Methane dynamics regulated by microbial community response to permafrost thaw

McCalley, Carmody K., Woodcroft, Ben J., Hodgkins, Suzanne B., Wehr, Richard A., Kim, Eun-Hae, Mondav, Rhiannon, Crill, Patrick M., Chanton, Jeffrey P., Rich, Virginia I., Tyson, Gene W. and Saleska, Scott R. (2014) Methane dynamics regulated by microbial community response to permafrost thaw. Nature, 514 7523: 478-481. doi:10.1038/nature13798


Author McCalley, Carmody K.
Woodcroft, Ben J.
Hodgkins, Suzanne B.
Wehr, Richard A.
Kim, Eun-Hae
Mondav, Rhiannon
Crill, Patrick M.
Chanton, Jeffrey P.
Rich, Virginia I.
Tyson, Gene W.
Saleska, Scott R.
Title Methane dynamics regulated by microbial community response to permafrost thaw
Journal name Nature   Check publisher's open access policy
ISSN 0028-0836
1476-4687
Publication date 2014-10-01
Year available 2014
Sub-type Article (original research)
DOI 10.1038/nature13798
Open Access Status Not yet assessed
Volume 514
Issue 7523
Start page 478
End page 481
Total pages 4
Place of publication London, United Kingdom
Publisher Nature Publishing Group
Language eng
Subject 1000 General
Abstract Permafrost contains about50% of the global soil carbon. It is thought that the thawing of permafrost can lead to a loss of soil carbon in the form of methane and carbon dioxide emissions. The magnitude of the resulting positive climate feedback of such greenhouse gas emissions is still unknown and may to a large extent depend on the poorly understood role of microbial community composition in regulating the metabolic processes that drive such ecosystem-scale greenhouse gas fluxes. Here we show that changes in vegetation and increasing methane emissionswith permafrost thaware associated with a switch from hydrogenotrophic to partly acetoclasticmethanogenesis, resulting inalargeshift in theδCsignature (10-15%) of emitted methane. We used a natural landscape gradient of permafrost thawinnorthern Sweden as a model to investigate the role of microbial communities in regulatingmethane cycling, and to test whether a knowledge of community dynamics could improvepredictions of carbonemissions under loss of permafrost. Abundance of the meth anogen Candidatus 'Meth anoflorens stordalenmirensis'6 is a key predictor of the shifts in methane isotopes, which in turn predicts the proportions of carbon emitted as methane and as carbon dioxide, an important factor for simulating the climate feedback associated with permafrost thaw in global models. By showing that the abundance of key microbial lineages can be used to predict atmospherically relevant patterns in methane isotopes and the proportion of carbonmetabolized to methane during permafrost thaw, we establish a basis for scaling changing microbial communities to ecosystem isotope dynamics. Our findings indicate that microbial ecology may be important in ecosystem-scale responses to global change.
Formatted abstract
Permafrost contains about 50% of the global soil carbon1. It is thought that the thawing of permafrost can lead to a loss of soil carbon in the form of methane and carbon dioxide emissions2, 3. The magnitude of the resulting positive climate feedback of such greenhouse gas emissions is still unknown3 and may to a large extent depend on the poorly understood role of microbial community composition in regulating the metabolic processes that drive such ecosystem-scale greenhouse gas fluxes. Here we show that changes in vegetation and increasing methane emissions with permafrost thaw are associated with a switch from hydrogenotrophic to partly acetoclastic methanogenesis, resulting in a large shift in the δ13C signature (10–15‰) of emitted methane. We used a natural landscape gradient of permafrost thaw in northern Sweden4, 5 as a model to investigate the role of microbial communities in regulating methane cycling, and to test whether a knowledge of community dynamics could improve predictions of carbon emissions under loss of permafrost. Abundance of the methanogen Candidatus ‘Methanoflorens stordalenmirensis’6 is a key predictor of the shifts in methane isotopes, which in turn predicts the proportions of carbon emitted as methane and as carbon dioxide, an important factor for simulating the climate feedback associated with permafrost thaw in global models3, 7. By showing that the abundance of key microbial lineages can be used to predict atmospherically relevant patterns in methane isotopes and the proportion of carbon metabolized to methane during permafrost thaw, we establish a basis for scaling changing microbial communities to ecosystem isotope dynamics. Our findings indicate that microbial ecology may be important in ecosystem-scale responses to global change.
Keyword Multidisciplinary Sciences
Science & Technology - Other Topics
Q-Index Code C1
Q-Index Status Confirmed Code
Grant ID DE-SC0004632
Institutional Status UQ

Document type: Journal Article
Sub-type: Article (original research)
Collections: Official 2015 Collection
School of Chemistry and Molecular Biosciences
 
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Created: Fri, 31 Oct 2014, 22:03:44 EST by Mrs Louise Nimwegen on behalf of School of Chemistry & Molecular Biosciences