甘南高寒草甸退化对植物功能群多样性与物种多度分布的影响

为分析甘南高寒草甸植物功能群多样性及其物种多度分布对退化的响应，探讨其多样性的形成与维持机制，采用样地调查法收集数据，并使用物种多度模型对其进行拟合分析。结果表明:随着退化程度的加深，植被优势种以禾草科和莎草科植物为主，逐渐变为杂草功能群植物为主，杂草功能群在群落多样性分布中起着主导作用；全部物种多度分布随着退化程度的加深发生变化，其中，无退化草甸的最优拟合模型是VOLKOV，轻度退化草甸的最优拟合模型是GEO，中度退化草甸和重度退化草甸的最优拟合模型为BRO，资源分配模式由随机分配转向固定分配的分配模式；禾草功能群的最优拟合模型以生态位模型为主，资源分配方式由固定分配和随机分配共同主导，豆科功能群的最优拟合模型是BRO，资源分配方式以固定分配为主，杂草功能群的最优拟合模型从中性模型向生态位模型转变，与全部物种多度分布的最优模型基本一致，且资源分配由随机分配向固定分配转变，可以认为杂草功能群是影响群落物种多度分布的主要原因，但是禾草和豆科功能群的贡献也不可忽视。

Effects of Alpine Meadow Degradation on Plant Functional Group Diversity and Species Abundance Distribution in Gannan

In order to analyze the response of plant functional group diversity and species abundance distribution to degradation in the alpine meadow of Gannan, and to explore the formation and maintenance mechanism of the diversity, data were collected by sample plot survey method, and the species abundance model was used for fitting analysis. The results showed that the dominant vegetation species were mainly grass and sedge, and gradually changed to weed functional groups, which played a leading role in the distribution of community diversity. The distribution of species abundance changed with the deterioration degree. The optimal fitting model of non-degraded meadow was VOLKOV, the optimal fitting model of mildly degraded meadow was GEO, and the optimal fitting model of moderately degraded meadow and severely degraded meadow was BRO. The distribution mode of resource allocation changed from random allocation to fixed allocation. The optimal fitting model of grass functional groups is mainly niche model, and the resource allocation mode is dominated by fixed allocation and random allocation. The optimal fitting model of leguminous functional groups is BRO, and the resource allocation mode is mainly fixed allocation. The optimal fitting model of weed functional groups changes from neutral model to niche model, which is basically consistent with the optimal model of all species abundance distribution. In addition, the resource allocation changed from random allocation to fixed allocation, so it can be considered that weed functional groups were the main factors affecting the distribution of community species abundance, but the contribution of grass and leguminous functional groups could not be ignored.