Biological invasions are responsible for substantial biodiversity declines as well as high economic losses to society and monetary expenditures associated with the management of these invasions
. The ...InvaCost database has enabled the generation of a reliable, comprehensive, standardized and easily updatable synthesis of the monetary costs of biological invasions worldwide
. Here we found that the total reported costs of invasions reached a minimum of US$1.288 trillion (2017 US dollars) over the past few decades (1970-2017), with an annual mean cost of US$26.8 billion. Moreover, we estimate that the annual mean cost could reach US$162.7 billion in 2017. These costs remain strongly underestimated and do not show any sign of slowing down, exhibiting a consistent threefold increase per decade. We show that the documented costs are widely distributed and have strong gaps at regional and taxonomic scales, with damage costs being an order of magnitude higher than management expenditures. Research approaches that document the costs of biological invasions need to be further improved. Nonetheless, our findings call for the implementation of consistent management actions and international policy agreements that aim to reduce the burden of invasive alien species.
virtualspecies is a freely available package for R designed to generate virtual species distributions, a procedure increasingly used in ecology to improve species distribution models. This package ...combines the existing methodological approaches with the objective of generating virtual species distributions with increased ecological realism. The package includes 1) generating the probability of occurrence of a virtual species from a spatial set of environmental conditions (i.e. environmental suitability), with two different approaches; 2) converting the environmental suitability into presence–absence with a probabilistic approach; 3) introducing dispersal limitations in the realised virtual species distributions and 4) sampling occurrences with different biases in the sampling procedure. The package was designed to be extremely flexible, to allow users to simulate their own defined species–environment relationships, as well as to provide a fine control over every simulation parameter. The package also includes a function to generate random virtual species distributions. We provide a simple example in this paper showing how increasing ecological realism of the virtual species impacts the predictive performance of species distribution models. We expect that this new package will be valuable to researchers willing to test techniques and protocols of species distribution models as well as various biogeographical hypotheses.
Inland aquatic ecosystems are vulnerable to both climate change and biological invasion at broad spatial scales. The aim of this study was to establish the current and future potential distribution ...of three invasive plant taxa,
Egeria densa
,
Myriophyllum aquaticum
and
Ludwigia
spp., in their native and exotic ranges. We used species distribution models (SDMs), with nine different algorithms and three global circulation models, and we restricted the suitability maps to cells containing aquatic ecosystems. The current bioclimatic range of the taxa was predicted to represent 6.6–12.3% of their suitable habitats at global scale, with a lot of variations between continents. In Europe and North America, their invasive ranges are predicted to increase up to two fold by 2070 with the highest gas emission scenario. Suitable new areas will mainly be located to the north of their current range. In other continents where they are exotic and in their native range (South America), the surface areas of suitable locations are predicted to decrease with climate change, especially for
Ludwigia
spp. in South America (down to −55% by 2070 with RCP 8.5 scenario). This study allows to identify areas vulnerable to ongoing invasions by aquatic plant species and thus could help the prioritisation of monitoring and management, as well as contribute to the public awareness regarding biological invasions.
AIM: Global changes are predicted to have severe consequences for biodiversity; 34 biodiversity hotspots have become international priorities for conservation, with important efforts allocated to ...their preservation, but the potential effects of global changes on hotspots have so far received relatively little attention. We investigate whether hotspots are quantitatively and qualitatively threatened to the same order of magnitude by the combined effects of global changes. LOCATION: Worldwide, in 34 biodiversity hotspots. METHODS: We quantify (1) the exposure of hotspots to climate change, by estimating the novelty of future climates and the disappearance of extant climates using climate dissimilarity analyses, (2) each hotspot's vulnerability to land modification and degradation by quantifying changes in land‐cover variables over the entire habitat, and (3) the future suitability of distribution ranges of ‘100 of the world's worst invasive alien species’, by characterizing the combined effects of climate and land‐use changes on the future distribution ranges of these species. RESULTS: Our findings show that hotspots may experience an average loss of 31% of their area under analogue climate, with some hotspots more affected than others (e.g. Polynesia–Micronesia). The greatest climate change was projected in low‐latitude hotspots. The hotspots were on average suitable for 17% of the considered invasive species. Hotspots that are mainly islands or groups of islands were disproportionally suitable for a high number of invasive species both currently and in the future. We also showed that hotspots will increase their area of pasture in the future. Finally, combining the three threats, we identified the Atlantic forest, Cape Floristic Region and Polynesia–Micronesia as particularly vulnerable to global changes. MAIN CONCLUSIONS: Given our estimates of hotspot vulnerability to changes, close monitoring is now required to evaluate the biodiversity responses to future changes and to test our projections against observations.
The spectre of increasing impacts on exploited fish stocks in consequence of warmer climate conditions has become a major concern over the last decades. It is now imperative to improve the way we ...project the effects of future climate warming on fisheries. While estimating future climate‐induced changes in fish distribution is an important contribution to sustainable resource management, the impacts on European small pelagic fish—representing over 50% of the landings in the Mediterranean and Black Sea between 2000 and 2013—are yet largely understudied. Here, we investigated potential changes in the spatial distribution of seven of the most harvested small pelagic fish species in Europe under several climate change scenarios over the 21st century. For each species, we considered eight Species Distribution Models (SDMs), five General Circulation Models (GCMs) and three emission scenarios (the IPCC Representative Concentration Pathways; RCPs). Under all scenarios, our results revealed that the environmental suitability for most of the seven species may strongly decrease in the Mediterranean and western North Sea while increasing in the Black and Baltic Seas. This potential northward range expansion of species is supported by a strong convergence among projections and a low variability between RCPs. Under the most pessimistic scenario (RCP8.5), climate‐related local extinctions were expected in the south‐eastern Mediterranean basin. Our results highlight that a multi‐SDM, multi‐GCM, multi‐RCP approach is needed to produce more robust ecological scenarios of changes in exploited fish stocks in order to better anticipate the economic and social consequences of global climate change.
Biological invasions continue to threaten the stability of ecosystems and societies that are dependent on their services. Whilst the ecological impacts of invasive alien species (IAS) have been ...widely reported in recent decades, there remains a paucity of information concerning their economic impacts. Europe has strong trade and transport links with the rest of the world, facilitating hundreds of IAS incursions, and largely centralised decision-making frameworks. The present study is the first comprehensive and detailed effort that quantifies the costs of IAS collectively across European countries and examines temporal trends in these data. In addition, the distributions of costs across countries, socioeconomic sectors and taxonomic groups are examined, as are socio-economic correlates of management and damage costs. Total costs of IAS in Europe summed to US$140.20 billion (or €116.61 billion) between 1960 and 2020, with the majority (60%) being damage-related and impacting multiple sectors. Costs were also geographically widespread but dominated by impacts in large western and central European countries, i.e. the UK, Spain, France, and Germany. Human population size, land area, GDP, and tourism were significant predictors of invasion costs, with management costs additionally predicted by numbers of introduced species, research effort and trade. Temporally, invasion costs have increased exponentially through time, with up to US$23.58 billion (€19.64 billion) in 2013, and US$139.56 billion (€116.24 billion) in impacts extrapolated in 2020. Importantly, although these costs are substantial, there remain knowledge gaps on several geographic and taxonomic scales, indicating that these costs are severely underestimated. We, thus, urge increased and improved cost reporting for economic impacts of IAS and coordinated international action to prevent further spread and mitigate impacts of IAS populations.
Over the past two decades, species distribution models (SDMs) have become one of the most popular modelling tools in biogeographical studies. SDMs try to quantify the relationship between a taxon and ...its environment, for example, to predict its geographical distribution, to assess potential impacts of climate or land use change, or to explore biogeographical hypotheses. In practice, SDMs generally correlate species distribution data in the form of spatially explicit presences and absences, to environmental predictors, such as climatic variables. In cases where presences and absences are difficult to obtain in quantity and quality—that is, for the majority of biodiversity—it is possible to use SDMs with presence data alone. These are dedicated approaches requiring the generation of additional data points (called ‘background points’ or ‘pseudoabsences’). Overall, the concept of SDMs is simple; however, their implementation is complex because a large number of decisions are required throughout the multiple steps of the process (Figure 1). Each of these decisions must be weighed carefully by the users because they have a strong influence on the outcomes of SDMs and their interpretation. Guidance on how to make these decisions can be found in methodological or pedagogical papers and books (e.g. Elith et al., 2006; Guillera-Arroita et al., 2015; Guisan et al., 2017; Guisan & Thuiller, 2005; Phillips et al., 2006; Thuiller et al., 2009). However, for the majority of these decisions, there is still a high degree of uncertainty, because of shortfalls in our knowledge (see my perception of this degree of uncertainty in Figure 1). This uncertainty often leads to either making arbitrary decisions or costly sensitivity analyses when preparing SDMs. Furthermore, the profusion of methodological studies makes it easy for users (especially new users) to either miss guidance or caveats relevant to their study, or to lack the ability to understand them.Two main issues in SDM implementation require further guidance: uncertainty in decision-making and inaccessibility of guidelines. Uncertainty can be addressed by studies comprehensively investigating a specific methodological issue, providing established guidelines for decision-making. Inaccessibility can be addressed by studies synthesising the methodological progress with sufficient pedagogy to propagate good practices in the field. Here, I appraise a recent study which has combined these two characteristics in such an outstanding way that it should be extremely helpful to both new and experienced users (Valavi et al., 2021). First, Valavi and colleagues comprehensively addressed the choice of modelling techniques in presence-only situations, which has been a prominent issue so far. Second, they detailed all their methodological choices pedagogically, explaining the underlying reasons, and thus providing accessible guidelines throughout the multiple steps of the modelling process. In the following text, I first explain the context of model choice and pinpoint the major progress provided by Valavi and colleagues, and then I explain why, beyond this progress, their study will improve practices in the field. Finally, I conclude with an outlook on the uncertain decisions in SDMs.
Various prioritisation strategies have been developed to cope with accelerating biodiversity loss and limited conservation resources. These strategies could become more engaging for decision-makers ...if they reflected the positive effects conservation can have on future projected biodiversity, by targeting net positive outcomes in future projected biodiversity, rather than reflecting the negative consequences of further biodiversity losses only. Hoping to inform the post-2020 biodiversity framework, we here apply this approach of targeting net positive outcomes in future projected biodiversity to phylogenetic diversity (PD) to re-identify species and areas of interest for conserving global mammalian PD. We identify priority species/areas as those whose protection would maximise gains in future projected PD. We also identify loss-significant species/areas as those whose/where extinction(s) would maximise losses in future projected PD. We show that our priority species/areas differ from loss-significant species/areas. While our priority species are mostly similar to those identified by the EDGE of Existence Programme, our priority areas generally differ from previously-identified ones for global mammal conservation. We further highlight that these newly-identified species/areas of interest currently lack protection and offer some guidance for their future management.
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•Need to develop integrative approaches to assess cumulative impacts on ecosystems.•ENA indices were used in multiple scenarios combining the effect of several drivers.•Drivers were: ...a future offshore wind farm combined with climate change.•ENA indices can help managers better grasp the reach of cumulative effects.•This would assist them in their decision-making process.
In an increasingly anthropogenic world, the scientific community and managers have to take interactions between the drivers of ecosystems into consideration. Tools like ecological network analysis (ENA) indices offer the opportunity to study those interactions at the ecosystem level. However, ENA indices have never been used to test the incidence of cumulative drivers. The present study uses models combining the effects of (i) the reef caused by the future offshore wind farm of Courseulles-sur-Mer and (ii) climate change on species distribution, to test the response of multiple ENA indices. ENA indices proved sensitive to this cumulative impact, displaying a wide variety of cumulative effects. They were also very powerful to characterize the role of the cumulative impact on ecosystem functioning. These results demonstrate the capacity of ENA indices to describe and understand cumulative effects at the ecosystem scale. Using a sensitivity analysis approach, this study shows that ENA indices could be viable tools for managers. To help them in their tasks, the next step could be to link ecosystem services to ENA indices for a more practical use.
The ever-increasing number of introduced species profoundly threatens global biodiversity. While the ecological and evolutionary consequences of invasive alien species are receiving increasing ...attention, their economic impacts have largely remained understudied, especially in France. Here, we aimed at providing a general overview of the monetary losses (damages caused by) and expenditures (management of) associated with invasive alien species in France. This country has a long history of alien species presence, partly due to its long-standing global trade activities, highly developed tourism, and presence of overseas territories in different regions of the globe, resulting in a conservative minimum of 2,750 introduced and invasive alien species. By synthesizing for the first time the monetary losses and expenditures incurred by invasive alien species in Metropolitan France and French overseas territories, we obtained 1,583 cost records for 98 invasive alien species. We found that they caused a conservative total amount ranging between US$ 1,280 million and 11,535 million in costs over the period 1993–2018. We extrapolated costs for species invading France, for which costs were reported in other countries but not in France, which yielded an additional cost ranging from US$ 151 to 3,030 millions. Damage costs were nearly eight times higher than management expenditure. Insects, and in particular the Asian tiger mosquito
Aedes albopictus
and the yellow fever mosquito
Ae. aegypti
, totalled very high economic costs, followed by non-graminoid terrestrial flowering and aquatic plants (
Ambrosia artemisiifolia
,
Ludwigia
sp. and
Lagarosiphon major
). Over 90% of alien species currently recorded in France had no costs reported in the literature, resulting in high biases in taxonomic, regional and activity sector coverages. To conclude, we report alarming costs and even more alarming knowledge gaps. Our results should raise awareness of the importance of biosecurity and biosurveillance in France, and beyond, as well as the crucial need for better reporting and documentation of cost data.
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