封育与放牧下氮添加对植物功能群氮、磷含量的影响

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中图分类号：S812 文献标识码：A 文章编号：1007-0435（2026）03-0960-13

doi：10.11733/j.issn.1007-0435.2026.03.020

引用格式：，等.封育与放牧下氮添加对植物功能群氮、磷含量的影响[J].草地学报，2026，34（3）：960 -972 HEFeng-yuan，CHEN Meng-jiao，REN Fei，et al.Efects of Nitrogen Addition on Nitrogen and Phosphorus Contents of Plant Functional Groups under Fencing and Grazing Management[J].Acta Agrestia Sinica，2O26，34（3）：960 -972

Abstract：Nitrogen deposition intensification influences nutrient cycling in grassland ecosystems，yet plant nutri ent 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 adition significantly increased the N concentrations in grasses， sedges，forbs，and the communityasa 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 phospho rus 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

草地约占全球陆地面积的 45% ，是陆地生态系统中分布最广的类型之一，对维持畜牧业可持续发展具有重要作用1。（剩余24477字）