Influence of Holocene permafrost aggradation and thaw on the paleoecology and carbon storage of a peatland complex in northwestern Canada
Permafrost in peatlands strongly influences ecosystem characteristics, including vegetation composition, hydrological functions, and carbon cycling. Large amounts of organic carbon are stored in permafrost peatlands in northwestern Canada. Their possible degradation into permafrost-free wetlands inc...
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crsagepubl:10.1177/0959683617693899 2024-03-03T08:44:27+00:00 Influence of Holocene permafrost aggradation and thaw on the paleoecology and carbon storage of a peatland complex in northwestern Canada Pelletier, Nicolas Talbot, Julie Olefeldt, David Turetsky, Merritt Blodau, Christian Sonnentag, Oliver Quinton, William L Canadian Network for Research and Innovation in Machining Technology, Natural Sciences and Engineering Research Council of Canada 2017 http://dx.doi.org/10.1177/0959683617693899 http://journals.sagepub.com/doi/pdf/10.1177/0959683617693899 http://journals.sagepub.com/doi/full-xml/10.1177/0959683617693899 en eng SAGE Publications http://journals.sagepub.com/page/policies/text-and-data-mining-license The Holocene volume 27, issue 9, page 1391-1405 ISSN 0959-6836 1477-0911 Paleontology Earth-Surface Processes Ecology Archeology Global and Planetary Change journal-article 2017 crsagepubl https://doi.org/10.1177/0959683617693899 2024-02-05T10:38:18Z Permafrost in peatlands strongly influences ecosystem characteristics, including vegetation composition, hydrological functions, and carbon cycling. Large amounts of organic carbon are stored in permafrost peatlands in northwestern Canada. Their possible degradation into permafrost-free wetlands including thermokarst bogs may affect carbon (C) stocks, but the direction and magnitude of change are uncertain. Using peat core reconstructions, we characterized the temporal and spatial variability in vegetation macrofossil, testate amoebae, C content, and peat decomposition along a permafrost thaw chronosequence in the southern portion of the Scotty Creek watershed near Fort Simpson, Northwest Territories. The accumulation of limnic and minerotrophic peat prevailed at the site until permafrost formed around 5000 cal. yr BP. Three distinct permafrost periods were identified in the permafrost peat plateau profile, while permafrost only aggraded once in the thermokarst bog profile. Permafrost thawed at ~550 and ~90 cal. yr BP in the thermokarst bog center and edge, respectively. Both allogenic (climatic shifts and wildfire) and autogenic (peat accumulation, Sphagnum growth) processes likely exerted control on permafrost aggradation and thaw. While apparent carbon accumulation rates (ACARs) were lower during present and past permafrost periods than during non-permafrost periods, long-term C accumulation remained similar between cores with different permafrost period lengths. Deep peat was less decomposed in the permafrost plateau compared with the thermokarst bog, which we speculate is due more to differences in peat type rather than differences in decomposition environment between these two ecosystem states. Our study highlights the importance of considering potential deep peat C losses to project the fate of thawing permafrost peat C stores. Article in Journal/Newspaper Fort Simpson Northwest Territories Peat Peat plateau permafrost Thermokarst SAGE Publications Northwest Territories Canada Fort Simpson ENVELOPE(-121.320,-121.320,61.808,61.808) Scotty Creek ENVELOPE(-121.561,-121.561,61.436,61.436) The Holocene 27 9 1391 1405 |
institution |
Open Polar |
collection |
SAGE Publications |
op_collection_id |
crsagepubl |
language |
English |
topic |
Paleontology Earth-Surface Processes Ecology Archeology Global and Planetary Change |
spellingShingle |
Paleontology Earth-Surface Processes Ecology Archeology Global and Planetary Change Pelletier, Nicolas Talbot, Julie Olefeldt, David Turetsky, Merritt Blodau, Christian Sonnentag, Oliver Quinton, William L Influence of Holocene permafrost aggradation and thaw on the paleoecology and carbon storage of a peatland complex in northwestern Canada |
topic_facet |
Paleontology Earth-Surface Processes Ecology Archeology Global and Planetary Change |
description |
Permafrost in peatlands strongly influences ecosystem characteristics, including vegetation composition, hydrological functions, and carbon cycling. Large amounts of organic carbon are stored in permafrost peatlands in northwestern Canada. Their possible degradation into permafrost-free wetlands including thermokarst bogs may affect carbon (C) stocks, but the direction and magnitude of change are uncertain. Using peat core reconstructions, we characterized the temporal and spatial variability in vegetation macrofossil, testate amoebae, C content, and peat decomposition along a permafrost thaw chronosequence in the southern portion of the Scotty Creek watershed near Fort Simpson, Northwest Territories. The accumulation of limnic and minerotrophic peat prevailed at the site until permafrost formed around 5000 cal. yr BP. Three distinct permafrost periods were identified in the permafrost peat plateau profile, while permafrost only aggraded once in the thermokarst bog profile. Permafrost thawed at ~550 and ~90 cal. yr BP in the thermokarst bog center and edge, respectively. Both allogenic (climatic shifts and wildfire) and autogenic (peat accumulation, Sphagnum growth) processes likely exerted control on permafrost aggradation and thaw. While apparent carbon accumulation rates (ACARs) were lower during present and past permafrost periods than during non-permafrost periods, long-term C accumulation remained similar between cores with different permafrost period lengths. Deep peat was less decomposed in the permafrost plateau compared with the thermokarst bog, which we speculate is due more to differences in peat type rather than differences in decomposition environment between these two ecosystem states. Our study highlights the importance of considering potential deep peat C losses to project the fate of thawing permafrost peat C stores. |
author2 |
Canadian Network for Research and Innovation in Machining Technology, Natural Sciences and Engineering Research Council of Canada |
format |
Article in Journal/Newspaper |
author |
Pelletier, Nicolas Talbot, Julie Olefeldt, David Turetsky, Merritt Blodau, Christian Sonnentag, Oliver Quinton, William L |
author_facet |
Pelletier, Nicolas Talbot, Julie Olefeldt, David Turetsky, Merritt Blodau, Christian Sonnentag, Oliver Quinton, William L |
author_sort |
Pelletier, Nicolas |
title |
Influence of Holocene permafrost aggradation and thaw on the paleoecology and carbon storage of a peatland complex in northwestern Canada |
title_short |
Influence of Holocene permafrost aggradation and thaw on the paleoecology and carbon storage of a peatland complex in northwestern Canada |
title_full |
Influence of Holocene permafrost aggradation and thaw on the paleoecology and carbon storage of a peatland complex in northwestern Canada |
title_fullStr |
Influence of Holocene permafrost aggradation and thaw on the paleoecology and carbon storage of a peatland complex in northwestern Canada |
title_full_unstemmed |
Influence of Holocene permafrost aggradation and thaw on the paleoecology and carbon storage of a peatland complex in northwestern Canada |
title_sort |
influence of holocene permafrost aggradation and thaw on the paleoecology and carbon storage of a peatland complex in northwestern canada |
publisher |
SAGE Publications |
publishDate |
2017 |
url |
http://dx.doi.org/10.1177/0959683617693899 http://journals.sagepub.com/doi/pdf/10.1177/0959683617693899 http://journals.sagepub.com/doi/full-xml/10.1177/0959683617693899 |
long_lat |
ENVELOPE(-121.320,-121.320,61.808,61.808) ENVELOPE(-121.561,-121.561,61.436,61.436) |
geographic |
Northwest Territories Canada Fort Simpson Scotty Creek |
geographic_facet |
Northwest Territories Canada Fort Simpson Scotty Creek |
genre |
Fort Simpson Northwest Territories Peat Peat plateau permafrost Thermokarst |
genre_facet |
Fort Simpson Northwest Territories Peat Peat plateau permafrost Thermokarst |
op_source |
The Holocene volume 27, issue 9, page 1391-1405 ISSN 0959-6836 1477-0911 |
op_rights |
http://journals.sagepub.com/page/policies/text-and-data-mining-license |
op_doi |
https://doi.org/10.1177/0959683617693899 |
container_title |
The Holocene |
container_volume |
27 |
container_issue |
9 |
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1391 |
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1405 |
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