Soil Moisture but Not Warming Dominates Nitrous Oxide Emissions During Freeze–Thaw Cycles in a Qinghai–Tibetan Plateau Alpine Meadow With Discontinuous Permafrost
Large quantities of organic matter are stored in frozen soils (permafrost) within the Qinghai–Tibetan Plateau (QTP). The most of QTP regions in particular have experienced significant warming and wetting over the past 50 years, and this warming trend is projected to intensify in the future. Such cli...
Published in: | Frontiers in Ecology and Evolution |
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ftdoajarticles:oai:doaj.org/article:e1d643b59518488d88a2e4d614eae64e 2023-05-15T17:56:52+02:00 Soil Moisture but Not Warming Dominates Nitrous Oxide Emissions During Freeze–Thaw Cycles in a Qinghai–Tibetan Plateau Alpine Meadow With Discontinuous Permafrost Zhe Chen Shidong Ge Zhenhua Zhang Yangong Du Buqing Yao Huichun Xie Pan Liu Yufang Zhang Wenying Wang Huakun Zhou 2021-06-01T00:00:00Z https://doi.org/10.3389/fevo.2021.676027 https://doaj.org/article/e1d643b59518488d88a2e4d614eae64e EN eng Frontiers Media S.A. https://www.frontiersin.org/articles/10.3389/fevo.2021.676027/full https://doaj.org/toc/2296-701X 2296-701X doi:10.3389/fevo.2021.676027 https://doaj.org/article/e1d643b59518488d88a2e4d614eae64e Frontiers in Ecology and Evolution, Vol 9 (2021) global climate change nitrous oxide permafrost active layer freeze–thaw nitrogen transformation Evolution QH359-425 Ecology QH540-549.5 article 2021 ftdoajarticles https://doi.org/10.3389/fevo.2021.676027 2022-12-31T06:42:14Z Large quantities of organic matter are stored in frozen soils (permafrost) within the Qinghai–Tibetan Plateau (QTP). The most of QTP regions in particular have experienced significant warming and wetting over the past 50 years, and this warming trend is projected to intensify in the future. Such climate change will likely alter the soil freeze–thaw pattern in permafrost active layer and toward significant greenhouse gas nitrous oxide (N2O) release. However, the interaction effect of warming and altered soil moisture on N2O emission during freezing and thawing is unclear. Here, we used simulation experiments to test how changes in N2O flux relate to different thawing temperatures (T5–5°C, T10–10°C, and T20–20°C) and soil volumetric water contents (VWCs, W15–15%, W30–30%, and W45–45%) under 165 F–T cycles in topsoil (0–20 cm) of an alpine meadow with discontinuous permafrost in the QTP. First, in contrast to the prevailing view, soil moisture but not thawing temperature dominated the large N2O pulses during F–T events. The maximum emissions, 1,123.16–5,849.54 μg m–2 h–1, appeared in the range of soil VWC from 17% to 38%. However, the mean N2O fluxes had no significant difference between different thawing temperatures when soil was dry or waterlogged. Second, in medium soil moisture, low thawing temperature is more able to promote soil N2O emission than high temperature. For example, the peak value (5,849.54 μg m–2 h–1) and cumulative emissions (366.6 mg m–2) of W30T5 treatment were five times and two to four times higher than W30T10 and W30T20, respectively. Third, during long-term freeze–thaw cycles, the patterns of cumulative N2O emissions were related to soil moisture. treatments; on the contrary, the cumulative emissions of W45 treatments slowly increased until more than 80 cycles. Finally, long-term freeze–thaw cycles could improve nitrogen availability, prolong N2O release time, and increase N2O cumulative emission in permafrost active layer. Particularly, the high emission was concentrated in the first 27 ... Article in Journal/Newspaper permafrost Directory of Open Access Journals: DOAJ Articles Frontiers in Ecology and Evolution 9 |
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Directory of Open Access Journals: DOAJ Articles |
op_collection_id |
ftdoajarticles |
language |
English |
topic |
global climate change nitrous oxide permafrost active layer freeze–thaw nitrogen transformation Evolution QH359-425 Ecology QH540-549.5 |
spellingShingle |
global climate change nitrous oxide permafrost active layer freeze–thaw nitrogen transformation Evolution QH359-425 Ecology QH540-549.5 Zhe Chen Shidong Ge Zhenhua Zhang Yangong Du Buqing Yao Huichun Xie Pan Liu Yufang Zhang Wenying Wang Huakun Zhou Soil Moisture but Not Warming Dominates Nitrous Oxide Emissions During Freeze–Thaw Cycles in a Qinghai–Tibetan Plateau Alpine Meadow With Discontinuous Permafrost |
topic_facet |
global climate change nitrous oxide permafrost active layer freeze–thaw nitrogen transformation Evolution QH359-425 Ecology QH540-549.5 |
description |
Large quantities of organic matter are stored in frozen soils (permafrost) within the Qinghai–Tibetan Plateau (QTP). The most of QTP regions in particular have experienced significant warming and wetting over the past 50 years, and this warming trend is projected to intensify in the future. Such climate change will likely alter the soil freeze–thaw pattern in permafrost active layer and toward significant greenhouse gas nitrous oxide (N2O) release. However, the interaction effect of warming and altered soil moisture on N2O emission during freezing and thawing is unclear. Here, we used simulation experiments to test how changes in N2O flux relate to different thawing temperatures (T5–5°C, T10–10°C, and T20–20°C) and soil volumetric water contents (VWCs, W15–15%, W30–30%, and W45–45%) under 165 F–T cycles in topsoil (0–20 cm) of an alpine meadow with discontinuous permafrost in the QTP. First, in contrast to the prevailing view, soil moisture but not thawing temperature dominated the large N2O pulses during F–T events. The maximum emissions, 1,123.16–5,849.54 μg m–2 h–1, appeared in the range of soil VWC from 17% to 38%. However, the mean N2O fluxes had no significant difference between different thawing temperatures when soil was dry or waterlogged. Second, in medium soil moisture, low thawing temperature is more able to promote soil N2O emission than high temperature. For example, the peak value (5,849.54 μg m–2 h–1) and cumulative emissions (366.6 mg m–2) of W30T5 treatment were five times and two to four times higher than W30T10 and W30T20, respectively. Third, during long-term freeze–thaw cycles, the patterns of cumulative N2O emissions were related to soil moisture. treatments; on the contrary, the cumulative emissions of W45 treatments slowly increased until more than 80 cycles. Finally, long-term freeze–thaw cycles could improve nitrogen availability, prolong N2O release time, and increase N2O cumulative emission in permafrost active layer. Particularly, the high emission was concentrated in the first 27 ... |
format |
Article in Journal/Newspaper |
author |
Zhe Chen Shidong Ge Zhenhua Zhang Yangong Du Buqing Yao Huichun Xie Pan Liu Yufang Zhang Wenying Wang Huakun Zhou |
author_facet |
Zhe Chen Shidong Ge Zhenhua Zhang Yangong Du Buqing Yao Huichun Xie Pan Liu Yufang Zhang Wenying Wang Huakun Zhou |
author_sort |
Zhe Chen |
title |
Soil Moisture but Not Warming Dominates Nitrous Oxide Emissions During Freeze–Thaw Cycles in a Qinghai–Tibetan Plateau Alpine Meadow With Discontinuous Permafrost |
title_short |
Soil Moisture but Not Warming Dominates Nitrous Oxide Emissions During Freeze–Thaw Cycles in a Qinghai–Tibetan Plateau Alpine Meadow With Discontinuous Permafrost |
title_full |
Soil Moisture but Not Warming Dominates Nitrous Oxide Emissions During Freeze–Thaw Cycles in a Qinghai–Tibetan Plateau Alpine Meadow With Discontinuous Permafrost |
title_fullStr |
Soil Moisture but Not Warming Dominates Nitrous Oxide Emissions During Freeze–Thaw Cycles in a Qinghai–Tibetan Plateau Alpine Meadow With Discontinuous Permafrost |
title_full_unstemmed |
Soil Moisture but Not Warming Dominates Nitrous Oxide Emissions During Freeze–Thaw Cycles in a Qinghai–Tibetan Plateau Alpine Meadow With Discontinuous Permafrost |
title_sort |
soil moisture but not warming dominates nitrous oxide emissions during freeze–thaw cycles in a qinghai–tibetan plateau alpine meadow with discontinuous permafrost |
publisher |
Frontiers Media S.A. |
publishDate |
2021 |
url |
https://doi.org/10.3389/fevo.2021.676027 https://doaj.org/article/e1d643b59518488d88a2e4d614eae64e |
genre |
permafrost |
genre_facet |
permafrost |
op_source |
Frontiers in Ecology and Evolution, Vol 9 (2021) |
op_relation |
https://www.frontiersin.org/articles/10.3389/fevo.2021.676027/full https://doaj.org/toc/2296-701X 2296-701X doi:10.3389/fevo.2021.676027 https://doaj.org/article/e1d643b59518488d88a2e4d614eae64e |
op_doi |
https://doi.org/10.3389/fevo.2021.676027 |
container_title |
Frontiers in Ecology and Evolution |
container_volume |
9 |
_version_ |
1766165168328278016 |