Changes in Organic Matter Chemistry and Methanogenesis Due to Permafrost Thaw in a Subarctic Peatland
As the Arctic warms, the ~277 Pg of carbon stored in permafrost peatlands faces an uncertain fate. Arctic and Subarctic peatlands are likely to release more methane (CH4) as permafrost thaw releases formerly-frozen carbon, thaw-induced land subsidence and inundation lead to anaerobic conditions, and...
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Tallahassee, Florida: Florida State University
2016
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ftfloridasu:oai:diginole.lib.fsu.edu:fsu_360372 2024-06-09T07:44:02+00:00 Changes in Organic Matter Chemistry and Methanogenesis Due to Permafrost Thaw in a Subarctic Peatland Hodgkins, Suzanne Berenice (authoraut) Chanton, Jeffrey P. (professor directing dissertation) Marshall, Alan G. (Alan George) (university representative) Landing, William M. (committee member) Wang, Yang (committee member) Burnett, William C. (committee member) Crill, Patrick (committee member) Florida State University (degree granting institution) College of Arts and Sciences (degree granting college) Department of Earth, Ocean, and Atmospheric Science (degree granting department) 2016 1 online resource (236 pages) computer https://diginole.lib.fsu.edu/islandora/object/fsu%3A360372/datastream/TN/view/Changes%20in%20Organic%20Matter%20Chemistry%20and%20Methanogenesis%20Due%20to%20Permafrost%20Thaw%20in%20a%20Subarctic%20Peatland.jpg English eng eng Tallahassee, Florida: Florida State University fsu:360372 (IID) FSU_2016SP_Hodgkins_fsu_0071E_13057 (URL) http://purl.flvc.org/fsu/fd/FSU_2016SP_Hodgkins_fsu_0071E_13057 https://diginole.lib.fsu.edu/islandora/object/fsu%3A360372/datastream/TN/view/Changes%20in%20Organic%20Matter%20Chemistry%20and%20Methanogenesis%20Due%20to%20Permafrost%20Thaw%20in%20a%20Subarctic%20Peatland.jpg This Item is protected by copyright and/or related rights. You are free to use this Item in any way that is permitted by the copyright and related rights legislation that applies to your use. For other uses you need to obtain permission from the rights-holder(s). The copyright in theses and dissertations completed at Florida State University is held by the students who author them. Biogeochemistry Text 2016 ftfloridasu 2024-05-10T08:08:13Z As the Arctic warms, the ~277 Pg of carbon stored in permafrost peatlands faces an uncertain fate. Arctic and Subarctic peatlands are likely to release more methane (CH4) as permafrost thaw releases formerly-frozen carbon, thaw-induced land subsidence and inundation lead to anaerobic conditions, and higher temperatures allow more rapid decomposition. In addition to these effects, CH4 and carbon dioxide (CO2) emissions may also change due to shifts in plant inputs and consequent changes in organic matter quality, but the exact relationships between organic matter and CH4 production are not well understood. In this study, we examined microbial CH4 and CO2 production and their relationship to organic matter chemistry in Stordalen Mire, a thawing Subarctic peatland in northern Sweden. We also used stable carbon isotopes (δ13C) of CH4 and CO2, and their apparent fractionation factor (αC), to examine the effect of thaw on the proportion of methanogenesis by hydrogenotrophic or acetoclastic pathways. At Stordalen, permafrost thaw causes dry, aerobic permafrost plateaus (palsas) to collapse and become inundated. These wet depressions are then colonized first by Sphagnum mosses and then by sedges as permafrost thaw and plant succession progress. In our study, we examined a chronosequence of sites with varying permafrost status and plant community composition. These sites included dry, intact palsas; recently-thawed collapsed palsa sinkholes; partially-thawed Sphagnum-dominated bogs; mostly-thawed poor fens with a combination of Sphagnum and tall sedges; and fully-thawed rich fens with mature stands of tall sedges and no Sphagnum. The changes in potential CH4 and CO2 production along the thaw progression were examined with anaerobic peat incubations, which were all performed with identical temperature and water saturation. These incubations showed increases in potential decomposition rates and CH4/CO2 production ratios along the thaw progression. Methanogenesis pathways also shifted from predominately hydrogenotrophic to ... Text Arctic Northern Sweden palsa palsas Peat permafrost Subarctic Florida State University: DigiNole Commons Arctic Stordalen ENVELOPE(7.337,7.337,62.510,62.510) |
institution |
Open Polar |
collection |
Florida State University: DigiNole Commons |
op_collection_id |
ftfloridasu |
language |
English |
topic |
Biogeochemistry |
spellingShingle |
Biogeochemistry Changes in Organic Matter Chemistry and Methanogenesis Due to Permafrost Thaw in a Subarctic Peatland |
topic_facet |
Biogeochemistry |
description |
As the Arctic warms, the ~277 Pg of carbon stored in permafrost peatlands faces an uncertain fate. Arctic and Subarctic peatlands are likely to release more methane (CH4) as permafrost thaw releases formerly-frozen carbon, thaw-induced land subsidence and inundation lead to anaerobic conditions, and higher temperatures allow more rapid decomposition. In addition to these effects, CH4 and carbon dioxide (CO2) emissions may also change due to shifts in plant inputs and consequent changes in organic matter quality, but the exact relationships between organic matter and CH4 production are not well understood. In this study, we examined microbial CH4 and CO2 production and their relationship to organic matter chemistry in Stordalen Mire, a thawing Subarctic peatland in northern Sweden. We also used stable carbon isotopes (δ13C) of CH4 and CO2, and their apparent fractionation factor (αC), to examine the effect of thaw on the proportion of methanogenesis by hydrogenotrophic or acetoclastic pathways. At Stordalen, permafrost thaw causes dry, aerobic permafrost plateaus (palsas) to collapse and become inundated. These wet depressions are then colonized first by Sphagnum mosses and then by sedges as permafrost thaw and plant succession progress. In our study, we examined a chronosequence of sites with varying permafrost status and plant community composition. These sites included dry, intact palsas; recently-thawed collapsed palsa sinkholes; partially-thawed Sphagnum-dominated bogs; mostly-thawed poor fens with a combination of Sphagnum and tall sedges; and fully-thawed rich fens with mature stands of tall sedges and no Sphagnum. The changes in potential CH4 and CO2 production along the thaw progression were examined with anaerobic peat incubations, which were all performed with identical temperature and water saturation. These incubations showed increases in potential decomposition rates and CH4/CO2 production ratios along the thaw progression. Methanogenesis pathways also shifted from predominately hydrogenotrophic to ... |
author2 |
Hodgkins, Suzanne Berenice (authoraut) Chanton, Jeffrey P. (professor directing dissertation) Marshall, Alan G. (Alan George) (university representative) Landing, William M. (committee member) Wang, Yang (committee member) Burnett, William C. (committee member) Crill, Patrick (committee member) Florida State University (degree granting institution) College of Arts and Sciences (degree granting college) Department of Earth, Ocean, and Atmospheric Science (degree granting department) |
format |
Text |
title |
Changes in Organic Matter Chemistry and Methanogenesis Due to Permafrost Thaw in a Subarctic Peatland |
title_short |
Changes in Organic Matter Chemistry and Methanogenesis Due to Permafrost Thaw in a Subarctic Peatland |
title_full |
Changes in Organic Matter Chemistry and Methanogenesis Due to Permafrost Thaw in a Subarctic Peatland |
title_fullStr |
Changes in Organic Matter Chemistry and Methanogenesis Due to Permafrost Thaw in a Subarctic Peatland |
title_full_unstemmed |
Changes in Organic Matter Chemistry and Methanogenesis Due to Permafrost Thaw in a Subarctic Peatland |
title_sort |
changes in organic matter chemistry and methanogenesis due to permafrost thaw in a subarctic peatland |
publisher |
Tallahassee, Florida: Florida State University |
publishDate |
2016 |
url |
https://diginole.lib.fsu.edu/islandora/object/fsu%3A360372/datastream/TN/view/Changes%20in%20Organic%20Matter%20Chemistry%20and%20Methanogenesis%20Due%20to%20Permafrost%20Thaw%20in%20a%20Subarctic%20Peatland.jpg |
long_lat |
ENVELOPE(7.337,7.337,62.510,62.510) |
geographic |
Arctic Stordalen |
geographic_facet |
Arctic Stordalen |
genre |
Arctic Northern Sweden palsa palsas Peat permafrost Subarctic |
genre_facet |
Arctic Northern Sweden palsa palsas Peat permafrost Subarctic |
op_relation |
fsu:360372 (IID) FSU_2016SP_Hodgkins_fsu_0071E_13057 (URL) http://purl.flvc.org/fsu/fd/FSU_2016SP_Hodgkins_fsu_0071E_13057 https://diginole.lib.fsu.edu/islandora/object/fsu%3A360372/datastream/TN/view/Changes%20in%20Organic%20Matter%20Chemistry%20and%20Methanogenesis%20Due%20to%20Permafrost%20Thaw%20in%20a%20Subarctic%20Peatland.jpg |
op_rights |
This Item is protected by copyright and/or related rights. You are free to use this Item in any way that is permitted by the copyright and related rights legislation that applies to your use. For other uses you need to obtain permission from the rights-holder(s). The copyright in theses and dissertations completed at Florida State University is held by the students who author them. |
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1801372837514051584 |