Plant carbon allocation drives turnover of old soil organic matter in permafrost tundra soils
Abstract Carbon cycle feedbacks from permafrost ecosystems are expected to accelerate global climate change. Shifts in vegetation productivity and composition in permafrost regions could influence soil organic carbon (SOC) turnover rates via rhizosphere (root zone) priming effects (RPEs), but these...
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crwiley:10.1111/gcb.15134 2024-09-15T18:02:21+00:00 Plant carbon allocation drives turnover of old soil organic matter in permafrost tundra soils Street, Lorna E. Garnett, Mark H. Subke, Jens‐Arne Baxter, Robert Dean, Joshua F. Wookey, Philip A. Natural Environment Research Council 2020 http://dx.doi.org/10.1111/gcb.15134 https://api.wiley.com/onlinelibrary/tdm/v1/articles/10.1111%2Fgcb.15134 https://onlinelibrary.wiley.com/doi/pdf/10.1111/gcb.15134 https://onlinelibrary.wiley.com/doi/full-xml/10.1111/gcb.15134 en eng Wiley http://creativecommons.org/licenses/by/4.0/ Global Change Biology volume 26, issue 8, page 4559-4571 ISSN 1354-1013 1365-2486 journal-article 2020 crwiley https://doi.org/10.1111/gcb.15134 2024-08-30T04:12:04Z Abstract Carbon cycle feedbacks from permafrost ecosystems are expected to accelerate global climate change. Shifts in vegetation productivity and composition in permafrost regions could influence soil organic carbon (SOC) turnover rates via rhizosphere (root zone) priming effects (RPEs), but these processes are not currently accounted for in model predictions. We use a radiocarbon (bomb‐ 14 C) approach to test for RPEs in two Arctic tall shrubs, alder ( Alnus viridis (Chaix) DC.) and birch ( Betula glandulosa Michx.), and in ericaceous heath tundra vegetation. We compare surface CO 2 efflux rates and 14 C content between intact vegetation and plots in which below‐ground allocation of recent photosynthate was prevented by trenching and removal of above‐ground biomass. We show, for the first time, that recent photosynthate drives mineralization of older (>50 years old) SOC under birch shrubs and ericaceous heath tundra. By contrast, we find no evidence of RPEs in soils under alder. This is the first direct evidence from permafrost systems that vegetation influences SOC turnover through below‐ground C allocation. The vulnerability of SOC to decomposition in permafrost systems may therefore be directly linked to vegetation change, such that expansion of birch shrubs across the Arctic could increase decomposition of older SOC. Our results suggest that carbon cycle models that do not include RPEs risk underestimating the carbon cycle feedbacks associated with changing conditions in tundra regions. Article in Journal/Newspaper Climate change permafrost Tundra Wiley Online Library Global Change Biology 26 8 4559 4571 |
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English |
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Abstract Carbon cycle feedbacks from permafrost ecosystems are expected to accelerate global climate change. Shifts in vegetation productivity and composition in permafrost regions could influence soil organic carbon (SOC) turnover rates via rhizosphere (root zone) priming effects (RPEs), but these processes are not currently accounted for in model predictions. We use a radiocarbon (bomb‐ 14 C) approach to test for RPEs in two Arctic tall shrubs, alder ( Alnus viridis (Chaix) DC.) and birch ( Betula glandulosa Michx.), and in ericaceous heath tundra vegetation. We compare surface CO 2 efflux rates and 14 C content between intact vegetation and plots in which below‐ground allocation of recent photosynthate was prevented by trenching and removal of above‐ground biomass. We show, for the first time, that recent photosynthate drives mineralization of older (>50 years old) SOC under birch shrubs and ericaceous heath tundra. By contrast, we find no evidence of RPEs in soils under alder. This is the first direct evidence from permafrost systems that vegetation influences SOC turnover through below‐ground C allocation. The vulnerability of SOC to decomposition in permafrost systems may therefore be directly linked to vegetation change, such that expansion of birch shrubs across the Arctic could increase decomposition of older SOC. Our results suggest that carbon cycle models that do not include RPEs risk underestimating the carbon cycle feedbacks associated with changing conditions in tundra regions. |
author2 |
Natural Environment Research Council |
format |
Article in Journal/Newspaper |
author |
Street, Lorna E. Garnett, Mark H. Subke, Jens‐Arne Baxter, Robert Dean, Joshua F. Wookey, Philip A. |
spellingShingle |
Street, Lorna E. Garnett, Mark H. Subke, Jens‐Arne Baxter, Robert Dean, Joshua F. Wookey, Philip A. Plant carbon allocation drives turnover of old soil organic matter in permafrost tundra soils |
author_facet |
Street, Lorna E. Garnett, Mark H. Subke, Jens‐Arne Baxter, Robert Dean, Joshua F. Wookey, Philip A. |
author_sort |
Street, Lorna E. |
title |
Plant carbon allocation drives turnover of old soil organic matter in permafrost tundra soils |
title_short |
Plant carbon allocation drives turnover of old soil organic matter in permafrost tundra soils |
title_full |
Plant carbon allocation drives turnover of old soil organic matter in permafrost tundra soils |
title_fullStr |
Plant carbon allocation drives turnover of old soil organic matter in permafrost tundra soils |
title_full_unstemmed |
Plant carbon allocation drives turnover of old soil organic matter in permafrost tundra soils |
title_sort |
plant carbon allocation drives turnover of old soil organic matter in permafrost tundra soils |
publisher |
Wiley |
publishDate |
2020 |
url |
http://dx.doi.org/10.1111/gcb.15134 https://api.wiley.com/onlinelibrary/tdm/v1/articles/10.1111%2Fgcb.15134 https://onlinelibrary.wiley.com/doi/pdf/10.1111/gcb.15134 https://onlinelibrary.wiley.com/doi/full-xml/10.1111/gcb.15134 |
genre |
Climate change permafrost Tundra |
genre_facet |
Climate change permafrost Tundra |
op_source |
Global Change Biology volume 26, issue 8, page 4559-4571 ISSN 1354-1013 1365-2486 |
op_rights |
http://creativecommons.org/licenses/by/4.0/ |
op_doi |
https://doi.org/10.1111/gcb.15134 |
container_title |
Global Change Biology |
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26 |
container_issue |
8 |
container_start_page |
4559 |
op_container_end_page |
4571 |
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1810439811389980672 |