The resilience of savanna ecosystems to changing fire regimes

This project will investigate how changes in fire frequency have influenced the structure and composition of vegetation and soil biogeochemistry in both tropical and temperate savanna ecosystems. The results of this work will address the question of how natural ecosystems will respond to the rapidly changing fire regimes across the globe. Fieldwork will take place in three sites where fire frequency has been experimentally manipulated for >40 years (South Africa, Brazil, and the United States). The fieldwork will characterize the vegetation community to test the hypothesis that frequent burning shifts the plant community to being increasingly sensitive to fire. The labwork involves soil sampling and analysis, which will characterize the storage and turnover of carbon and nutrients via microbial activity assays and organic and inorganic chemistry measurements. These assays will be used to test the hypothesis that fire depletes ecosystem carbon and dampens nutrient turnover, inhibiting vegetation and microbial recovery.