Hummock Vegetation at the Arctic Tree-line near Churchill, Manitoba
Hummocks, small earth or peat mounds, are widely distributed in the arctic and develop as a consequence of biomass accumulation and cryoturbation in the active layer. There is general agreement that the type of vegetation covering peat hummocks may alter the accumulation rate of organic material and...
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2004
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Online Access: | https://www.canadianfieldnaturalist.ca/index.php/cfn/article/view/61 https://doi.org/10.22621/cfn.v118i4.61 |
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ftjcfn:oai:canadianfieldnaturalist.ca:article/61 2024-09-15T18:02:05+00:00 Hummock Vegetation at the Arctic Tree-line near Churchill, Manitoba Tews, Jörg 2004-10-01 application/pdf https://www.canadianfieldnaturalist.ca/index.php/cfn/article/view/61 https://doi.org/10.22621/cfn.v118i4.61 eng eng The Ottawa Field-Naturalists' Club https://www.canadianfieldnaturalist.ca/index.php/cfn/article/view/61/60 https://www.canadianfieldnaturalist.ca/index.php/cfn/article/view/61 doi:10.22621/cfn.v118i4.61 The Canadian Field-Naturalist; Vol. 118 No. 4 (2004); 590-594 0008-3550 peat hummocks Tomenthypnum nitens Golden Fuzzy Fen Moss Hylocomium splendens Stair-step Moss Pleurozium schreberi Red-stemmed Feathermoss subarctic forest-tundra ecotone Hudson Bay Lowlands Manitoba info:eu-repo/semantics/article info:eu-repo/semantics/publishedVersion 2004 ftjcfn https://doi.org/10.22621/cfn.v118i4.61 2024-08-06T03:02:00Z Hummocks, small earth or peat mounds, are widely distributed in the arctic and develop as a consequence of biomass accumulation and cryoturbation in the active layer. There is general agreement that the type of vegetation covering peat hummocks may alter the accumulation rate of organic material and thus hummock growth and local carbon sink dynamics. Studies on hummock plant community compositions from the arctic are very scarce. Here, I present results of a case study from the arctic tree-line near Churchill, Manitoba (Canada). Vegetation composition, hummock height and soil moisture content were recorded in 40 peat hummocks located along a tree-line gradient from open forest to tundra. Based on a cluster analysis I found three moss-dominated types of hummock vegetation, according to (1) a Tomenthypnum nitens (golden fuzzy fen moss) type on low hummocks, (2) a Hylocomium splendens (stair-step moss) type on medium-sized hummocks, and (3) a Pleurozium schreberi (red-stemmed feathermoss) type on hummocks higher than 60-70 cm. I found hummock height to increase towards the forest interior with decreasing water content of the upper organic layer on the hummock top. This is indicated by a significant change in vegetation composition towards drought resistant moss species on higher hummocks. Furthermore, species richness decreased with increase in hummock height. Based on evidence from historical tree-line invasion the overall results suggest that hummock height increases due to peat accumulation over the course of time resulting in a typical change in plant community composition. Article in Journal/Newspaper Churchill Hudson Bay Subarctic Tundra The Canadian Field-Naturalist The Canadian Field-Naturalist 118 4 590 |
institution |
Open Polar |
collection |
The Canadian Field-Naturalist |
op_collection_id |
ftjcfn |
language |
English |
topic |
peat hummocks Tomenthypnum nitens Golden Fuzzy Fen Moss Hylocomium splendens Stair-step Moss Pleurozium schreberi Red-stemmed Feathermoss subarctic forest-tundra ecotone Hudson Bay Lowlands Manitoba |
spellingShingle |
peat hummocks Tomenthypnum nitens Golden Fuzzy Fen Moss Hylocomium splendens Stair-step Moss Pleurozium schreberi Red-stemmed Feathermoss subarctic forest-tundra ecotone Hudson Bay Lowlands Manitoba Tews, Jörg Hummock Vegetation at the Arctic Tree-line near Churchill, Manitoba |
topic_facet |
peat hummocks Tomenthypnum nitens Golden Fuzzy Fen Moss Hylocomium splendens Stair-step Moss Pleurozium schreberi Red-stemmed Feathermoss subarctic forest-tundra ecotone Hudson Bay Lowlands Manitoba |
description |
Hummocks, small earth or peat mounds, are widely distributed in the arctic and develop as a consequence of biomass accumulation and cryoturbation in the active layer. There is general agreement that the type of vegetation covering peat hummocks may alter the accumulation rate of organic material and thus hummock growth and local carbon sink dynamics. Studies on hummock plant community compositions from the arctic are very scarce. Here, I present results of a case study from the arctic tree-line near Churchill, Manitoba (Canada). Vegetation composition, hummock height and soil moisture content were recorded in 40 peat hummocks located along a tree-line gradient from open forest to tundra. Based on a cluster analysis I found three moss-dominated types of hummock vegetation, according to (1) a Tomenthypnum nitens (golden fuzzy fen moss) type on low hummocks, (2) a Hylocomium splendens (stair-step moss) type on medium-sized hummocks, and (3) a Pleurozium schreberi (red-stemmed feathermoss) type on hummocks higher than 60-70 cm. I found hummock height to increase towards the forest interior with decreasing water content of the upper organic layer on the hummock top. This is indicated by a significant change in vegetation composition towards drought resistant moss species on higher hummocks. Furthermore, species richness decreased with increase in hummock height. Based on evidence from historical tree-line invasion the overall results suggest that hummock height increases due to peat accumulation over the course of time resulting in a typical change in plant community composition. |
format |
Article in Journal/Newspaper |
author |
Tews, Jörg |
author_facet |
Tews, Jörg |
author_sort |
Tews, Jörg |
title |
Hummock Vegetation at the Arctic Tree-line near Churchill, Manitoba |
title_short |
Hummock Vegetation at the Arctic Tree-line near Churchill, Manitoba |
title_full |
Hummock Vegetation at the Arctic Tree-line near Churchill, Manitoba |
title_fullStr |
Hummock Vegetation at the Arctic Tree-line near Churchill, Manitoba |
title_full_unstemmed |
Hummock Vegetation at the Arctic Tree-line near Churchill, Manitoba |
title_sort |
hummock vegetation at the arctic tree-line near churchill, manitoba |
publisher |
The Ottawa Field-Naturalists' Club |
publishDate |
2004 |
url |
https://www.canadianfieldnaturalist.ca/index.php/cfn/article/view/61 https://doi.org/10.22621/cfn.v118i4.61 |
genre |
Churchill Hudson Bay Subarctic Tundra |
genre_facet |
Churchill Hudson Bay Subarctic Tundra |
op_source |
The Canadian Field-Naturalist; Vol. 118 No. 4 (2004); 590-594 0008-3550 |
op_relation |
https://www.canadianfieldnaturalist.ca/index.php/cfn/article/view/61/60 https://www.canadianfieldnaturalist.ca/index.php/cfn/article/view/61 doi:10.22621/cfn.v118i4.61 |
op_doi |
https://doi.org/10.22621/cfn.v118i4.61 |
container_title |
The Canadian Field-Naturalist |
container_volume |
118 |
container_issue |
4 |
container_start_page |
590 |
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1810439204522426368 |