HR: 08:00h
AN: B41E-01 INVITED     [Abstracts]
TI: Amazon Rainforest Phenology Observed From Space
AU: * Huete, A R
EM: ahuete@ag.arizona.edu
AF: University of Arizona, Dept. Soil, Water And Environmental Science, POB 210038, Tucson, AZ 85721 United States
AU: Didan, K
EM: kamel@ag.arizona.edu
AF: University of Arizona, Dept. Soil, Water And Environmental Science, POB 210038, Tucson, AZ 85721 United States
AU: Shimabukuro, Y
EM: yosio@ltid.inpe.br
AF: INPE, Av. dos Astronautas, 1758, Sao Jose dos Campos, SP 12.244-450 Brazil
AU: Ratana, P
EM: piyachat@ag.arizona.edu
AF: University of Arizona, Dept. Soil, Water And Environmental Science, POB 210038, Tucson, AZ 85721 United States
AU: Yang, W
EM: ywze@crsa.bu.edu
AF: Boston University, Dept. Geography, 675 Commonwealth Ave., Boston, MA 02215 United States
AU: Nemani, R
EM: ramakrishna.r.nemani@nasa.gov
AF: NASA Ames Research Center, Mail Stop 242-2, Moffett Field, CA 94035 United States
AU: Myneni, R
EM: rmyneni@bu.edu
AF: Boston University, Dept. Geography, 675 Commonwealth Ave., Boston, MA 02215 United States
AB: The rainforests of the Amazon basin form the largest contiguous, undisturbed forest on our planet, influencing global climate, water, and carbon dynamics, and housing the largest reservoir of biological diversity. Yet Amazon rainforest phenology remains poorly understood due to complex patterns of moisture, sunlight, and biological constraints on productivity. Here we show increases in photosynthetic activity at the start of the dry season using five years of data from the MODIS satellite and suggest that Amazon rainforests green-up and are more active in the sunnier dry season. Rainforest sites in eastern Amazonia started greenning one month into the dry season and reached peak greenness towards the end of the dry season or early wet season. Synchronous patterns of green-up were also observed in an extended climate transect and in basin-wide images with the magnitude of green-up most pronounced over eastern Amaz“nia which has an extended, 4-5 month dry season period. The perhumid forests to the west showed none or little variation in seasonality while the drier transitional forests to the south showed declining greenness in the dry season while complete reversals in phenology were observed in areas where secondary forests and pastures remain following deforestation. Our results suggest that sunlight may exert more influence than rainfall on rainforest phenology and productivity, however, both climatic and human drivers may alter this balance.
DE: 0428 Carbon cycling (4806)
DE: 0429 Climate dynamics (1620)
DE: 0439 Ecosystems, structure and dynamics (4815)
DE: 1632 Land cover change
SC: Biogeosciences [B]
MN: Fall Meeting 2005