Robinson Negrón-Juárez and his co-authors have now published the first study on windthrow variability, focusing on Central Amazonia. Windthrows destroy large swaths of trees, play a significant role in forest structures and dynamics, and affect carbon storage. In this study the co-authors present the seasonal and interannual variability of windthrows, and discuss the potential meteorological factors associated with this variability.
Negrón-Juárez, R.I., H. S. Jenkins, C. F. M. Raupp, W. J. Riley, L. M. Kueppers, D. Magnabosco Marra, G. H. P. Ribeiro, M. T. Monterio, L. A. Candido, J. Q. Chambers, N. Higuch (2017). Windthrow Variability in Central Amazonia. Atmosphere 8(2), 28, doi:10.3390/atmos8020028
They used Landsat images for the 1998–2010 time period to detect windthrows, which were identified based on their spectral characteristics and shape. Meteorological data were used to investigate the causes of windthrows. They found that windthrows occurred every year throughout Central Amazonia, but were more frequent from September through February. Organized convective activity associated with multicell storms embedded in mesoscale convective systems, such as northerly squall lines (which move from northeast to southwest) and southerly squall lines (which move from southwest to northeast), can cause windthrows. They also found that southerly squall lines occurred more frequently than the previously reported ~50 year interval. At the interannual scale, they did not find an association between ENSO and windthrows.
Given that windthrow-related tree mortality is not currently represented in Earth System Models (ESMs), this study shows that inclusion of windthrows in ESMs could reduce the uncertainties of climate prediction.
This research was supported as part of the Next Generation Ecosystem Experiments-Tropics and the Regional and Global Climate Modeling, both funded by the U.S. Department of Energy, Office of Science, under contract DE-AC02-05CH11231.
Windthrow photos are credited to Ms. Raquel Araujo, who used an unmanned aerial system to photograph. This windthow (2.88S, 60.28W) occurred in 2015 close to the city of Taruma in Central Amazonia. One of the “dots” below is author Robinson Negrón-Juárez.