Acta Agrestia Sinica ›› 2026, Vol. 34 ›› Issue (3): 960-972.DOI: 10.11733/j.issn.1007-0435.2026.03.020

Previous Articles    

Effects of Nitrogen Addition on Nitrogen and Phosphorus Contents of Plant Functional Groups under Fencing and Grazing Management

HE Feng-yuan1,2, CHEN Meng-jiao1,2, REN Fei1,3, LIU Xin-yan1,2, LI Xiao-feng1,2, LI Lan-ping1,3, LIANG De-fei1,3, HAN Cheng-long1,3   

  1. 1. State Key Laboratory of Plateau Ecology and Agriculture, Qinghai University, Xining, Qinghai Province 810016, China;
    2. College of Eco-Environmental Engineering, Qinghai University, Xining, Qinghai Province 810016, China;
    3. Sanjiangyuan Grassland Ecosystem National Observation and Research Station, Xining, Qinghai Province 810016, China
  • Received:2025-07-01 Revised:2025-09-10 Published:2026-03-23

封育与放牧下氮添加对植物功能群氮、磷含量的影响

何丰媛1,2, 陈梦娇1,2, 任飞1,3, 刘鑫燕1,2, 李晓凤1,2, 李兰平1,3, 梁德飞1,3, 韩成龙1,3   

  1. 1. 青海大学省部共建三江源生态与高原农牧业国家重点实验室, 青海 西宁 810016;
    2. 青海大学生态环境 工程学院, 青海 西宁 810016;
    3. 青海三江源草地生态系统国家野外科学观测研究站, 青海 西宁 810016
  • 通讯作者: 任飞,fei_ren2016@163.com
  • 作者简介:何丰媛(2001-),女,汉族,甘肃白银人,硕士研究生,主要从事草地生态学研究,E-mail:hefengyuan_2023@163.com;
  • 基金资助:
    青海省帅才科学家负责制项目(2024-SF-102);国家自然科学基金(U21A20185,31901171);青海大学省部共建三江源生态与高原农牧业国家重点实验室开放研究项目(2019-KF-001)资助

Abstract: Nitrogen deposition intensification influences nutrient cycling in grassland ecosystems, yet plant nutrient responses under grazing and enclosure remain unclear. This study conducted a two-year multi-level nitrogen addition experiment in an alpine steppe in Qinghai to investigate the responses of nitrogen (N) and phosphorus (P) contents at both the plant functional group and community levels to nitrogen addition under enclosure and grazing conditions. The results showed that N addition significantly increased the N concentrations in grasses, sedges, forbs, and the community as a whole (P<0.001), but had no significant effect on legumes (P>0.05); N addition significantly enhanced the P concentrations in grasses, sedges, and the community (P<0.001), while significantly reducing that in legumes and forbs (P<0.05). Management practices further regulated the nutrient response pathways: under enclosure condition, nitrogen addition primarily induced a phosphorus dilution effect, thereby increasing the N∶P; while under grazing condition, it promoted nitrogen absorption and altered phosphorus dynamics, leading to an elevated N∶P, with the overall N∶P being higher in enclosed grasslands. The study demonstrated that grazing and fencing, as distinct management approaches, were key factors regulating the response of plant nutrients to nitrogen deposition in the alpine steppe, holding significant implications for understanding regional nutrient limitations and guiding sustainable grassland management.

Key words: Fencing, Grazing, Nutrients addition, Alpine grassland, Plant functional groups, Plant nitrogen and phosphorus content

摘要: 氮沉降加剧影响草地生态系统养分循环,但放牧与封育下植物养分响应尚不明确。本研究在青海高寒草原开展为期2年的多梯度氮添加实验,探讨封育与放牧条件下植物功能群及群落水平氮(Nitrogen,N)、磷(Phosphorus,P)含量对氮添加的响应。结果表明:氮添加显著增加了禾草类、莎草类和杂类草以及群落水平的氮含量(P<0.001),但对豆科植物的氮含量无显著影响;同时氮添加显著增加了禾草类、莎草类及群落水平的磷含量(P<0.001),显著降低了豆科植物和杂类草的磷含量(P<0.001)。管理措施进一步调控了养分响应途径:封育条件下,氮添加主要引发磷稀释效应提升N∶P;而放牧条件下,氮添加则通过促进氮吸收并改变磷动态导致N∶P升高,且封育草地的N∶P整体更高。研究表明,放牧与封育作为不同的管理方式,是调控高寒草原植物养分对氮沉降响应的关键因素,对理解区域养分限制及草地可持续管理具有重要意义。

关键词: 封育, 放牧, 养分添加, 高寒草地, 功能群, 氮、磷含量

CLC Number: