Carbon Dioxide Exchange in a Permafrost-Dominated Boreal Wetland in the Northwest Territories, Canada
Northern boreal wetland complexes are substantial reservoirs for carbon and play a crucial role in both regional and global carbon budgets but they are showing significant signs of impact by climate change. This study examined the carbon dioxide flux of a high boreal wetland during the snowmelt and...
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ftwlaurieruniv:oai:scholars.wlu.ca:etd-1983 2023-06-11T04:11:45+02:00 Carbon Dioxide Exchange in a Permafrost-Dominated Boreal Wetland in the Northwest Territories, Canada Kenward, Andrea J. 2010-01-01T08:00:00Z application/pdf https://scholars.wlu.ca/etd/984 https://scholars.wlu.ca/context/etd/article/1983/viewcontent/MR68712.PDF unknown Scholars Commons @ Laurier https://scholars.wlu.ca/etd/984 https://scholars.wlu.ca/context/etd/article/1983/viewcontent/MR68712.PDF Theses and Dissertations (Comprehensive) Biogeochemistry text 2010 ftwlaurieruniv 2023-05-07T16:37:29Z Northern boreal wetland complexes are substantial reservoirs for carbon and play a crucial role in both regional and global carbon budgets but they are showing significant signs of impact by climate change. This study examined the carbon dioxide flux of a high boreal wetland during the snowmelt and growing season of 2008 in Scotty Creek Basin, located near Fort Simpson (61°18'N, 121°18'W), Northwest Territories. This basin is not only responding to shifts in atmospheric temperatures, but it is also under additional pressure from increasing permafrost degradation. A dynamic closed-system chamber was used to monitor and quantify mid-day total respiration (Rtot), gross ecosystem production (GEP), and net ecosystem exchange (NEE) at nine sites, in order to characterize and compare the gas flux gradients for three landscape units typical of the lower Liard River valley (channel fens, ombrotrophic flat bogs and peat plateaus). Each landscape unit exhibited increasing rates of Rtot and GEP for the duration of study. Instantaneous rates of Rtot and NEE were highest in the permafrost plateau and channel fen, while the flat bog remained consistently low throughout the season. While there was significant variation in magnitude, the results demonstrated relatively similar temporal variability between landscapes. Temporal and spatial variability in CO2 exchange was further examined through the relationships with local environmental conditions: photo synthetically active radiation, air temperature, soil temperature, soil moisture, and frost table and water table depth. Light response curves derived using an exponential model showed GEP was primarily driven by photosynthetically active radiation, yet significant scatter suggested additional environmental influences. Differential development in Rtot appeared to be most influenced by temperature and moisture regimes. Ambient air temperature, and soil and water temperatures at 20 cm all showed strong positive correlations with Rtot, while decreasing frost and water table depth, ... Text Fort Simpson Liard River Northwest Territories Peat permafrost Wilfrid Laurier University, Ontario: Scholars Commons@Laurier Canada Fort Simpson ENVELOPE(-121.320,-121.320,61.808,61.808) Liard ENVELOPE(-67.417,-67.417,-66.850,-66.850) Northwest Territories Scotty Creek ENVELOPE(-121.561,-121.561,61.436,61.436) |
institution |
Open Polar |
collection |
Wilfrid Laurier University, Ontario: Scholars Commons@Laurier |
op_collection_id |
ftwlaurieruniv |
language |
unknown |
topic |
Biogeochemistry |
spellingShingle |
Biogeochemistry Kenward, Andrea J. Carbon Dioxide Exchange in a Permafrost-Dominated Boreal Wetland in the Northwest Territories, Canada |
topic_facet |
Biogeochemistry |
description |
Northern boreal wetland complexes are substantial reservoirs for carbon and play a crucial role in both regional and global carbon budgets but they are showing significant signs of impact by climate change. This study examined the carbon dioxide flux of a high boreal wetland during the snowmelt and growing season of 2008 in Scotty Creek Basin, located near Fort Simpson (61°18'N, 121°18'W), Northwest Territories. This basin is not only responding to shifts in atmospheric temperatures, but it is also under additional pressure from increasing permafrost degradation. A dynamic closed-system chamber was used to monitor and quantify mid-day total respiration (Rtot), gross ecosystem production (GEP), and net ecosystem exchange (NEE) at nine sites, in order to characterize and compare the gas flux gradients for three landscape units typical of the lower Liard River valley (channel fens, ombrotrophic flat bogs and peat plateaus). Each landscape unit exhibited increasing rates of Rtot and GEP for the duration of study. Instantaneous rates of Rtot and NEE were highest in the permafrost plateau and channel fen, while the flat bog remained consistently low throughout the season. While there was significant variation in magnitude, the results demonstrated relatively similar temporal variability between landscapes. Temporal and spatial variability in CO2 exchange was further examined through the relationships with local environmental conditions: photo synthetically active radiation, air temperature, soil temperature, soil moisture, and frost table and water table depth. Light response curves derived using an exponential model showed GEP was primarily driven by photosynthetically active radiation, yet significant scatter suggested additional environmental influences. Differential development in Rtot appeared to be most influenced by temperature and moisture regimes. Ambient air temperature, and soil and water temperatures at 20 cm all showed strong positive correlations with Rtot, while decreasing frost and water table depth, ... |
format |
Text |
author |
Kenward, Andrea J. |
author_facet |
Kenward, Andrea J. |
author_sort |
Kenward, Andrea J. |
title |
Carbon Dioxide Exchange in a Permafrost-Dominated Boreal Wetland in the Northwest Territories, Canada |
title_short |
Carbon Dioxide Exchange in a Permafrost-Dominated Boreal Wetland in the Northwest Territories, Canada |
title_full |
Carbon Dioxide Exchange in a Permafrost-Dominated Boreal Wetland in the Northwest Territories, Canada |
title_fullStr |
Carbon Dioxide Exchange in a Permafrost-Dominated Boreal Wetland in the Northwest Territories, Canada |
title_full_unstemmed |
Carbon Dioxide Exchange in a Permafrost-Dominated Boreal Wetland in the Northwest Territories, Canada |
title_sort |
carbon dioxide exchange in a permafrost-dominated boreal wetland in the northwest territories, canada |
publisher |
Scholars Commons @ Laurier |
publishDate |
2010 |
url |
https://scholars.wlu.ca/etd/984 https://scholars.wlu.ca/context/etd/article/1983/viewcontent/MR68712.PDF |
long_lat |
ENVELOPE(-121.320,-121.320,61.808,61.808) ENVELOPE(-67.417,-67.417,-66.850,-66.850) ENVELOPE(-121.561,-121.561,61.436,61.436) |
geographic |
Canada Fort Simpson Liard Northwest Territories Scotty Creek |
geographic_facet |
Canada Fort Simpson Liard Northwest Territories Scotty Creek |
genre |
Fort Simpson Liard River Northwest Territories Peat permafrost |
genre_facet |
Fort Simpson Liard River Northwest Territories Peat permafrost |
op_source |
Theses and Dissertations (Comprehensive) |
op_relation |
https://scholars.wlu.ca/etd/984 https://scholars.wlu.ca/context/etd/article/1983/viewcontent/MR68712.PDF |
_version_ |
1768387047139049472 |