HR: 15:25h
AN: B33F-08 INVITED    [Abstracts]
TI: Global N2 fixation and its response to global climate change and increasing CO2 level
AU: wang, y
EM: yingping.wang@csiro.au
AF: CSIRO Marine and Atmospheric Research, Private Bag #1, Aspendale, Victoria 3195, Australia, 107-121 Station Street, Aspendale, vic 3195, Australia
AU: * Houlton, B Z
EM: bzhoulton@ucdavis.edu
AF: Department of Land, Air, and Water Resources, University of California, One Shields Avenue, Davis, CA 95616, USA, Davis, CA 95616, United States
AU: Field, C B
EM: cfield@globalecology.stanford.edu
AF: Department of Global Ecology, Carnegie Institution of Washington, 260 Panama Street, Stanford, CA 94305, USA, Stanford, CA 94305, United States
AU: Vitousek, P M
EM: vitousek@stanford.edu
AF: Department of Biological Sciences Stanford University, Herrin Labs, Stanford, stanford, CA 94305-5020, United States
AB: Biological nitrogen fixation is the largest nitrogen input to many natural terrestrial ecosystems, particularly tropical ecosystems, thereby influencing primary production, CO2 uptake, and responses to climate change. However, our understanding of biological nitrogen fixation is still very limited, and the dominant plant family capable of fixing N2 symbiotically, the Leguminasae, exhibits considerable geographic variation in the terrestrial biosphere. Based on the principles of resource optimization, we developed a new model to constrain our understanding of the geographic distribution of N fixation globally. Our model treats N fixation according to the C cost of fixing N, coupled with the N cost associated with acquiring P from the soil for plant growth. The model was used to estimate the rate of global symbiotic N2 fixation and the response of symbiotic N2 fixers to changes in climate and rising atmospheric CO2. We shall discuss global N limitation of terrestrial carbon uptake and its implications for climate-carbon cycle feedbacks from present to year 2100.
DE: 0315 Biosphere/atmosphere interactions (0426, 1610)
DE: 0414 Biogeochemical cycles, processes, and modeling (0412, 0793, 1615, 4805, 4912)
DE: 0428 Carbon cycling (4806)
DE: 0470 Nutrients and nutrient cycling (4845, 4850)
DE: 0476 Plant ecology (1851)
SC: Biogeosciences [B]
MN: 2007 Fall Meeting