15 research outputs found

    Susceptibility of tropical mountain forests to biological invasions from the temperate and subtropical zone, exemplified by <i>Zonitoides</i> (Gastropoda: Gastrodontidae)

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    Colonisation by, and spread of, animal species from the temperate zone are rather uncommon observations in the tropics. The study provides the first reports of two snail species of the genus Zonitoides in Sabah, Borneo, namely Z. arboreus (Say, 1819) and Z. nitidus (O.F. Muller, 1774). The identification was aided using partial sequences of 28S rDNA, and the barcoding sequence of COI. So far, the two Zonitoides species were found in locations where the natural forest cover had been disturbed, and only in the montane forest at elevations between 1500 and 2000 m a.s.l.. Niche modeling suggests that both taxa could be widely distributed in the mountains of tropical South America and Africa. Z. arboreus finds suitable climates in many places in SE Asia and especially at many conservation areas in Borneo. In contrast, Z. nitidus finds only marginal climatic conditions in the same area, and introductions of Z. nitidus probably will remain spatially restricted. This prediction, however, needs to be monitored because the latter species can display molluscivory. Our results additionally point to the possibility of Z. arboreus being a species complex that, given its potential economic impact, urgently needs a taxonomic revision.</p

    Drivers of future alien species impacts: An expert‐based assessment

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    Understanding the likely future impacts of biological invasions is crucial yet highly challenging given the multiple relevant environmental, socio‐economic and societal contexts and drivers. In the absence of quantitative models, methods based on expert knowledge are the best option for assessing future invasion trajectories. Here, we present an expert assessment of the drivers of potential alien species impacts under contrasting scenarios and socioecological contexts through the mid‐21st century. Based on responses from 36 experts in biological invasions, moderate (20%–30%) increases in invasions, compared to the current conditions, are expected to cause major impacts on biodiversity in most socioecological contexts. Three main drivers of biological invasions—transport, climate change and socio‐economic change—were predicted to significantly affect future impacts of alien species on biodiversity even under a best‐case scenario. Other drivers (e.g. human demography and migration in tropical and subtropical regions) were also of high importance in specific global contexts (e.g. for individual taxonomic groups or biomes). We show that some best‐case scenarios can substantially reduce potential future impacts of biological invasions. However, rapid and comprehensive actions are necessary to use this potential and achieve the goals of the Post‐2020 Framework of the Convention on Biological Diversity

    Global economic costs of aquatic invasive alien species

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    Much research effort has been invested in understanding ecological impacts of invasive alien species (IAS) across ecosystems and taxonomic groups, but empirical studies about economic effects lack synthesis. Using a comprehensive global database, we determine patterns and trends in economic costs of aquatic IAS by examining: (i) the distribution of these costs across taxa, geographic regions and cost types; (ii) the temporal dynamics of global costs; and (iii) knowledge gaps, especially compared to terrestrial IAS. Based on the costs recorded from the existing literature, the global cost of aquatic IAS conservatively summed to US345billion,withthemajorityattributedtoinvertebrates(62345 billion, with the majority attributed to invertebrates (62%), followed by vertebrates (28%), then plants (6%). The largest costs were reported in North America (48%) and Asia (13%), and were principally a result of resource damages (74%); only 6% of recorded costs were from management. The magnitude and number of reported costs were highest in the United States of America and for semi-aquatic taxa. Many countries and known aquatic alien species had no reported costs, especially in Africa and Asia. Accordingly, a network analysis revealed limited connectivity among countries, indicating disparate cost reporting. Aquatic IAS costs have increased in recent decades by several orders of magnitude, reaching at least US23 billion in 2020. Costs are likely considerably underrepresented compared to terrestrial IAS; only 5% of reported costs were from aquatic species, despite 26% of known invaders being aquatic. Additionally, only 1% of aquatic invasion costs were from marine species. Costs of aquatic IAS are thus substantial, but likely underreported. Costs have increased over time and are expected to continue rising with future invasions. We urge increased and improved cost reporting by managers, practitioners and researchers to reduce knowledge gaps. Few costs are proactive investments; increased management spending is urgently needed to prevent and limit current and future aquatic IAS damages. (c) 2021 The Authors. Published by Elsevier B.V. This is an open access article under the CC BY license (http://creativecommons.org/licenses/by/4.0/).Peer reviewe

    Non-English languages enrich scientific knowledge : The example of economic costs of biological invasions

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    We contend that the exclusive focus on the English language in scientific researchmight hinder effective communication between scientists and practitioners or policymakerswhose mother tongue is non-English. This barrier in scientific knowledge and data transfer likely leads to significant knowledge gaps and may create biases when providing global patterns in many fields of science. To demonstrate this, we compiled data on the global economic costs of invasive alien species reported in 15 non-English languages. We compared it with equivalent data from English documents (i.e., the InvaCost database, the most up-to-date repository of invasion costs globally). The comparison of both databases (similar to 7500 entries in total) revealed that non-English sources: (i) capture a greater amount of data than English sources alone (2500 vs. 2396 cost entries respectively); (ii) add 249 invasive species and 15 countries to those reported by English literature, and (iii) increase the global cost estimate of invasions by 16.6% (i.e., US$ 214 billion added to 1.288 trillion estimated fromthe English database). Additionally, 2712 cost entries - not directly comparable to the English database - were directly obtained frompractitioners, revealing the value of communication between scientists and practitioners. Moreover, we demonstrated how gaps caused by overlooking non-English data resulted in significant biases in the distribution of costs across space, taxonomic groups, types of cost, and impacted sectors. Specifically, costs from Europe, at the local scale, and particularly pertaining to management, were largely under-represented in the English database. Thus, combining scientific data from English and non-English sources proves fundamental and enhances data completeness. Considering non-English sources helps alleviate biases in understanding invasion costs at a global scale. Finally, it also holds strong potential for improving management performance, coordination among experts (scientists and practitioners), and collaborative actions across countries. Note: non-English versions of the abstract and figures are provided in Appendix S5 in 12 languages. (c) 2021 The Authors. Published by Elsevier B.V. This is an open access article under the CC BY license (http:// creativecommons.org/licenses/ by/4.0/).Peer reviewe

    Drivers of future alien species impacts: an expert‐based assessment

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    Understanding the likely future impacts of biological invasions is crucial yet highly challenging given the multiple relevant environmental, socio‐economic and societal contexts and drivers. In the absence of quantitative models, methods based on expert knowledge are the best option for assessing future invasion trajectories. Here, we present an expert assessment of the drivers of potential alien species impacts under contrasting scenarios and socioecological contexts through the mid‐21st century. Based on responses from 36 experts in biological invasions, moderate (20%–30%) increases in invasions, compared to the current conditions, are expected to cause major impacts on biodiversity in most socioecological contexts. Three main drivers of biological invasions—transport, climate change and socio‐economic change—were predicted to significantly affect future impacts of alien species on biodiversity even under a best‐case scenario. Other drivers (e.g. human demography and migration in tropical and subtropical regions) were also of high importance in specific global contexts (e.g. for individual taxonomic groups or biomes). We show that some best‐case scenarios can substantially reduce potential future impacts of biological invasions. However, rapid and comprehensive actions are necessary to use this potential and achieve the goals of the Post‐2020 Framework of the Convention on Biological Diversity

    Response of non-native European terrestrial gastropods to novel climates correlates with biogeographical and biological traits

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    Aim Anticipating the propensity of species to persist outside the climatic conditions in which they are observed is important in assessing the uncertainty in climate-matching when applied to different locations or times. By using data from 27 European terrestrial gastropods (slugs and snails) established in new regions, we measured (1) the degree of climate match between native and non-native ranges and (2) the diversity of novel climatic conditions inhabited. We then tested for species traits as predictors of the patterns found. Location Worldwide. Methods We projected the occurrences of each species onto the climatic space defined by the two main axes of a principal components analysis. On the basis of the convex hull of native occurrences, we measured the proportion of non-native occurrences in novel climates and the diversity of the newly occupied climates. Generalized estimating equations were used to test for associations between climatic responses and species traits, while considering phylogenetic relatedness and introduction effort. Results Approximately half of the species had a large proportion (> 25%) of non-native occurrences in novel climates. Climate mismatch was significantly higher for species with narrow native climatic niches, native ranges elongated in a north-south direction or native ranges with the southern limit at lower latitudes. Slugs occupied a higher diversity of novel climatic conditions than snails. Main conclusions Climate matching showed varying levels of accuracy in predicting the non-native ranges of the studied species. Lower accuracy appeared to be mainly related to low levels of distributional equilibrium in native ranges. In addition, coarse-scale predictions for species that are able to take advantage of microclimatic variability - as appears to be the case with slugs - may be challenging. We conclude that species traits can contribute to understanding uncertainties in climate-matching exercises

    Native and alien grassland diversity respond differently to environmental and anthropogenic drivers across spatial scales

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    Aims To identify environmental and anthropogenic drivers of alpha- and beta-diversity for native and alien plant species. Location Río de la Plata grasslands, South America (Argentina, Brazil and Uruguay; 27.3–39.1°S, 50.1–66.5°W). Methods We assembled a data set of 597 vegetation plots distributed across the Río de la Plata grasslands. To assess the drivers of native and alien alpha-diversity (species richness), we performed a generalized least-squares regression using environmental and anthropogenic predictors. We evaluated differences in beta-diversity using Simpson's pairwise dissimilarity between pairs of plots and used multiple regression on distance matrixes to investigate environmental and anthropogenic drivers on compositional dissimilarity for both native and alien plant species. Results Native species richness was higher in sites with less demanding environmental conditions, such as lower precipitation seasonality and soils with higher cation exchange capacity. Numbers of alien species were positively related to soil pH, cropland density and road density and negatively to precipitation seasonality, mean temperatures and soil cation exchange capacity. The compositional dissimilarity was similar for native and alien species assemblages (mean ± SD: 0.64 ± 0.16 and 0.64 ± 0.35 respectively). Areas having similar climates and being geographically close shared more taxonomically similar assemblages, for both native and alien assemblages, while soil had disparate effects. Compositional dissimilarity of alien plants decreased with increasing road density. Conclusions Our results highlight a grassland ecosystem where native species richness is still shaped only by environmental factors, but both sets of factors influence its composition. On the other hand, alien plants carry a strong signal of both environmental and human factors. As time progresses the number of alien species tend to increase, eroding the patterns of native biodiversity. To avoid this, efforts should be made to reduce road encroachment and the conversion of natural grasslands into croplands
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