放牧干扰下高寒草甸物种多样性指数评价与选择

发布时间：2018-02-12 17:58

本文关键词： 高寒草甸放牧干扰多样性指数　出处：《应用生态学报》2017年06期 　论文类型：期刊论文

【摘要】：在青藏高原东北缘高寒草甸设置6个放牧强度样地,连续4年研究10个多样性指数(Richness和Abundance 2个实测指数,优势度指数、均匀度指数、丰富度指数和综合指数各2个)对放牧强度和年限影响植物群落的解释能力.结果表明:相对于重要值,利用多度计算的多样性指数对放牧干扰更敏感.优势度指数(Berger-Parker、Dominance)与放牧强度和年限均无关,不能将放牧干扰对群落优势种的影响有效区分.均匀度指数(Equitability、Evenness)均与放牧强度无关,但Evenness指数与放牧年限呈显著负相关,不受偶见种影响且与物种多度的变异系数呈显著正相关,在基于时间尺度的均匀度比较中可以选择Evenness指数.丰富度指数(Menhinick、Margalef)均与放牧年限无关,但Margalef指数与放牧强度呈显著正相关,且不受偶见种影响.综合指数(Shannon、Simpson)均与放牧强度无关,但Shannon指数与物种丰富度和多度呈显著正相关,且随放牧年限增加而显著升高,不受偶见种影响,Shannon指数可用于在长时间尺度下比较物种多样性变化.在所有多样性指数中,只有实测物种丰富度和多度均与放牧强度呈显著负相关,与放牧年限呈显著正相关,且不受偶见种影响,故实测物种丰富度和多度相结合可作为放牧干扰下多样性比较的首选指标.此外,多样性指数选择须考虑放牧干扰的强度与时间特征、多样性组分和研究目的.
[Abstract]:Six grazing intensity plots were set up in the alpine meadow on the northeast margin of the Qinghai-Xizang Plateau. Ten diversity indices (Richness and Abundance), dominance index and evenness index were studied for 4 consecutive years. The richness index and composite index (2 each) affect the herding intensity and the number of years of grazing, the results show that, relative to the important value, The diversity index calculated by multiplicity was more sensitive to grazing disturbance, and the dominance index Berger-ParkerDomino was independent of grazing intensity and duration, and could not distinguish the effect of grazing disturbance on dominant species effectively, but evenness index equitability and Evennesshad nothing to do with grazing intensity. However, Evenness index was negatively correlated with grazing years, not affected by rare species, and positively correlated with the coefficient of variation of species abundance. In the comparison of evenness based on time scale, Evenness index can be selected. The richness index Menhinicki Margalef. is independent of grazing years, but Margalef index is significantly positively correlated with grazing intensity and is not affected by rare species. The comprehensive index Shannon Simpsonis independent of grazing intensity. However, Shannon index was positively correlated with species richness and abundance, and increased significantly with grazing years, and could be used to compare species diversity over a long period of time. Only the measured species richness and abundance were negatively correlated with grazing intensity, and positively correlated with grazing years, and not affected by rare species. Therefore, the combination of measured species richness and abundance can be used as the first choice for diversity comparison under grazing disturbance. In addition, the selection of diversity index should consider the intensity and time characteristics of grazing disturbance, diversity components and research purposes.
【作者单位】：甘肃农业大学草业学院/草业生态系统教育部重点实验室/中-美草地畜牧业可持续发展研究中心;
【基金】：国家自然科学基金项目(31460635)资助~~
【分类号】：S812

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