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.