Lability of dissolved organic carbon from boreal peatlands: interactions between permafrost thaw, wildfire, and season1
Boreal peatlands are major sources of dissolved organic carbon (DOC) to downstream aquatic ecosystems, where it influences carbon cycling and food web structure. Wildfire and permafrost thaw alter peatland vegetation and hydrology and may affect the quantity and chemical composition of exported DOC....
Published in: | Canadian Journal of Soil Science |
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2020
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ftbioone:10.1139/cjss-2019-0154 2024-06-02T08:12:52+00:00 Lability of dissolved organic carbon from boreal peatlands: interactions between permafrost thaw, wildfire, and season1 Katheryn Burd Cristian Estop-Aragonés Suzanne E. Tank David Olefeldt Katheryn Burd Cristian Estop-Aragonés Suzanne E. Tank David Olefeldt world 2020-02-25 text/HTML https://doi.org/10.1139/cjss-2019-0154 en eng Canadian Science Publishing doi:10.1139/cjss-2019-0154 All rights reserved. https://doi.org/10.1139/cjss-2019-0154 Text 2020 ftbioone https://doi.org/10.1139/cjss-2019-0154 2024-05-07T01:01:34Z Boreal peatlands are major sources of dissolved organic carbon (DOC) to downstream aquatic ecosystems, where it influences carbon cycling and food web structure. Wildfire and permafrost thaw alter peatland vegetation and hydrology and may affect the quantity and chemical composition of exported DOC. We studied the influence of wildfire and thaw on microbial and photochemical lability of near-surface porewater DOC, assessed through 7 d incubations. We carried out these incubations in spring, summer, and fall but only found differences in spring when DOC biodegradability (% loss during dark incubations) increased with lower DOC aromaticity and C/N ratios. During spring, the most labile DOC was found in recently formed thermokarst bogs along collapsing peat plateau edges (25% loss), which was greater than in mature sections of thermokarst bogs (3%), and peat plateaus with intact permafrost (9%). Increased DOC lability following thaw was likely linked to high DOC production and turnover associated with productive hydrophilic Sphagnum mosses and sedges, rather than thawed permafrost peat. A wildfire (3 yr prior) reduced DOC biodegradability in both peat plateaus (4%) and rapidly collapsing peat plateau edges (14%). Biodegradability of DOC in summer and fall was low across all sites; 2% and 4%, respectively. Photodegradation was shown to potentially contribute significantly to downstream DOC degradation but did not vary across peatland sites. We show that disturbances such as permafrost thaw and wildfire have the potential to affect downstream carbon cycling, particularly as the largest influences were found in spring when peatlands are well connected to downstream aquatic ecosystems. Text Peat Peat plateau permafrost Thermokarst BioOne Online Journals Canadian Journal of Soil Science 100 4 503 515 |
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BioOne Online Journals |
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English |
description |
Boreal peatlands are major sources of dissolved organic carbon (DOC) to downstream aquatic ecosystems, where it influences carbon cycling and food web structure. Wildfire and permafrost thaw alter peatland vegetation and hydrology and may affect the quantity and chemical composition of exported DOC. We studied the influence of wildfire and thaw on microbial and photochemical lability of near-surface porewater DOC, assessed through 7 d incubations. We carried out these incubations in spring, summer, and fall but only found differences in spring when DOC biodegradability (% loss during dark incubations) increased with lower DOC aromaticity and C/N ratios. During spring, the most labile DOC was found in recently formed thermokarst bogs along collapsing peat plateau edges (25% loss), which was greater than in mature sections of thermokarst bogs (3%), and peat plateaus with intact permafrost (9%). Increased DOC lability following thaw was likely linked to high DOC production and turnover associated with productive hydrophilic Sphagnum mosses and sedges, rather than thawed permafrost peat. A wildfire (3 yr prior) reduced DOC biodegradability in both peat plateaus (4%) and rapidly collapsing peat plateau edges (14%). Biodegradability of DOC in summer and fall was low across all sites; 2% and 4%, respectively. Photodegradation was shown to potentially contribute significantly to downstream DOC degradation but did not vary across peatland sites. We show that disturbances such as permafrost thaw and wildfire have the potential to affect downstream carbon cycling, particularly as the largest influences were found in spring when peatlands are well connected to downstream aquatic ecosystems. |
author2 |
Katheryn Burd Cristian Estop-Aragonés Suzanne E. Tank David Olefeldt |
format |
Text |
author |
Katheryn Burd Cristian Estop-Aragonés Suzanne E. Tank David Olefeldt |
spellingShingle |
Katheryn Burd Cristian Estop-Aragonés Suzanne E. Tank David Olefeldt Lability of dissolved organic carbon from boreal peatlands: interactions between permafrost thaw, wildfire, and season1 |
author_facet |
Katheryn Burd Cristian Estop-Aragonés Suzanne E. Tank David Olefeldt |
author_sort |
Katheryn Burd |
title |
Lability of dissolved organic carbon from boreal peatlands: interactions between permafrost thaw, wildfire, and season1 |
title_short |
Lability of dissolved organic carbon from boreal peatlands: interactions between permafrost thaw, wildfire, and season1 |
title_full |
Lability of dissolved organic carbon from boreal peatlands: interactions between permafrost thaw, wildfire, and season1 |
title_fullStr |
Lability of dissolved organic carbon from boreal peatlands: interactions between permafrost thaw, wildfire, and season1 |
title_full_unstemmed |
Lability of dissolved organic carbon from boreal peatlands: interactions between permafrost thaw, wildfire, and season1 |
title_sort |
lability of dissolved organic carbon from boreal peatlands: interactions between permafrost thaw, wildfire, and season1 |
publisher |
Canadian Science Publishing |
publishDate |
2020 |
url |
https://doi.org/10.1139/cjss-2019-0154 |
op_coverage |
world |
genre |
Peat Peat plateau permafrost Thermokarst |
genre_facet |
Peat Peat plateau permafrost Thermokarst |
op_source |
https://doi.org/10.1139/cjss-2019-0154 |
op_relation |
doi:10.1139/cjss-2019-0154 |
op_rights |
All rights reserved. |
op_doi |
https://doi.org/10.1139/cjss-2019-0154 |
container_title |
Canadian Journal of Soil Science |
container_volume |
100 |
container_issue |
4 |
container_start_page |
503 |
op_container_end_page |
515 |
_version_ |
1800759446395158528 |