Thermo-erosion gullies boost the transition from wet to mesic tundra vegetation
Continuous permafrost zones with well-developed polygonal ice-wedge networks are particularly vulnerable to climate change. Thermo-mechanical erosion can initiate the development of gullies that lead to substantial drainage of adjacent wet habitats. How vegetation responds to this particular disturb...
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ftdoajarticles:oai:doaj.org/article:68eeff8a19e844cda56f574ad05329cb 2023-05-15T14:56:41+02:00 Thermo-erosion gullies boost the transition from wet to mesic tundra vegetation N. Perreault E. Lévesque D. Fortier L. J. Lamarque 2016-03-01T00:00:00Z https://doi.org/10.5194/bg-13-1237-2016 https://doaj.org/article/68eeff8a19e844cda56f574ad05329cb EN eng Copernicus Publications http://www.biogeosciences.net/13/1237/2016/bg-13-1237-2016.pdf https://doaj.org/toc/1726-4170 https://doaj.org/toc/1726-4189 1726-4170 1726-4189 doi:10.5194/bg-13-1237-2016 https://doaj.org/article/68eeff8a19e844cda56f574ad05329cb Biogeosciences, Vol 13, Iss 4, Pp 1237-1253 (2016) Ecology QH540-549.5 Life QH501-531 Geology QE1-996.5 article 2016 ftdoajarticles https://doi.org/10.5194/bg-13-1237-2016 2022-12-30T21:28:49Z Continuous permafrost zones with well-developed polygonal ice-wedge networks are particularly vulnerable to climate change. Thermo-mechanical erosion can initiate the development of gullies that lead to substantial drainage of adjacent wet habitats. How vegetation responds to this particular disturbance is currently unknown but has the potential to significantly disrupt function and structure of Arctic ecosystems. Focusing on three major gullies of Bylot Island, Nunavut, we estimated the impacts of thermo-erosion processes on plant community changes. We explored over 2 years the influence of environmental factors on plant species richness, abundance and biomass in 62 low-centered wet polygons, 87 low-centered disturbed polygons and 48 mesic environment sites. Gullying decreased soil moisture by 40 % and thaw-front depth by 10 cm in the center of breached polygons within less than 5 years after the inception of ice wedge degradation, entailing a gradual yet marked vegetation shift from wet to mesic plant communities within 5 to 10 years. This transition was accompanied by a five times decrease in graminoid above-ground biomass. Soil moisture and thaw-front depth changed almost immediately following gullying initiation as they were of similar magnitude between older (> 5 years) and recently (< 5 years) disturbed polygons. In contrast, there was a lag-time in vegetation response to the altered physical environment with plant species richness and biomass differing between the two types of disturbed polygons. To date (10 years after disturbance), the stable state of the mesic environment cover has not been fully reached yet. Our results illustrate that wetlands are highly vulnerable to thermo-erosion processes, which drive landscape transformation on a relative short period of time for High Arctic perennial plant communities (5 to 10 years). Such succession towards mesic plant communities can have substantial consequences on the food availability for herbivores and carbon emissions of Arctic ecosystems. Article in Journal/Newspaper Arctic Bylot Island Climate change Ice Nunavut permafrost Tundra wedge* Directory of Open Access Journals: DOAJ Articles Arctic Nunavut Bylot Island Biogeosciences 13 4 1237 1253 |
institution |
Open Polar |
collection |
Directory of Open Access Journals: DOAJ Articles |
op_collection_id |
ftdoajarticles |
language |
English |
topic |
Ecology QH540-549.5 Life QH501-531 Geology QE1-996.5 |
spellingShingle |
Ecology QH540-549.5 Life QH501-531 Geology QE1-996.5 N. Perreault E. Lévesque D. Fortier L. J. Lamarque Thermo-erosion gullies boost the transition from wet to mesic tundra vegetation |
topic_facet |
Ecology QH540-549.5 Life QH501-531 Geology QE1-996.5 |
description |
Continuous permafrost zones with well-developed polygonal ice-wedge networks are particularly vulnerable to climate change. Thermo-mechanical erosion can initiate the development of gullies that lead to substantial drainage of adjacent wet habitats. How vegetation responds to this particular disturbance is currently unknown but has the potential to significantly disrupt function and structure of Arctic ecosystems. Focusing on three major gullies of Bylot Island, Nunavut, we estimated the impacts of thermo-erosion processes on plant community changes. We explored over 2 years the influence of environmental factors on plant species richness, abundance and biomass in 62 low-centered wet polygons, 87 low-centered disturbed polygons and 48 mesic environment sites. Gullying decreased soil moisture by 40 % and thaw-front depth by 10 cm in the center of breached polygons within less than 5 years after the inception of ice wedge degradation, entailing a gradual yet marked vegetation shift from wet to mesic plant communities within 5 to 10 years. This transition was accompanied by a five times decrease in graminoid above-ground biomass. Soil moisture and thaw-front depth changed almost immediately following gullying initiation as they were of similar magnitude between older (> 5 years) and recently (< 5 years) disturbed polygons. In contrast, there was a lag-time in vegetation response to the altered physical environment with plant species richness and biomass differing between the two types of disturbed polygons. To date (10 years after disturbance), the stable state of the mesic environment cover has not been fully reached yet. Our results illustrate that wetlands are highly vulnerable to thermo-erosion processes, which drive landscape transformation on a relative short period of time for High Arctic perennial plant communities (5 to 10 years). Such succession towards mesic plant communities can have substantial consequences on the food availability for herbivores and carbon emissions of Arctic ecosystems. |
format |
Article in Journal/Newspaper |
author |
N. Perreault E. Lévesque D. Fortier L. J. Lamarque |
author_facet |
N. Perreault E. Lévesque D. Fortier L. J. Lamarque |
author_sort |
N. Perreault |
title |
Thermo-erosion gullies boost the transition from wet to mesic tundra vegetation |
title_short |
Thermo-erosion gullies boost the transition from wet to mesic tundra vegetation |
title_full |
Thermo-erosion gullies boost the transition from wet to mesic tundra vegetation |
title_fullStr |
Thermo-erosion gullies boost the transition from wet to mesic tundra vegetation |
title_full_unstemmed |
Thermo-erosion gullies boost the transition from wet to mesic tundra vegetation |
title_sort |
thermo-erosion gullies boost the transition from wet to mesic tundra vegetation |
publisher |
Copernicus Publications |
publishDate |
2016 |
url |
https://doi.org/10.5194/bg-13-1237-2016 https://doaj.org/article/68eeff8a19e844cda56f574ad05329cb |
geographic |
Arctic Nunavut Bylot Island |
geographic_facet |
Arctic Nunavut Bylot Island |
genre |
Arctic Bylot Island Climate change Ice Nunavut permafrost Tundra wedge* |
genre_facet |
Arctic Bylot Island Climate change Ice Nunavut permafrost Tundra wedge* |
op_source |
Biogeosciences, Vol 13, Iss 4, Pp 1237-1253 (2016) |
op_relation |
http://www.biogeosciences.net/13/1237/2016/bg-13-1237-2016.pdf https://doaj.org/toc/1726-4170 https://doaj.org/toc/1726-4189 1726-4170 1726-4189 doi:10.5194/bg-13-1237-2016 https://doaj.org/article/68eeff8a19e844cda56f574ad05329cb |
op_doi |
https://doi.org/10.5194/bg-13-1237-2016 |
container_title |
Biogeosciences |
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13 |
container_issue |
4 |
container_start_page |
1237 |
op_container_end_page |
1253 |
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1766328772961763328 |