HR: 17:15h
AN: B44A-05    [Abstracts]
TI: Stoichiometric and Climatic Controls on Litter Nitrogen Mineralization
AU: * Manzoni, S
EM: sm86@duke.edu
AF: Duke University, Pratt School of Engineering, 121 Hudson Hall, Box 90287, Durham, NC 27708-0287, United States
AU: Porporato, A
EM: amilcare@duke.edu
AF: Duke University, Pratt School of Engineering, 121 Hudson Hall, Box 90287, Durham, NC 27708-0287, United States
AB: The release of nitrogen from decomposing plant residues is intimately coupled with its carbon losses through microbial respiration. At a global scale, the availability of C substrates drives the growth of microbial communities and together with their stoichiometry determines the microbial N demand. In turn, microbial demand controls the immobilization or mineralization of N and ultimately the nutrient availability in the soil. A simple mechanistic model of litter decomposition, accounting for chemistry and microbial characteristics (namely microbial C-to-N ratio and respiration rate), allows us to derive analytical N release curves. These curves are used to study the variability of N-release patterns in global-scale datasets from a microbiological perspective. Macroclimate is found to affect the microbial characteristics and hence the N mineralization patterns across biomes, suggesting that altered macroclimate and litter chemistry may affect N availability under climate change scenarios.
DE: 0414 Biogeochemical cycles, processes, and modeling (0412, 0793, 1615, 4805, 4912)
DE: 0428 Carbon cycling (4806)
DE: 0466 Modeling
DE: 0469 Nitrogen cycling
DE: 1615 Biogeochemical cycles, processes, and modeling (0412, 0414, 0793, 4805, 4912)
SC: Biogeosciences [B]
MN: 2007 Fall Meeting