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草业学报 ›› 2025, Vol. 34 ›› Issue (9): 38-52.DOI: 10.11686/cyxb2024462

• 研究论文 • 上一篇    下一篇

退化高寒草甸土壤有机碳组分变化与增汇潜力研究

冉健民1,2(), 宋小艳1,2(), 王丹1,2,3, 王长庭1,2   

  1. 1.西南民族大学草地资源学院,四川 成都 610041
    2.青藏高原高寒草地生态保护与利用四川林业草原重点实验室,四川 成都 610041
    3.四川省畜牧科学研究院饲草所,四川 成都 610066
  • 收稿日期:2024-11-21 修回日期:2025-01-17 出版日期:2025-09-20 发布日期:2025-07-02
  • 通讯作者: 宋小艳
  • 作者简介:E-mail: songxy@swun.edu.cn
    冉健民(1999-),男,四川达州人,在读硕士。E-mail: imyun1999@163.com
  • 基金资助:
    国家自然科学基金项目(32101350);四川省科技厅自然科学项目(2023NSFSC1190);西南民族大学研究生“创新型科研项目”重点项目(YCZD2024009)

Changes in soil organic carbon fractions and carbon sequestration potential of degraded alpine meadows

Jian-min RAN1,2(), Xiao-yan SONG1,2(), Dan WANG1,2,3, Chang-ting WANG1,2   

  1. 1.College of Grassland Resources,Southwest Minzu University,Chengdu 610041,China
    2.Sichuan Provincial Forest and Grassland Key Laboratory of Alpine Grassland Conservation and Utilization of Tibetan Plateau,Chengdu 610041,China
    3.Sichuan Animal Science Academy,Chengdu 610066,China
  • Received:2024-11-21 Revised:2025-01-17 Online:2025-09-20 Published:2025-07-02
  • Contact: Xiao-yan SONG

摘要:

为探究青藏高原退化高寒草甸土壤有机碳(SOC)组分变化以及各退化程度碳增汇潜力,本研究采用国际推荐的将SOC分组为颗粒态有机碳(POC)与矿物结合态有机碳(MAOC)的物理分组方法,分析了不同退化程度[未退化(ND)、轻度退化(LD)、中度退化(MD)、重度退化(HD)]下高寒草甸土壤有机碳组分变化特征与退化高寒草甸恢复增汇潜力,并探究其关键影响因子。结果显示:1)轻度、中度和重度退化导致高寒草甸0~30 cm土壤有机碳分别降低24.54%、34.45%和34.81%,其中0~10 cm与10~20 cm土层受退化影响显著(P<0.05)。退化使高寒草甸0~30 cm土壤POC降低43.47%~56.01%,MAOC降低17.61%~31.20%,POC是SOC流失的主要组分。2)随机森林分析结果显示土壤全氮(TN)、容重(BD)、pH是土壤有机碳及其组分变化的主要影响因子,其中土壤TN对土壤有机碳及其组分的影响最关键(P<0.01)。相关性分析结果显示SOC、POC和MAOC分别与TN呈正相关,与BD、pH呈负相关。3)研究估算,轻度、中度和重度退化高寒草甸恢复的土壤(0~30 cm)碳增汇潜力分别为1.97、2.78和2.86 kg·m-2。就土层来看,表层(0~10 cm)占总增汇量的54.93%,是该区域高寒草甸碳增汇潜力的核心土层。研究结果可为退化高寒草甸恢复提供理论依据,同时为青藏高原草地生态系统碳增汇提供科学支撑。

关键词: 草地退化, 土壤有机碳, 颗粒态有机碳, 矿物结合态有机碳, 土壤碳增汇潜力

Abstract:

This study investigates the changes in soil organic carbon (SOC) components and the carbon sequestration potential associated with varying degrees of degradation in alpine meadow soil on the Qinghai-Xizang Plateau. Utilizing the internationally recognized physical grouping method, SOC is categorized into particulate organic carbon (POC) and mineral-associated organic carbon (MAOC). The analysis focuses on the characteristics of SOC component alterations and the carbon sequestration potential in alpine meadow soil subjected to different degradation levels: [no degradation (ND), light degradation (LD), moderate degradation (MD), and heavily degradation (HD)]. The findings reveal that light, moderate, and heavy degradation led to reductions in soil organic carbon in the 0-30 cm layer of the alpine meadow by 24.54%, 34.45%, and 34.81%, respectively, with significant impacts observed in the 0-10 cm and 10-20 cm layers (P<0.05). Degradation resulted in a decrease of POC by 43.47%-56.01% and MAOC by 17.61%-31.20%, indicating that POC constitutes the primary component of SOC loss. Furthermore, the relative analysis using random forest methodologies identifies soil total nitrogen (TN), bulk density (BD), and pH as the principal influencing factors on soil organic carbon and its components, with soil TN exerting the most significant influence (P<0.01). Correlation analysis indicates a significant positive relationship between SOC, POC, and MAOC with TN, while a negative correlation exists between BD and pH. The study estimates the carbon sequestration potential of the soil (0-30 cm) for the recovery of light, moderate, and heavy degradation in alpine meadows at 1.97, 2.78, and 2.86 kg·m-2, respectively. Notably, the surface layer (0-10 cm) contributes 54.93% of the total carbon sequestration, highlighting its critical role in carbon sequestration potential in this region. The research findings provide a theoretical foundation for restoring degraded alpine meadows and offer scientific support for carbon sequestration strategies within grassland ecosystems on the Qinghai-Xizang Plateau.

Key words: grassland degradation, soil organic carbon, particulate organic carbon, mineral-associated organic carbon, soil carbon increment potential