OOS 41
Scaling Microbial Functions from Molecule to the Globe: Integrated Experiment-Model Approaches

Wednesday, August 12, 2015: 8:00 AM-11:30 AM
327, Baltimore Convention Center
Jianwei Li
Steven D. Allison and Yiqi Luo
Jianwei Li
Soil carbon (C) is the largest organic C pool in terrestrial biosphere and soil responses to climate change represent a major portion of uncertainty in global carbon cycle. Microbial communities are the primary drivers of soil organic matter (SOM) decomposition and thus accounting for the response of soil microbial communities to environmental parameters in Earth system models hold promise for improving predictions of climate effects on soil decomposition, yet the regulatory mechanisms governing microbial processes remain a major gap in understanding soil responses to climate change. Field and laboratory experiments have been deployed across a wide range of ecosystems and advanced our mechanistic understanding of microbial regulation of soil decay. Extracellular enzymes produced by microbes are responsible for the degradation of complex organic C that is ultimately taken up by microbial biomass and released to the atmosphere as CO2. In contrast to the assumptions of conventional first-order decomposition models, SOM decomposition rates depend on not only the size of the soil C pool but also on the size and composition of the decomposer microbe pool. As climate changes, soil carbon stocks will likely depend on sequestration and loss pathways regulated by microbial physiology, and first-order models may have difficulty simulating climate responses over short time scales. Yet even with recent integration of microbial components in global models, nearly 50% of the spatial variation in global soil C stocks is still unexplained. Therefore, identifying accurate and simple models at microbial to large spatial scales is essential for improving global soil models. A data-model integration approach could help facilitate both experimental investigation and modeling representation of microbial processes to simulate soil-climate interactions and feedbacks. Our session invites papers that address this topic by employing field and laboratory experiments, modeling analysis, data synthesis and assimilation approaches at the molecular, community, ecosystem, regional to global scales.
8:00 AM
 Modeling microsite processes for gigatons of soil carbon
Eric A. Davidson, University of Maryland Center for Environmental Science
8:20 AM
 Tradeoffs in incorporating microbial function into soil organic carbon decomposition models
Melanie A. Mayes, Oak Ridge National Laboratory; Jiang Jiang, University of Tennessee; Gangsheng Wang, Oak Ridge National Laboratory; Aimee Classen, University of Copenhagen; Chris W. Schadt, Oak Ridge National Laboratory; Christine V. Hawkes, University of Texas; Tim Keitt, The University of Texas at Austin
8:40 AM
 Effect of explicit microbial dynamics on the performance of soil carbon cycle models
Oleksandra Hararuk, Pacific Forestry Centre; Matthew Smith, Microsoft Research; Yiqi Luo, University of Oklahoma
9:20 AM
 Scaling microbial ecology to peatland biogeochemistry
Kirsten S. Hofmockel, Iowa State University; Fan Yang, Iowa State University; Ashley D. Keiser, Iowa State University; Erik A. Hobbie, University of New Hampshire
9:40 AM
9:50 AM
 Soil carbon and nitrogen mineralization with flexible soil and microbial C:N ratios
Gangsheng Wang, Oak Ridge National Laboratory; Peter E. Thornton, Oak Ridge National Laboratory; Melanie A. Mayes, Oak Ridge National Laboratory; Forrest M. Hoffman, Oak Ridge National Laboratory
10:10 AM
 Climate warming causes increased ecosystem carbon fluxes without decreasing soil carbon stocks in boreal forests
Susan Ziegler, Memorial University; Katherine Edwards, Canadian Forest Service; Ronald Benner, University of South Carolina; Sharon A. Billings, University of Kansas; Jerome Laganiere, Canadian Forest Service; Michael Philben, Memorial University; Xinbiao Zhu, Canadian Forest Service
10:30 AM
 Feedback responses of soil microbial communities to climate warming
Jizhong Zhou, University of Oklahoma; Mengting Yuan, University of Oklahoma; Cong Wang, University of Oklahoma; Xue Guo, University of Oklahoma; Katherine Todd-Brown, University of Oklahoma; Liyou Wu, University of Oklahoma; Zhili He, University of Oklahoma; Kostas Konstantinidis, Georgia Institute of Technology; Yiqi Luo, University of Oklahoma; Edward A. G. Schuur, Northern Arizona University; James R. Cole, Michigan State University; James M. Tiedje, Michigan State University
10:50 AM
 Does microbial community affect soil organic carbon decomposition directly across ecosystems?
Wenting Feng, University of Oklahoma; Jizhong Zhou, University of Oklahoma; James M. Tiedje, Michigan State University; Konstantinos Konstantinidis, Georgia Institute of Technology; Edward A. G. Schuur, Northern Arizona University; Yiqi Luo, University of Oklahoma
11:10 AM
 Substrate limitation in microbial decomposition models
Stefan Gerber, University of Florida IFAS; Debjani Sihi, University of Florida; Patrick W. Inglett, University of Florida; Kanika S. Inglett, University of Florida