HR: 09:30h
AN: B21D-07    [Abstracts]
TI: Preliminary Observations of Water and Carbon Dioxide Fluxes Across an Alpine Treeline.
AU: * Blanken, P D
EM: blanken@colorado.edu
AF: University of Colorado, Department of Geography 260 UCB, Boulder, CO 80309-0260, United States
AU: Williams, M
EM: markw@culter.colorado.edu
AF: University of Colorado, Department of Geography 260 UCB, Boulder, CO 80309-0260, United States
AU: Williams, M
EM: markw@culter.colorado.edu
AF: University of Colorado, INSTAAR, Boulder, CO 80309, United States
AU: Monson, R
EM: monsonr@colorado.edu
AF: University of Colorado, Department of Ecology and Evolutionary Biology, Boulder, CO 80309, United States
AU: Burns, S
EM: sean.burns@colorado.edu
AF: University of Colorado, Department of Ecology and Evolutionary Biology, Boulder, CO 80309, United States
AU: Chowanski, K
EM: chowansk@colorado.edu
AF: University of Colorado, INSTAAR, Boulder, CO 80309, United States
AU: Ackerman, T
EM: todda@colorado.edu
AF: University of Colorado, INSTAAR, Boulder, CO 80309, United States
AU: Knowles, J
EM: knowles@colorado.edu
AF: University of Colorado, Department of Geography 260 UCB, Boulder, CO 80309-0260, United States
AU: Bailey, A
EM: adrianar@cires.colorado.edu
AF: University of Colorado, Department of Geography 260 UCB, Boulder, CO 80309-0260, United States
AB: Several studies have shown that alpine treeline (timberline) is especially sensitive to environmental changes, and is therefore a strong "early-warning" indicator of regional climate change. Many of these changes may be induced by factors including local land use changes, and understanding the difference and dynamics of water and carbon dioxide fluxes across the alpine treeline is important to help understand and assess regional climate change. Preliminary observations of water and carbon dioxide fluxes from a recently installed eddy covariance tower situated over alpine tundra are compared to fluxes measured over adjacent subalpine forest. During June-July 2007, the carbon dioxide, latent heat, and sensible heat half-hour fluxes over the tundra were 69%, 50%, and 44% less than over the forest, respectively. The evaporative fraction, however, was similar for both sites, and the cumulative carbon uptake was only 40% less at the tundra site compared to the forest site. Describing the differences and dynamics of fluxes across the alpine treeline is the first step towards understanding how changes in land use are/will affect the alpine environment.
UR: http://culter.colorado.edu/NWT/
DE: 0426 Biosphere/atmosphere interactions (0315)
DE: 1813 Eco-hydrology
DE: 1818 Evapotranspiration
DE: 1843 Land/atmosphere interactions (1218, 1631, 3322)
DE: 3307 Boundary layer processes
SC: Biogeosciences [B]
MN: 2007 Fall Meeting