载畜率对荒漠草原植物群落影响的研究

Effects of Different Stocking Rate on Plant Community in Desert Steppe

对不同载畜率下短花针茅荒漠草原植物群落特征进行比较,结果表明:不同植物种群的盖度对载畜率的响应不同,无芒隐子草盖度在轻度放牧区最大,栉叶蒿盖度在7月份、8月份分别以中度放牧区和轻度放牧区最大;短花针茅、冷蒿、阿氏旋花、细叶葱、木地肤随载畜率增大高度下降明显,猪毛菜高度在四个载畜率下差异均不显著;随着载畜率的增大,植物群落生物量呈下降趋势,且重度放牧与不放牧、轻度放牧有显著差异;随着载畜率的增大,建群种、优势种地位改变不明显,但一年生的猪毛菜重要值增大,在重度放牧区达到最大并占据优势地位;Shannon-wiener指数、Simpson指数、Pielou均匀度指数均以轻度放牧区最大,Shannon-wiener指数、Simpson指数均为轻度放牧>中度放牧>重度放牧>不放牧,且不放牧与轻度放牧差异显著。

Through the research on the compare of the characteristics of plant community under different stocking rates on Stipa breviflora in desert steppe,the results showed that the coverage of different plant populations had the different response to the different stocking rates,the coverage of Cleistogenes songorica under light grazing was the highest,and the highest coverages of Neopallasia pectinata in July and August were found in medium grazing areas and light grazing areas.The height of Stipa breviflora,Artemisia frigida,Convolvulus ammannii,Allium tenuissimum,Kochia prostrate decreased significantly as the stocking rate increasing.While there＇s no significant difference in height of Salsola collina under these four stocking rates.With the increasing stocking rate,the aboveground biomass of the plant community decreased,and it had a significant difference among different stocking rates.The status of community constructive species and dominant species were not significant different on different stocking rate.However,the importance value of annual Salsola collina enhanced and reached the maximum under heavy grazing;Shannon-wiener index,Simpson index and Pielou evenness index reached the maximum under light grazing,the value of Shannon-wiener index and Simpson index showed that light grazing moderate grazing heavy grazing no grazing,and there were significant differences between no grazing and light grazing.