Radiation, soil water content, and temperature effects on carbon cycling in an alpine swamp meadow of the northeastern Qinghai–Tibetan Plateau
Predicted intensified climate warming will likely alter the ecosystem net carbon (C) uptake of the Qinghai–Tibetan Plateau (QTP). Variations in C sink–source responses to climate warming have been linked to water availability; however, the mechanisms by which net C uptake responds to soil water cont...
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ftdoajarticles:oai:doaj.org/article:8265e1e7dab4477085d51703457faef2 2023-05-15T17:58:12+02:00 Radiation, soil water content, and temperature effects on carbon cycling in an alpine swamp meadow of the northeastern Qinghai–Tibetan Plateau J. Wei X. Li L. Liu T. R. Christensen Z. Jiang Y. Ma X. Wu H. Yao E. López-Blanco 2022-02-01T00:00:00Z https://doi.org/10.5194/bg-19-861-2022 https://doaj.org/article/8265e1e7dab4477085d51703457faef2 EN eng Copernicus Publications https://bg.copernicus.org/articles/19/861/2022/bg-19-861-2022.pdf https://doaj.org/toc/1726-4170 https://doaj.org/toc/1726-4189 doi:10.5194/bg-19-861-2022 1726-4170 1726-4189 https://doaj.org/article/8265e1e7dab4477085d51703457faef2 Biogeosciences, Vol 19, Pp 861-875 (2022) Ecology QH540-549.5 Life QH501-531 Geology QE1-996.5 article 2022 ftdoajarticles https://doi.org/10.5194/bg-19-861-2022 2022-12-31T15:19:18Z Predicted intensified climate warming will likely alter the ecosystem net carbon (C) uptake of the Qinghai–Tibetan Plateau (QTP). Variations in C sink–source responses to climate warming have been linked to water availability; however, the mechanisms by which net C uptake responds to soil water content in saturated swamp meadow ecosystems remain unclear. To explore how soil moisture and other environmental drivers modulate net C uptake in the QTP, field measurements were conducted using the eddy covariance technique in 2014, 2015, 2017, and 2018. The alpine swamp meadow presented in this study was a persistent and strong C sink of CO 2 ( −168.0 ± 62.5 g C m −2 yr −1 , average ± standard deviation) across the entire 4-year study period. A random forest machine-learning analysis suggested that the diurnal and seasonal variations of net ecosystem exchange (NEE) and gross primary productivity (GPP) were regulated by temperature and net radiation. Ecosystem respiration (Re), however, was found mainly regulated by the variability of soil water content (SWC) at different temporal aggregations, followed by temperature, the second contributing driver. We further explored how Re is controlled by nearly saturated soil moisture and temperature comparing two different periods featuring almost identical temperatures and significant differences on SWC and vice versa. Our data suggest that, despite the relatively abundant water supply, periods with a substantial decrease in SWC or increase in temperature produced higher Re and therefore weakened the C sink strength. Our results reveal that nearly saturated soil conditions during the growing seasons can help maintain lower ecosystem respiration rates and thus enhance the overall C sequestration capacity in this alpine swamp meadow. We argue that soil respiration and subsequent ecosystem C sink magnitude in alpine swamp meadows could likely be affected by future changes in soil hydrological conditions caused by permafrost degradation or accelerated thawing–freezing cycling due to ... Article in Journal/Newspaper permafrost Directory of Open Access Journals: DOAJ Articles Biogeosciences 19 3 861 875 |
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English |
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Ecology QH540-549.5 Life QH501-531 Geology QE1-996.5 |
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Ecology QH540-549.5 Life QH501-531 Geology QE1-996.5 J. Wei X. Li L. Liu T. R. Christensen Z. Jiang Y. Ma X. Wu H. Yao E. López-Blanco Radiation, soil water content, and temperature effects on carbon cycling in an alpine swamp meadow of the northeastern Qinghai–Tibetan Plateau |
topic_facet |
Ecology QH540-549.5 Life QH501-531 Geology QE1-996.5 |
description |
Predicted intensified climate warming will likely alter the ecosystem net carbon (C) uptake of the Qinghai–Tibetan Plateau (QTP). Variations in C sink–source responses to climate warming have been linked to water availability; however, the mechanisms by which net C uptake responds to soil water content in saturated swamp meadow ecosystems remain unclear. To explore how soil moisture and other environmental drivers modulate net C uptake in the QTP, field measurements were conducted using the eddy covariance technique in 2014, 2015, 2017, and 2018. The alpine swamp meadow presented in this study was a persistent and strong C sink of CO 2 ( −168.0 ± 62.5 g C m −2 yr −1 , average ± standard deviation) across the entire 4-year study period. A random forest machine-learning analysis suggested that the diurnal and seasonal variations of net ecosystem exchange (NEE) and gross primary productivity (GPP) were regulated by temperature and net radiation. Ecosystem respiration (Re), however, was found mainly regulated by the variability of soil water content (SWC) at different temporal aggregations, followed by temperature, the second contributing driver. We further explored how Re is controlled by nearly saturated soil moisture and temperature comparing two different periods featuring almost identical temperatures and significant differences on SWC and vice versa. Our data suggest that, despite the relatively abundant water supply, periods with a substantial decrease in SWC or increase in temperature produced higher Re and therefore weakened the C sink strength. Our results reveal that nearly saturated soil conditions during the growing seasons can help maintain lower ecosystem respiration rates and thus enhance the overall C sequestration capacity in this alpine swamp meadow. We argue that soil respiration and subsequent ecosystem C sink magnitude in alpine swamp meadows could likely be affected by future changes in soil hydrological conditions caused by permafrost degradation or accelerated thawing–freezing cycling due to ... |
format |
Article in Journal/Newspaper |
author |
J. Wei X. Li L. Liu T. R. Christensen Z. Jiang Y. Ma X. Wu H. Yao E. López-Blanco |
author_facet |
J. Wei X. Li L. Liu T. R. Christensen Z. Jiang Y. Ma X. Wu H. Yao E. López-Blanco |
author_sort |
J. Wei |
title |
Radiation, soil water content, and temperature effects on carbon cycling in an alpine swamp meadow of the northeastern Qinghai–Tibetan Plateau |
title_short |
Radiation, soil water content, and temperature effects on carbon cycling in an alpine swamp meadow of the northeastern Qinghai–Tibetan Plateau |
title_full |
Radiation, soil water content, and temperature effects on carbon cycling in an alpine swamp meadow of the northeastern Qinghai–Tibetan Plateau |
title_fullStr |
Radiation, soil water content, and temperature effects on carbon cycling in an alpine swamp meadow of the northeastern Qinghai–Tibetan Plateau |
title_full_unstemmed |
Radiation, soil water content, and temperature effects on carbon cycling in an alpine swamp meadow of the northeastern Qinghai–Tibetan Plateau |
title_sort |
radiation, soil water content, and temperature effects on carbon cycling in an alpine swamp meadow of the northeastern qinghai–tibetan plateau |
publisher |
Copernicus Publications |
publishDate |
2022 |
url |
https://doi.org/10.5194/bg-19-861-2022 https://doaj.org/article/8265e1e7dab4477085d51703457faef2 |
genre |
permafrost |
genre_facet |
permafrost |
op_source |
Biogeosciences, Vol 19, Pp 861-875 (2022) |
op_relation |
https://bg.copernicus.org/articles/19/861/2022/bg-19-861-2022.pdf https://doaj.org/toc/1726-4170 https://doaj.org/toc/1726-4189 doi:10.5194/bg-19-861-2022 1726-4170 1726-4189 https://doaj.org/article/8265e1e7dab4477085d51703457faef2 |
op_doi |
https://doi.org/10.5194/bg-19-861-2022 |
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Biogeosciences |
container_volume |
19 |
container_issue |
3 |
container_start_page |
861 |
op_container_end_page |
875 |
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