HR: 1340h
AN: B43C-1456    [Abstracts]
TI: Severe storms and blow-down disturbances in the Amazon forest
AU: * Espirito-Santo, F D
EM: fernando@guero.sr.unh.edu
AF: Institute for the Study of Earth, Oceans and Space (EOS), Complex System Research Center (CSRC), Morse Hall, University of New Hampshire, Duham, NH 03824, United States
AU: Keller, M
EM: michael.keller@unh.edu
AF: Institute for the Study of Earth, Oceans and Space (EOS), Complex System Research Center (CSRC), Morse Hall, University of New Hampshire, Duham, NH 03824, United States
AU: Keller, M
EM: michael.keller@unh.edu
AF: USDA Forest Service, International Institute of Tropical Forestry, Rio Piedras, s/n s/n, Puerto Rico
AU: Keller, M
EM: michael.keller@unh.edu
AF: CENA, Universidade de SàŁo Paulo, Piracicaba, SP 13416-000, Brazil
AU: Braswell, B
EM: rob.braswell@unh.edu
AF: Institute for the Study of Earth, Oceans and Space (EOS), Complex System Research Center (CSRC), Morse Hall, University of New Hampshire, Duham, NH 03824, United States
AU: Nelson, B W
EM: bnelsonbr@yahoo.com.br
AF: INPA, National Institute for Research in the Amazon, Manaus, MA 69060-001, Brazil
AU: Vicente, G
EM: gilberto.vicente@noaa.gov
AF: NOAA, Product Implementation Branch, Camp Springs, MD s/n, United States
AU: Frolking, S
EM: steve.frolking@unh.edu
AF: Institute for the Study of Earth, Oceans and Space (EOS), Complex System Research Center (CSRC), Morse Hall, University of New Hampshire, Duham, NH 03824, United States
AB: Large natural disturbances (> 1 ha) in old-growth tropical forests are caused by a variety of processes such as landslides, fires, wind, and cyclonic storms. We analyzed the pattern of large forest disturbances apparently caused by severe winds (blow-downs) in a mostly unmanaged portion of the Brazilian Amazon using a longitudinal transect of Landsat images (27 scenes between 6°43'W 68°50'S and 2°16'W 51°51'S) and daily precipitation estimates based on NOAA satellite data. We found 170 blow-downs with an average area of 3 km2. Most blow-down disturbances occurred in the Western Amazon between 67°W and 58°W. A map of heavy rainfall (> 20 mm d-1) showed that the maximum frequency of heavy daily rainfall (~80 days y-1) occurred around 63°W in our study region. We found a close relationship between the frequency of heavy storms and the occurrence of blow-down disturbances events. This, in turns, suggests a close connection between severe weather and the rate of forest turnover caused by blow-down disturbances. The forest turnover time calculated for these disturbances within 9 Eastern Landsat scenes studied was almost 9000 years whereas for the 18 scenes in the Western Amazon, turnover time was closer to 1200 year. Large disturbances may have a significant influence on the spatial pattern of forest dynamics and productivity of the Amazon.
DE: 0439 Ecosystems, structure and dynamics (4815)
DE: 0476 Plant ecology (1851)
DE: 0480 Remote sensing
DE: 1632 Land cover change
DE: 1640 Remote sensing (1855)
SC: Biogeosciences [B]
MN: 2007 Fall Meeting