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Application of a two‐pool model to soil carbon dynamics under elevated CO 2
Author(s) -
Groenigen Kees Jan,
Xia Jianyang,
Osenberg Craig W.,
Luo Yiqi,
Hungate Bruce A.
Publication year - 2015
Publication title -
global change biology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 4.146
H-Index - 255
eISSN - 1365-2486
pISSN - 1354-1013
DOI - 10.1111/gcb.13074
Subject(s) - soil carbon , decomposition , environmental science , carbon cycle , carbon fibers , soil science , soil water , productivity , atmosphere (unit) , environmental chemistry , chemistry , ecology , ecosystem , biology , mathematics , physics , macroeconomics , algorithm , composite number , economics , thermodynamics
Elevated atmospheric CO 2 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 CO 2 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 CO 2 on decomposition rates. To address this issue, we refit our data to a two‐pool soil C model. We found that CO 2 enrichment increases decomposition rates of both fast and slow C pools. In addition, elevated CO 2 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.