Évolution récente d'une tourbière à palses (Québec subarctique) : analyse cartographique et dendrochronologique
During the past 100 years, palsa bogs located on the eastern coast of Hudson Bay have undergone major changes associated with global climatic warming of the northern hemisphere. The recent main developmental stages of palsas, collapse scars, and thermokarstic pools were reconstructed within a repres...
Published in: | Canadian Journal of Botany |
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Language: | French |
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Canadian Science Publishing
1988
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Online Access: | http://dx.doi.org/10.1139/b88-304 http://www.nrcresearchpress.com/doi/pdf/10.1139/b88-304 |
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crcansciencepubl:10.1139/b88-304 2023-12-17T10:31:24+01:00 Évolution récente d'une tourbière à palses (Québec subarctique) : analyse cartographique et dendrochronologique Laprise, Danielle Payette, Serge 1988 http://dx.doi.org/10.1139/b88-304 http://www.nrcresearchpress.com/doi/pdf/10.1139/b88-304 fr fre Canadian Science Publishing http://www.nrcresearchpress.com/page/about/CorporateTextAndDataMining Canadian Journal of Botany volume 66, issue 11, page 2217-2227 ISSN 0008-4026 Plant Science journal-article 1988 crcansciencepubl https://doi.org/10.1139/b88-304 2023-11-19T13:38:23Z During the past 100 years, palsa bogs located on the eastern coast of Hudson Bay have undergone major changes associated with global climatic warming of the northern hemisphere. The recent main developmental stages of palsas, collapse scars, and thermokarstic pools were reconstructed within a representative permafrost peatland located in the southern part of the forest–tundra, using detailed mapping and tree-ring analyses. Maps of the peatland in 1957, 1973, and 1983 indicate a 49% decrease of the total cover of palsas and collapse scars between 1957 and 1983 and a 44% increase of the thermokarstic pool surface. Degradation of the palsa bog was more pronounced between 1957 and 1973 than between 1973 and 1983. Tree-ring analysis of reaction wood on black spruce (Picea mariana (Mill.) BSP.) exposed to unstable peat substratum indicates that permafrost degradation, which began as early as 1880, increased markedly between 1930 and 1965. During the 19th century, the permafrost peatland was mainly composed of large peat plateaus, which subsequently disintegrated into residual palsas, collapse scars, and thermokarstic pools. In addition the increase in temperature during the 20th century, it seems that milder winters with heavier snowfalls promoted conditions conducive to permafrost degradation. The constantly increasing contrast in the microtopographic pattern of the peatland, resulting from the transformation of peat plateaus into smaller palsa units, created more snow cover on east and southeast palsa slopes, thus accelerating permafrost degradation. This autocatalytic process seems to have also played a role in some sections of the peatland with abundant thermokarstic pools, where major changes in drainage conditions have stimulated thermokarstic erosion. Article in Journal/Newspaper Hudson Bay palsa palsas Peat permafrost subarctique* Tundra Canadian Science Publishing (via Crossref) Hudson Bay Hudson Canadian Journal of Botany 66 11 2217 2227 |
institution |
Open Polar |
collection |
Canadian Science Publishing (via Crossref) |
op_collection_id |
crcansciencepubl |
language |
French |
topic |
Plant Science |
spellingShingle |
Plant Science Laprise, Danielle Payette, Serge Évolution récente d'une tourbière à palses (Québec subarctique) : analyse cartographique et dendrochronologique |
topic_facet |
Plant Science |
description |
During the past 100 years, palsa bogs located on the eastern coast of Hudson Bay have undergone major changes associated with global climatic warming of the northern hemisphere. The recent main developmental stages of palsas, collapse scars, and thermokarstic pools were reconstructed within a representative permafrost peatland located in the southern part of the forest–tundra, using detailed mapping and tree-ring analyses. Maps of the peatland in 1957, 1973, and 1983 indicate a 49% decrease of the total cover of palsas and collapse scars between 1957 and 1983 and a 44% increase of the thermokarstic pool surface. Degradation of the palsa bog was more pronounced between 1957 and 1973 than between 1973 and 1983. Tree-ring analysis of reaction wood on black spruce (Picea mariana (Mill.) BSP.) exposed to unstable peat substratum indicates that permafrost degradation, which began as early as 1880, increased markedly between 1930 and 1965. During the 19th century, the permafrost peatland was mainly composed of large peat plateaus, which subsequently disintegrated into residual palsas, collapse scars, and thermokarstic pools. In addition the increase in temperature during the 20th century, it seems that milder winters with heavier snowfalls promoted conditions conducive to permafrost degradation. The constantly increasing contrast in the microtopographic pattern of the peatland, resulting from the transformation of peat plateaus into smaller palsa units, created more snow cover on east and southeast palsa slopes, thus accelerating permafrost degradation. This autocatalytic process seems to have also played a role in some sections of the peatland with abundant thermokarstic pools, where major changes in drainage conditions have stimulated thermokarstic erosion. |
format |
Article in Journal/Newspaper |
author |
Laprise, Danielle Payette, Serge |
author_facet |
Laprise, Danielle Payette, Serge |
author_sort |
Laprise, Danielle |
title |
Évolution récente d'une tourbière à palses (Québec subarctique) : analyse cartographique et dendrochronologique |
title_short |
Évolution récente d'une tourbière à palses (Québec subarctique) : analyse cartographique et dendrochronologique |
title_full |
Évolution récente d'une tourbière à palses (Québec subarctique) : analyse cartographique et dendrochronologique |
title_fullStr |
Évolution récente d'une tourbière à palses (Québec subarctique) : analyse cartographique et dendrochronologique |
title_full_unstemmed |
Évolution récente d'une tourbière à palses (Québec subarctique) : analyse cartographique et dendrochronologique |
title_sort |
évolution récente d'une tourbière à palses (québec subarctique) : analyse cartographique et dendrochronologique |
publisher |
Canadian Science Publishing |
publishDate |
1988 |
url |
http://dx.doi.org/10.1139/b88-304 http://www.nrcresearchpress.com/doi/pdf/10.1139/b88-304 |
geographic |
Hudson Bay Hudson |
geographic_facet |
Hudson Bay Hudson |
genre |
Hudson Bay palsa palsas Peat permafrost subarctique* Tundra |
genre_facet |
Hudson Bay palsa palsas Peat permafrost subarctique* Tundra |
op_source |
Canadian Journal of Botany volume 66, issue 11, page 2217-2227 ISSN 0008-4026 |
op_rights |
http://www.nrcresearchpress.com/page/about/CorporateTextAndDataMining |
op_doi |
https://doi.org/10.1139/b88-304 |
container_title |
Canadian Journal of Botany |
container_volume |
66 |
container_issue |
11 |
container_start_page |
2217 |
op_container_end_page |
2227 |
_version_ |
1785584701155573760 |