Aridification Inhibits the Release of Dissolved Organic Carbon from Alpine Soils in Southwest China

The alpine peatlands in western Sichuan Province are currently experiencing aridification. To understand the effects of aridification on the characteristics of organic carbon release from alpine soils, the soil in the northwest Sichuan Plateau was investigated. Soil columns were incubated under diff...

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Main Authors: Yanmei Li, Jihong Qin, Yuwen Chen, Hui Sun, Xinyue Hu
Format: Article
Language:English
Published: MDPI AG 2025-03-01
Series:Soil Systems
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Online Access:https://www.mdpi.com/2571-8789/9/1/24
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author Yanmei Li
Jihong Qin
Yuwen Chen
Hui Sun
Xinyue Hu
author_facet Yanmei Li
Jihong Qin
Yuwen Chen
Hui Sun
Xinyue Hu
author_sort Yanmei Li
collection DOAJ
description The alpine peatlands in western Sichuan Province are currently experiencing aridification. To understand the effects of aridification on the characteristics of organic carbon release from alpine soils, the soil in the northwest Sichuan Plateau was investigated. Soil columns were incubated under different moisture conditions in situ and in the laboratory, and ultraviolet-visible absorption spectroscopy and three-dimensional fluorescence spectroscopy were used to assess the soil dissolved organic carbon (DOC) levels. The results revealed that (1) the cumulative release of DOC from alpine soil in the northwest Sichuan Plateau decreased with decreasing moisture content. The cumulative release of soil DOC in the laboratory (0–5 cm soil reached 1.93 ± 0.43 g/kg) was greater than that from soil incubated in situ (0–5 cm soil reached 1.40 ± 0.13 g/kg); (2) the cumulative release of DOC in 0–5 cm soil exhibited the greatest response to changes in water content, and the cumulative release of DOC from the 0–5 cm soil layer (1.40 ± 0.13 g/kg) was greater than that from the 5–15 cm soil layer (1.25 ± 0.03 g/kg); and (3) UV-visible absorption spectra and 3D fluorescence spectral characteristics indicated that aridification increases the content of chromophoric dissolved organic matter (CDOM) components with strong hydrophobicity, especially tyrosine components (surface soil increased 39.59~63.31%), in alpine soil DOC. This increase in hydrophobic CDOM components enhances the aromaticity and degree of humification of DOC. Our results revealed that drought inhibits the release of soil DOC, which is unfavorable for the sequestration of organic carbon in alpine soils, potentially resulting in the loss of soil carbon pools and further degradation of alpine ecosystem functions.
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spelling doaj-art-06db6f328ace45d0be6b50db5bab19432025-08-20T03:43:54ZengMDPI AGSoil Systems2571-87892025-03-01912410.3390/soilsystems9010024Aridification Inhibits the Release of Dissolved Organic Carbon from Alpine Soils in Southwest ChinaYanmei Li0Jihong Qin1Yuwen Chen2Hui Sun3Xinyue Hu4Department of Environmental Science and Engineering, Sichuan University, Chengdu 610065, ChinaDepartment of Environmental Engineering, Chengdu University, Chengdu 610106, ChinaDepartment of Environmental Science and Engineering, Sichuan University, Chengdu 610065, ChinaDepartment of Environmental Science and Engineering, Sichuan University, Chengdu 610065, ChinaDepartment of Environmental Science and Engineering, Sichuan University, Chengdu 610065, ChinaThe alpine peatlands in western Sichuan Province are currently experiencing aridification. To understand the effects of aridification on the characteristics of organic carbon release from alpine soils, the soil in the northwest Sichuan Plateau was investigated. Soil columns were incubated under different moisture conditions in situ and in the laboratory, and ultraviolet-visible absorption spectroscopy and three-dimensional fluorescence spectroscopy were used to assess the soil dissolved organic carbon (DOC) levels. The results revealed that (1) the cumulative release of DOC from alpine soil in the northwest Sichuan Plateau decreased with decreasing moisture content. The cumulative release of soil DOC in the laboratory (0–5 cm soil reached 1.93 ± 0.43 g/kg) was greater than that from soil incubated in situ (0–5 cm soil reached 1.40 ± 0.13 g/kg); (2) the cumulative release of DOC in 0–5 cm soil exhibited the greatest response to changes in water content, and the cumulative release of DOC from the 0–5 cm soil layer (1.40 ± 0.13 g/kg) was greater than that from the 5–15 cm soil layer (1.25 ± 0.03 g/kg); and (3) UV-visible absorption spectra and 3D fluorescence spectral characteristics indicated that aridification increases the content of chromophoric dissolved organic matter (CDOM) components with strong hydrophobicity, especially tyrosine components (surface soil increased 39.59~63.31%), in alpine soil DOC. This increase in hydrophobic CDOM components enhances the aromaticity and degree of humification of DOC. Our results revealed that drought inhibits the release of soil DOC, which is unfavorable for the sequestration of organic carbon in alpine soils, potentially resulting in the loss of soil carbon pools and further degradation of alpine ecosystem functions.https://www.mdpi.com/2571-8789/9/1/24southwest alpine soilenvironmental changeorganic carbonorganic carbon releaseenvironmental effect
spellingShingle Yanmei Li
Jihong Qin
Yuwen Chen
Hui Sun
Xinyue Hu
Aridification Inhibits the Release of Dissolved Organic Carbon from Alpine Soils in Southwest China
Soil Systems
southwest alpine soil
environmental change
organic carbon
organic carbon release
environmental effect
title Aridification Inhibits the Release of Dissolved Organic Carbon from Alpine Soils in Southwest China
title_full Aridification Inhibits the Release of Dissolved Organic Carbon from Alpine Soils in Southwest China
title_fullStr Aridification Inhibits the Release of Dissolved Organic Carbon from Alpine Soils in Southwest China
title_full_unstemmed Aridification Inhibits the Release of Dissolved Organic Carbon from Alpine Soils in Southwest China
title_short Aridification Inhibits the Release of Dissolved Organic Carbon from Alpine Soils in Southwest China
title_sort aridification inhibits the release of dissolved organic carbon from alpine soils in southwest china
topic southwest alpine soil
environmental change
organic carbon
organic carbon release
environmental effect
url https://www.mdpi.com/2571-8789/9/1/24
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AT yuwenchen aridificationinhibitsthereleaseofdissolvedorganiccarbonfromalpinesoilsinsouthwestchina
AT huisun aridificationinhibitsthereleaseofdissolvedorganiccarbonfromalpinesoilsinsouthwestchina
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