Showing papers in "Global Ecology and Biogeography in 2018"

Bio-ORACLE v2.0: Extending marine data layers for bioclimatic modelling

Abstract: Motivation: The availability of user-friendly, high-resolution global environmental datasets is crucial for bioclimatic modelling. For terrestrial environments, WorldClim has served this purpose since 2005, but equivalent marine data only became available in 2012, with pioneer initiatives like Bio-ORACLE providing data layers for several ecologically relevant variables. Currently, the available marine data packages have not yet been updated to the most recent Intergovernmental Panel on Climate Change (IPCC) predictions nor to present times, and are mostly restricted to the top surface layer of the oceans, precluding the modelling of a large fraction of the benthic diversity that inhabits deeper habitats. To address this gap, we present a significant update of Bio-ORACLE for new future climate scenarios, present-day conditions and benthic layers (near sea bottom). The reliability of data layers was assessed using a cross-validation framework against in situ quality-controlled data. This test showed a generally good agreement between our data layers and the global climatic patterns. We also provide a package of functions in the R software environment (sdmpredictors) to facilitate listing, extraction and management of data layers and allow easy integration with the available pipelines for bioclimatic modelling. Main types of variable contained: Surface and benthic layers for water temperature, salinity, nutrients, chlorophyll, sea ice, current velocity, phytoplankton, primary productivity, iron and light at bottom. Spatial location and grain: Global at 5 arcmin (c.0.08 degrees or 9.2 km at the equator). Time period and grain: Present (2000-2014) and future (2040-2050 and 2090-2100) environmental conditions based on monthly averages. Major taxa and level of measurement: Marine biodiversity associated with sea surface and epibenthic habitats. Software format: ASCII and TIFF grid formats for geographical information systems and a package of functions developed for R software.

Paintings predict the distribution of species, or the challenge of selecting environmental predictors and evaluation statistics

Abstract: Aim: Species distribution modelling, a family of statistical methods that predicts species distribu- tions from a set of occurrences and environmental predictors, is now routinely applied in many macroecological studies. However, the reliability of evaluation metrics usually employed to validate these models remains questioned. Moreover, the emergence of online databases of environmental variables with global coverage, especially climatic, has favoured the use of the same set of standard predictors. Unfortunately, the selection of variables is too rarely based on a careful examination of the species’ ecology. In this context, our aim was to highlight the importance of selecting ad hoc variables in species distribution models, and to assess the ability of classical evaluation statistics to identify models with no biological realism. Innovation: First, we reviewed the current practices in the field of species distribution modelling in terms of variable selection and model evaluation. Then, we computed distribution models of 509 European species using pseudo-predictors derived from paintings or using a real set of climatic and topographic predictors. We calculated model performance based on the area under the receiver operating curve (AUC) and true skill statistics (TSS), partitioning occurrences into training and test data with different levels of spatial independence. Most models computed from pseudo- predictors were classified as good and sometimes were even better evaluated than models com- puted using real environmental variables. However, on average they were better discriminated when the partitioning of occurrences allowed testing for model transferability. Main conclusions: These findings confirm the crucial importance of variable selection and the inability of current evaluation metrics to assess the biological significance of distribution models. We recommend that researchers carefully select variables according to the species’ ecology and evaluate models only according to their capacity to be transfered in distant areas. Nevertheless, statistics of model evaluations must still be interpreted with great caution.

Global importance of large‐diameter trees

Abstract: Aim: To examine the contribution of large-diameter trees to biomass, stand structure, and species richness across forest biomes. Location: Global. Time period: Early 21st century. Major taxa studied: Woody plants. Methods: We examined the contribution of large trees to forest density, richness and biomass using a global network of 48 large (from 2 to 60 ha) forest plots representing 5,601,473 stems across 9,298 species and 210 plant families. This contribution was assessed using three metrics: the largest 1% of trees >= 1 cm diameter at breast height (DBH), all trees >= 60 cm DBH, and those rank-ordered largest trees that cumulatively comprise 50% of forest biomass. Results: Averaged across these 48 forest plots, the largest 1% of trees >= 1 cm DBH comprised 50% of aboveground live biomass, with hectare-scale standard deviation of 26%. Trees >= 60 cm DBH comprised 41% of aboveground live tree biomass. The size of the largest trees correlated with total forest biomass (r(2) 5.62, p < .001). Large-diameter trees in high biomass forests represented far fewer species relative to overall forest richness (r(2) = 5.45, p < .001). Forests with more diverse large-diameter tree communities were comprised of smaller trees (r(2) = 5.33, p < .001). Lower large-diameter richness was associated with large-diameter trees being individuals of more common species (r(2) =5.17, p=5.002). The concentration of biomass in the largest 1% of trees declined with increasing absolute latitude (r(2) = 5.46, p < .001), as did forest density (r(2) = 5.31, p < .001). Forest structural complexity increased with increasing absolute latitude (r(2) = 5.26, p < .001). Main conclusions: Because large-diameter trees constitute roughly half of the mature forest biomass worldwide, their dynamics and sensitivities to environmental change represent potentially large controls on global forest carbon cycling. We recommend managing forests for conservation of existing large-diameter trees or those that can soon reach large diameters as a simple way to conserve and potentially enhance ecosystem services.

A meta-analysis of nestedness and turnover components of beta diversity across organisms and ecosystems

Abstract: Aim The number of studies investigating the nestedness and turnover components of beta diversity has increased substantially, but our general understanding of the drivers of turnover and nestedness remains elusive. Here, we examined the effects of species traits, spatial extent, latitude and ecosystem type on the nestedness and turnover components of beta diversity. Location Global. Time period 1968–2017. Major taxa studied From bacteria to mammals. Methods From the 99 studies that partition total beta diversity into its turnover and nestedness components, we assembled 269 and 259 data points for the pairwise and multiple site beta-diversity metrics, respectively. Our data covered a broad variation in species dispersal type, body size and trophic position. The data were from freshwater, marine and terrestrial realms, and encompassed geographical areas from the tropics to near polar regions. We used linear modelling as a meta-regression tool to analyse the data. Results Pairwise turnover, multiple site turnover and total beta diversity all decreased significantly with latitude. In contrast, multiple site nestedness showed a positive relationship with latitude. Beta-diversity components did not generally differ among the realms. The turnover component and total beta diversity increased with spatial extent, whereas nestedness was scale invariant for pairwise metrics. Multiple site beta-diversity components did not vary with spatial extent. Surprisingly, passively dispersed organisms had lower turnover and total beta diversity than flying organisms. Body size showed a relatively weak relationship with beta diversity but had important interactions with trophic position, thus also affecting beta diversity via interactive effects. Producers had significantly higher average pairwise turnover and total beta diversity than carnivores. Main conclusions The present results provide evidence that species turnover, being consistently the larger component of total beta diversity, and nestedness are related to the latitude of the study area and intrinsic organismal features. We showed that two beta-diversity components had generally opposing patterns with regard to latitude. We highlight that beta-diversity partition may give additional insights into the underlying causes of spatial variability in biotic communities compared with total beta diversity alone.

BioTIME: A database of biodiversity time series for the Anthropocene

Abstract: Motivation: The BioTIME database contains raw data on species identities and abundances in ecological assemblages through time. These data enable users to calculate temporal trends in biodiversity within and amongst assemblages using a broad range of metrics. BioTIME is being developed as a community-led open-source database of biodiversity time series. Our goal is to accelerate and facilitate quantitative analysis of temporal patterns of biodiversity in the Anthropocene.Main types of variables included: The database contains 8,777,413 species abundance records, from assemblages consistently sampled for a minimum of 2 years, which need not necessarily be consecutive. In addition, the database contains metadata relating to sampling methodology and contextual information about each record.Spatial location and grain: BioTIME is a global database of 547,161 unique sampling locations spanning the marine, freshwater and terrestrial realms. Grain size varies across datasets from 0.0000000158 km(2) (158 cm(2)) to 100 km(2) (1,000,000,000,000 cm(2)).Time period and grainBio: TIME records span from 1874 to 2016. The minimal temporal grain across all datasets in BioTIME is a year.Major taxa and level of measurement: BioTIME includes data from 44,440 species across the plant and animal kingdoms, ranging from plants, plankton and terrestrial invertebrates to small and large vertebrates.

Biotic interactions in species distribution modelling: 10 questions to guide interpretation and avoid false conclusions

Abstract: AIM: Recent studies increasingly use statistical methods to infer biotic interactions from co‐occurrence information at a large spatial scale. However, disentangling biotic interactions from other factors that can affect co‐occurrence patterns at the macroscale is a major challenge. APPROACH: We present a set of questions that analysts and reviewers should ask to avoid erroneously attributing species association patterns to biotic interactions. Our questions relate to the appropriateness of data and models, the causality behind a correlative signal, and the problems associated with static data from dynamic systems. We summarize caveats reported by macroecological studies of biotic interactions and examine whether conclusions on the presence of biotic interactions are supported by the modelling approaches used. FINDINGS: Irrespective of the method used, studies that set out to test for biotic interactions find statistical associations in species’ co‐occurrences. Yet, when compared with our list of questions, few purported interpretations of such associations as biotic interactions hold up to scrutiny. This does not dismiss the presence or importance of biotic interactions, but it highlights the risk of too lenient interpretation of the data. Combining model results with information from experiments and functional traits that are relevant for the biotic interaction of interest might strengthen conclusions. MAIN CONCLUSIONS: Moving from species‐ to community‐level models, including biotic interactions among species, is of great importance for process‐based understanding and forecasting ecological responses. We hope that our questions will help to improve these models and facilitate the interpretation of their results. In essence, we conclude that ecologists have to recognize that a species association pattern in joint species distribution models will be driven not only by real biotic interactions, but also by shared habitat preferences, common migration history, phylogenetic history and shared response to missing environmental drivers, which specifically need to be discussed and, if possible, integrated into models.

Expanding, shifting and shrinking: The impact of global warming on species’ elevational distributions

Abstract: 1Biodiversity Research Centre, University of British Columbia, Vancouver, British Columbia, Canada 2Department of Zoology, University of British Columbia, Vancouver, British Columbia, Canada 3Department of Botany, University of British Columbia, Vancouver, British Columbia, Canada 4School of Marine and Environmental Affairs, University of Washington, Seattle 5Department of Biology, McGill University, Montreal, Quebec, Canada

Traits of lizards of the world: Variation around a successful evolutionary design

Abstract: Lizards form a remarkable radiation of land vertebrates. The basic tetrapod design, of a four‐legged sprawling‐postured ectothermic animal, has been highly successful ever since vertebrates first moved to land. Together with the amniote adaptations for fully terrestrial lives it has set crown group squamates on a path to ecological and evolutionary success since they evolved over 200 million years ago (Evans, 2003; Zheng & Wiens, 2016). Over this time period lizards have diversified into all terrestrial habitats except the coldest ones (but see Berman, Bulakhova, Alfimov, & Meshcheryakova, 2016), filling multiple ecological niches, and showing a remarkable array of adaptations. Lizards have repeatedly evolved legless forms (e.g., Brandley, Huelsenbeck, & Wiens, 2008; Gans, 1975), including the hugely successful and highly derived, group of snakes ‐ comprising over a third of the total diversity of squamates (Uetz, 2018). Even without snakes, over 6,650 species of lizards (here including the amphisbaenians) are nowadays recognized (Uetz, 2018), and about 120 new forms are added to the list yearly (Meiri, 2016). This makes lizards more species rich than all of the Mammalia (6,369 species, with 83 species on average, added per year since 2005; Burgin, Colella, Kahn, & Upham, 2018). This extraordinary radiation has made lizards a highly studied model system for evolutionary (e.g., Gamble, Greenbaum, Jackman, Russell, & Bauer, 2016; Losos, 2009; Losos, Jackman, Larson, Queiroz, & Rodriguez‐Schettino, 2009; Rabosky, Donnellan, Talaba, Received: 21 June 2017 | Revised: 13 May 2018 | Accepted: 22 May 2018 DOI: 10.1111/geb.12773

Biome stability in South America over the last 30 kyr: Inferences from long-term vegetation dynamics and habitat modelling

Abstract: Center for Environmental Complexity Synthesis; Conselho Nacional de Pesquisa Cientifica, Grant/Award Number: 563352/ 2010-8, 302297/2015-4, 201413/2014-0, 563352/2010–8, 374307/2012-1, 401342/2012-3 and 475559/2013-4; Coordenac~ao de Aperfeicoamento de Pessoal de Nivel Superior, Grant/Award Number: PVE 018/2012; National Science Foundation, Grant/Award Number: DEB 1035184, 1343578; U.S. National Academy of Sciences and U.S. Agency of International Development, Grant/Award Number: PEER NAS/USAID PGA2000005316

Phylogenetic scale in ecology and evolution

Abstract: AIM: Many important patterns and processes vary across the phylogeny and depend on phylogenetic scale. Nonetheless, phylogenetic scale has never been formally conceptualized, and its potential remains largely unexplored. Here, we formalize the concept of phylogenetic scale, review how phylogenetic scale has been considered across multiple fields and provide practical guidelines for the use of phylogenetic scale to address a range of biological questions. INNOVATION: We summarize how phylogenetic scale has been treated in macroevolution, community ecology, biogeography and macroecology, illustrating how it can inform, and possibly resolve, some of the longstanding controversies in these fields. To promote the concept empirically, we define phylogenetic grain and extent, scale dependence, scaling and the domains of phylogenetic scale. We illustrate how existing phylogenetic data and statistical tools can be used to investigate the effects of scale on a variety of well‐known patterns and processes, including diversification rates, community structure, niche conservatism or species‐abundance distributions. MAIN CONCLUSIONS: Explicit consideration of phylogenetic scale can provide new and more complete insight into many longstanding questions across multiple fields (macroevolution, community ecology, biogeography and macroecology). Building on the existing resources and isolated efforts across fields, future research centred on phylogenetic scale might enrich our understanding of the processes that together, but over different scales, shape the diversity of life.

Response of soil microbial communities to altered precipitation: A global synthesis

Abstract: Aim: Climate change intensifies the hydrological cycle and consequently alters precipitation regimes. Accurately assessing future carbon (C) budgets depends on understanding the influence of altered precipitation on both aboveground C cycling and belowground processes. Our goal was to explore generalities and mechanisms of responses of soil microbial communities to altered precipitation and implications for C cycling in terrestrial ecosystems.

Effects of forest degradation on microbial communities and soil carbon cycling: A global meta-analysis

Abstract: Results: Forest degradation decreased the ratios of K-strategists to r-strategists (i.e., ratios of fungi to bacteria, Acidobacteria to Proteobacteria, Actinobacteria to Bacteroidetes and Acidobacteria1Actinobacteria to Proteobacteria1Bacteroidetes). The response ratios (RRs) of the K-strategist to r-strategist ratios to forest degradation decreased and increased with increased RRs of soil pH and soil C to nitrogen ratio (C:N), respectively. Forest degradation increased the bacterial alpha-diversity indexes, of which the RRs increased and decreased as the RRs of soil pH and soil C:N increased, respectively. The overall RRs across all the forest degradation types ranked as microbial C (240.4%)> soil C (233.3%)>microbial respiration (218.9%)>microbial C to soil C ratio (qMBC;215.9%), leading to the RRs of microbial respiration rate per unit microbial C (qCO2) and soil C decomposition rate (respiration rate per unit soil C), on average, increasing by 143.2 and 125.0%, respectively. Variances of the RRs of qMBC and qCO2 were significantly explained by the soil C, soil C:N andmean annual precipitation.

Salvage logging in the world's forests: Interactions between natural disturbance and logging need recognition

Abstract: Aim: Large disturbances increasingly shape the world's forests. Concomitantly, increasing amounts of forest are subject to salvage logging. Understanding and managing the world's forests thus increasingly hinges upon understanding the combined effects of natural disturbance and logging disturbance, including interactions so far unnoticed. Here, we use recent advances in disturbance-interaction theory to disentangle and describe the mechanisms through which natural disturbance (e.g., wildfire, insect outbreak or windstorm) can interact with anthropogenic disturbance (logging) to produce unanticipated effects. We also explore to what extent such interactions have been addressed in empirical research globally. Insights: First, many ecological responses to salvage logging likely result from interaction modifications-i.e., from non-additive effects-between natural disturbance and logging. However, based on a systematic review encompassing 209 relevant papers, we found that interaction modifications have been largely neglected. Second, salvage logging constitutes an interaction chain because natural disturbances increase the likelihood, intensity and extent of subsequent logging disturbance due to complex socio-ecological interactions. Both interaction modifications and interaction chains can be driven by nonlinear responses to the severity of each disturbance. We show that, whereas many of the effects of salvage logging likely arise from the multiple kinds of disturbance interactions between natural disturbance and logging, they have mostly been overlooked in research to date. Conclusions: Interactions between natural disturbance and logging imply that increasing disturbances will produce even more disturbance, and with unknown characteristics and consequences. Disentangling the pathways producing disturbance interactions is thus crucial to guide management and policy regarding naturally disturbed forests.

The sedimentary and remote-sensing reflection of biomass burning in Europe

Abstract: Aim: We provide the first European-scale geospatial training set relating the charcoal signal in surface lake sediments to fire parameters (number, intensity and area) recorded by satellite moderat ...

Habitat suitability estimated by niche models is largely unrelated to species abundance

Abstract: Understanding the climatic conditions that enable species persistence is a central goal in ecology, and numerous statistical techniques have been developed to understand and forecast species geographic distributions based on climatic conditions (Drake, 2015; Elith & Leathwick, 2009; Phillips & Dudík, 2008). These models – commonly referred to as species distribution models or niche models (Peterson & Soberón, 2012) – attempt to estimate species occurrence probabilities or habitat suitability based on presence (and Received: 7 December 2017 | Revised: 5 July 2018 | Accepted: 18 July 2018 DOI: 10.1111/geb.12820

Climate and soils together regulate photosynthetic carbon isotope discrimination within C3 plants worldwide

Abstract: Aim: Within C3 plants, photosynthesis is a balance between CO2 supply from the atmosphere via stomata and demand by enzymes within chloroplasts. This process is dynamic and a complex but crucial aspect of photosynthesis. We sought to understand the spatial pattern in CO2 supply–demand balance on a global scale, via analysis of stable isotopes of carbon within leaves (Δ13C), which provide an integrative record of CO2 drawdown during photosynthesis. Location: Global Time period: 1951–2011. Major taxa studied: Vascular plants. Methods: We assembled a database of leaf carbon isotope ratios containing 3,979 species–site combinations from across the globe, including 3,645 for C3 species. We examined a wide array of potential climate and soil drivers of variation in Δ13C. Results: The strongest drivers of carbon isotope discrimination at the global scale included atmospheric pressure, potential evapotranspiration and soil pH, which explained 44% of the variation in Δ13C. Addition of eight more climate and soil variables (each explaining small but highly significant amounts of variation) increased the explained variation to 60%. On top of this, the largest plant trait effect was leaf nitrogen per area, which explained 11% of Δ13C variation. Main conclusions: By considering variation in Δ13C at a considerably larger scale than previously, we were able to identify and quantify key drivers in CO2 supply–demand balance previously unacknowledged. Of special note is the key role of soil properties, with greater discrimination on low‐pH and high‐silt soils. Unlike other plant traits, which show typically wide variation within sets of coexisting species, the global pattern in carbon stable isotope ratios is much more conservative; there is relatively narrow variation in time‐integrated CO2 concentrations at the site of carboxylation among plants in a given soil and climate.

Pan-tropical prediction of forest structure from the largest trees

Abstract: Aim Large tropical trees form the interface between ground and airborne observations, offering a unique opportunity to capture forest properties remotely and to investigate their variations on broad scales. However, despite rapid development of metrics to characterize the forest canopy from remotely sensed data, a gap remains between aerial and field inventories. To close this gap, we propose a new pan-tropical model to predict plot-level forest structure properties and biomass from only the largest trees. Location Time period Pan-tropical. Early 21st century. Major taxa studied Methods Woody plants. Using a dataset of 867 plots distributed among 118 sites across the tropics, we tested the prediction of the quadratic mean diameter, basal area, Lorey's height, community wood density and aboveground biomass (AGB) from the ith largest trees. Results Main conclusions Measuring the largest trees in tropical forests enables unbiased predictions of plot- and site-level forest structure. The 20 largest trees per hectare predicted quadratic mean diameter, basal area, Lorey's height, community wood density and AGB with 12, 16, 4, 4 and 17.7% of relative error, respectively. Most of the remaining error in biomass prediction is driven by differences in the proportion of total biomass held in medium-sized trees (50-70 cm diameter at breast height), which shows some continental dependency, with American tropical forests presenting the highest proportion of total biomass in these intermediate-diameter classes relative to other continents. Our approach provides new information on tropical forest structure and can be used to generate accurate field estimates of tropical forest carbon stocks to support the calibration and validation of current and forthcoming space missions. It will reduce the cost of field inventories and contribute to scientific understanding of tropical forest ecosystems and response to climate change.

Historical cropland expansion and abandonment in the continental U.S. during 1850 to 2016

Abstract: AIM: Land use and land cover changes (LCLUC) are among the most important driving forces that alter terrestrial ecosystem functions and their feedbacks to climate systems, but reliable, spatially explicit datasets over century‐long periods are still lacking for fine‐scale earth system modeling. We aimed to combine multiple data sources and reconstruct long‐term land use history in the continental U.S., examining cropland expansion and abandonment since 1850. LOCATION: Conterminous U.S. TIME PERIOD: 1850 to 2016. MAJOR TAXA STUDIED: Cropland. METHODS: Cropland density maps, displaying the distribution and percentage of cultivated land each year (excluding summer idle/fallow, cropland pasture), were reconstructed by harmonizing multiple sources of inventory data and high‐resolution satellite images. The cropland data are freely available to the public. RESULTS: In total, national cropland expansion was 104 million hectares (Mha) from 1850 to 2016 and peaked at about 127 Mha in 1920. Forests and shrublands were the dominant land cover types that croplands were converted from during 1850 to 1880, which may be primarily attributed to agriculture development in the northeast U.S. Croplands began to expand into grasslands from 1870 onwards and the encroached area dramatically increased, mainly due to cultivation development in the Great Plain and midwestern areas. In comparison, the area of abandoned cropland in the U.S. was 65 Mha during the study period. We found cropland abandonment mostly occurred in the central and southeast U.S., while cropland expansion was centered upon the midwestern states, central California, and the Mississippi Alluvial Plain. MAIN CONCLUSIONS: Nationally, cultivated lands shifted from the eastern to midwestern U.S. during the study period, contributing to the increasingly important role of the Midwest in the rise of food and biofuel production, enhanced greenhouse gas (GHG) emissions, and high nitrogen loads into the Gulf of Mexico. Our cropland database is essential for modeling assessments of LCLUC impacts, crop production estimation and socioeconomic analysis.

Global patterns of Rhododendron diversity: The role of evolutionary time and diversification rates

Abstract: Institute of Ecology and Key Laboratory for Earth Surface Processes of the Ministry of Education, College of Urban and Environmental Sciences, Peking University, Beijing, China Center for Macroecology, Evolution and Climate, Natural History Museum of Denmark, University of Copenhagen, Copenhagen, Denmark College of Life Science, Sichuan University, Chengdu, China School of Urban Planning and Design, Shenzhen Graduate School, Peking University, Shenzhen, China Natural History Museum, University of Oslo, Oslo, Norway State Key Laboratory of Vegetation and Environmental Change, Institute of Botany, Chinese Academy of Sciences, Beijing, China

Using tree species inventories to map biomes and assess their climatic overlaps in lowland tropical South America

Abstract: Aim: To define and map the main biomes of lowland tropical South America (LTSA) using data from tree species inventories and to test the ability of climatic and edaphic variables to distinguish amongst them. Location: Lowland Tropical South America (LTSA), including Argentina, Bolivia, Brazil, Ecuador, Paraguay, Peru and Uruguay. Time period: Present. Major taxa studied: Trees. Methods: We compiled a database of 4,103 geo‐referenced tree species inventories distributed across LTSA. We used a priori vegetation classifications and cluster analyses of floristic composition to assign sites to biomes. We mapped these biomes geographically and assessed climatic overlaps amongst them. We implemented classification tree approaches to quantify how well climatic and edaphic data can assign inventories to biomes. Results: Our analyses distinguish savanna and seasonally dry tropical forest (SDTF) as distinct biomes, with the Chaco woodlands potentially representing a third dry biome in LTSA. Amongst the wet forests, we find that the Amazon and Atlantic Forests might represent different biomes, because they are distinct in both climate and species composition. Our results show substantial environmental overlap amongst biomes, with error rates for classifying sites into biomes of 19–21 and 16–18% using only climatic data and with the inclusion of edaphic data, respectively. Main conclusions: Tree species composition can be used to determine biome identity at continental scales. We find high biome heterogeneity at small spatial scales, probably attributable to variation in edaphic conditions and disturbance history. This points to the challenges of using climatic and/or interpolation‐based edaphic data or coarse‐resolution, remotely sensed imagery to map tropical biomes. From this perspective, we suggest that using floristic information in biome delimitation will allow for greater synergy between conservation efforts centred on species diversity and management efforts centred on ecosystem function.

Vegetation cover of Brazil in the last 21 ka: New insights into the Amazonian refugia and Pleistocenic arc hypotheses

Abstract: Aim The two main hypotheses about the Neotropical palaeovegetation, namely that of Amazonian refugia by Haffer and of the Pleistocene arc by Prado and Gibbs, are still constantly debated. We offer new insights on this debate using ecological niche modelling with combined climate–soil predictors to test both hypotheses, reconstruct the palaeovegetation of the Last Glacial Maximum (LGM; 21 ka) and Mid-Holocene (Mid-H; 6 ka) and indicate the configuration of refugia areas. Location Brazil. Time period Last 21 ka. Major taxa studied Biomes. Methods We modelled the environmental space of the 10 most representative biomes with the RandomForest classifier, using climate predictors from three atmospheric general circulation models (CCSM4, MPI-ESM-P and MIROC-ESM) and soil predictors, the same for the different situations. Based on the consensus among the models, we reconstructed the palaeovegetation cover for LGM and Mid-H and used fossil pollen sites to validate the reconstructions in a direct comparison. Results The climate in the past was cooler and wetter throughout most of the territory. The Amazon basin region was the most affected by climate change in the last 21 ka, with equatorial rain forest retracting to refugia areas, while the tropical rain forest (with climatic preferences similar to the Atlantic forest) expanded in the basin. In southern Brazil, the mixed forest (Araucaria forest) shifted to lower latitudes, while the grasslands expanded. In most biomes, the greatest changes occurred in the ecotonal zones, supported by pollen fossils. Main conclusions With regard to Haffer's hypothesis, the forests of the Amazonian lowlands retreated to refugia areas, while the colder and wetter climate of the basin created a favourable niche for another type of forest, instead of savanna. The advance of dry vegetation was restricted to ecotonal conditions, preventing the formation of a continuous Pleistocene arc, predicted by Prado and Gibbs's hypothesis.

Spatial and species‐level predictions of road mortality risk using trait data

Abstract: Aim: Wildlife-vehicle collisions are recognized as one of the major causes of mortality for many species. Empirical estimates of road mortality show that some species are more likely to be killed than others but to what extend this variation can be explained and predicted using intrinsic species characteristics remains poorly understood. This study aims to identify general macroecological patterns associated to road mortality and generate spatial and species-level predictions of risks. Location: Brazil Time period: 2001-2014 Major taxa: Birds and mammals Methods: We fitted trait-based random forest regression models (controlling for survey characteristics) to explain 783 empirical road mortality rates from Brazil, representing 170 bird and 73 mammalian species. Fitted models were then used to make spatial and species-level prediction of road mortality risk in Brazil considering 1775 birds and 623 mammals which occur within the country’s continental boundaries. Results: Survey frequency and geographic location were key predictors of observed rates, but mortality was also explained by species’ body size, reproductive speed and ecological specialization. Spatial predictions revealed high potential standardized (per km road) mortality risk in Amazonia for birds and mammals, and additionally high risk in Southern Brazil for mammals. Given the existing road network, these predictions mean more than 8 million birds and 2 million mammals could be killed per year in Brazilian roads. Furthermore, predicted rates for all Brazilian endotherm uncovered potential vulnerability to road mortality of several understudied species which are currently listed as threatened by the IUCN. Conclusion: With a fast-expanding global road network, there is an urgent need to develop improved approaches to assess and predict road-related impacts. This study illustrates the potential of trait-based models as assessment tools to better understand correlates of vulnerability to road mortality across species, and as predictive tools for difficult to sample or understudied species and areas.

Soil biodiversity and soil erosion: It is time to get married

Abstract: AIM: The relationship between erosion and biodiversity is reciprocal. Soil organisms can both reduce soil loss, by improving porosity, and increase it, by diminishing soil stability as a result of their mixing activities. Simultaneously, soil runoff has ecological impacts on belowground communities. Despite clear research into interactions, soil erosion models do not consider biodiversity in their estimates and soil ecology has poorly investigated the effects of erosion. In order to start filling in these research gaps, we present a novel biological factor and introduce it into a well‐known soil erosion model (the revised universal soil loss equation). Furthermore, we propose insights to advance soil erosion ecology. LOCATION: Pan‐European. TIME PERIOD: Simulation of present‐day conditions. MAJOR TAXA STUDIED: Earthworms. METHODS: We present three pathways to fill in current knowledge gaps in soil biodiversity and erosion studies: (a) introducing a biological factor into soil erosion models; (b) developing plot‐scale experiments to clarify and quantify the positive/negative effects of soil organisms on erosion; (c) promoting ecological studies to assess both short‐ and long‐term effects of soil erosion on soil biota. RESULTS: We develop a biological factor to be included in soil erosion modelling. Thanks to available data on earthworm diversity (richness and abundance), we generate an “earthworm factor”, incorporate it into a model of soil erosion and produce the first pan‐European maps of it. MAIN CONCLUSIONS: New estimates of soil loss can be generated by including biological factors in soil erosion models. At the same time, the effects of soil loss on belowground diversity require further investigation. Available data and technologies make both processes possible. We think that it is time to commit to fostering the fundamental, although complex, relationship between soil biodiversity and erosion.

Global drivers of population density in terrestrial vertebrates

Abstract: Department of Environmental Science, Institute for Water and Wetland Research, Radboud University, Nijmegen, The Netherlands Centre for Ecology & Hydrology, Crowmarsh Gifford, Wallingford, United Kingdom Department of Biology and Biotechnologies, Sapienza Universit!a di Roma, Rome, Italy Integrative Marine Ecology Department, ‘A. Dohrn’ Zoological Station, Naples, Italy Departement of Environmental Science and Policy, Universit!a degli Studi di Milano, Milano, Italy Laboratoire d’Ecologie Alpine (LECA), CNRS, Universit\" e Grenoble Alpes, Grenoble, France PBL Netherlands Environmental Assessment Agency, The Hague, The Netherlands Institute of Zoology, Zoological Society of London, London, United Kingdom

Creating individual accessible area hypotheses improves stacked species distribution model performance

Abstract: Correspondence Jacob C. Cooper, University of Kansas Biodiversity Institute and Department of Ecology and Evolutionary Biology, 1345 Jayhawk Boulevard, Lawrence, KS 66045, USA. Email: jccooper@uchicago.edu Present address Jacob C. Cooper, Committee on Evolutionary Biology, The University of Chicago, Culver Hall 402, Chicago, IL 60637, USA and Life Sciences Section, Integrative Research Center, The Field Museum, 1400 South Lake Shore Drive, Chicago, IL 60605, USA.