[Show abstract][Hide abstract] ABSTRACT: Population trends play a large role in species risk assessments and conservation planning, and species are often considered threatened if their recent rate of decline meets certain thresholds, regardless how large the population is. But how reliable an indicator of extinction risk is a single estimate of population trend? Given the integral role this decline-based approach has played in setting conservation priorities, it is surprising that it has undergone little empirical scrutiny. We compile an extensive global dataset of time series of abundance data for over 1300 vertebrate populations to provide the first major test of the predictability of population growth rates in nature. We divided each time series into assessment and response periods and examined the correlation between growth rates in the two time periods. In birds, population declines tended to be followed by further declines, but mammals, salmon, and other bony fishes showed the opposite pattern: past declines were associated with subsequent population increases, and vice versa. Furthermore, in these taxa subsequent growth rates were higher when initial declines were more severe. These patterns agreed with data simulated under a null model for a dynamically stable population experiencing density dependence. However, this type of result could also occur if conservation actions positively affected the population following initial declines—a scenario that our data were too limited to rigorously evaluate. This ambiguity emphasizes the importance of understanding the underlying causes of population trajectories in drawing inferences about rates of decline in abundance.
[Show abstract][Hide abstract] ABSTRACT: Despite increasing concerns about the vulnerability of species’ populations to climate change, there has been little overall synthesis of how individual population responses to variation in climate differ between taxa, with trophic level or geographically. To address this, we extracted data from 132 long-term (greater than or equal to 20 years) studies of population responses to temperature and precipitation covering 236 animal and plant species across terrestrial and freshwater habitats. Our results identify likely geographical differences in the effects of climate change on populations and communities in line with macroecological theory. Temperature tended to have a greater overall impact on populations than precipitation, although the effects of increased precipitation varied strongly with latitude, being most positive at low latitudes. Population responses to increased temperature were generally positive, but did not vary significantly with latitude. Studies reporting significant climatic trends through time tended to show more negative effects of temperature and more positive effects of precipitation upon populations than other studies, indicating climate change has already impacted many populations. Most studies of climate change impacts on biodiversity have focused on temperature and are from middle to high northern latitudes. Our results suggest their findings may be less applicable to low latitudes.
Proceedings of the Royal Society B: Biological Sciences 11/2015; 282(1818):20151561. DOI:10.1098/rspb.2015.1561 · 5.05 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: To accommodate climate-driven changes in biological communities, conservation plans are increasingly making use of models to predict species’ responses to climate change. To date, species distribution models have been the most commonly used approach for assessing species’ vulnerability to climate change. Biological trait-based approaches, which have emerged recently, and which include consideration of species’ sensitivity and adaptive capacity, provide alternative and potentially conflicting vulnerability assessments and present conservation practitioners and planners with difficult choices. Here we discuss the differing objectives and strengths of the approaches, and provide guidance to conservation practitioners for their application. We outline an integrative methodological framework for assessing climate change impacts on species that uses both traditional species distribution modelling approaches and biological trait-based assessments. We show how these models can be used conceptually as inputs to guide conservation monitoring and planning.
[Show abstract][Hide abstract] ABSTRACT: World governments have committed to increase the global protected areas coverage by 2020, but the effectiveness of this commitment for protecting biodiversity depends on where new protected areas are located. Threshold-based and complementarity-based approaches have been independently used to identify important sites for biodiversity. Here we bring together these approaches by performing a complementarity-based analysis of irreplaceability in Important Bird and Biodiversity Areas (IBAs; which are sites identified using a threshold-based approach). We determined whether irreplaceability values are higher inside than outside IBAs, and whether any observed difference depends on known characteristics of the IBAs. We focussed on three regions having comprehensive IBAs inventories and bird distribution atlases: Australia, Southern Africa and Europe. Irreplaceability values were significantly higher inside than outside IBAs, although differences were much smaller in Europe than elsewhere. Higher irreplaceability values in IBAs were associated with: presence and number of restricted-range species; number of criteria under which the site was identified; and mean geographic range size of the species for which the site was identified ('trigger species'). In addition, IBAs were characterised by higher irreplaceability values when using proportional species representation targets, rather than fixed targets. There were broadly comparable results both when measuring irreplaceability for trigger species and when considering all bird species, indicating a good surrogacy effect of the former. Recently the International Union for Conservation of Nature has convened a consultation to consolidate global standards for the identification of Key Biodiversity Areas (KBAs), building from existing approaches like IBAs. Our results are important for informing this consultation, and in particular for a proposed irreplaceability criterion that will allow the new KBA standard to draw on the strengths of both threshold-based and complementarity-based approaches. This article is protected by copyright. All rights reserved.
This article is protected by copyright. All rights reserved.
[Show abstract][Hide abstract] ABSTRACT: Extent of Occurrence (EOO) is a key metric in assessing extinction risk using the IUCN Red List categories and criteria. However, the way in which EOO is estimated from maps of species' distributions is inconsistent between assessments of different species, and between major taxonomic groups. It is often estimated from the area of mapped distribution, but these maps often exclude areas of unsuitable habitat in idiosyncratic ways and are not created at the same spatial resolutions. We assessed the impact on extinction risk categories of applying different methods for estimating EOO for 21763 species of mammals, birds and amphibians. Overall, we found that the percentage of threatened species requiring downlisting to a lower category of threat, taking into account other Red List criteria under which they qualified, spanned 11-13% for all species combined (14-15% for mammals, 7-8% for birds and 12-15% for amphibians) depending on the method used. Extrapolating from birds for missing data for amphibians and mammals suggests that 14% of threatened and Near Threatened species potentially require downlisting using a Minimum Convex Polygon (MCP) approach, as now recommended by IUCN, with other metrics (such as alpha hull) having marginally smaller impacts. We conclude that uniformly applying the MCP approach will potentially lead to a one-time downlisting of hundreds of species, but ultimately ensure consistency across assessments and realign the calculation of EOO with the theoretical basis upon which the metric was founded. This article is protected by copyright. All rights reserved.
This article is protected by copyright. All rights reserved.
[Show abstract][Hide abstract] ABSTRACT: For 50 years, the IUCN Commissions, Secretariat, Members such as BirdLife International and partners such as UNEP-WCMC have been mobilising biodiversity and conservation knowledge products, which are fundamentally important for tracking progress towards 10 of the 20 Aichi Targets, and should similarly become so for seven of the emerging 17 UN Sustainable Development Goals. Each of these knowledge products comprises standards, governance and quality control, data sets, tools, capacity building and ongoing processes for derivation of biodiversity indicators. The IUCN Red List of Threatened Species, established in 1964, documents extinction risk for more than 76,000 species. Protected Planet, working from the mandate to provide the UN List of Protected Areas, is convened jointly with UNEP and documents ~220,000 protected areas. The Red List of Ecosystems aims to assess the risk of collapse of ecosystems, and is currently being piloted in a number of countries. Key Biodiversity Areas are sites contributing significantly to the global persistence of biodiversity, identified at national levels using globally standard criteria. The system has been developed over the last four decades by BirdLife International and others with ~15,000 sites identified; it is anticipated that IUCN will approve the umbrella standard around these existing approaches in 2015. Of the 55 global indicators mobilised for mid-term assessment of progress towards the Aichi Targets for the fourth Global Biodiversity Outlook, nearly a third were wholly or partly based on these knowledge products (spanning 10 of the Aichi Targets). Indicators derived from these knowledge products will also be applicable to seven of the Sustainable Development Goals. However, annual investment into these knowledge products is currently only a fraction of that necessary to maintain their currency, quality, and scope. If these key indicators towards the Aichi Targets are to be maintained, sustainable long-term financing mechanisms must be established to resource the underlying knowledge products.
[Show abstract][Hide abstract] ABSTRACT: Human activities are largely responsible for the processes that threaten biodiversity, yet potential changes in human behaviour as a response to climate change are ignored in most species and site-based vulnerability assessments (VAs). Here we assess how incorporation of the potential impact of climate change on humans alters our view of vulnerability when using well-established site and species VA methodologies. Southern Africa. Our baseline was two published studies that used accepted VA methodologies aimed at examining the direct impacts of climate changes on species and sites. The first identified potential shifts in the distributions of 164 restricted-range avian species, the second forecasted species turnover in 331 Important Bird and Biodiversity Areas (IBAs). We used a published spatially explicit assessment of potential climate change impacts on people to evaluate which species and sites overlap with human populations most likely to be impacted. By doing this, we were able to assess how the integration of potential climate impacts on human populations changes our perception of which species and sites are most vulnerable to climate change. We found no correlation between species and sites most likely to be impacted directly by climate change and those where the potential response of human populations could drive major indirect impacts. The relative vulnerability of individual species and sites shifted when potential impacts of climate change on human communities were considered, with more than one-fifth of species and one-tenth of sites moving from ‘low’ to ‘high’ risk. Standard VA methodologies that fail to consider how people are likely to respond to climate change will result in systematically biased assessments. This may lead to the implementation of inappropriate management actions, and a failure to address those species or sites that may be uniquely, or additionally, imperilled by the impacts of human responses to climate change.
Diversity and Distributions 07/2015; 21(9). DOI:10.1111/ddi.12355 · 3.67 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: Following their failure to achieve a significant reduction in the global rate of biodiversity loss by 2010, world governments adopted 20 new ambitious Aichi biodiversity targets to be met by 2020.There is growing recognition that efforts to achieve one particular biodiversity target can contribute to achieving others, yet little attention is given to the fact that different targets may require conflicting solutions. Consequently, there is a risk that lack of strategic thinking might result, once again, in a failure to achieve governmental commitments to biodiversity conservation. We illustrate this dilemma by focusing on Aichi Target 11. This requires an expansion of terrestrial protected area coverage, which could also contribute to reducing the loss of natural habitats (Target 5), reducing human-induced species decline and extinction (Target 12), and maintaining global carbon stocks (Target 15). We consider the potential impact of expanding protected areas to mitigate global deforestation and the consequences for the distribution of suitable habitat for >10000 species of forest vertebrates (amphibians, birds and mammals). We found that expanding protected areas toward locations with the highest deforestation rates (Target 5) or the highest potential loss of aggregate species' suitable habitat (Target 12) would result in partially different protected area network configurations (overlapping with each other by ca. 73%). Moreover, the latter approach would contribute to safeguarding ca. 30% more global carbon stocks (measures as tons/ha) than the former. Further investigation of synergies and trade-offs between targets would shed light on these and other complex interactions, such as the interaction between reducing overexploitation of natural resources (Targets 6, 7), controlling invasive alien species (Target 9) and preventing extinctions of native species (Target 12). Synergies between targets must be identified and secured soon and trade-offs must be minimized, before the options for co-benefits are reduced by human pressures. This article is protected by copyright. All rights reserved.
This article is protected by copyright. All rights reserved.
[Show abstract][Hide abstract] ABSTRACT: AimWe conduct the first assessment of likely future climate change impacts for biodiversity across the West African protected area (PA) network using climate projections that capture important climate regimes (e.g. West African Monsoon) and mesoscale processes that are often poorly simulated in general circulation models (GCMs).LocationWest Africa.Methods
We use correlative species distribution models to relate species (amphibians, birds, mammals) distributions to modelled contemporary climates, and projected future distributions across the PA network. Climate data were simulated using a physically based regional climate model to dynamically downscale GCMs. GCMs were selected because they accurately reproduce important regional climate regimes and generate a range of regional climate change responses. We quantify uncertainty arising from projected climate change, modelling methodology and spatial dependency, and assess the spatial and temporal patterns of climate change impacts for biodiversity across the PA network.ResultsSubstantial species turnover across the network is projected for all three taxonomic groups by 2100 (amphibians = 42.5% (median); birds = 35.2%; mammals = 37.9%), although uncertainty is high, particularly for amphibians and mammals, and, importantly, increases across the century. However, consistent patterns of impacts across taxa emerge by early to mid-century, suggesting high impacts across the Lower Guinea forest.Main conclusionsReducing (e.g. using appropriate climate projections) and quantifying uncertainty in climate change impact assessments helps clarify likely impacts. Consistent patterns of high biodiversity impacts emerge in the early and mid-century projections, while end-of-century projections are too uncertain for reliable assessments. We recommend that climate change adaptation should focus on earlier projections, where we have most confidence in species responses, rather than on end-of-century projections that are frequently used. In addition, our work suggests climate impact should consider a broad range of species, as we simulate divergent responses across taxonomic groups.
Diversity and Distributions 05/2015; 21(9). DOI:10.1111/ddi.12337 · 3.67 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: The effects of climate change on biodiversity are increasingly well documented, and many methods have been developed to assess species' vulnerability to climatic changes, both ongoing and projected in the coming decades. To minimize global biodiversity losses, conservationists need to identify those species that are likely to be most vulnerable to the impacts of climate change. In this Review, we summarize different currencies used for assessing species' climate change vulnerability. We describe three main approaches used to derive these currencies (correlative, mechanistic and trait-based), and their associated data requirements, spatial and temporal scales of application and modelling methods. We identify strengths and weaknesses of the approaches and highlight the sources of uncertainty inherent in each method that limit projection reliability. Finally, we provide guidance for conservation practitioners in selecting the most appropriate approach(es) for their planning needs and highlight priority areas for further assessments.
[Show abstract][Hide abstract] ABSTRACT: To address the ongoing global biodiversity crisis, governments have set strategic objectives and have adopted indicators to monitor progress towards their achievement. Projecting the likely impacts on biodiversity of different policy decisions allows decision makers to understand if and how these targets can be met. We projected trends in two widely used indicators of population abundance (the Living Planet Index; LPI) and extinction risk (the Red List Index; RLI) under different climate and land-use change scenarios. Testing these on terrestrial carnivore and ungulate species, we found that both indicators decline steadily, and by 2050, under a business-as-usual scenario, the LPI declines by 18–35% while extinction risk increases for 8–23% of the species, depending on assumptions about species responses to climate change. Business-as-usual will therefore fail CBD target 12 of improving the conservation status of known threatened species. An alternative sustainable development scenario reduces both extinction risk and population losses compared with Business-as-usual and could lead to population increases. Our approach to model species responses to global changes brings the focus of scenarios directly to the species level, thus taking into account an additional dimension of biodiversity and paving the way for including stronger ecological foundations into future biodiversity scenario assessments.This article is protected by copyright. All rights reserved.
[Show abstract][Hide abstract] ABSTRACT: Biodiversity is declining, with direct and indirect effects on ecosystem functions and services that are poorly quantified. Here we develop the first global assessment of trends in pollinators, focusing on pollinating birds and mammals. A Red List Index for these species shows that, overall, pollinating bird and mammal species are deteriorating in status, with more species moving towards extinction than away from it. On average, 2.4 species per year have moved one Red List category towards extinction in recent decades, representing a substantial increase in extinction risk across this set of species. This may be impacting the delivery of benefits to people that these species provide. We recommend that the index is expanded to include taxonomic groups that contribute more significantly to pollination, such as bees, wasps and butterflies, thereby giving a more complete picture of the state of pollinating species worldwide.
[Show abstract][Hide abstract] ABSTRACT: Governments have committed to conserving ≥17% of terrestrial and ≥10% of marine environments globally, especially “areas of particular importance for biodiversity” through “ecologically representative” Protected Area (PA) systems or other “area-based conservation measures,” while individual countries have committed to conserve 3–50% of their land area. We estimate that PAs currently cover 14.6% of terrestrial and 2.8% of marine extent, but 59–68% of ecoregions, 77–78% of important sites for biodiversity, and 57% of 25,380 species have inadequate coverage. The existing 19.7 million km2 terrestrial PA network needs only 3.3 million km2 to be added to achieve 17% terrestrial coverage. However, it would require nearly doubling to achieve, cost-efficiently, coverage targets for all countries, ecoregions, important sites, and species. Poorer countries have the largest relative shortfalls. Such extensive and rapid expansion of formal PAs is unlikely to be achievable. Greater focus is therefore needed on alternative approaches, including community- and privately managed sites and other effective area-based conservation measures.This article is protected by copyright. All rights reserved.
[Show abstract][Hide abstract] ABSTRACT: Local stakeholders at the important but vulnerable Centre Hills on Montserrat consider that the continued presence of feral livestock (particularly goats and pigs) may lead to widespread replacement of the reserve’s native vegetation by invasive alien trees (Java plum and guava), and consequent negative impacts on native animal species. Since 2009, a hunting programme to control the feral livestock has been in operation. However long-term funding is not assured. Here, we estimate the effect of feral livestock control on ecosystem services provided by the forest to evaluate whether the biodiversity conservation rationale for continuation of the control programme is supported by an economic case. A new practical tool (Toolkit for Ecosystem Service Site-based Assessment) was employed to measure and compare ecosystem service provision between two states of the reserve (i.e. presence and absence of feral livestock control) to estimate the net consequences of the hunting programme on ecosystem services provided by the forest. Based on this we estimate that cessation of feral livestock management would substantially reduce the net benefits provided by the site, including a 46 % reduction in nature-based tourism (from $419,000 to $228,000) and 36 % reduction in harvested wild meat (from $205,000 to $132,000). The overall net benefit generated from annual ecosystem service flows associated with livestock control in the reserve, minus the management cost, was $214,000 per year. We conclude that continued feral livestock control is important for maintaining the current level of ecosystem services provided by the reserve.
[Show abstract][Hide abstract] ABSTRACT: Global and project-level biodiversity indicators have received considerable attention, but indicators of the conservation actions and impacts of programmes and institutions appear to be under-developed. The IUCN Red List Index (RLI) has potential to be a useful indicator at an organizational-level to evaluate long-term impact of conservation on the extinction risk of species, thereby supporting institutional decision-making and communications. However, it has not yet been tested for its utility in tracking changes in extinction risk of a set of species targeted specifically by an individual conservation agency. Here, we examine the feasibility of using the RLI as one metric of the conservation impact of the Durrell Wildlife Conservation Trust, a conservation charity which runs multi-decadal programmes on a modest number of globally threatened terrestrial vertebrate species. Of 17 target amphibian, bird and mammal species, eight underwent improvements in Red List category (reductions in extinction risk) owing to conservation. This drove a 67% increase in the value of the Red List Index between 1988 and 2012. This contrasts with a 23% decline in a counterfactual RLI showing projected trends if conservation had been withdrawn in 1988. For organizations that target sets of species with circumscribed geographic distributions and that are regularly assessed by the IUCN Red List, the RLI is a useful indicator for measuring and demonstrating long-term conservation impact to technical and non-technical audiences.
[Show abstract][Hide abstract] ABSTRACT: The world's governments have committed to preventing the extinction of threatened species and improving their conservation status by 2020. However, biodiversity is not evenly distributed across space, and neither are the drivers of its decline, and so different regions face very different challenges. Here, we quantify the contribution of regions and countries towards recent global trends in vertebrate conservation status (as measured by the Red List Index), to guide action towards the 2020 target. We found that>50% of the global deterioration in the conservation status of birds, mammals and amphibians is concentrated in <1% of the surface area, 39/1098 ecoregions (4%) and eight/195 countries (4%) - Australia, China, Colombia, Ecuador, Indonesia, Malaysia, Mexico, and the United States. These countries hold a third of global diversity in these vertebrate groups, partially explaining why they concentrate most of the losses. Yet, other megadiverse countries - most notably Brazil (responsible for 10% of species but just 1% of deterioration), plus India and Madagascar - performed better in conserving their share of global vertebrate diversity. Very few countries, mostly island nations (e.g. Cook Islands, Fiji, Mauritius, Seychelles, and Tonga), have achieved net improvements. Per capita wealth does not explain these patterns, with two of the richest countries - United States and Australia - fairing conspicuously poorly. Different countries were affected by different combinations of threats. Reducing global rates of biodiversity loss will require investment in the regions and countries with the highest responsibility for the world's biodiversity, focusing on conserving those species and areas most in peril and on reducing the drivers with the highest impacts.
PLoS ONE 11/2014; 9(11):e113934. DOI:10.1371/journal.pone.0113934 · 3.23 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: Recognizing the imperiled status of biodiversity and its benefit to human well-being, the world's governments committed in 2010 to take effective and urgent action to halt biodiversity loss through the Convention on Biological Diversity's “Aichi Targets”. These targets, and many conservation programs, require monitoring to assess progress toward specific goals. However, comprehensive and easily understood information on biodiversity trends at appropriate spatial scales is often not available to the policy makers, managers, and scientists who require it. We surveyed conservation stakeholders in three geographically diverse regions of critical biodiversity concern (the Tropical Andes, the African Great Lakes, and the Greater Mekong) and found high demand for biodiversity indicator information but uneven availability. To begin to address this need, we present a biodiversity “dashboard” – a visualization of biodiversity indicators designed to enable tracking of biodiversity and conservation pe
PLoS ONE 11/2014; 9(11-11):e112046. DOI:10.1371/journal.pone.0112046 · 3.23 Impact Factor