We have just received support from NASA’s Interdisciplinary Science program to examine multiscale effects of fire on long-term climate and precipitation
Our group has received – along with the University of Virginia (Paolo D’Odorico and Todd Scanlon) and lead institution UCLA (Greg Okin and Yongkang Xue) – new support to advance the understanding of feedbacks between energy/water fluxes and vegetation/fire dynamics in savannas at multiple scales. The coupled nature of fires and water/energy fluxes at the Earth’s surface is perhaps nowhere more evident than in savanna ecosystems. Frequently stressed and sensitive to change, savanna ecosystems are responsive to climate variability over relatively short time scales, and both water and fires are the main driving forces in shaping their vegetation distribution, composition, and dynamics. Fires also have major impacts on the flux of water and energy from savanna ecosystems, both indirectly by controlling vegetation structure and plant community composition, and directly by altering soil moisture, surface temperature, and other surface physical characteristics. The coupling between fires and vegetation dynamics is complex. It involves patch-scale interactions with hydrological processes, landscape-scale feedbacks with tree-grass plant communities, and land-atmosphere feedbacks through the impact of fire scars on the dynamics of the near surface atmosphere. We will perform targeted field work in southern Africa to address hypotheses about the linkages between vegetation and water-fire coupling across scales, use remote sensing data to characterize spatial and temporal relationships between fire and vegetation, develop models that will include embedded feedback effects, and evaluate the effect of these feedbacks on the sensitivity of savanna ecosystems to changing climate forcing. The project will provide over $1,000,000 in support to UCLA, UVA, and Princeton over the next three years.