Adding stable carbon isotopes improves model representation of the role of microbial communities in peatland methane cycling
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Deng, Jia
McCalley, Carmody K

Frolking, Steve
Chanton, Jeff

Crill, Patrick

Varner, Ruth

Tyson, Gene
Rich, Virginia

Hines, Mark
Saleska, Scott R.
Li, Changsheng
Affiliation
Univ Arizona, Dept Ecol & Evolutionary BiolIssue Date
2017-06
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AMER GEOPHYSICAL UNIONCitation
Adding stable carbon isotopes improves model representation of the role of microbial communities in peatland methane cycling 2017, 9 (2):1412 Journal of Advances in Modeling Earth SystemsRights
© 2017. The Authors. This is an open access article under the terms of the Creative Commons Attribution-NonCommercial-NoDerivs License.Collection Information
This item from the UA Faculty Publications collection is made available by the University of Arizona with support from the University of Arizona Libraries. If you have questions, please contact us at repository@u.library.arizona.edu.Abstract
Climate change is expected to have significant and uncertain impacts on methane (CH4) emissions from northern peatlands. Biogeochemical models can extrapolate site-specificCH(4) measurements to larger scales and predict responses of CH4 emissions to environmental changes. However, these models include considerable uncertainties and limitations in representing CH4 production, consumption, and transport processes. To improve predictions of CH4 transformations, we incorporated acetate and stable carbon (C) isotopic dynamics associated with CH4 cycling into a biogeochemistry model, DNDC. By including these new features, DNDC explicitly simulates acetate dynamics and the relative contribution of acetotrophic and hydro-genotrophic methanogenesis (AM and HM) to CH4 production, and predicts the C isotopic signature (delta C-13) in soil C pools and emitted gases. When tested against biogeochemical and microbial community observations at two sites in a zone of thawing permafrost in a subarctic peatland in Sweden, the new formulation substantially improved agreement with CH4 production pathways and delta C-13 in emitted CH4 (delta C-13-CH4), a measure of the integrated effects of microbial production and consumption, and of physical transport. We also investigated the sensitivity of simulated delta C-13-CH4 to C isotopic composition of substrates and, to fractionation factors for CH4 production (alpha(AM) and alpha(HM)), CH4 oxidation (alpha(MO)), and plant-mediated CH4 transport (alpha(TP)). The sensitivity analysis indicated that the delta C-13-CH4 is highly sensitive to the factors associated with microbial metabolism (alpha(AM), alpha(HM), and alpha(MO)). The model framework simulating stable C isotopic dynamics provides a robust basis for better constraining and testing microbial mechanisms in predicting CH4 cycling in peatlands.Note
Open access journal.ISSN
19422466Version
Final published versionSponsors
U.S. Department of Energy [DE-SC0004632, DE-SC0010580]; U.S. National Science Foundation (MacroSystems Biology) [1241937]; Northern Ecosystems Research for undergraduates REU Site (NSF EAR) [1063037]; Vetenskapradet (DR) [2007-4547, 2013-5562]Additional Links
http://doi.wiley.com/10.1002/2016MS000817ae974a485f413a2113503eed53cd6c53
10.1002/2016MS000817
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Except where otherwise noted, this item's license is described as © 2017. The Authors. This is an open access article under the terms of the Creative Commons Attribution-NonCommercial-NoDerivs License.