放牧扰动对山地荒漠草地植物群落结构的影响

Impacts of Grazing Pressure on Structure of Vegetation Communities in Montane Desert-grassland

对祁连山北坡山地荒漠草地植物群落放牧干扰下的物种组成、丰富度及丰盛度进行了初步测定,结果表明:在不同放牧压力梯度下,物种丰富度呈单峰状曲线,植物高度、覆盖度和地面凋落物随放牧强度的增加而显著减少,植被组成也相应发生变化,杂草随放牧强度的增大而增多。

Effect of the level of grazing intensity in six gradients for livestocks on the structures of vegetation communities and the species richness were examined quantitatively using data collected on a montane desert-grassland at midsection of the northern slope of Mt. Qilian, from July to August period of plant lives. The result showed that species richness showed a single-peak curve under different gradients of grazing impact, and species composition, height, coverage, and litters of vegetation showed strong reductions with the increase of grazing intensity. The ratios of densities for weed enhanced with grazing intensity increasing.