生物多样性 ›› 2025, Vol. 33 ›› Issue (12): 25251.  DOI: 10.17520/biods.2025251  cstr: 32101.14.biods.2025251

• 研究报告: 植物多样性 • 上一篇    下一篇

氮和牛粪输入对典型草原植物种–面积关系的影响

卢炜煜1,2,3, 陈旭1,3, 张日谦1,3, 张云海1,3, 李昭4*   

  1. 1. 中国科学院植物研究所植被与环境变化重点实验室, 北京 100093; 2. 中南安全环境技术研究院股份有限公司, 武汉 430061; 3. 中国科学院大学, 北京 100049; 4. 国家林业和草原局国家公园(自然保护地)发展中心, 北京 100714
  • 收稿日期:2025-06-30 修回日期:2025-11-17 接受日期:2025-12-12 出版日期:2025-12-20 发布日期:2026-01-09
  • 通讯作者: 李昭
  • 基金资助:
    国家重点研发项目(2022YFF1302800); 国家自然科学基金优秀青年科学基金项目(32122055)

Effects of nitrogen and cow dung input on plant species–area relationship in a typical grassland

Weiyu Lu1,2,3, Xu Chen1,3, Riqian Zhang1,3, Yunhai Zhang1,3, Zhao Li4*   

  1. 1 Key Laboratory of Vegetation and Environmental Change, Institute of Botany, Chinese Academy of Sciences, Beijing 100093, China 

    2 Central Southern Safety and Environment Technology Institute Co., Ltd., Hubei Wuhan 430061, China 

    3 University of Chinese Academy of Sciences, Beijing 100049, China 

    4 Development Centre of National Park (Natural Protected Areas), National Forestry and Grassland Administration, Beijing 100714, China

  • Received:2025-06-30 Revised:2025-11-17 Accepted:2025-12-12 Online:2025-12-20 Published:2026-01-09
  • Contact: Zhao Li

摘要: 氮富集通常会降低样方尺度的植物多样性, 而牛粪输入被认为能维持天然草原植物多样性。但是氮沉降增加和牛粪周转时间延长等复合情景如何影响草原植物多样性及种–面积关系尚不明确。本研究依托位于中国科学院内蒙古草原生态系统定位研究站, 在附近典型草原建立了氮和牛粪添加实验, 并于实验第3年即2024年8月测定了每个实验小区1–8 m2植物物种数及表层土壤理化特性指标。结果表明: 围封显著降低了18.9%空间尺度平均植物物种数。围封显著降低了种–面积关系截距(单位面积植物多样性), 但并未改变物种共存最小面积和种–面积关系斜率(群落组成空间异质性)。氮和牛粪添加均未显著改变植物种–面积关系的截距、斜率和物种共存最小面积。结构方程模型结果显示, 围封通过降低土壤pH值使种–面积关系斜率增加, 但通过增加植物地上生产力降低了种–面积关系截距; 牛粪添加通过增加土壤铵态氮同时降低种–面积关系斜率和物种共存最小面积。本文结果表明, 典型草原生态系统牛粪输入会带来适量的养分输入, 有利于物种共存。因此, 应在保障草畜平衡的基础上评估牛粪输入对草原生态功能和畜牧生产的协同效益。

关键词: 草地, 植物多样性, 牛粪, 氮沉降, 种–面积关系

Abstract

Aims: Nitrogen (N) enrichment can reduce grassland plant diversity, while dung decomposition and nutrient release are important for maintaining plant diversity in native grassland ecosystems. Grasslands have been subjected to both atmospheric N deposition and dung inputs. However, it remains unclear how these factors affect plant richness and species–area relationship (SAR). 

Methods: In 2022, we conducted a field experiment at the Inner Mongolia Grassland Ecosystem Research Station, Chinese Academy of Sciences. A split–plot completely randomized design was used, with enclosure and grazing as the two main effects. Within each main effect, four treatments were applied: control, cow dung addition (Dung), N addition (N), combined cow dung and N addition (Dung + N). In August 2024, species richness was recorded at four spatial scales (1 m2, 2 m2, 4 m2, and 8 m2). At the same time, aboveground net primary productivity (ANPP) and relevant soil physicochemical indicators were measured. 

Results: We found that enclosure significantly reduced the mean plant species richness at multiple spatial scales by 18.9%. Enclosure significantly reduced the intercept of the species–area relationship (i.e., plant diversity per unit area), but did not affect the minimum area for species coexistence or the slope (i.e., spatial heterogeneity of community composition). Neither N nor dung addition significantly changed the intercept, or slope of the species–area relationship. Results from the structural equation model showed that enclosure had a positive effect on the slope by lowering soil pH. It also exerted a negative effect on the intercept by increasing aboveground net primary productivity. Dung addition had a negatively affected on both the slope and intercept of the species–area relationship by increasing soil ammonium nitrogen content. 

Conclusions: Our findings suggest that dung inputs in typical steppe ecosystems can facilitate species coexistence through moderate nutrient supplementation, highlighting the importance of evaluating the ecological, productive, and livelihood benefits of dung coverage under the premise of grass–livestock balance.

Key words: grassland, plant diversity, cow dung, nitrogen deposition, species–area relationship