I am a permanent research scientist in the Computational Ecology and Environmental Science Group, a part of the European Science Initiative at Microsoft Research Cambridge.

It is immensely exciting to be an ecologist at a time when society is awakening to the urgency of environmental issues, but society has a tendency to ask important questions of a kind that ecologists are not accustomed to answering.

How, and how quickly, will ecosystems respond to climate change? How does pollution affect biodiversity? Which communities are most vulnerable to ecological invasions?

These questions are simultaneously quantitative, focused on particular species and communities, and are concerned with particular anthropogenic perturbations.

Our current inability to provide rigorous answers to these questions highlights the fundamental questions in ecology that are still awaiting answers.

What determines spatial variation in species composition in ecological communities? What are the dominant life history axes determining diversity at local, regional, and continental scales? Are communities structured primarily by ecological determinism, or neutral processes?

Providing answers to all of these questions – both fundamental and applied – requires the development, parameterization, testing and analysis of quantitative models. This approach is reaching increasing prominence in ecology, and seems especially timely given the increasing availability of the large data sets and computational tools that it requires. My research aims to take a combined theoretical, computational and empirical approach to answer fundamental questions in ecology, with the simultaneous aim of developing models whose predictions can be trusted enough to guide policy. I focus on a number of fundamental questions in plant community ecology, with the majority of my current research time devoted to the regional and continental-scale dynamics of eastern US forests (see below). However, I am keen to collaborate with other scientists to help them develop quantitative models for various other taxa, questions, and scales. For example, current collaborative projects include work on the ecophysiology and growth of annual plants, grasslands and tropical trees; nitrogen fixation in tropical trees; and the climate dependency of fire at global scales.

Current research projects include

Understanding and Predicting Forest Dynamics. Forests harbour around 60% of the world’s biodiversity and around half of its terrestrial carbon, so there is an urgent need to predict how forests will respond to continuing anthropogenic perturbations including increased atmospheric CO2, logging and land-use change. A new toolbox of techniques for understanding forests -- consisting of new kinds of simulation models, new analystical techniques for understanding the models, and new statistical techniques for parameterizing the models using widely-available inventory data -- is beginning to deliver a fundamentally new, quantitative and predictive level of understanding of how forests work.

Using 25 Years of Infra-red Satellite Data to Derive a New Global Fire Model. The future of terrestrial carbon will be determined by the inputs and outputs of carbon to and from ecosystems, one of which – fire – is particularly poorly understood at global scales. This collaboration will process a large amount of infra-red satellite data to create a global, monthly time-scale map of carbon fluxes due to fire; and use these data to parameterize a new global fire model for use in Earth system models.

Data-constrained Simulation Modelling of Plant Growth. Plant communities may act to amplify, or dampen, changes in the Earth’s climate system caused by anthropogenic CO2 pollution; but current understanding of these potential effects is limited by a lack of quantitative knowledge and modelling capabilities for individual plant growth. This project will build a user-friendly interface for defining, parameterizing, and running simulations of non-linear biological models, and then use this tool to generate rigorously-parameterized plant growth models whose predictions can be trusted enough to integrate into larger analyses.

Building a Global Database of Forest Inventory Data. To aid in the development and parameterization of forest models and related scientific questions, this collaboration will collate millions of pre-existing field measurements of trees from national forest inventories, into a coherent, user-friendly database.

Publications

In press and in review

Strigul, N., Pristinski, D., Purves, DW, Dushoff, J., Pacala, SW (in press Ecological Monographs). Crown plasticity and large-scale forest dynamics: a new method of modeling vegetation dynamics. [abstract]

Purves, DW, Lichstein, JW, Strigul, N, Pacala, SW (in review). Predicting and understanding forest dynamics using a simple tractable model.

Turnbull, LT, Purves, DW, Rees, M. (in review). Why equalizing trade-offs aren't always neutral.

Published

Turnbull, LA, Paul-Victor, C., Schmid, B., Purves, DW (2008). Growth rates, seed size, and physiology: do small-seeded species really grow faster? Ecology, 89, 1352 - 1363  [abstract]

Adams, TA, Purves, DW, Pacala, SW. (2007) Understanding height-structured competition in forests: is there an R* for light?  Proc Roy Soc B doi 10.1098/rspb.2007.0891 [abstract]

Purves, DW, Lichstein, JW & Pacala, SW. (2007) Crown plasticity and competition for canopy space: a spatially implicit model parameterized for 250 North American tree species. PLoS-ONE 2(9): e870. doi:10.1371/journal.pone.0000870 [article]

Purves, DW, Zavala MA, Ogle, K., Prieto F & Ray-Benayas J. (2007) Environmental heterogeneity, bird-mediated directed dispersal, and oak woodland dynamics in Mediterranean Spain. Ecological Monographs, 77, 77 - 98. 

Zavala, MA, Diaz-Sierra, R., Purves, DW, Zea, GE, Urbieta, IR (2006). Modelos espacialmente explicitos. Ecosistemas. 2006/3 [article]

Turnbull, LA, Coomes, DA, Purves, DW, Rees, M. (2006) How spatial structure alters population and community dynamics in a natural plant community. Journal of Ecology, 95, 78 - 89.  

Purves DW & Pacala SW (2005) Ecological drift in niche-structured communities: neutral pattern does not imply neutral process. In Biotic Interactions in the Tropics (eds. D. Burslem, M. Pinard, S. Hartley). Cambridge University Press.

Purves DW & Dushoff J (2005) Directed seed dispersal and metapopulation response to habitat loss and disturbance: application to Eichhornia paniculata. Journal of Ecology, 93, 658 - 669.

Fiore, AM, LW Horowitz, DW Purves, H. Levy II, MJ Evans, Y Wang, Q Li, & RM Yantosca (2005) Evaluating the contribution of changes in isoprene emissions to surface ozone trends over the eastern United States. J. Geophys. Res - Atmos, Vol 110, DS12303. 

Purves DW, Caspersen JP, Moorcroft PR, Hurtt GC, Pacala SW (2004) Human-induced changes in U.S. biogenic VOC emissions: evidence from long-term forest inventory data. Global Change Biology, 10, 1737 - 1755.

Purves DW & Law R (2002) Experimental derivation of functions relating growth of Arabidopsis thaliana to neighbour size and distance. Journal of Ecology, 90, 882 - 894.

Murrell DJ, Purves DW & Law R (2002) Intraspecific aggregation and species coexistence. Trends in Ecology and Evolution, 17, 211. 

Purves DW & Law R (2002) Fine-scale spatial pattern in a grassland community: quantifying the plant's-eye view. Journal of Ecology, 90, 121 - 129. 

Murrell DJ, Purves DW & Law R (2001) Uniting pattern and process in plant ecology. Trends in Ecology and Evolution, 16, 529 - 530.

Law R, Purves DW, Murrell DJ & Dieckmann U (2001) Causes and effects of small-scale spatial structure in plant populations. In Integrating Ecology and Evolution in a Spatial Context, (eds J Silvertown & J Antonovics): pp 21-44. Blackwell Science, Oxford.