HR: 0800h
AN: B51C-0958 [Abstracts]
TI: Using Biome-BGC to estimate production in annual crops - A study in Nebraska
AU: * Heinsch, F A
EM: faithann@ntsg.umt.edu
AF: NTSG, College of Forestry & Conservation, The University of Montana, 32 Campus Dr, Missoula, MT 59812
United States
AU: Jolly, W M
EM: mattj@ntsg.umt.edu
AF: NTSG, College of Forestry & Conservation, The University of Montana, 32 Campus Dr, Missoula, MT 59812
United States
AU: Kimball, J S
EM: johnk@ntsg.umt.edu
AF: NTSG, College of Forestry & Conservation, The University of Montana, 32 Campus Dr, Missoula, MT 59812
United States
AU: Kimball, J S
EM: johnk@ntsg.umt.edu
AF: The University of Montana Flathead Lake Biological Station, 311 BioStation Lane, Polson, MT 59860
United States
AU: Oechel, W C
EM: oechel@sunstroke.sdsu.edu
AF: Global Change Research Group, Department of Biology, San Diego State University, San Diego, CA 92182
United States
AU: Verma, S B
EM: sverma1@unl.edu
AF: School of Natural Resource Sciences, University of Nebraska, Lincoln, PO Box 830725, Lincoln, NE 68583
United States
AB:
The Biome-BGC ecosystem process model (Version 4.1.2) has been used successfully in many ecosystems, but was not developed
for use with agricultural crops. Therefore, program modifications are needed for use with crops, including the addition of
carbon allocation to fruiting and the inclusion of springtime planting. The program has been modified and tested using both
C3 (soybean) and C4 (maize) vegetation. Results from the Biome-BGC model runs were validated using AmeriFlux tower eddy
CO$_{2}$ flux-based estimates as well as two years of biomass and yield estimates at the University of Nebraska Agricultural
Research and Development Center (ARDL) near Mead, NE. The model was also used to obtain tower site and regional estimates
of NEE, GPP and NPP. Preliminary results indicate that the model works well in estimating both productivity and yield of
both maize and soybean. These results are combined and scaled to a 7 x 7-km area equivalent to that of the MODIS subset
(resolution = 1 km$^{2}$) centered on the research farm and available from Fluxnet and the Oak Ridge National Laboratory
(http://www.fluxnet.ornl.gov/fluxnet/modis.cfm). The comparisons provide a means to test the ability of the MODIS algorithms
to capture seasonal variations and agricultural carbon dynamics. The results of this study will be used in the future for
spatial extrapolation to scales from 1 - 20,000 km$^{2}$ to evaluate relative accuracies of MODIS GPP/NPP regional data and
provide estimates of the regional carbon balance for the larger 20,000 km$^{2}$ area within the National Institute for Global
Environmental Change (NIGEC) Great Plains and Midwestern study regions.
DE: 1615 Biogeochemical processes (4805)
DE: 0315 Biosphere/atmosphere interactions
DE: 0400 Biogeosciences
SC: Biogeosciences [B]
MN: 2004 AGU Fall Meeting