Ben G. Holt, Gabriel C. Costa, Caterina Penone, Jean-Philippe Lessard, Thomas M. Brooks, Ana D. Davidson, S. Blair Hedges, Volker C. Radeloff, Carsten Rahbek, Carlo Rondinini, Catherine H. Graham
To evaluate how environment and evolutionary history interact to influence global patterns of mammal trait diversity (a combination of 14 morphological and life-history traits). We calculated patterns of spatial turnover for mammalian traits and phylogenetic lineages using the mean nearest taxon distance. We then used a variance partitioning approach to establish the relative contribution of trait conservatism, ecological adaptation and clade specific ecological preferences on global trait turnover.
We provide a global scale analysis of trait turnover across mammalian terrestrial assemblages, which demonstrates that phylogenetic turnover by itself does not predict trait turnover better than random expectations. Conversely, trait turnover is consistently more strongly associated with environmental variation than predicted by our null models. The influence of clade-specific ecological preferences, reflected by the shared component of phylogenetic turnover and environmental variation, was considerably higher than expectations. Although global patterns of trait turnover are dependent on the trait under consideration, there is a consistent association between trait turnover and environmental predictive variables, regardless of the trait considered.
Our results suggest that changes in phylogenetic composition are not always coupled with changes in trait composition on a global scale and that environmental conditions are strongly associated with patterns of trait composition across species assemblages, both within and across phylogenetic clades.
Michela Pacifici, Piero Visconti and Carlo Rondinini
As rates of global warming increase rapidly, identifying species at risk of decline due to climate impacts and the factors affecting this risk have become key challenges in ecology and conservation biology. Here we present a framework for assessing three components of climate-related risk for species: vulnerability, exposure and hazard. We used the relationship between the observed response of species to climate change and a set of intrinsic traits (e.g., weaning age) and extrinsic factors (e.g., precipitation seasonality within a species geographic range) to predict, respectively, the vulnerability and exposure of all data-sufficient terrestrial non-volant mammals (3953 species). Combining this information with hazard (the magnitude of projected climate change within a species geographic range) we identified global hotspots of species at risk from climate change that includes the western Amazon basin, south-western Kenya, north-eastern Tanzania, north-eastern South Africa, Yunnan province in China, and mountain chains in Papua-New Guinea. Our framework identifies priority areas for monitoring climate change effects on species and directing climate mitigation actions for biodiversity.
Fernanda T. Bruma, Catherine H. Graham, Gabriel C. Costa, S. Blair Hedges, Caterina Penone, Volker C. Radeloff, Carlo Rondinini, Rafael Loyola, and Ana D. Davidsonc
Conservation priorities that are based on species distribution, endemism, and vulnerability may underrepresent biologically unique species as well as their functional roles and evolutionary histories. To ensure that priorities are biologically comprehensive, multiple dimensions of diversity must be considered. Further, understanding how the different dimensions relate to one another spatially is important for conservation prioritization, but the relationship remains poorly understood. Here, we use spatial conservation planning to (i) identify and compare priority regions for global mammal conservation across three key dimensions of biodiversity—taxonomic, phylogenetic, and traits—and (ii) determine the overlap of these regions with the locations of threatened species and existing protected areas. We show that priority areas for mammal conservation exhibit low overlap across the three dimensions, highlighting the need for an integrative approach for biodiversity conservation. Additionally, currently protected areas poorly represent the three dimensions of mammalian biodiversity. We identify areas of high conservation priority among and across the dimensions that should receive special attention for expanding the global protected area network. These high-priority areas, combined with areas of high priority for other taxonomic groups and with social, economic, and political considerations, provide a biological foundation for future conservation planning efforts.Conservation priorities that are based on species distribution, endemism, and vulnerability may underrepresent biologically unique species as well as their functional roles and evolutionary histories. To ensure that priorities are biologically comprehensive, multiple dimensions of diversity must be considered. Further, understanding how the different dimensions relate to one another spatially is important for conservation prioritization, but the relationship remains poorly understood. Here, we use spatial conservation planning to (i) identify and compare priority regions for global mammal conservation across three key dimensions of biodiversity—taxonomic, phylogenetic, and traits—and (ii) determine the overlap of these regions with the locations of threatened species and existing protected areas. We show that priority areas for mammal conservation exhibit low overlap across the three dimensions, highlighting the need for an integrative approach for biodiversity conservation. Additionally, currently protected areas poorly represent the three dimensions of mammalian biodiversity. We identify areas of high conservation priority among and across the dimensions that should receive special attention for expanding the global protected area network. These high-priority areas, combined with areas of high priority for other taxonomic groups and with social, economic, and political considerations, provide a biological foundation for future conservation planning efforts.
Kevin R. Crooks, Christopher L. Burdett, David M. Theobald, Sarah R. B. King, Moreno Di Marco, Carlo Rondinini, and Luigi Boitani
Although habitat fragmentation is often assumed to be a primary driver of extinction, global patterns of fragmentation and its relationship to extinction risk have not been consistently quantified for any major animal taxon. We developed high-resolution habitat fragmentation models and used phylogenetic comparative methods to quantify the effects of habitat fragmentation on the world’s terrestrial mammals, including 4,018 species across 26 taxonomic Orders. Results demonstrate that species with more fragmentation are at greater risk of extinction, even after accounting for the effects of key macroecological predictors, such as body size and geographic range size. Species with higher fragmentation had smaller ranges and a lower proportion of high-suitability habitat within their range, and most high-suitability habitat occurred outside of protected areas, further elevating extinction risk. Our models provide a quantitative evaluation of extinction risk assessments for species, allow for identification of emerging threats in species not classified as threatened, and provide maps of global hotspots of fragmentation for the world’s terrestrial mammals. Quantification of habitat fragmentation will help guide threat assessment and strategic priorities for global mammal conservation.
Luca Santini, Manuela González-Suárez, Carlo Rondinini and Moreno Di Marco
Human activities have led to hundreds of species extinctions and have narrowed the distribution of many of the remaining species. These changes influence our understanding of global macroecological patterns, but their effects have been rarely explored. One of these patterns, the Bergmann’s rule, has been largely investigated in macroecology, but often under the assumption that observed patterns reflect “natural” processes. We assessed the extent to which humans have re-shaped the observable patterns of body mass distribution in terrestrial mammals, and how this has altered the macroecological baseline.
Using a comprehensive set of ecological, climatic and anthropogenic variables, we tested several alternative hypotheses to explain the body mass pattern observed in terrestrial mammals’ assemblages at a one-degree resolution. We then explored how model predictions and the Bergmann’s latitudinal pattern are affected by the inclusion of human impact variables and identified areas where predicted body mass differs from the expected due to human impact.
Our model suggests that median and maximum body mass predicted in grid cells would be higher, and skewness in local mass distributions reduced, if human impacts were minimal, especially in areas that are highly accessible to humans and where natural land cover has been converted for human activities.
Our study provides evidence of the pervasive effects of anthropogenic impact on nature and shows human-induced distortion of global macroecological patterns. This extends the notion of “shifting baseline”, suggesting that when the first macroecological investigations started, our understanding of global geographic patterns was based on a situation which was already compromised. While in the short term human impact is causing species decline and extinction, in the long term, it is causing a broad re-shaping of animal communities with yet unpredicted ecological implications.
Michela Pacifici, Piero Visconti, Stuart Butchart, James Watson, Francesca Cassola, Carlo Rondinini
The paper ‘Species traits influenced their response to recent climate change’ has just been published in the journal Nature Climate Change.
The study reviews the observed impacts of climate change on birds and mammals and aims to identify the relationships between their response to climate change and a set of selected intrinsic traits and spatial factors, based on a total of 70 studies covering 120 mammal species and 66 studies relating to 569 bird species whose populations had (or sought evidence for) a response to climate change in recent decades.
The authors found evidence of observed responses to recent changes in climate for almost 700 species, but only 7% of mammals and 4% of birds that showed a negative response are coded on the IUCN Red List of Threatened Species as threatened by ‘climate change and severe weather’ under the ‘threats classification scheme’.
Mammals most at risk from climate change are not fossorial, and have low precipitation seasonality within their distributions. For birds, negative responses in both breeding and non-breeding areas were generally observed in species that live at high altitudes, and have low temperature seasonality within their distributions. In addition, large changes in temperature in the last decades negatively affected both mammals and birds.
According to predictions, it is likely that for 47% of threatened mammals and 23% of threatened birds at least one population has already responded negatively to climate change. “This implies that, in the presence of adverse environmental conditions, populations of these species have a high probability of being negatively impacted also by future climatic changes” says lead author Dr. Michela Pacifici at Sapienza University of Rome. The lab is partner of the IUCN Red List with the Global Mammal Assessment Program.
The list of charismatic species likely to have been negatively impacted include the snow leopard, the cheetah, the Bornean orangutan, both species of elephants, the western and eastern gorillas, the Javan, Sumatran and black rhinos among mammals, and the Fiordland crested penguin, the Spanish eagle and the Steller’s eider among birds.
By making predictions on the species for which the levels of climatic hazard experienced are known, the authors provide the first quantification of the number of taxa that may have already been impacted, and also validate trait-based vulnerability assessments. The results of this work suggest that the impact of climate change on mammals and birds in the recent past is currently greatly underappreciated, and this may have important implications for both the scientific community and intergovernmental policy fora.
“Solid evidence is accumulating that climate change has already affected some species, but not others. Based on this evidence, we identify the traits that can help species cope with change, or doom them to decline and endangerment” says lead Dr. Carlo Rondinini, coordinator of the Global Mammal Assessment Program at Sapienza University of Rome. “Our conclusion is that many more species not yet affected may be threatened by climate change in the near future”.
SharedIt link to access a view-only version of ther paper http://rdcu.be/pd2w
Brett R. Scheffers, Luc De Meester, Tom C. L. Bridge, Ary A. Hoffmann, John M. Pandolfi, Richard T. Corlett, Stuart H.M. Butchart, Paul Pearce-Kelly, Kit M. Kovacs, David Dudgeon, Michela Pacifici, Carlo Rondinini, Wendy B. Foden, Tara G. Martin, Camilo Mora, David Bickford, James, E.M. Watson.
Climate change impacts have now been documented across every ecosystem on Earth, despite an average warming of only ~1°C so far. Here, we describe the full range
and scale of climate change effects on global biodiversity that have been observed in natural systems. To do this, we identify a set of core ecological processes (32 in terrestrial and 31 each in marine and freshwater ecosystems) that underpin ecosystem functioning and support services to people. Of the 94 processes considered, 82% show evidence of impact from climate change in the peer-reviewed literature. Examples of observed impacts from metaanalyses and case studies go beyond wellestablished shifts in species ranges and changes to phenology and population dynamics to include disruptions that scale from the gene to the ecosystem.
Luca Santini, Santiago Saura & Carlo Rondinini
One of the biggest challenges in large-scale conservation is quantifying connectivity at broad geographic scales and for a large set of species. Because connectivity analyses can be computationally intensive, and the planning process quite complex when multiple taxa are involved, assessing connectivity at large spatial extents for many species turns to be often intractable. Such limitation results in that conducted assessments are often partial by focusing on a few key species only, or are generic by considering a range of dispersal distances and a fixed set of areas to connect that are not directly linked to the actual spatial distribution or mobility of particular species. By using a graph theory framework, here we propose an approach to reduce computational effort and effectively consider large assemblages of species in obtaining multi-species connectivity priorities. We demonstrate the potential of the approach by identifying defragmentation priorities in the Italian road network focusing on medium and large terrestrial mammals. We show that by combining probabilistic species graphs prior to conducting the network analysis (i) it is possible to analyse connectivity once for all species simultaneously, obtaining conservation or restoration priorities that apply for the entire species assemblage; and that (ii) those priorities are well aligned with the ones that would be obtained by aggregating the results of separate connectivity analysis for each of the individual species. This approach offers great opportunities to extend connectivity assessments to large assemblages of species and broad geographic scales.
Fig 2. (a) Amount of suitable habitat (node weight), (b) Road density (used for obtaining the link weights), (c) restoration priority as given by varPC values (cells where actions to mitigate the barrier effect of roads would yield the highest benefit) according to the cumulative results (sum of individual species restoration priorities), and (d) restoration priority according to the best performing composite network (composite network F).
Jelle P. Hilbers, Luca Santini, Piero Visconti, Aafke M. Schipper, Cecilia Pinto, Carlo Rondinini, and Mark A.J. Huijbregts
Conservation planning and biodiversity assessments need quantitative targets to optimize planning options and assess the adequacy of current species protection. However, targets aiming at persistence require population-specific data, which limits their use in favor of fixed and non-specific targets, likely leading to unequal distribution of conservation efforts among species. Here we propose a method to derive equitable population targets, which are quantitative targets of population size that ensure equal probabilities of persistence across a set of species, and can be easily inferred from species-specific traits. We applied population dynamics models across a range of life-history traits representative for mammals, and estimated minimum viable population targets intrinsically related to species body mass. Our approach provides a compromise between pragmatic non-specific targets, and detailed context-specific estimates of population viability for which only limited data is available. It enables a first estimation of species-specific population targets based on a readily available trait, and thus allows setting equitable targets for population persistence in large-scale and multispecies conservation assessments and planning.