HR: 1340h
AN: B23C-1494    [Abstracts]
TI: Ecosystem carbon budgets and crop yields in a tropical savanna ecosystem as related to changes in climate and management
AU: Tan, Z
EM: ztan@usgs.gov
AF: Science Applications International Corp (SAIC), 47914 252nd Street, Sioux Falls, SDA 57198, United States
AU: * Tieszen, L L
EM: tieszen@usgs.gov
AF: USGS Center for Earth Resources Observation and Science, 47914 252nd Street, Sioux Falls, SD 57198, United States
AU: Liu, S
EM: sliu@usgs.gov
AF: Science Applications International Corp (SAIC), 47914 252nd Street, Sioux Falls, SDA 57198, United States
AU: Tachie-Obeng, E
EM: eobeng@epaghana.org
AF: Environmental Protection Agency, Post Office Box M326, Accra, M326, Ghana
AB: The tropical savanna in West Africa is a critical ecosystem that provides products for people and livestock. It is, however, vulnerable to land disturbances and sensitive to climate change. We selected the Bawku savanna ecoregion in northern Ghana to evaluate the responses of both natural and managed ecosystems to climate change and management scenarios. Our results from this study show that the conversion of forest to agricultural use resulted in a substantial reduction in ecosystem carbon stocks across this ecoregion during the past century. Climate changes would lead to a continuous decline in soil carbon stock of the entire ecoregion through the 21rst century; however, this result could be offset by increasing nitrogen fertilization on the cultivated lands. An increase in nitrogen fertilization could also significantly increase grain yields of all crops, except groundnut. The biomass production and soil carbon stocks within woodlands would depend heavily on cutting options and little on climate change. In summary, this study indicates that food security and agricultural sustainability in the Bawku ecoregion would rely heavily on the level of nitrogen fertilizer applied in the future.
DE: 0402 Agricultural systems
DE: 0414 Biogeochemical cycles, processes, and modeling (0412, 0793, 1615, 4805, 4912)
DE: 0428 Carbon cycling (4806)
SC: Biogeosciences [B]
MN: 2007 Fall Meeting