title: Application of a two-pool model to soil carbon dynamics under elevated CO2.
abstract: Elevated atmospheric CO2 concentrations increase plant productivity and affect soil microbial communities, with possible consequences for the turnover rate of soil carbon (C) pools and feedbacks to the atmosphere. In a previous analysis (Van Groenigen et al., 2014), we used experimental data to inform a one-pool model and showed that elevated CO2 increases the decomposition rate of soil organic C, negating the storage potential of soil. However, a two-pool soil model can potentially explain patterns of soil C dynamics without invoking effects of CO2 on decomposition rates. To address this issue, we refit our data to a two-pool soil C model. We found that CO2 enrichment increases decomposition rates of both fast and slow C pools. In addition, elevated CO2 decreased the carbon use efficiency of soil microbes (CUE), thereby further reducing soil C storage. These findings are consistent with numerous empirical studies and corroborate the results from our previous analysis. To facilitate understanding of C dynamics, we suggest that empirical and theoretical studies incorporate multiple soil C pools with potentially variable decomposition rates.
authors: Center for Ecosystem Science and Society, Northern Arizona University, Flagstaff, AZ, 86011, USA.
authors: Kees Jan
authors: KJ
authors: van Groenigen
authors: Department of Botany and Microbiology, University of Oklahoma, Norman, OK, 73019-0245, USA.|Tiantong National Forest Ecosystem Observation and Research Station, School of Ecological and Environmental Sciences, East China Normal University, Shanghai, 200241, China.
authors: Jianyang
authors: J
authors: Xia
authors: Odum School of Ecology, University of Georgia, Athens, GA, 30602, USA.
authors: Craig W
authors: CW
authors: Osenberg
authors: Department of Botany and Microbiology, University of Oklahoma, Norman, OK, 73019-0245, USA.|Center for Earth System Sciences, Tsinghua University, Beijing, 100084, China.
authors: Yiqi
authors: Y
authors: Luo
authors: Center for Ecosystem Science and Society, Northern Arizona University, Flagstaff, AZ, 86011, USA.|Department of Biological Sciences, Northern Arizona University, Flagstaff, AZ, 86011, USA.
authors: Bruce A
authors: BA
authors: Hungate
mesh_terms: D001272:Atmosphere / Q000737:chemistry*; D057486:Carbon Cycle; D002245:Carbon Dioxide / Q000737:chemistry*; D057231:Climate Change; D008962:Models, Theoretical; D012987:Soil / Q000737:chemistry*
chemical_list: D012987:Soil; D002245:Carbon Dioxide
keywords: carbon cycle; data assimilation; data-model fusion; priming; soil carbon model