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中国沙漠 ›› 2025, Vol. 45 ›› Issue (3): 131-140.DOI: 10.7522/j.issn.1000-694X.2025.00039

• • 上一篇    下一篇

极端环境生物土壤结皮发育对碳循环的影响

李佳(), 贾晓红(), 周德正, 吴波   

  1. 中国林业科学研究院生态保护与修复研究所 荒漠生态系统与全球变化国家林业和草原局重点实验室,北京 100091
  • 收稿日期:2025-04-07 修回日期:2025-04-27 出版日期:2025-05-20 发布日期:2025-06-30
  • 通讯作者: 贾晓红
  • 作者简介:李佳(2000—),女,河北玉田人,硕士研究生,研究方向为碳循环。E-mail: lijialijia@caf.ac.cn
  • 基金资助:
    国家重点研发计划项目(2023YFF1305300);内蒙古自治区揭榜挂帅项目(2024LKY-TH01-2);国家自然科学基金项目(42371074);中国林业科学研究院生态保护与修复研究所科技项目(STSTC2023001)

Effects of biological soil crusts development on carbon cycling in extreme environments

Jia Li(), Xiaohong Jia(), Dezheng Zhou, Bo Wu   

  1. Key Laboratory of State Forestry and Grassland Administration on Desert Ecosystem and Global Change,Institute of Ecological Conservation and Restoration,Chinese Academy of Forestry,Beijing 100091,China
  • Received:2025-04-07 Revised:2025-04-27 Online:2025-05-20 Published:2025-06-30
  • Contact: Xiaohong Jia

摘要:

在维管植物发育受限的高寒、干旱、高温等极端环境,生物土壤结皮作为重要的地表活体覆盖物,在生态系统碳循环过程中扮演关键角色。明确生物土壤结皮发育在生态系统碳循环中的作用机制,可以为极端环境下碳中和目标的科学管理与实现提供理论依据。为准确评估极端环境生物土壤结皮发育对碳循环的影响,本文系统梳理了国内外相关研究,全面探讨生物土壤结皮的光合固碳、呼吸碳排放、净光合作用等关键过程,及其对大气碳交换和土壤有机碳的影响,并归纳不同结皮类型、不同区域环境条件下生物土壤结皮及结皮土壤系统碳循环过程的差异性,阐述其内在成因。综合分析表明,生物土壤结皮具有较强的光合固碳和呼吸碳排放能力,且在正常生理状态下表现为有机物的净积累;生物土壤结皮发育对土壤向大气碳排放速率具有双重调节作用,从长期效应来看,其发育增加了土壤向大气的碳排放量,激发碳源效应。生物土壤结皮发育增加土壤有机碳含量。苔藓结皮光合固碳能力、结皮土壤系统碳排放及其发育对土壤有机碳的促进作用明显强于藻类。降水和增温是引起不同区域生物土壤结皮及结皮土壤系统碳循环差异的主要因素,降水变化、增温等气候变化情景下生物土壤结皮碳循环动态响应及结皮土壤系统与大气碳交换呈非线性响应规律。

关键词: 生物土壤结皮, 光合固碳, 呼吸, 土壤有机碳

Abstract:

In extreme environments such as high-altitude cold, arid, and high-temperature regions where the development of vascular plants is restricted, biological soil crusts (BSCs) act as vital living surface coverings and play a crucial role in the ecosystem carbon cycle. To accurately assess the impact of BSC development in extreme environments on the carbon cycle, this paper systematically reviews relevant domestic and international research literature. It comprehensively explores key carbon cycle processes of BSCs, including photosynthetic carbon fixation,respiratory carbon emission, and net photosynthesis, as well as their impacts on atmospheric carbon exchange and soil organic carbon. Additionally, it summarizes the differences in the carbon cycling processes of various BSCs types and under different regional environmental conditions, and elucidates the underlying causes. The comprehensive analysis indicates that BSCs possess strong capabilities for photosynthetic carbon fixation and respiratory carbon emission, and they typically exhibit net accumulation of organic matter under normal physiological conditions. The development of BSCs has a dual regulatory effect on the rate of carbon emission from soil to the atmosphere. In the long term, their development increases the amount of carbon emitted from soil to the atmosphere, thereby enhancing the carbon source effect. The development of BSCs also increases the soil organic carbon content. Moss-dominated BSCs show significantly stronger capabilities in photosynthetic carbon fixation, carbon emission from the BSC-soil system, and promotion of soil organic carbon compared to algae-dominated BSCs. Precipitation and warming are the main factors causing differences in the carbon cycling of BSCs and BSC-soil system across different regions. Under climate change scenarios such as changes in precipitation and increased temperatures, the dynamic responses of BSC carbon cycling and the non-linear responses of carbon exchange between the BSC-soil system and the atmosphere are observed. This study clarifies the mechanisms by which BSC development affects the ecosystem carbon cycle and provides a solid theoretical basis for the scientific management and effective achievement of “carbon neutrality” goals in extreme environments.

Key words: biological soil crusts, photosynthetic carbon fixation, respiration, soil organic carbon

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