Adding stable carbon isotopes improves model representation of the role of microbial communities in peatland methane cycling
Climate change is expected to have significant and uncertain impacts on methane (CH 4 ) emissions from northern peatlands. Biogeochemical models can extrapolate site-specific CH 4 measurements to larger scales and predict responses of CH 4 emissions to environmental changes. However, these models in...
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ftosti:oai:osti.gov:1393576 2023-07-30T04:06:19+02:00 Adding stable carbon isotopes improves model representation of the role of microbial communities in peatland methane cycling Deng, Jia McCalley, Carmody K. Frolking, Steve Chanton, Jeff Crill, Patrick Varner, Ruth Tyson, Gene Rich, Virginia Hines, Mark Saleska, Scott R. Li, Changsheng 2021-08-30 application/pdf http://www.osti.gov/servlets/purl/1393576 https://www.osti.gov/biblio/1393576 https://doi.org/10.1002/2016MS000817 unknown http://www.osti.gov/servlets/purl/1393576 https://www.osti.gov/biblio/1393576 https://doi.org/10.1002/2016MS000817 doi:10.1002/2016MS000817 54 ENVIRONMENTAL SCIENCES 58 GEOSCIENCES 2021 ftosti https://doi.org/10.1002/2016MS000817 2023-07-11T09:21:15Z Climate change is expected to have significant and uncertain impacts on methane (CH 4 ) emissions from northern peatlands. Biogeochemical models can extrapolate site-specific CH 4 measurements to larger scales and predict responses of CH 4 emissions to environmental changes. However, these models include considerable uncertainties and limitations in representing CH4 production, consumption, and transport processes. To improve predictions of CH 4 transformations, we incorporated acetate and stable carbon (C) isotopic dynamics associated with CH 4 cycling into a biogeochemistry model, DNDC. By including these new features, DNDC explicitly simulates acetate dynamics and the relative contribution of acetotrophic and hydrogenotrophic methanogenesis (AM and HM) to CH 4 production, and predicts the C isotopic signature (δ 13 C) 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 CH 4 production pathways and δ 13 C in emitted CH 4 (δ 13 C-CH 4 ), a measure of the integrated effects of microbial production and consumption, and of physical transport. We also investigated the sensitivity of simulated δ 13 C-CH 4 to C isotopic composition of substrates and, to fractionation factors for CH4 production (α AM and α HM ), CH 4 oxidation (α MO ), and plant-mediated CH 4 transport (α TP ). The sensitivity analysis indicated that the δ13C-CH 4 is highly sensitive to the factors associated with microbial metabolism (α AM , α HM , and α MO ). The model framework simulating stable C isotopic dynamics provides a robust basis for better constraining and testing microbial mechanisms in predicting CH 4 cycling in peatlands. Other/Unknown Material permafrost Subarctic SciTec Connect (Office of Scientific and Technical Information - OSTI, U.S. Department of Energy) Journal of Advances in Modeling Earth Systems 9 2 1412 1430 |
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SciTec Connect (Office of Scientific and Technical Information - OSTI, U.S. Department of Energy) |
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54 ENVIRONMENTAL SCIENCES 58 GEOSCIENCES |
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54 ENVIRONMENTAL SCIENCES 58 GEOSCIENCES Deng, Jia McCalley, Carmody K. Frolking, Steve Chanton, Jeff Crill, Patrick Varner, Ruth Tyson, Gene Rich, Virginia Hines, Mark Saleska, Scott R. Li, Changsheng Adding stable carbon isotopes improves model representation of the role of microbial communities in peatland methane cycling |
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54 ENVIRONMENTAL SCIENCES 58 GEOSCIENCES |
description |
Climate change is expected to have significant and uncertain impacts on methane (CH 4 ) emissions from northern peatlands. Biogeochemical models can extrapolate site-specific CH 4 measurements to larger scales and predict responses of CH 4 emissions to environmental changes. However, these models include considerable uncertainties and limitations in representing CH4 production, consumption, and transport processes. To improve predictions of CH 4 transformations, we incorporated acetate and stable carbon (C) isotopic dynamics associated with CH 4 cycling into a biogeochemistry model, DNDC. By including these new features, DNDC explicitly simulates acetate dynamics and the relative contribution of acetotrophic and hydrogenotrophic methanogenesis (AM and HM) to CH 4 production, and predicts the C isotopic signature (δ 13 C) 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 CH 4 production pathways and δ 13 C in emitted CH 4 (δ 13 C-CH 4 ), a measure of the integrated effects of microbial production and consumption, and of physical transport. We also investigated the sensitivity of simulated δ 13 C-CH 4 to C isotopic composition of substrates and, to fractionation factors for CH4 production (α AM and α HM ), CH 4 oxidation (α MO ), and plant-mediated CH 4 transport (α TP ). The sensitivity analysis indicated that the δ13C-CH 4 is highly sensitive to the factors associated with microbial metabolism (α AM , α HM , and α MO ). The model framework simulating stable C isotopic dynamics provides a robust basis for better constraining and testing microbial mechanisms in predicting CH 4 cycling in peatlands. |
author |
Deng, Jia McCalley, Carmody K. Frolking, Steve Chanton, Jeff Crill, Patrick Varner, Ruth Tyson, Gene Rich, Virginia Hines, Mark Saleska, Scott R. Li, Changsheng |
author_facet |
Deng, Jia McCalley, Carmody K. Frolking, Steve Chanton, Jeff Crill, Patrick Varner, Ruth Tyson, Gene Rich, Virginia Hines, Mark Saleska, Scott R. Li, Changsheng |
author_sort |
Deng, Jia |
title |
Adding stable carbon isotopes improves model representation of the role of microbial communities in peatland methane cycling |
title_short |
Adding stable carbon isotopes improves model representation of the role of microbial communities in peatland methane cycling |
title_full |
Adding stable carbon isotopes improves model representation of the role of microbial communities in peatland methane cycling |
title_fullStr |
Adding stable carbon isotopes improves model representation of the role of microbial communities in peatland methane cycling |
title_full_unstemmed |
Adding stable carbon isotopes improves model representation of the role of microbial communities in peatland methane cycling |
title_sort |
adding stable carbon isotopes improves model representation of the role of microbial communities in peatland methane cycling |
publishDate |
2021 |
url |
http://www.osti.gov/servlets/purl/1393576 https://www.osti.gov/biblio/1393576 https://doi.org/10.1002/2016MS000817 |
genre |
permafrost Subarctic |
genre_facet |
permafrost Subarctic |
op_relation |
http://www.osti.gov/servlets/purl/1393576 https://www.osti.gov/biblio/1393576 https://doi.org/10.1002/2016MS000817 doi:10.1002/2016MS000817 |
op_doi |
https://doi.org/10.1002/2016MS000817 |
container_title |
Journal of Advances in Modeling Earth Systems |
container_volume |
9 |
container_issue |
2 |
container_start_page |
1412 |
op_container_end_page |
1430 |
_version_ |
1772818860074860544 |