1 ORGANIZERS: SUSAN G. CONARD, USDA FS, DOUGLAS MCRAE, CANADIAN FOREST SERVICE THE ROLE OF FIRE IN ALTERING VEGETATION DISTRIBUTION UNDER FUTURE CLIMATE CHANGE Ronald P. Neilson USDA Forest Service Corvallis, Oregon James M. Lenihan USDA Forest Service Corvallis, Oregon Dominique Bachelet Oregon State University Corvallis, Oregon Raymond J. Drapek USDA Forest Service Corvallis, Oregon John Wells Oregon State University Corvallis, Oregon INTRODUCTION Most forecasts of vegetation change under climate change have been made using ‘static’ Biogeography models, such as MAPSS and BIOME3 (Neilson et al. 1998), which produced simulations of Potential Natural Vegetation under current (e.g. 1961 – 1990) compared to future average conditions (e.g. 2071 – 2100) (Neilson et al. 1998). More recently, a new class of models was created, Dynamic General (Global) Vegetation Models (DGVM), in order to simulate the actual trajectory of change. DGVMs combine two separate fields within ecology, vegetation distribution (based in population ecology) and biogeochemical cycles (based in ecosystem science or nutrient cycling) and also include a third element, wildfire simulation, to stimulate vegetation change and rapid carbon fluxes. New DGVM simulations are now emerging that provide considerable insight into the role of drought and fire disturbance in vegetation distribution and change. Preliminary results will be presented here from two ongoing projects, one focused on North America and another focused on global simulations. The MC1 DGVM (MAPSS-CENTURY, version 1) simulated potential future vegetation and fire dynamics under 6 future climate scenarios (3 General Circulation Models, GCMs x 2 SRES-IPCC emissions scenarios) as part of the VINCERA Project (Vulnerability and Impacts of North American forests to Climate: Ecosystem Responses and Adaptation). Preliminary results are also available from MC1 simulations over the entire globe using 9 future climate scenarios (3 GCMs x 2 SRES-IPCC emissions scenarios). Results from both of these projects, using both the MAPSS and MC1 models, will be presented in order to provide some qualitative indication of