Ecosystem changes across a gradient of permafrost degradation in subarctic Québec (Tasiapik Valley, Nunavik, Canada)
Abstract Permafrost thaw, tundra shrubification, and changes in snow cover properties are documented impacts of climate warming, particularly in subarctic regions where discontinuous permafrost is disappearing. To obtain some insight into those changes, permafrost, active layer thickness, vegetation...
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ftunivquebectr:oai:depot-e.uqtr.ca:11076 2024-02-04T09:52:14+01:00 Ecosystem changes across a gradient of permafrost degradation in subarctic Québec (Tasiapik Valley, Nunavik, Canada) Pelletier, M. Allard, M. Levesque, E. 2019 application/pdf https://depot-e.uqtr.ca/id/eprint/11076/ https://depot-e.uqtr.ca/id/eprint/11076/1/LEVESQUE_E_197_ED.pdf https://doi.org/10.1139/as-2016-0049 en eng https://depot-e.uqtr.ca/id/eprint/11076/1/LEVESQUE_E_197_ED.pdf Pelletier, M., Allard, M. et Levesque, E. (2019). Ecosystem changes across a gradient of permafrost degradation in subarctic Québec (Tasiapik Valley, Nunavik, Canada). Arctic Science, 5 (1). pp. 1-26. ISSN 2368-7460 DOI 10.1139/as-2016-0049 <https://doi.org/10.1139/as-2016-0049> doi:10.1139/as-2016-0049 cc_by_4 Permafrost Shrubification Snow cover Subarctic Thermokarst Pergélisol Subarctique Augmentation du couvert arbustif Couverture de neige Article 2019 ftunivquebectr https://doi.org/10.1139/as-2016-0049 2024-01-07T00:10:25Z Abstract Permafrost thaw, tundra shrubification, and changes in snow cover properties are documented impacts of climate warming, particularly in subarctic regions where discontinuous permafrost is disappearing. To obtain some insight into those changes, permafrost, active layer thickness, vegetation, snow cover, ground temperature, soil profiles, and carbon content were surveyed in an integrated approach in six field plots along a chronosequence of permafrost thaw on an ice-rich silty soil. Historical air photographs and dendrochronology provided the chronological context. Comparison of the plots reveals a positive feedback effect between thaw settlement, increased snow cover thickness, shrub growth, increase in soil temperature, and the process of permafrost decay. By the end of the sequence permafrost was no longer sustainable. Along the estimated 90 year duration of the chronosequence, the originally centimeter-thin pedogenic horizons under mosses and lichens increased to a thickness of nearly 65 cm under shrubs and trees. Snow cover increased from negligible to over 2 m. The thickness of soil organic layers and soil organic matter content increased manyfold, likely a result of the increased productivity in the shrub-dominated landscape. The results of this study strongly suggest that permafrost ecosystems in the subarctic are being replaced under climate warming by shrub and forest ecosystems enriched in carbon on more evolved soils. Résumé Le dégel du pergélisol, l’augmentation du couvert arbustif de la toundra (« shrubification ») et les changements de propriétés de la couverture de neige constituent des impacts déjà connus du réchauffement du climat, particulièrement dans les régions subarctiques où le pergélisol discontinu est en voie de disparition. Afin d’obtenir un aperçu de ces changements, le pergélisol, l’épaisseur de la couche active, la végétation, la couverture de neige, la température au sol, les profils de sol et le contenu en carbone ont été examinés selon une approche intégrée dans six ... Article in Journal/Newspaper Active layer thickness Arctic Ice permafrost Subarctic subarctique* Thermokarst toundra Tundra Nunavik pergélisol Université du Québec à Trois-Rivières: Dépôt numérique de UQTR Canada Nunavik Arctic Science 5 1 1 26 |
institution |
Open Polar |
collection |
Université du Québec à Trois-Rivières: Dépôt numérique de UQTR |
op_collection_id |
ftunivquebectr |
language |
English |
topic |
Permafrost Shrubification Snow cover Subarctic Thermokarst Pergélisol Subarctique Augmentation du couvert arbustif Couverture de neige |
spellingShingle |
Permafrost Shrubification Snow cover Subarctic Thermokarst Pergélisol Subarctique Augmentation du couvert arbustif Couverture de neige Pelletier, M. Allard, M. Levesque, E. Ecosystem changes across a gradient of permafrost degradation in subarctic Québec (Tasiapik Valley, Nunavik, Canada) |
topic_facet |
Permafrost Shrubification Snow cover Subarctic Thermokarst Pergélisol Subarctique Augmentation du couvert arbustif Couverture de neige |
description |
Abstract Permafrost thaw, tundra shrubification, and changes in snow cover properties are documented impacts of climate warming, particularly in subarctic regions where discontinuous permafrost is disappearing. To obtain some insight into those changes, permafrost, active layer thickness, vegetation, snow cover, ground temperature, soil profiles, and carbon content were surveyed in an integrated approach in six field plots along a chronosequence of permafrost thaw on an ice-rich silty soil. Historical air photographs and dendrochronology provided the chronological context. Comparison of the plots reveals a positive feedback effect between thaw settlement, increased snow cover thickness, shrub growth, increase in soil temperature, and the process of permafrost decay. By the end of the sequence permafrost was no longer sustainable. Along the estimated 90 year duration of the chronosequence, the originally centimeter-thin pedogenic horizons under mosses and lichens increased to a thickness of nearly 65 cm under shrubs and trees. Snow cover increased from negligible to over 2 m. The thickness of soil organic layers and soil organic matter content increased manyfold, likely a result of the increased productivity in the shrub-dominated landscape. The results of this study strongly suggest that permafrost ecosystems in the subarctic are being replaced under climate warming by shrub and forest ecosystems enriched in carbon on more evolved soils. Résumé Le dégel du pergélisol, l’augmentation du couvert arbustif de la toundra (« shrubification ») et les changements de propriétés de la couverture de neige constituent des impacts déjà connus du réchauffement du climat, particulièrement dans les régions subarctiques où le pergélisol discontinu est en voie de disparition. Afin d’obtenir un aperçu de ces changements, le pergélisol, l’épaisseur de la couche active, la végétation, la couverture de neige, la température au sol, les profils de sol et le contenu en carbone ont été examinés selon une approche intégrée dans six ... |
format |
Article in Journal/Newspaper |
author |
Pelletier, M. Allard, M. Levesque, E. |
author_facet |
Pelletier, M. Allard, M. Levesque, E. |
author_sort |
Pelletier, M. |
title |
Ecosystem changes across a gradient of permafrost degradation in subarctic Québec (Tasiapik Valley, Nunavik, Canada) |
title_short |
Ecosystem changes across a gradient of permafrost degradation in subarctic Québec (Tasiapik Valley, Nunavik, Canada) |
title_full |
Ecosystem changes across a gradient of permafrost degradation in subarctic Québec (Tasiapik Valley, Nunavik, Canada) |
title_fullStr |
Ecosystem changes across a gradient of permafrost degradation in subarctic Québec (Tasiapik Valley, Nunavik, Canada) |
title_full_unstemmed |
Ecosystem changes across a gradient of permafrost degradation in subarctic Québec (Tasiapik Valley, Nunavik, Canada) |
title_sort |
ecosystem changes across a gradient of permafrost degradation in subarctic québec (tasiapik valley, nunavik, canada) |
publishDate |
2019 |
url |
https://depot-e.uqtr.ca/id/eprint/11076/ https://depot-e.uqtr.ca/id/eprint/11076/1/LEVESQUE_E_197_ED.pdf https://doi.org/10.1139/as-2016-0049 |
geographic |
Canada Nunavik |
geographic_facet |
Canada Nunavik |
genre |
Active layer thickness Arctic Ice permafrost Subarctic subarctique* Thermokarst toundra Tundra Nunavik pergélisol |
genre_facet |
Active layer thickness Arctic Ice permafrost Subarctic subarctique* Thermokarst toundra Tundra Nunavik pergélisol |
op_relation |
https://depot-e.uqtr.ca/id/eprint/11076/1/LEVESQUE_E_197_ED.pdf Pelletier, M., Allard, M. et Levesque, E. (2019). Ecosystem changes across a gradient of permafrost degradation in subarctic Québec (Tasiapik Valley, Nunavik, Canada). Arctic Science, 5 (1). pp. 1-26. ISSN 2368-7460 DOI 10.1139/as-2016-0049 <https://doi.org/10.1139/as-2016-0049> doi:10.1139/as-2016-0049 |
op_rights |
cc_by_4 |
op_doi |
https://doi.org/10.1139/as-2016-0049 |
container_title |
Arctic Science |
container_volume |
5 |
container_issue |
1 |
container_start_page |
1 |
op_container_end_page |
26 |
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1789962946253684736 |