草地学报 ›› 2026, Vol. 34 ›› Issue (6): 2207-2216.DOI: 10.11733/j.issn.1007-0435.2026.06.023

• 研究论文 • 上一篇    

氮磷添加对退化高寒草原生产力与生物多样性的影响

冯探1, 蒲鑫1, 吕春磊1, 孙磊1,2   

  1. 1. 西藏农牧大学林草学院, 西藏 林芝 860000;
    2. 羌塘高寒草地生态系统定位研究站, 西藏 那曲 852000
  • 收稿日期:2026-01-08 修回日期:2026-03-09 发布日期:2026-06-02
  • 通讯作者: 孙磊,E-mail:xizangsunlei@163.com
  • 作者简介:冯探(1996-),男,汉族,江苏连云港人,硕士研究生,主要从事高寒草地生态与保护培育研究,E-mail:1501255948@qq.com
  • 基金资助:
    西藏农牧大学研究生创新项目(YJS2025-14);羌塘高原项目(603325037);羌塘科技小院项目(XY2024-02)资助

Effects of Nitrogen and Phosphorus Addition on the Productivity and Biodiversity in Degraded Alpine Steppe

FENG Tan1, PU Xing1, Lü Chun-lei1, SUN Lei1,2   

  1. 1. The Forestry and Grassland College of Xizang Agricultural and Animal Husbandry University, Linzhi, Xizang 860000;
    2. Qiangtang Alpine Grassland Ecosystem Research Station, Naqu, Xizang 852000
  • Received:2026-01-08 Revised:2026-03-09 Published:2026-06-02

摘要: 为探究协同恢复退化高寒草原生产力与维持生物多样性的适宜氮添加浓度,本研究在藏北高寒草原(海拔4634 m)开展随机区组试验,设置自然条件及施磷条件下的6个氮添加梯度(0,5,10,15,20和25 g·m-2·a-1 N),利用混合效应模型分析氮添加对植物地上生物量、群落结构及多样性的影响。结果表明,短期氮添加显著提高植物地上生物量,且促进效应随氮浓度升高而增强;同时显著降低植物多样性,抑制效应随氮浓度增加而加剧,禾本科植物重要值的提高,以及莎草科和杂类草植物重要值的降低。施磷增强了氮添加对植物地上生物量的正向效应,但未显著加剧对植物多样性的抑制。本研究揭示,施磷条件下适度氮添加(10~15 g·m-2·a-1 N)可能是恢复退化高寒草原的有效恢复措施,为高寒草原生态系统的可持续管理提供了科学依据。

关键词: 氮添加, 磷限制, 高寒草原, 植物地上生物量, 植物多样性, 群落结构

Abstract: To investigate the appropriate nitrogen addition concentration for synergistically restoring productivity and maintaining biodiversity in degraded alpine steppe, this study conducted a randomized block experiment in the northern Xizang alpine steppe (elevation 4634 m). Six nitrogen addition gradients (0,5,10,15,20, and 25 g·m-2·a-1 N) were set under natural conditions and with phosphorus application. Mixed-effect models were used to analyze the effects of nitrogen addition on plant aboveground biomass, community structure, and diversity. The results showed that short-term nitrogen addition significantly increased plant aboveground biomass, with the promoting effect strengthening as nitrogen concentration increased. Simultaneously, nitrogen addition significantly reduced plant diversity, with the inhibitory effect intensifying with higher nitrogen concentrations, accompanied by an increase in the importance value of grasses and a decrease in the importance values of sedges and forbs. Phosphorus application enhanced the positive effect of nitrogen addition on aboveground biomass but did not significantly exacerbate the inhibition of plant diversity. This study reveals that moderate nitrogen addition (10~15 g·m-2·yr-1N) with phosphorus application may be an effective restoration measure for degraded alpine steppe, providing a scientific basis for the sustainable management of alpine steppe ecosystem.

Key words: Nitrogen addition, Phosphorus limitation, Alpine steppe, Plant aboveground biomass, Plant species diversity, Community structure

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