Can the Amazon take the strain?

The vast forest–river system of the Amazon basin is changing rapidly owing to human impacts. Humans have been there for many thousands of years, but the region is now home to some 25 million people. Here Eric Davidson and colleagues synthesize recent research — much of it from the Large Scale Biosphere-Atmosphere Experiment in Amazonia — on the effects of climate change and disturbances such as deforestation and fire on the functioning of the Amazon basin. Although the forest is resilient to individual disturbances, and Brazil may well be able to maintain economic development without destroying its forests, the interacting effects of multiple disturbances have already altered the regional hydrology and energy balance. And there are indications that the Amazon may even be transitioning from a net carbon sink to a net carbon source.