干扰对云顶山亚高山草甸群落物种多样性的影响

放牧等干扰会对亚高山草甸群落的外貌、结构及功能造成影响。为了揭示在外界干扰下云顶山草甸群落的变化规律，对云顶山草甸进行群落学调查，共取45个样方（1×1 m）。在此基础上，应用TWINSPAN对草甸群落进行数量分类；运用丰富度指数、物种多样性指数和均匀度指数分析了不同程度干扰对草甸植物物种多样性的影响及其变化规律。结果表明：该草甸划分为6个群丛，受干扰程度中等的群丛3的丰富度、多样性以及均匀度都最高，受干扰程度轻的群丛1次之，而受干扰程度较重的群丛6最低。同时干扰对该草甸不同植物功能群及不同物种的影响趋势是不一致的。随着干扰程度加重,灌木和豆科等植物在群落中的优势地位逐渐减弱，甚至消失；禾草中的部分种如披针叶苔草（Carex lanceolata）等对干扰响应不明显；毒草和一些杂草种类在群丛中的优势地位明显上升。

Effect of Disturbance on the Community Species Diversity in Yunding Mount. Subalpine Meadow

Disturbances, such as grazing and so on, can affect the appearance, structure and function of subalpine meadow community. In order to indicate the changing law of subalpine meadow community, 45 plots (1×1 m) were investigated using the community sample method. On these bases, the meadow communities were classified with TWINSPAN, the effects of different disturbances on the species diversity and their changing law were studied using the richness index, Shannon-Wiener index, Simpson index and Pielou evenness index.The results showed that: the meadows were classified into 6 associations. The richness index is the highest in association 3 where the disturbance degree is moderate; followed by association 1 where the disturbance degree is relatively light; the lowest is in association 6 where the disturbance degree is heavy. At the same time, disturbances have brought different influences on the plant function group and species. Along with the disturbance getting serious, the dominant station of shrub and legumes is wearing off, even disappearing, some graminoids such as Carex lanceolata did not have obvious response to the disturbance, and the dominant station of toxic grasses is rising in the community.