What drives the distribution of global vertebrate biodiversity?

One of the primary questions in ecology is: why is biodiversity distributed heterogeneously across space? Thanks to newly-available data on the distribution, evolutionary relationships, and biological attributes of a multitude of vertebrate species around the globe, we can finally gain a better grasp of this age-old question.

Recent and ongoing projects

  • Are hotspots of species diversity also hotspots of phylogentic and functional diversity? To answer this question, we are exploring the geographical overlap among taxonomic, phylogenetic, and functional diversity in birds and mammals across the globe.
  • Are species being excluded from geographical areas where many other species have similar functional traits? To answer this question, we are examining geographical variation in the functional distinctness of birds across the globe.
  • In addition, we are also concerned with the likely consequences of climate and land use change on the vertebrate biodiversity. Are we likely to lose vast amounts of essential functional diversity and evolutionary history in the future?

Collaborators

Catherine Graham, Ben Weinstein (Stony Brook University), Bruce Young (NatureServe), Thomas Brooks (IUCN), Blair Hedges (Temple University), Carlo Rondinini (Sapienza university Rome), Gabriel Costa (UFRN), Volker Radeloff (University of Wisconsin, Madison)

How have species responded to recent changes in climate?

Climate change is predicted to greatly impact living systems in the coming decades, from single organisms to entire biomes, potentially surpassing habitat loss as the greatest driver of biodiversity change.

Recent and ongoing projects

  • In a recent review, we showed that many responses to climate change in California are inconsistent with expectations based solely on temperature increase; we identified a number of potential direct and indirect mechanisms for these responses. Read paper »
  • We tested whether correlative species distribution models based on climate change provided useful approximations of recently-documented distribution shifts in British vascular plants, birds, and butterflies and found that climate variables did not accurately predict where these taxa had expanded to or retracted from over time. Read paper »
  • Using data from a variety of sources including wildlife surveys, natural history museum and herbaria collections, and climate and hydrology model outputs, we are investigating the impacts of climate change on the distribution of Odonates and the density and physiognomy of forests across California.

Collaborators

Andy Purvis (Grand Challenges in Ecosystems and the Environment, Natural History Museum, Grantham Institute for Climate Change), David Roy (Biological Records Centre), Kevin Walker (Botanical Society of the British Isles), Richard Fox (Butterfly Conservation), Simon Gillings (British Trust for Ornithology); David Ackerly, Steve Beissinger, Sean Maher (Berkeley Inititive in Global Change Biology), Museum of Vertebrate Zoology, Jepson Herbarium, Essig Museum of Entomology

What attributes determine the sensitivity of species to global change?

The magnitude of global environmental change experienced by species over their geographical range alone does not determine how they will respond to such changes. A number of intrinsic factors that reflect the degree to which population persistence and resilience depend on the environment determine how sensitive species are to environmental changes. My research aims to further our understanding of the attributes that make some species more vulnerable and some more resilient to the environmental changes they experience.

Recent and ongoing projects

  • We examined ecological and life-history correlates of range change in the flora of Britain since the 1930s using some of the best plant distribution, trait and phylogenetic data available in Europe. We found that more competitive habitat generalists fared better than habitat specialists and attributed this result to the greater ability of generalists to adapt to environmental perturbation, but also to the negative impacts of agricultural intensification on the flora of Britain. Read paper »
  • We are developing a new framework for prioritising which species should be conserved based on a series of attributes which are informative of their likely vulnerability to environmental change. This new approach incorporates species' evolutionary distinctiveness, the magnitude of their ongoing decline, and the accuracy with which their recent decline can be predicted. We use this approach to find which vascular plants of Britain should become the focus of conservation efforts.

Collaborators

Andy Purvis (Grand Challenges in Ecosystems and the Environment, Natural History Museum, Grantham Institute for Climate Change), Gary Powney, Chris Preston, David Roy (Biological Records Centre); Will Pearse (McGill University)

How accurate are predictions from models of global change impacts?

Climate change is predicted to greatly impact living systems in the coming decades, from single organisms to entire biomes, potentially surpassing habitat loss as the greatest driver of biodiversity change.

Recent and ongoing projects

  • We developed a tool – the temporal validation (TV) plot – specifically aimed at making use of species’ distribution records at two times for a comprehensive assessment of the prediction accuracy of SDMs over time. Together with existing approaches, TV plots and their associated measures offer a simple tool for testing of how well SDMs model species’ observed range changes – perhaps the best way available to assess their ability to predict likely future changes. Read paper » Find code »
  • It is unclear whether predictions of species' probability of presence derived from SDMs relate to fundamental population parameters such as mean population density and stability over time. We tested probability of presence predictions generated from SDMs built using species occupancy data against independent empirical data on population density and stability for 20 bird and butterfly species over 15 years and found that SDM predictions were positively correlated with population density but not stability. Read paper »

Collaborators

Andy Purvis (Grand Challenges in Ecosystems and the Environment, Natural History Museum, Grantham Institute for Climate Change), Tom Oliver, David Roy (Biological Records Centre), Simon Gillings (British Trust for Ornithology)

Integrating and visualizing global change data from various sources

Predicting biotic responses to global environmental change necessitates a holistic understanding of the complex interactions and feedbacks among organisms, climate, and their physical and biotic environments across space and time. This level of understanding can only be achieved through the integration and analysis of diverse data types spanning a range of biological, spatial, and temporal scales.

I am part of the Holos team. Together, we are building a web-based tool to rescue and integrate a wealth of data including specimens in natural history collections, field surveys and observations, aerial and satellite imagery, measurements from environmental sensor networks, and global change model predictions. Holos provides an open, technical infrastructure for researchers and policymakers to explore, visualize, and analyze this wealth of data on global change.