Permafrost thaw causes large carbon loss in boreal peatlands while changes to peat quality are limited
Abstract Rapid, ongoing permafrost thaw of peatlands in the discontinuous permafrost zone is exposing a globally significant store of soil carbon (C) to microbial processes. Mineralization and release of this peat C to the atmosphere as greenhouse gases is a potentially important feedback to climate...
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crwiley:10.1111/gcb.16894 2024-06-23T07:56:01+00:00 Permafrost thaw causes large carbon loss in boreal peatlands while changes to peat quality are limited Harris, Lorna I. Olefeldt, David Pelletier, Nicolas Blodau, Christian Knorr, Klaus‐Holger Talbot, Julie Heffernan, Liam Turetsky, Merritt 2023 http://dx.doi.org/10.1111/gcb.16894 https://onlinelibrary.wiley.com/doi/pdf/10.1111/gcb.16894 en eng Wiley http://creativecommons.org/licenses/by-nc-nd/4.0/ Global Change Biology volume 29, issue 19, page 5720-5735 ISSN 1354-1013 1365-2486 journal-article 2023 crwiley https://doi.org/10.1111/gcb.16894 2024-06-13T04:25:33Z Abstract Rapid, ongoing permafrost thaw of peatlands in the discontinuous permafrost zone is exposing a globally significant store of soil carbon (C) to microbial processes. Mineralization and release of this peat C to the atmosphere as greenhouse gases is a potentially important feedback to climate change. Here we investigated the effects of permafrost thaw on peat C at a peatland complex in western Canada. We collected 15 complete peat cores (between 2.7 and 4.5 m deep) along four chronosequences, from elevated permafrost peat plateaus to saturated thermokarst bogs that thawed up to 600 years ago. The peat cores were analysed for peat C storage and peat quality, as indicated by decomposition proxies (FTIR and C/N ratios) and potential decomposability using a 200‐day aerobic laboratory incubation. Our results suggest net C loss following thaw, with average total peat C stocks decreasing by ~19.3 ± 7.2 kg C m −2 over <600 years (~13% loss). Average post‐thaw accumulation of new peat at the surface over the same period was ~13.1 ± 2.5 kg C m −2 . We estimate ~19% (±5.8%) of deep peat (>40 cm below surface) C is lost following thaw (average 26 ± 7.9 kg C m −2 over <600 years). Our FTIR analysis shows peat below the thaw transition in thermokarst bogs is slightly more decomposed than peat of a similar type and age in permafrost plateaus, but we found no significant changes to the quality or lability of deeper peat across the chronosequences. Our incubation results also showed no increase in C mineralization of deep peat across the chronosequences. While these limited changes in peat quality in deeper peat following permafrost thaw highlight uncertainty in the exact mechanisms and processes for C loss, our analysis of peat C stocks shows large C losses following permafrost thaw in peatlands in western Canada. Article in Journal/Newspaper Peat permafrost Thermokarst Wiley Online Library Canada Global Change Biology 29 19 5720 5735 |
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Wiley Online Library |
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crwiley |
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English |
description |
Abstract Rapid, ongoing permafrost thaw of peatlands in the discontinuous permafrost zone is exposing a globally significant store of soil carbon (C) to microbial processes. Mineralization and release of this peat C to the atmosphere as greenhouse gases is a potentially important feedback to climate change. Here we investigated the effects of permafrost thaw on peat C at a peatland complex in western Canada. We collected 15 complete peat cores (between 2.7 and 4.5 m deep) along four chronosequences, from elevated permafrost peat plateaus to saturated thermokarst bogs that thawed up to 600 years ago. The peat cores were analysed for peat C storage and peat quality, as indicated by decomposition proxies (FTIR and C/N ratios) and potential decomposability using a 200‐day aerobic laboratory incubation. Our results suggest net C loss following thaw, with average total peat C stocks decreasing by ~19.3 ± 7.2 kg C m −2 over <600 years (~13% loss). Average post‐thaw accumulation of new peat at the surface over the same period was ~13.1 ± 2.5 kg C m −2 . We estimate ~19% (±5.8%) of deep peat (>40 cm below surface) C is lost following thaw (average 26 ± 7.9 kg C m −2 over <600 years). Our FTIR analysis shows peat below the thaw transition in thermokarst bogs is slightly more decomposed than peat of a similar type and age in permafrost plateaus, but we found no significant changes to the quality or lability of deeper peat across the chronosequences. Our incubation results also showed no increase in C mineralization of deep peat across the chronosequences. While these limited changes in peat quality in deeper peat following permafrost thaw highlight uncertainty in the exact mechanisms and processes for C loss, our analysis of peat C stocks shows large C losses following permafrost thaw in peatlands in western Canada. |
format |
Article in Journal/Newspaper |
author |
Harris, Lorna I. Olefeldt, David Pelletier, Nicolas Blodau, Christian Knorr, Klaus‐Holger Talbot, Julie Heffernan, Liam Turetsky, Merritt |
spellingShingle |
Harris, Lorna I. Olefeldt, David Pelletier, Nicolas Blodau, Christian Knorr, Klaus‐Holger Talbot, Julie Heffernan, Liam Turetsky, Merritt Permafrost thaw causes large carbon loss in boreal peatlands while changes to peat quality are limited |
author_facet |
Harris, Lorna I. Olefeldt, David Pelletier, Nicolas Blodau, Christian Knorr, Klaus‐Holger Talbot, Julie Heffernan, Liam Turetsky, Merritt |
author_sort |
Harris, Lorna I. |
title |
Permafrost thaw causes large carbon loss in boreal peatlands while changes to peat quality are limited |
title_short |
Permafrost thaw causes large carbon loss in boreal peatlands while changes to peat quality are limited |
title_full |
Permafrost thaw causes large carbon loss in boreal peatlands while changes to peat quality are limited |
title_fullStr |
Permafrost thaw causes large carbon loss in boreal peatlands while changes to peat quality are limited |
title_full_unstemmed |
Permafrost thaw causes large carbon loss in boreal peatlands while changes to peat quality are limited |
title_sort |
permafrost thaw causes large carbon loss in boreal peatlands while changes to peat quality are limited |
publisher |
Wiley |
publishDate |
2023 |
url |
http://dx.doi.org/10.1111/gcb.16894 https://onlinelibrary.wiley.com/doi/pdf/10.1111/gcb.16894 |
geographic |
Canada |
geographic_facet |
Canada |
genre |
Peat permafrost Thermokarst |
genre_facet |
Peat permafrost Thermokarst |
op_source |
Global Change Biology volume 29, issue 19, page 5720-5735 ISSN 1354-1013 1365-2486 |
op_rights |
http://creativecommons.org/licenses/by-nc-nd/4.0/ |
op_doi |
https://doi.org/10.1111/gcb.16894 |
container_title |
Global Change Biology |
container_volume |
29 |
container_issue |
19 |
container_start_page |
5720 |
op_container_end_page |
5735 |
_version_ |
1802648853773549568 |