不同放牧梯度上草原群落空间异质性的比较研究

Comparative Study on Spatial Heterogeneity of Grassland Community in Different Grazing Gradients

以内蒙古呼伦贝尔草原为研究对象,利用幂函数法则定量地分析在轻度放牧、中度放牧和重度放牧3种不同利用方式下,群落的物种组成、物种多样性、群落空间异质性等群落特征。结果表明:随着放牧强度的增加,群落组成结构改变,群落丰富度逐渐降低,轻牧>中牧>重牧;不同放牧梯度上,各物种种群在实际分布上均具有较强的空间异质性,即偏离随机分布呈现集中分布趋势;不同放牧梯度上,群落总体空间异质性指数变化规律为轻牧=重牧>中牧,均匀度指数的变化规律为中牧>轻牧>重牧。

In this paper, taking Inner Mongolia Hulunbeier grassland as the research object, the species composition, species diversity, community spatial heterogeneity and other community characteristics are quantitatively analyzed by using the power law quantitatively in three cases of light grazing, moderate grazing and heavy grazing. The results showed that： （1） as grazing in- tensity increased, community composition changed and community richness decreased ; （2） in different grazing gradients, all populations had strong spatial heterogeneity in the actual distribu- tion, that is distribution characteristic of space is not random distribution, but concentration dis- tribution; （3） in different grazing gradients, community overall spatial heterogeneity index in the light grazing was equal that in the heavy grazing, but more than that in the moderate grazing, evenness index in the moderate grazing was more than that in light grazing, and that in the light grazing more than that in the heavy grazing.