Storm intensity and old-growth forest disturbances in the Amazon region

Authors

Fernando D.B. Espirito-Santo, University of New Hampshire - Main CampusFollow
Michael Keller, USDA Forest ServiceFollow
Rob Braswell, University of New Hampshire - Main Campus
Bruce Nelson, National Institute for Research in Amazonia, Brazil
Steve Frolking, University of New Hampshire - Main CampusFollow
G Vicente, NOAA

Abstract

We analyzed the pattern of large forest disturbances or blow-downs apparently caused by severe storms in a mostly unmanaged portion of the Brazilian Amazon using 27 Landsat images and daily precipitation estimates from NOAA satellite data. For each Landsat a spectral mixture analysis (SMA) was applied. Based on SMA, we detected and mapped 279 patches (from 5 ha to 2,223 ha) characteristic of blow-downs. A total of 21,931 ha of forest were disturbed. We found a strong correlation between occurrence of blow-downs and frequency of heavy rainfall (Spearman's rank, r² = 0.84, p < 0.0003). The recurrence intervals of large disturbances were estimated to be 90,000 yr for the eastern Amazon and 27,000 yr for the western Amazon. This suggests that weather patterns affect the frequency of large forest disturbances that may produce different rates of forest turnover in the eastern and western Amazon basin.

Department

Earth Sciences, Earth Systems Research Center

Publication Date

6-2010

Journal Title

Geophysical Research Letters

Publisher

Wiley

Digital Object Identifier (DOI)

10.1029/2010GL043146

Document Type

Article

Recommended Citation

Espírito-Santo, F. D. B., M. Keller, B. Braswell, B. W. Nelson, S. Frolking, and G. Vicente (2010), Storm intensity and old-growth forest disturbances in the Amazon region, Geophys. Res. Lett., 37, L11403, doi:10.1029/2010GL043146.

Rights

Copyright 2010 by the American Geophysical Union.