While deforestation has declined in some tropical areas, forests are undergoing an increase in the number and area of fires. There is large uncertainty about how fire affects forests and the degree to which historical fires have contributed to the formation of modern forests. I currently coordinate two projects evaluating the effects of fire on tropical forests at two time scales: historical fires (over hundreds to thousands of years) and modern fires (within the last few decades).
Historical fire: Under a three-year project (PI Feldpausch; NERC NE/N011570/1), we are evaluating the extent of past fires in Amazonia, including the chronology, contribution to soil pyrogenic carbon storage and the isotopic signature of past fires to evaluate whether past fires have legacy effects on the composition, structure, and dynamics of modern forests. The results will have significant impacts in predicting the future magnitude and longevity of the Amazon carbon sink, understanding long-term fire effects, redirecting conservation practices, improving vegetation models, and affecting policy such as REDD+.
Modern fires: Using a combination of ground-based measurements, airborne lidar, and radar data, we are quantifying how human-induced disturbances affect the uptake and release of carbon in degraded Amazon forests across the basin-wide degradation frontier (Feldpausch, SilvaCarbon Fund). We are evaluating how logging and fire disturbance modifies forest structure and species composition, and whether these changes alter trajectories of degradation and/or recovery, and forest resilience to disturbance.
Fire occurrence in Mato Grosso State, southern border of Amazonia. Photo credit: Prof Ben Hur Marimon.