High peatland methane emissions following permafrost thaw: enhanced acetoclastic methanogenesis during early successional stages
Permafrost thaw in northern peatlands often leads to increased methane (CH4) emissions, but the underlying controls responsible for increased emissions and the duration for which they persist have yet to be fully elucidated. We assessed how shifting environmental conditions affect microbial communit...
Published in: | Biogeosciences |
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Copernicus Publications
2022
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ftnonlinearchiv:oai:noa.gwlb.de:cop_mods_00061642 2023-05-15T17:54:53+02:00 High peatland methane emissions following permafrost thaw: enhanced acetoclastic methanogenesis during early successional stages Heffernan, Liam Cavaco, Maria A. Bhatia, Maya P. Estop-Aragonés, Cristian Knorr, Klaus-Holger Olefeldt, David 2022-06 electronic https://doi.org/10.5194/bg-19-3051-2022 https://noa.gwlb.de/receive/cop_mods_00061642 https://noa.gwlb.de/servlets/MCRFileNodeServlet/cop_derivate_00061075/bg-19-3051-2022.pdf https://bg.copernicus.org/articles/19/3051/2022/bg-19-3051-2022.pdf eng eng Copernicus Publications Biogeosciences -- http://www.bibliothek.uni-regensburg.de/ezeit/?2158181 -- http://www.copernicus.org/EGU/bg/bg.html -- 1726-4189 https://doi.org/10.5194/bg-19-3051-2022 https://noa.gwlb.de/receive/cop_mods_00061642 https://noa.gwlb.de/servlets/MCRFileNodeServlet/cop_derivate_00061075/bg-19-3051-2022.pdf https://bg.copernicus.org/articles/19/3051/2022/bg-19-3051-2022.pdf https://creativecommons.org/licenses/by/4.0/ uneingeschränkt info:eu-repo/semantics/openAccess CC-BY article Verlagsveröffentlichung article Text doc-type:article 2022 ftnonlinearchiv https://doi.org/10.5194/bg-19-3051-2022 2022-06-26T23:11:40Z Permafrost thaw in northern peatlands often leads to increased methane (CH4) emissions, but the underlying controls responsible for increased emissions and the duration for which they persist have yet to be fully elucidated. We assessed how shifting environmental conditions affect microbial communities and the magnitude and stable isotopic signature (δ13C) of CH4 emissions along a thermokarst bog transect in boreal western Canada. Thermokarst bogs develop following permafrost thaw when dry, elevated peat plateaus collapse and become saturated and dominated by Sphagnum mosses. We differentiated between a young and a mature thermokarst bog stage (∼ 30 and ∼ 200 years since thaw, respectively). The young bog located along the thermokarst edge was wetter, warmer, and dominated by hydrophilic vegetation compared to the mature bog. Using high-throughput 16S rRNA gene sequencing, we show that microbial communities were distinct near the surface and converged with depth, but fewer differences remained down to the lowest depth (160 cm). Microbial community analysis and δ13C data from CH4 surface emissions and dissolved gas depth profiles show that hydrogenotrophic methanogenesis was the dominant pathway at both sites. However, mean δ13C-CH4 signatures of both dissolved gas profiles and surface CH4 emissions were found to be isotopically heavier in the young bog (−63 ‰ and −65 ‰, respectively) compared to the mature bog (−69 ‰ and −75 ‰, respectively), suggesting that acetoclastic methanogenesis was relatively more enhanced throughout the young bog peat profile. Furthermore, mean young bog CH4 emissions of 82 mg CH4 m−2 d−1 were ∼ 3 times greater than the 32 mg CH4 m−2 d−1 observed in the mature bog. Our study suggests that interactions between the methanogenic community, hydrophilic vegetation, warmer temperatures, and saturated surface conditions enhance CH4 emissions in young thermokarst bogs but that these favourable conditions only persist for the initial decades after permafrost thaw. Article in Journal/Newspaper Peat permafrost Thermokarst Niedersächsisches Online-Archiv NOA Canada Biogeosciences 19 12 3051 3071 |
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article Verlagsveröffentlichung |
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article Verlagsveröffentlichung Heffernan, Liam Cavaco, Maria A. Bhatia, Maya P. Estop-Aragonés, Cristian Knorr, Klaus-Holger Olefeldt, David High peatland methane emissions following permafrost thaw: enhanced acetoclastic methanogenesis during early successional stages |
topic_facet |
article Verlagsveröffentlichung |
description |
Permafrost thaw in northern peatlands often leads to increased methane (CH4) emissions, but the underlying controls responsible for increased emissions and the duration for which they persist have yet to be fully elucidated. We assessed how shifting environmental conditions affect microbial communities and the magnitude and stable isotopic signature (δ13C) of CH4 emissions along a thermokarst bog transect in boreal western Canada. Thermokarst bogs develop following permafrost thaw when dry, elevated peat plateaus collapse and become saturated and dominated by Sphagnum mosses. We differentiated between a young and a mature thermokarst bog stage (∼ 30 and ∼ 200 years since thaw, respectively). The young bog located along the thermokarst edge was wetter, warmer, and dominated by hydrophilic vegetation compared to the mature bog. Using high-throughput 16S rRNA gene sequencing, we show that microbial communities were distinct near the surface and converged with depth, but fewer differences remained down to the lowest depth (160 cm). Microbial community analysis and δ13C data from CH4 surface emissions and dissolved gas depth profiles show that hydrogenotrophic methanogenesis was the dominant pathway at both sites. However, mean δ13C-CH4 signatures of both dissolved gas profiles and surface CH4 emissions were found to be isotopically heavier in the young bog (−63 ‰ and −65 ‰, respectively) compared to the mature bog (−69 ‰ and −75 ‰, respectively), suggesting that acetoclastic methanogenesis was relatively more enhanced throughout the young bog peat profile. Furthermore, mean young bog CH4 emissions of 82 mg CH4 m−2 d−1 were ∼ 3 times greater than the 32 mg CH4 m−2 d−1 observed in the mature bog. Our study suggests that interactions between the methanogenic community, hydrophilic vegetation, warmer temperatures, and saturated surface conditions enhance CH4 emissions in young thermokarst bogs but that these favourable conditions only persist for the initial decades after permafrost thaw. |
format |
Article in Journal/Newspaper |
author |
Heffernan, Liam Cavaco, Maria A. Bhatia, Maya P. Estop-Aragonés, Cristian Knorr, Klaus-Holger Olefeldt, David |
author_facet |
Heffernan, Liam Cavaco, Maria A. Bhatia, Maya P. Estop-Aragonés, Cristian Knorr, Klaus-Holger Olefeldt, David |
author_sort |
Heffernan, Liam |
title |
High peatland methane emissions following permafrost thaw: enhanced acetoclastic methanogenesis during early successional stages |
title_short |
High peatland methane emissions following permafrost thaw: enhanced acetoclastic methanogenesis during early successional stages |
title_full |
High peatland methane emissions following permafrost thaw: enhanced acetoclastic methanogenesis during early successional stages |
title_fullStr |
High peatland methane emissions following permafrost thaw: enhanced acetoclastic methanogenesis during early successional stages |
title_full_unstemmed |
High peatland methane emissions following permafrost thaw: enhanced acetoclastic methanogenesis during early successional stages |
title_sort |
high peatland methane emissions following permafrost thaw: enhanced acetoclastic methanogenesis during early successional stages |
publisher |
Copernicus Publications |
publishDate |
2022 |
url |
https://doi.org/10.5194/bg-19-3051-2022 https://noa.gwlb.de/receive/cop_mods_00061642 https://noa.gwlb.de/servlets/MCRFileNodeServlet/cop_derivate_00061075/bg-19-3051-2022.pdf https://bg.copernicus.org/articles/19/3051/2022/bg-19-3051-2022.pdf |
geographic |
Canada |
geographic_facet |
Canada |
genre |
Peat permafrost Thermokarst |
genre_facet |
Peat permafrost Thermokarst |
op_relation |
Biogeosciences -- http://www.bibliothek.uni-regensburg.de/ezeit/?2158181 -- http://www.copernicus.org/EGU/bg/bg.html -- 1726-4189 https://doi.org/10.5194/bg-19-3051-2022 https://noa.gwlb.de/receive/cop_mods_00061642 https://noa.gwlb.de/servlets/MCRFileNodeServlet/cop_derivate_00061075/bg-19-3051-2022.pdf https://bg.copernicus.org/articles/19/3051/2022/bg-19-3051-2022.pdf |
op_rights |
https://creativecommons.org/licenses/by/4.0/ uneingeschränkt info:eu-repo/semantics/openAccess |
op_rightsnorm |
CC-BY |
op_doi |
https://doi.org/10.5194/bg-19-3051-2022 |
container_title |
Biogeosciences |
container_volume |
19 |
container_issue |
12 |
container_start_page |
3051 |
op_container_end_page |
3071 |
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1766162750836310016 |