HR: 1330h
AN: B22A-0801    [PDF]
TI: Relating Optical Indices to Carbon and Water Fluxes in a Chaparral Ecosystem
AU: * Claudio, H C
EM: helenclaudio@hotmail.com
AF: California State Univeristy, Los Angeles, Department of Biological Sciences 5151 State University Drive, Los Angeles, CA 90032 United States
AU: Gamon, J
EM: jgamon@calstatela.edu
AF: California State Univeristy, Los Angeles, Department of Biological Sciences 5151 State University Drive, Los Angeles, CA 90032 United States
AU: Sims, D A
EM: dsims3@calstatela.edu
AF: Ball State Univeristy, Department of Geography CL425 Ball State University, Muncie, IN 47306 United States
AU: Luo, H
EM: luo@sunstroke.sdsu.edu
AF: San Diego State University, Global Change Research Group Department of Biology, PS-240 San Diego State University 5500 Campanile Drive, San Diego, CA 92182 United States
AU: Oechel, W
EM: oechel@sunstroke.sdsu.edu
AF: San Diego State University, Global Change Research Group Department of Biology, PS-240 San Diego State University 5500 Campanile Drive, San Diego, CA 92182 United States
AB: Between 2001 and 2003, spectral reflectance coupled with CO$_{2}$ and H$_{2}$O flux data were collected at Sky Oaks Biological Field Station, a chaparral-dominated ecosystem in southern California. The reflectance data were collected by walking along a transect (early 2001) and semi-automated 100 meter tram system installed at the site (after mid 2001), while CO$_{2}$ and H$_{2}$O flux data were gathered with an eddy covariance flux tower. Over the study, which included a normal wet (2001), an extremely dry (2002), and a recovery year (2003), the water band index (WBI) was more closely correlated with ecosystem H$_{2}$O flux than CO$_{2}$ flux. In the wet year, WBI was closely correlated with both the H$_{2}$O and CO$_{2}$ fluxes, but when a record drought struck in 2002, the correlation between WBI and CO$_{2}$ disappeared as vegetation died off. Also, WBI is dynamic over time, precipitation conditions, and between species in the region. These results suggest that the ecosystem average WBI is an overall more robust estimator of the H$_{2}$O flux than CO$_{2}$ flux at the ecosystem level and water fluxes can be directly estimated from optical remote sensing.
DE: 0400 Biogeosciences
DE: 1640 Remote sensing
DE: 1694 Instruments and techniques
DE: 1851 Plant ecology
DE: 3322 Land/atmosphere interactions
SC: Biogeosciences [B]
MN: 2003 Fall Meeting