HR: 08:15h
AN: B21C-02 INVITED    [Abstracts]
TI: Ecosystem-Scale Sensitivity of Carbon Cycling Processes to Climate Warming
AU: * Luo, Y
EM: yluo@ou.edu
AF: University of Oklahoma, Department of Botany and Microbiology 770 Van Vleet Oval, Norman, OK 73019, United States
AU: Sherry, R
EM: rsherry@ou.edu
AF: University of Oklahoma, Department of Botany and Microbiology 770 Van Vleet Oval, Norman, OK 73019, United States
AU: Zhou, X
EM: zxuhui14@ou.edu
AF: University of Oklahoma, Department of Botany and Microbiology 770 Van Vleet Oval, Norman, OK 73019, United States
AB: The coupled carbon-climate models reported in the literature all demonstrate a positive feedback between terrestrial carbon cycles and climate warming. The positive feedback results from decreased net primary production (NPP) in most models and increased respiratory carbon release by all the models under climate warming. Past experimental research has been focused on sensitivity of soil carbon decomposition to climate warming. Research results so far are controversial on directions and magnitudes of decomposition sensitivity to warming largely because the latter is not only dependent on quality and kinetics of carbon substrates but also tightly coupled with ecosystem carbon uptake. In this talk, we show that ecosystem warming in a North American prairie stimulated plant biomass production, enhanced dominance of C4 plants, extended growing seasons, enhanced root/shoot ratio, and increased nitrogen uptake and use efficiency. The stimulated biomass growth led to increases in litter mass and soil respiration, but no significant change in soil carbon storage. Our results demonstrate that plant ecophysiological processes play a critical role in regulation of ecosystem-scale responses to global change and future climate warming.
UR: http://bomi.ou.edu/luo
DE: 0426 Biosphere/atmosphere interactions (0315)
DE: 0428 Carbon cycling (4806)
DE: 0439 Ecosystems, structure and dynamics (4815)
DE: 1615 Biogeochemical cycles, processes, and modeling (0412, 0414, 0793, 4805, 4912)
DE: 1630 Impacts of global change (1225)
SC: Biogeosciences [B]
MN: 2007 Fall Meeting