HR: 1340h
AN: B33E-1092    [Abstracts]
TI: Climate, Plant Biomass, NDVI, and LAI Relationships Along The Full Arctic Bioclimate Gradient
AU: * Epstein, H E
EM: hee2b@virginia.edu
AF: Department of Environmental Sciences, University of Virginia, Charlottesville, VA 22904 United States
AU: Walker, D A
EM: ffdaw@uaf.edu
AF: Institute of Arctic Biology, University of Alaska, Fairbanks, AK 99775 United States
AU: Jia, G J
EM: jiongjia@cnr.colostate.edu
AF: Department of Environmental Sciences, University of Virginia, Charlottesville, VA 22904 United States
AU: Kelley, A M
EM: amk5d@virginia.edu
AF: Department of Environmental Sciences, University of Virginia, Charlottesville, VA 22904 United States
AB: A common methodology for assessing the potential effects of terrestrial ecosystems to environmental change is to develop present-day spatial relationships between environmental variables and ecosystem properties. Spatial relationships between climate variables and ecosystem variables should of course be used cautiously when extrapolating these patterns over time, i.e. space-for-time substitutions. Nevertheless, this approach has been extremely useful along regional climate gradients, in addition to providing support for vegetation dynamics models. We are developing several datasets of latitude, temperature, aboveground plant biomass, the NDVI (normalized difference vegetation index) and LAI (leaf area index) for arctic tundra ecosystems along an 1800-km transect from the Low Arctic tundra in northern Alaska to the Polar Desert of the northern Canadian Archipelago. Another useful application of these data is the relationships between NDVI and aboveground plant biomass, which can allow for the conversion of satellite data to on-the-ground ecosystem properties. For the portion of our transect on the northern slope of Alaska, NDVI (from NOAA AVHRR data) decreased with increasing latitude, explaining 45% of the variance in LAI, 65% of aboveground biomass and 42% of shrub biomass. Along the same portion of the transect, LAI (measured from above the mosses and lichens) explained 69% of vascular plant biomass and 68% of shrub biomass. For the higher arctic portion of the transect, NDVI (measured using a handheld spectroradiometer) continued to decrease with latitude, and latitude explained 90% of the variation in NDVI. For these sites in the High Arctic, NDVI was most strongly related to the sum of moss and graminoid biomass (r²=0.60). Ultimately, our dataset will contain climate data, satellite NDVI, handheld NDVI, LAI, and various components of aboveground plant biomass for a complete synthesis along the full arctic bioclimate gradient.
DE: 0400 BIOGEOSCIENCES
DE: 0428 Carbon cycling (4806)
DE: 0439 Ecosystems, structure and dynamics (4815)
DE: 0475 Permafrost, cryosphere, and high-latitude processes (0702, 0716)
DE: 0480 Remote sensing
SC: Biogeosciences [B]
MN: Fall Meeting 2005