Fire and drought may push Amazonian forests beyond tipping point
PostedApril 16, 2014
Future simulations of climate in the Amazon suggest a longer dry season leading to more drought and fires. Woods Hole Research Center scientists Michael Coe, Paulo Brando, Marcia Macedo and colleagues have published a new study on the impacts of fire and drought on Amazon tree mortality. Their paper entitled “Abrupt increases in Amazonian tree mortality due to drought-fire interactions,” published in the Proceedings of the National Academy of Sciences, found that prolonged droughts caused more intense and widespread wildfires, which consumed more forests in Amazonia than previously understood.
Over an eight-year period, the team repeatedly burned 50-hectare forest plots in southeast Amazonia to learn how fire frequency and weather conditions affected tree deaths. The surprise, according to Dr. Coe, was “the importance of drought. The forest didn’t burn much in average years, but burned extensively in drought years.” Climate change is expected to cause shorter more intense rainy seasons and longer dry seasons, with more frequent droughts like those observed in this study. According to Dr. Coe, “We tend to think only about average conditions but it is the non-average conditions we have to worry about.”