Rainforest tree loss produced by a squall line

Robinson Negrón-Juárez, Jeffrey Chambers, Giuliano Guimaraes, Hongcheng Zeng, Carlos Raupp, Daniel Marra, Gabriel Ribeiro, Sassan Saatchi, Bruce Nelson, and Niro Higuchi, Widespread Amazon forest tree mortality from a single cross-basin squall line event, Geophysical Research Letters, 10.1029/2010GL043733

The year 2005 brought intense drought to parts of Amazonia, as well as reports of high tree mortality across the basin. In this analysis, the authors link satellite data with field measurements of tree mortality and an empirical model to analyze the impact of a single squall line that moved northeast across Amazonia on 16–18 January 2005. Downburst winds are estimated to have reached speeds as 41 meters per second (92 mph). The authors calculate that between 420 and 660 million trees may have been damaged or destroyed across the basin, representing 23% of the average amount of carbon believed to be accumulated in Amazon forests each year. In the Manaus area, the squall line may account for more than 30% of the year’s total deforestation. The squall line’s timing and location suggest that drought was not the only factor in the region’s 2005 tree loss.

TULANE UNIVERSITY • NATIONAL INSTITUTE FOR AMAZONIAN RESEARCH • MAX PLANCK INSTITUTE FOR BIOGEOCHEMISTRY • UNIVERSITY OF WINDSOR • SAO PAULO STATE UNIVERSITY • CALIFORNIA INSTITUTE OF TECHNOLOGY