Journal of Integrative Agriculture ›› 2026, Vol. 25 ›› Issue (2): 448-459.DOI: 10.1016/j.jia.2024.12.035

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土地利用类型调控青藏高寒生态系统的碳通路:13C丰度在团聚体和密度组分中的特征

  

  • 收稿日期:2024-08-01 修回日期:2024-12-30 接受日期:2024-12-06 出版日期:2026-02-20 发布日期:2026-01-06

Land use type shapes carbon pathways in Tibetan alpine ecosystems: Characterization of 13C abundance in aggregates and density fractions

Xin Wan1, 3, Dangjun Wang4, Junya Li1, 3, Shuaiwen Zhang1, 3, Linyang Li1, 3, Minghui He1,3, Zhiguo Li1, 2, Hao Jiang1, Peng Chen1, 2#, Yi Liu1, 2   

  1. 1 Hubei Key Laboratory of Wetland Evolution & Ecological Restoration, Wuhan Botanical Garden, Chinese Academy of Sciences, Wuhan 430074, China

    2 Danjiangkou Wetland Ecosystem Field Scientific Observation and Research Station, Chinese Academy of Sciences & Hubei Province, Wuhan 430074, China

    3 University of Chinese Academy of Sciences, Beijing 100049, China

    4 College of Grassland Agriculture, Northwest A&F University, Yangling 712100, China

  • Received:2024-08-01 Revised:2024-12-30 Accepted:2024-12-06 Online:2026-02-20 Published:2026-01-06
  • About author:Xin Wan, E-mail: wanxin20@mails.ucas.ac.cn; #Correspondence Peng Chen, E-mail: chenpeng@wbgcas.cn
  • Supported by:

    This work was financially supported by the National Natural Science Foundation of China (42477044, 32171648 and  U23A2017) and the Hubei Provincial Science and Technology Program, China (2025AFD451 and 2022CFB030).

摘要:

为降低青藏高原碳库估算的不确定性,深入探究土壤团聚体与密度组分中的碳周转至关重要。同时,这些变化在不同土地利用类型下的异质性仍需进一步明晰。本研究基于有机碳及其13C丰度,在青藏高原土壤团聚体与密度组分的微观尺度,量化了土地利用类型对碳储存及分馏的影响。结果表明土壤团聚破碎率呈现人工林(13.1%)<灌丛(32.7%)<草地(47.9%)<农田(61.8%)的趋势,表明人工林有助于增强土壤结构稳定性。相较于农田(13.5,70.3%),人工林轻组分有机碳对碳储量的贡献提升至28.3%,而矿物结合态有机碳的贡献降至40.6%。值得注意的是,植被覆盖促进了有机碳与13C在各密度组分中的团聚体分化效应,而此现象在土壤总有机碳中并未出现。碳同位素分析结果显示,人工林中碳转移表现为从大团聚体中的轻组组分(-24.9‰)向小团聚体中的矿物组分(-19.9‰)转移。与其他三种土地利用类型相比,人工林中团聚体和密度组分的碳转移率较低,从而为青藏高原构建了相对稳定的碳库。本研究在团聚体和密度组分的微观尺度下证实了人工林能减缓土壤中碳的转移并增加碳储存,对缓解全球气候变化发挥积极作用。

Abstract:

Insight into the carbon turnover in soil aggregates and density fractions is essential for reducing the uncertainty in estimating carbon pools on the Tibetan Plateau, and how they vary with land use type is unclear.  In this study, the effect of land use type on carbon storage and fractionation was quantified based on organic carbon and its 13C abundance at the microscale of soil aggregates and density fractions in Tibetan alpine ecosystems.  The sequence of soil aggregate destruction in the land use types of plantation (13.1%)<shrubland (32.7%)<grassland (47.9%)<farmland (61.8%) shows that plantations strengthen the soil structure.  Plantation land had a greater contribution of light fraction organic carbon (28.3%) but a lower contribution of mineral-associated organic carbon (40.6%) to the carbon stock compared to farmland (13.5 and 70.3%).  Interestingly, plantation land enhanced the aggregational differentiation of organic carbon and 13C in each density fraction, whereas no such phenomenon existed in the soil organic carbon.  Carbon isotope analyses revealed that carbon transfer in the plantation land occurred from the light fraction in macroaggregates (–24.9‰) to the mineral-associated fraction in microaggregates (–19.9‰).  When compared to the other three land use types, the low transferability of carbon in aggregates and density fractions in plantation land provides a stable carbon pool for the Tibetan Plateau.  This study shows that plantations can mitigate global climate change by slowing carbon transfer and increasing carbon storage at the microscale of aggregates and density fractions in alpine regions.


Key words: land-use type ,  soil aggregate ,  density fractions ,  carbon transfer ,  Tibetan Plateau