HR: 0800h
AN: B51C-0210    [Abstracts]
TI: Regional Patterns of Ecosystem Response to Climate Change and Elevated CO2 Levels in the Great Plains
AU: * Parton, W
EM: billp@nrel.colostate.edu
AF: Natural Resource Ecology Lab/Colorado State Univ, Campus Delivery 1499 NREL/CSU, Fort Collins, CO 80523-1499 United States
AB: This paper will describe the results and procedures used to simulate the potential impact of climate change and elevated CO2 levels on ecosystem properties (soil carbon, trace gas fluxes, plant production, and nitrogen cycling) for grasslands in the Central and Southern Great Plains region. Extensive weather, soils and land use data is currently available at regional scales in the US. This paper will describe the procedure used to use this data as input into the Daycent ecosystem model and simulate the potential impact of elevated CO2, and climate changes on grassland ecosystem properties at the regional scale. Extensive field level elevated CO2 experiments from the Southern and Central Great Plains region were used to test and calibrate the Daycent model's ability to simulate ecosystem responses to elevated CO2 levels. The model results show that elevated CO2 levels will result in increased above and belowground plant production, and plant nitrogen uptake for the whole region, while soil carbon levels are decreased in the Western Shortgrass Steppe parts of the Great Plains and increased in Eastern Tallgrass Prairie region. The enhanced plant nitrogen uptake results from a reduction in nitrogen trace gas fluxes and enhanced nitrogen uptake from the soil. The enhanced plant nitrogen uptake from the soil results from elevated CO2 induced increases in soil water content which increase the soil carbon turnover rate. Increasing air temperatures causes a general pattern of decreased soil carbon levels in the whole region. Increasing temperatures has little impact on plant production in the Shortgrass Steppe Region and small increases in plant production in the Tallgrass Prairie Region.
DE: 0414 Biogeochemical cycles, processes, and modeling (0412, 0793, 1615, 4805, 4912)
DE: 0428 Carbon cycling (4806)
DE: 0490 Trace gases
SC: Biogeosciences [B]
MN: Fall Meeting 2005