Fire, Land Use and the Savannazation of Seasonally-dry Amazon Forests

Woodwell Climate Research Center, Inc., Falmouth MA

Investigators

Abstract

Each year, about one fifth of all of the carbon dioxide that is emitted to the atmosphere through human activities around the world comes from the clearing and burning of moist tropical forests. During years of severe drought, large areas of forest catch fire, doubling these emissions. Once burned, forests are more likely to burn again in a vicious cycle of forest degradation that further increases carbon emissions to the atmosphere as it damages rainforests. This research will shed light on the processes that determine the response of forests to fire, and the likelihood of large-scale "savannization" of the Amazon - the transformation of rainforest into fire-prone brush vegetation. It will achieve this through field experiments and measurements of burned forests that determine the effects of Amazon forest fire on subsequent invasion by flammable weeds and tree death - two factors that strongly influence the risk of further burning. The data obtained will be used to modify a vegetation model of the Amazon that will be used to predict the likelihood of large-scale savannization and its potential contribution of carbon to the atmosphere. Currently, models that predict the future of tropical forests in a warming world do not include fire, weed invasion, and land use. This research will fill an important gap in knowledge of how tropical forests in the Amazon will respond to climate change and growing economic pressures on tropical forests. This project also will support international education student exchanges and public-outreach activities aimed at environmental literacy.