植物生态学报 ›› 2025, Vol. 49 ›› Issue (9): 1399-1409.DOI: 10.17521/cjpe.2024.0243  cstr: 32100.14.cjpe.2024.0243

• 研究论文 • 上一篇    下一篇

氮添加和降水改变对高寒草甸生态系统地上与地下碳储的影响

张法伟1,*()(), 李红琴2, 祝景彬3, 樊博1, 周华坤1, 李英年1, 梁乃申4   

  1. 1中国科学院西北高原生物研究所高原生物适应与进化重点实验室, 西宁 810008
    2洛阳师范学院生命科学学院, 河南洛阳 471934
    3枣庄学院旅游与资源环境学院, 山东枣庄 277160
    4National Institute for Environmental Studies, Tsukuba, Ibaraki 3058506, Japan
  • 收稿日期:2024-07-25 接受日期:2025-01-14 出版日期:2025-09-20 发布日期:2025-01-15
  • 作者简介:*张法伟: ORCID: 0000-0003-0693-7956 E-mail: mywing963@126.com
  • 基金资助:
    青海省重点研发与转化计划科技国际合作专项(2024-HZ-801);河南省自然科学基金(242300420170);国家自然科学基金(32471752);青海省2021昆仑英才-拔尖人才项目

Response of aboveground and belowground carbon storage to nitrogen addition and precipitation change in an alpine meadow ecosystem

ZHANG Fa-Wei1,*()(), LI Hong-Qin2, ZHU Jing-Bin3, FAN Bo1, ZHOU Hua-Kun1, LI Ying-Nian1, LIANG Nai-Shen4   

  1. 1Key Laboratory of Adaptation and Evolution of Plateau Biota, Northwest Institute of Plateau Biology, Chinese Academy of Sciences, Xining 810008, China
    2College of Life Sciences, Luoyang Normal University, Luoyang, Henan 471934, China
    3College of Tourism, Resources and Environment, Zaozhuang University, Zaozhuang, Shandong 277160, China
    4National Institute for Environmental Studies, Tsukuba, Ibaraki 3058506, Japan
  • Received:2024-07-25 Accepted:2025-01-14 Online:2025-09-20 Published:2025-01-15
  • Supported by:
    Program of Key Research and Transformation of Qinghai Province of China(2024-HZ-801);Natural Science Foundation of Henan Province(242300420170);National Natural Science Foundation of China(32471752);Qinghai Kunlun Talents-Top Talents of 2021

摘要: 高寒草甸生态系统具有重要的碳储功能但相对脆弱, 理解其对大气氮沉降和降水格局改变的响应是准确评估全球变化下系统碳收支的科学基础。基于2017年在青藏高原东北隅建立的高寒草甸氮添加(10 g·m-2·a-1)和降水改变(减雨50%和增雨50%)实验平台, 分析2022-2023年植被生物量和土壤有机碳含量(SOCC)及组分的变化, 探讨高寒草甸生态系统碳储对氮水改变的响应。结果表明氮添加和降水改变对群落地上生物量(AGB)无显著交互作用。群落AGB对氮水改变的响应具有显著的功能群依赖性, 氮添加处理显著提高莎草类和禾草类AGB。减雨50%处理显著降低群落AGB约27%, 但增雨50%处理无显著作用。除了莎草类, 其他功能群AGB在群落AGB中的占比无显著变化。0-40 cm地下生物量(BGB)和SOCC对氮水改变的响应微弱, 表现出土壤深度和年际的依赖性。氮添加和减雨50%处理分别降低和提高根冠比约31%和83%。氮添加处理仅显著提升土壤表层(0-10 cm)矿物结合态有机碳(MAOC)含量约31%。氮水改变下群落AGB的响应比(RR)主要受控于禾草类AGB。0-40 cm BGB的RR受土壤表层和深层(20-40 cm) BGB的影响。0-40 cm SOCC的RR由各层SOCC共同驱动。土壤表层BGB直接正向调控表层颗粒态有机碳(POC)含量并通过POC间接负向影响表层MAOC。群落AGB正向调控深层MAOC含量但负向影响深层POC含量。因此, 氮水改变的主效应而非交互效应影响了高寒草甸AGB, 但对BGB和SOCC的作用微弱。植被生物量对土壤有机碳组分含量的影响具有深度依赖性。

关键词: 高寒草甸, 生物量, 土壤有机碳, 颗粒态有机碳, 矿物结合态有机碳, 氮添加, 降水改变

Abstract:

Aims Alpine grassland ecosystems store vast amounts of organic carbon while are fragile. Understanding the responses of the ecosystem carbon storage to the synchronous atmospheric nitrogen deposition and changing precipitation regimes is critical to project the fate of ecosystem carbon budgets under the context of global change.
Methods Based on a manipulation field experiment of nitrogen addition (10 g·m-2·a-1) and precipitation change (precipitation reduction by 50% and increase by 50%) in an alpine meadow on the northeastern Qing-zang Plateau in 2017, the plant biomass, soil organic carbon content (SOCC) and its fractions were observed from 2022 to 2023, in order to explore the response of ecosystem carbon storage to the changes in nitrogen and precipitation.
Important findings The results showed that there were little interaction effects of nitrogen addition and precipitation change on vegetation aboveground biomass (AGB). The response of vegetation AGB to the changes in nitrogen and precipitation was functional group-dependent. Nitrogen addition treatment increased the AGB of graminoid and sedge. Decreased precipitation treatment reduced AGB by 27% while increased precipitation treatment impacted AGB insignificantly. Except for sedge, the proportion of functional group AGB against community AGB changed undetectably. The responses of 0-40 cm belowground biomass (BGB) and SOCC to the changes in nitrogen and precipitation were weak and depth- and year-dependent. The root/shoot ratio reduced by 31% in nitrogen addition treatment and increased by 83% in decreased precipitation treatment, respectively. Nitrogen addition treatment increased soil surface (0-10 cm) mineral-associated organic carbon (MAOC) content by 31%. The response ratio (RR) of vegetation AGB was positively related to graminoid. The RR of 0-40 cm BGB was determined by soil surface and deep (20-40 cm) BGB positively. The RR of 0-40 cm SOCC was equivalently regulated by each layer SOCC. Soil surface BGB directly impacted the surface particulate organic carbon (POC) content positively and indirectly impacted the surface MAOC content via POC content negatively. The vegetation AGB affected the deep MAOC content positively and the deep POC content negatively. The main effects, rather than the interaction effects of the changes in nitrogen and precipitation, affect AGB significantly while BGB and SOCC undetectably. The differential effects of plant biomass on soil organic carbon fractions are depth-dependent.

Key words: alpine meadow, biomass, soil organic carbon, particulate organic carbon, mineral-associated organic carbon, nitrogen addition, precipitation change