abstract: The IUCN Red List is the most useful list of species that are at risk for extinction worldwide, as it relies on a number of objective criteria. Nevertheless, there is a taxonomic bias that excludes species with small body sizes, narrow distribution ranges and low dispersal abilities, which constitute the vast majority of the planet’s biota, particularly local endemics. By evaluating each IUCN criterion separately, we (i) identify the shortcomings for invertebrate applications, (ii) explain how risk categories may be wrongly applied due to inapplicable and/or misleading thresholds, (iii) suggest alternative ways of applying the existing criteria in a more realistic way and (iv) suggest possible new criteria that were not considered in the current evaluation framework but that could allow a more comprehensive and effective assessment of invertebrates. By adapting the criteria to rely more explicitly on the Area of Occupancy and the Extent of Occurrence, their respective trends and by using ecological modelling methods, the criteria’s applicability would be increased. The change in some thresholds or, eventually, the creation of sub-categories would further increase their adequacy. Additionally, co-extinction could be introduced as an explicit part of the classification process. As a case study, we evaluated 48 species of Azorean arthropods and Iberian spiders according to the current criteria. More than one-quarter (27%) of all evaluated species were classified as Critically Endangered, 19% as Endangered, 6% as Vulnerable and 8% as Least Concern. The remaining 40% did not have enough data to reach a classification. [Copyright &y& Elsevier]

Animal parasites are species rich and ecologically diverse, some with complex life cycles and life histories and consequently many are vulnerable to extinction. While the conservation biology community is becoming cognisant of the plight of threatened parasites, coupled at times with potential host co-extinction, feasible criteria have not been developed to specifically assess their threat risk and methods to conserve them have also received limited attention. Methodologies and criteria are presented here to aid the assessment of the conservation status of threatened parasites in a way consistent with the criteria of the International Union for the Conservation of Nature (IUCN). Such assessments assist in prioritizing conservation efforts, a crucial task given parasites are integral to the functioning and survival of global ecosystems. • Animal parasites are ecologically important and highly vulnerable to extinction. • Available conservation rubrics are poorly suited for assessing animal parasites. • The first assessment framework designed for animal parasites is presented. • Widescale assessments of the conservation status of animal parasites can now occur. [ABSTRACT FROM AUTHOR]

Species differ in their biological susceptibility to extinction, but the set of traits determining susceptibility varies across taxa. It is yet unclear which patterns are common to all taxa, and which are taxon-specific, with consequences to conservation practice. In this study we analysed the generality of trait-based prediction of extinction risk across terrestrial (including freshwater) vertebrates, invertebrates and plants at a global scale. For each group, we selected five representative taxa and within each group we explored whether risk can be related to any of 10 potential predictors. We then synthesized outcomes across taxa using a meta-analytic approach. High habitat specificity was a consistent predictor across vertebrates, invertebrates and plants, being a universal predictor of risk. Slow life-history traits – large relative offspring size, low fecundity, long generation length –, and narrow altitudinal range were also found to be good predictors across most taxa, but their universality needs to be supported with additional data. Poor dispersal ability was a common predictor of extinction risk among invertebrate and plant taxa, but not consistently among vertebrates. The remaining traits (body size, microhabitat verticality, trophic level, and diet breadth) were useful to predict extinction risk but only at lower taxonomical levels. Our study shows that despite the idiosyncrasies among taxa, universal susceptibility to extinction exists and several traits might influence extinction risk for most taxa. Informing conservation prioritization at lower taxonomic scales should however include taxon-specific trait-based predictors of extinction risk. [ABSTRACT FROM AUTHOR]