草地学报

草地学报 ›› 2022, Vol. 30 ›› Issue (3): 513-522.DOI: 10.11733/j.issn.1007-0435.2022.03.002

• 生态与草原修复 • 上一篇    

不同放牧强度对拉萨河谷温性草原主要植物生态位及种间联结的影响

吴姣姣1, 向明学2,3, 拉多1, 武俊喜2,3   

  1. 1. 西藏大学理学院, 西藏 拉萨 850000;
    2. 中国科学院地理科学与资源研究所生态系统网络观测与模拟重点实验室, 北京 100101;
    3. 中国科学院地理科学与资源研究所, 北京 100101
  • 收稿日期:2021-08-12 修回日期:2021-10-10 发布日期:2022-03-30
  • 通讯作者: 拉多,E-mail:lhaduo@hotmail.com;武俊喜,E-mail:wujx@igsnrr.ac.cn
  • 作者简介:吴姣姣(1996-),女,汉族,陕西西安人,硕士研究生,主要从事草地生态学研究,E-mail:wjpion@163.com
  • 基金资助:
    国家重点研发计划项目(2016YFC0502004)；2020年中央财政支持地方高校改革发展专项资金“生态学黄大年教师团队建设”(藏财教指[2020]1号)；国家自然基金委联合基金项目“高寒高海拔草地生态系统对非对称气候变暖的响应机制”(U20A2005)；西藏重大科技专项(XZ202101ZD0003 N)；西藏重大饲草专项“拉洛灌区粮草畜一体化关键技术研究与示范”(YDZX20195400004489)资助

Analysis of Niche and Interspecific Association of Dominant Plant Species of Temperate Grassland under Different Grazing Intensities in Lhasa River Valley

WU Jiao-jiao1, XIANG Ming-xue2,3, LHA Duo1, WU Jun-xi2,3   

  1. 1. College of Science, Tibet University, Lhasa, Tibet 850000, China;
    2. Key Laboratory of Ecosystem Network Observation and Modeling, Institute of Geographic Sciences and Natural Resources Research, Chinese Academy of Sciences, Beijing 100101, China;
    3. Institute of Geographic Sciences and Natural Resources Research, Chinese Academy of Sciences, Beijing 100101, China
  • Received:2021-08-12 Revised:2021-10-10 Published:2022-03-30

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摘要： 为了探明不同放牧强度如何影响物种的生态位和种间联结，本研究设置三种放牧强度，采用“Levins”方法计算物种的生态位宽度和生态位重叠值，以及使用方差比率法(VR)、卡方检验、联结系数(association coefficient,AC)和Ochiai (OI)指数分析了种间联结性。结果表明，中度放牧和禁牧增加了优势种的生态位宽度，但重度放牧却减小了优势种的生态位宽度；卡方检验表明三种处理下的15个主要物种所组成的105个种对中，分别有53.3%，52.4%，50.5%的种对表现出负联结性；联结系数AC表明，三种放牧强度下白草(Pennisetum centrasiaticum)与高山嵩草(Kobresia pygmaea)和黑褐穗薹草(Carex atrofusca)之间均呈负联结；OI指数表明，随放牧强度的增加，OI指数逐渐降低。因此，重度放牧使拉萨河谷温性草原主要物种生态位宽度和生态位重叠值降低，使群落内物种间联系不紧密，群落处于不稳定状态，不利于植物群落的发展。

关键词: 放牧, 生态位宽度, 生态位重叠, 拉萨河谷, 种间联结

Abstract: To examine the effects of different grazing intensities on interspecific association and species niches,we performed three grazing intensities,e.g.non-grazing (CK),moderate grazing (MG) and heavy grazing (HG). We used the method of “Levins” to calculate plant species niche characters,and used variance ratio (VR) to analyze all interspecific associations on the plant community. Finally,we calculated the species association coefficient (AC),Ochiai index (OI) on dominant plant species and used the Chi-square test to detect the significance of the interspecific association. The results showed that CK and MG had enhanced the niche width of dominant plant species,but HG decreased the niche width of dominant plant species. According to the Chi-square test,53.3%,52.4%,and 50.5% of the 15 dominant plant species showed negative association under the three treatments,respectively. The species association coefficient showed that Pennisetum centrasiaticum negatively associated with Kobresia pygmaea and Carex atrofusca under the three treatments,it indicated that P. centrasiaticum had a strong competition on resources with them. The result of OI value showed that interspecific association was decreased with the increased grazing intensity,and the OI value of HG was lowest among three treatments indicating that the interspecific relationship was looser under the heavy grazing condition. In conclusion,HG altered grassland plant species niche width and overlapping value in the plant community,and modified the plant interspecific association in friable condition,the plant community is in an unstable state.

Key words: Grazing, Niche width, Niche overlap, The Lhasa River Valley, Interspecific association

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