Oxygen depletion in subarctic peatland thaw lakes
Permafrost thawing and erosion results in the enrichment of northern lakes by soil organic matter. These allochthonous inputs favour bacterial decomposition and may cause the draw-down of dissolved oxygen to anoxic conditions that promote methanogenesis. Our objective in the present study was to det...
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crcansciencepubl:10.1139/as-2016-0048 2024-06-23T07:48:16+00:00 Oxygen depletion in subarctic peatland thaw lakes Deshpande, Bethany N. Maps, Frédéric Matveev, Alex Vincent, Warwick F. 2017 http://dx.doi.org/10.1139/as-2016-0048 https://cdnsciencepub.com/doi/full-xml/10.1139/as-2016-0048 https://cdnsciencepub.com/doi/pdf/10.1139/as-2016-0048 en eng Canadian Science Publishing http://www.nrcresearchpress.com/page/about/CorporateTextAndDataMining Arctic Science volume 3, issue 2, page 406-428 ISSN 2368-7460 2368-7460 journal-article 2017 crcansciencepubl https://doi.org/10.1139/as-2016-0048 2024-06-13T04:10:47Z Permafrost thawing and erosion results in the enrichment of northern lakes by soil organic matter. These allochthonous inputs favour bacterial decomposition and may cause the draw-down of dissolved oxygen to anoxic conditions that promote methanogenesis. Our objective in the present study was to determine the seasonal variations in dissolved oxygen in a set of permafrost peatland lakes in subarctic Quebec, Canada, and to relate these changes to metabolic rates, ice cover, and mixing. The lakes had high dissolved organic carbon concentrations, and their surface waters in summer had greenhouse gas concentrations that were up to one (CO 2 ) to three (CH 4 ) orders of magnitude above air-equilibrium values, indicating their strongly heterotrophic character. Consistent with these observations, the peatland lakes had elevated rates of bacterial production and oxygen consumption. Continuous measurements of oxygen by in situ sensors and of ice cover by automated field cameras showed that the lakes became fully anoxic shortly after freeze-up. The waters were partially re-oxygenated by mixing events in spring and fall, but in one lake, the bottom waters remained anoxic throughout the year. These observations provide a foundation for subsequent biogeochemical and modelling studies of peatland thaw lakes as an abundant class of Arctic freshwater ecosystems. Article in Journal/Newspaper Arctic Arctic Ice permafrost Subarctic Canadian Science Publishing Arctic Canada Arctic Science 3 2 406 428 |
institution |
Open Polar |
collection |
Canadian Science Publishing |
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crcansciencepubl |
language |
English |
description |
Permafrost thawing and erosion results in the enrichment of northern lakes by soil organic matter. These allochthonous inputs favour bacterial decomposition and may cause the draw-down of dissolved oxygen to anoxic conditions that promote methanogenesis. Our objective in the present study was to determine the seasonal variations in dissolved oxygen in a set of permafrost peatland lakes in subarctic Quebec, Canada, and to relate these changes to metabolic rates, ice cover, and mixing. The lakes had high dissolved organic carbon concentrations, and their surface waters in summer had greenhouse gas concentrations that were up to one (CO 2 ) to three (CH 4 ) orders of magnitude above air-equilibrium values, indicating their strongly heterotrophic character. Consistent with these observations, the peatland lakes had elevated rates of bacterial production and oxygen consumption. Continuous measurements of oxygen by in situ sensors and of ice cover by automated field cameras showed that the lakes became fully anoxic shortly after freeze-up. The waters were partially re-oxygenated by mixing events in spring and fall, but in one lake, the bottom waters remained anoxic throughout the year. These observations provide a foundation for subsequent biogeochemical and modelling studies of peatland thaw lakes as an abundant class of Arctic freshwater ecosystems. |
format |
Article in Journal/Newspaper |
author |
Deshpande, Bethany N. Maps, Frédéric Matveev, Alex Vincent, Warwick F. |
spellingShingle |
Deshpande, Bethany N. Maps, Frédéric Matveev, Alex Vincent, Warwick F. Oxygen depletion in subarctic peatland thaw lakes |
author_facet |
Deshpande, Bethany N. Maps, Frédéric Matveev, Alex Vincent, Warwick F. |
author_sort |
Deshpande, Bethany N. |
title |
Oxygen depletion in subarctic peatland thaw lakes |
title_short |
Oxygen depletion in subarctic peatland thaw lakes |
title_full |
Oxygen depletion in subarctic peatland thaw lakes |
title_fullStr |
Oxygen depletion in subarctic peatland thaw lakes |
title_full_unstemmed |
Oxygen depletion in subarctic peatland thaw lakes |
title_sort |
oxygen depletion in subarctic peatland thaw lakes |
publisher |
Canadian Science Publishing |
publishDate |
2017 |
url |
http://dx.doi.org/10.1139/as-2016-0048 https://cdnsciencepub.com/doi/full-xml/10.1139/as-2016-0048 https://cdnsciencepub.com/doi/pdf/10.1139/as-2016-0048 |
geographic |
Arctic Canada |
geographic_facet |
Arctic Canada |
genre |
Arctic Arctic Ice permafrost Subarctic |
genre_facet |
Arctic Arctic Ice permafrost Subarctic |
op_source |
Arctic Science volume 3, issue 2, page 406-428 ISSN 2368-7460 2368-7460 |
op_rights |
http://www.nrcresearchpress.com/page/about/CorporateTextAndDataMining |
op_doi |
https://doi.org/10.1139/as-2016-0048 |
container_title |
Arctic Science |
container_volume |
3 |
container_issue |
2 |
container_start_page |
406 |
op_container_end_page |
428 |
_version_ |
1802638683705180160 |