Nonlinear CO2 flux response to 7years of experimentally induced permafrost thaw.
Rapid Arctic warming is expected to increase global greenhouse gas concentrations as permafrost thaw exposes immense stores of frozen carbon (C) to microbial decomposition. Permafrost thaw also stimulates plant growth, which could offset C loss. Using data from 7years of experimental Air and Soil wa...
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ftcdlib:oai:escholarship.org/ark:/13030/qt7521h0gw 2023-05-15T14:56:47+02:00 Nonlinear CO2 flux response to 7years of experimentally induced permafrost thaw. Mauritz, Marguerite Bracho, Rosvel Celis, Gerardo Hutchings, Jack Natali, Susan M Pegoraro, Elaine Salmon, Verity G Schädel, Christina Webb, Elizabeth E Schuur, Edward AG 3646 - 3666 2017-09-01 application/pdf https://escholarship.org/uc/item/7521h0gw unknown eScholarship, University of California qt7521h0gw https://escholarship.org/uc/item/7521h0gw public Global change biology, vol 23, iss 9 Carbon Dioxide Soil Arctic Regions Carbon Cycle Tundra Permafrost Arctic carbon ecosystem respiration experimental warming gross primary productivity net ecosystem exchange thaw Ecology Environmental Sciences Biological Sciences article 2017 ftcdlib 2021-08-23T17:10:22Z Rapid Arctic warming is expected to increase global greenhouse gas concentrations as permafrost thaw exposes immense stores of frozen carbon (C) to microbial decomposition. Permafrost thaw also stimulates plant growth, which could offset C loss. Using data from 7years of experimental Air and Soil warming in moist acidic tundra, we show that Soil warming had a much stronger effect on CO2 flux than Air warming. Soil warming caused rapid permafrost thaw and increased ecosystem respiration (Reco ), gross primary productivity (GPP), and net summer CO2 storage (NEE). Over 7years Reco , GPP, and NEE also increased in Control (i.e., ambient plots), but this change could be explained by slow thaw in Control areas. In the initial stages of thaw, Reco , GPP, and NEE increased linearly with thaw across all treatments, despite different rates of thaw. As thaw in Soil warming continued to increase linearly, ground surface subsidence created saturated microsites and suppressed Reco , GPP, and NEE. However Reco and GPP remained high in areas with large Eriophorum vaginatum biomass. In general NEE increased with thaw, but was more strongly correlated with plant biomass than thaw, indicating that higher Reco in deeply thawed areas during summer months was balanced by GPP. Summer CO2 flux across treatments fit a single quadratic relationship that captured the functional response of CO2 flux to thaw, water table depth, and plant biomass. These results demonstrate the importance of indirect thaw effects on CO2 flux: plant growth and water table dynamics. Nonsummer Reco models estimated that the area was an annual CO2 source during all years of observation. Nonsummer CO2 loss in warmer, more deeply thawed soils exceeded the increases in summer GPP, and thawed tundra was a net annual CO2 source. Article in Journal/Newspaper Arctic Eriophorum permafrost Tundra University of California: eScholarship Arctic |
institution |
Open Polar |
collection |
University of California: eScholarship |
op_collection_id |
ftcdlib |
language |
unknown |
topic |
Carbon Dioxide Soil Arctic Regions Carbon Cycle Tundra Permafrost Arctic carbon ecosystem respiration experimental warming gross primary productivity net ecosystem exchange thaw Ecology Environmental Sciences Biological Sciences |
spellingShingle |
Carbon Dioxide Soil Arctic Regions Carbon Cycle Tundra Permafrost Arctic carbon ecosystem respiration experimental warming gross primary productivity net ecosystem exchange thaw Ecology Environmental Sciences Biological Sciences Mauritz, Marguerite Bracho, Rosvel Celis, Gerardo Hutchings, Jack Natali, Susan M Pegoraro, Elaine Salmon, Verity G Schädel, Christina Webb, Elizabeth E Schuur, Edward AG Nonlinear CO2 flux response to 7years of experimentally induced permafrost thaw. |
topic_facet |
Carbon Dioxide Soil Arctic Regions Carbon Cycle Tundra Permafrost Arctic carbon ecosystem respiration experimental warming gross primary productivity net ecosystem exchange thaw Ecology Environmental Sciences Biological Sciences |
description |
Rapid Arctic warming is expected to increase global greenhouse gas concentrations as permafrost thaw exposes immense stores of frozen carbon (C) to microbial decomposition. Permafrost thaw also stimulates plant growth, which could offset C loss. Using data from 7years of experimental Air and Soil warming in moist acidic tundra, we show that Soil warming had a much stronger effect on CO2 flux than Air warming. Soil warming caused rapid permafrost thaw and increased ecosystem respiration (Reco ), gross primary productivity (GPP), and net summer CO2 storage (NEE). Over 7years Reco , GPP, and NEE also increased in Control (i.e., ambient plots), but this change could be explained by slow thaw in Control areas. In the initial stages of thaw, Reco , GPP, and NEE increased linearly with thaw across all treatments, despite different rates of thaw. As thaw in Soil warming continued to increase linearly, ground surface subsidence created saturated microsites and suppressed Reco , GPP, and NEE. However Reco and GPP remained high in areas with large Eriophorum vaginatum biomass. In general NEE increased with thaw, but was more strongly correlated with plant biomass than thaw, indicating that higher Reco in deeply thawed areas during summer months was balanced by GPP. Summer CO2 flux across treatments fit a single quadratic relationship that captured the functional response of CO2 flux to thaw, water table depth, and plant biomass. These results demonstrate the importance of indirect thaw effects on CO2 flux: plant growth and water table dynamics. Nonsummer Reco models estimated that the area was an annual CO2 source during all years of observation. Nonsummer CO2 loss in warmer, more deeply thawed soils exceeded the increases in summer GPP, and thawed tundra was a net annual CO2 source. |
format |
Article in Journal/Newspaper |
author |
Mauritz, Marguerite Bracho, Rosvel Celis, Gerardo Hutchings, Jack Natali, Susan M Pegoraro, Elaine Salmon, Verity G Schädel, Christina Webb, Elizabeth E Schuur, Edward AG |
author_facet |
Mauritz, Marguerite Bracho, Rosvel Celis, Gerardo Hutchings, Jack Natali, Susan M Pegoraro, Elaine Salmon, Verity G Schädel, Christina Webb, Elizabeth E Schuur, Edward AG |
author_sort |
Mauritz, Marguerite |
title |
Nonlinear CO2 flux response to 7years of experimentally induced permafrost thaw. |
title_short |
Nonlinear CO2 flux response to 7years of experimentally induced permafrost thaw. |
title_full |
Nonlinear CO2 flux response to 7years of experimentally induced permafrost thaw. |
title_fullStr |
Nonlinear CO2 flux response to 7years of experimentally induced permafrost thaw. |
title_full_unstemmed |
Nonlinear CO2 flux response to 7years of experimentally induced permafrost thaw. |
title_sort |
nonlinear co2 flux response to 7years of experimentally induced permafrost thaw. |
publisher |
eScholarship, University of California |
publishDate |
2017 |
url |
https://escholarship.org/uc/item/7521h0gw |
op_coverage |
3646 - 3666 |
geographic |
Arctic |
geographic_facet |
Arctic |
genre |
Arctic Eriophorum permafrost Tundra |
genre_facet |
Arctic Eriophorum permafrost Tundra |
op_source |
Global change biology, vol 23, iss 9 |
op_relation |
qt7521h0gw https://escholarship.org/uc/item/7521h0gw |
op_rights |
public |
_version_ |
1766328855257153536 |