草地学报

草地学报 ›› 2026, Vol. 34 ›› Issue (6): 2077-2089.DOI: 10.11733/j.issn.1007-0435.2026.06.011

• 研究论文 • 上一篇    

氮添加对高寒草甸表层土壤有机碳及其组分的初期影响

岳磊1,2, 唐庄生1,2, 孟天乐1,2, 杨健1,2, 马晶1,2, 张文柳1,2, 杨洁1,2   

  1. 1. 甘肃农业大学草业学院, 甘肃 兰州 730070;
    2. 草业生态系统教育部重点实验室, 甘肃 兰州 730070
  • 收稿日期:2025-09-08 修回日期:2025-09-27 发布日期:2026-06-02
  • 通讯作者: 杨洁,E-mail:yang_jie@gsau.edu.cn
  • 作者简介:岳磊(2000-),男,汉族,甘肃榆中人,硕士研究生,主要从事草地土壤碳循环研究,E-mail:yuelei5.22@foxmail.com
  • 基金资助:
    国家自然科学基金项目（32360345）；中国农业大学对口支援项目（GSAU-DKZY-2024-004）；甘肃农业大学伏羲青年英才（GAUfx-04Y06）；甘肃省杰出青年基金（24JRRA632）资助

Initial Effects of Nitrogen Addition on Surface Soil Organic Carbon and its Components in an Alpine Meadow

YUE Lei1,2, TANG Zhuang-sheng1,2, MENG Tian-le1,2, YANG Jian1,2, MA Jing1,2, ZHANG Wen-liu1,2, YANG Jie1,2   

  1. 1. College of Pratacultural Science, Gansu Agricultural University, Lanzhou, Gansu Province 730070, China;
    2. Key Laboratory of Grassland Ecosystem, Ministry of Education, Lanzhou, Gansu Province 730070, China
  • Received:2025-09-08 Revised:2025-09-27 Published:2026-06-02

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摘要： 为揭示氮沉降对高寒草甸土壤有机碳（Soil organic carbon， SOC）及其稳定性的初期影响，本研究在祁连山东段开展野外氮添加试验，系统测定植被生物量、土壤理化性质、酶活性及SOC组分，并结合方差分解分析其主导因子。结果表明，氮添加显著提高地上生物量，但显著降低纤维素酶和β-葡萄糖苷酶活性（P<0.05）。颗粒有机碳（Particulate organic carbon， POC）含量和比例显著下降，而易氧化有机碳（Easily oxidizable organic carbon， EOC）和矿物结合态有机碳（Mineral-associated organic carbon， MAOC）显著升高（P<0.05）。POC主要受全磷和碳获取酶调控，MAOC与地上生物量、pH及β-葡萄糖苷酶密切相关，EOC则受速效磷和纤维素酶驱动。总体而言，SOC短期变化的解释率主要来自微生物生物量碳（Microbial biomass carbon， MBC， 17%）和溶解性有机碳（Dissolved organic carbon， DOC， 14.1%）。综上，氮添加通过促进植被碳输入、调节酶活性并重塑碳组分分配，增强了土壤的稳定碳库。本研究揭示了氮沉降下高寒草甸SOC稳定化的途径，对理解脆弱生态区碳循环机制及评估氮沉降条件下的碳汇潜力具有重要意义。

关键词: 高寒草甸, 氮添加, 活性碳组分, 碳库稳定性, 方差分解

Abstract: To elucidate the initial effects of nitrogen deposition on soil organic carbon （SOC） and its stability in alpine meadows， we conducted a field nitrogen addition experiment in the eastern Qilian Mountains. Aboveground biomass， soil physicochemical properties， enzyme activities， and SOC fractions were measured， and their key drivers were identified using variance partitioning. Nitrogen addition significantly increased aboveground biomass but reduced cellulase and β-glucosidase activities （P<0.05）. Particulate organic carbon （POC） content and proportion decreased markedly， whereas easily oxidizable organic carbon （EOC） and mineral-associated organic carbon （MAOC） increased significantly （P<0.05）. POC dynamics were mainly regulated by total phosphorus and carbon-acquiring enzymes， MAOC was closely associated with aboveground biomass， pH， and β-glucosidase， while EOC was primarily driven by available phosphorus and cellulase. Overall， microbial biomass carbon （17%） and dissolved organic carbon （14.1%） primarily explained short-term SOC variations. In summary， nitrogen addition enhanced soil carbon pool stability by promoting plant carbon inputs， modulating enzyme activities， and reshaping the distribution of SOC fractions. These findings reveal the pathways through which nitrogen deposition stabilizes SOC in alpine meadows， providing critical insights into carbon cycling processes and the carbon sequestration potential of fragile ecosystems under nitrogen enrichment.

Key words: Alpine meadow, Nitrogen addition, Activated carbon components, Carbon pool stability, Variance decomposition

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