牦牛放牧率对小嵩草高寒草甸植物群落的影响  

Effects of Stocking Rates on Plant Community Diversity,Aboveground Present Biomass and its Composition in Kobrecia Parva Alpine Meadow.

作　　者：董全民[1] 马玉寿[1] 李青云[1] 施建军[1] 

机构地区：[1]青海省畜牧兽医科学院,青海西宁810003

出　　处：《中国草地》2004年第3期24-32,共9页Grassland of China

基　　金：青海省"九五"攻关项目(96-N-112)

摘　　要：两年的放牧实验结果表明:随着放牧率的提高,优良牧草的盖度和比例降低,杂草的盖度和比例增加;两季草场各放牧处理植物群落发生了变化:轻度放牧和重度放牧的优势种没有变化,中度放牧的优势种发生了变化。在暖季草场,放牧率与植物群落多样性指数、均匀度指数和植物群落组成种的种数呈显著的线性回归关系(R=0.9840,P<0.01;R=0.9986,P<0.01;R=-0.8660,P<0.05);在冷季草场,放牧率与植物群落多样性指数、均匀度指数和植物群落组成种的种数均呈显著的二次回归关系(P<0.05)。地上现存量的变化基本呈"S"型变化,而且随着放牧率的提高,地上现存量减小。在冷季草场,放牧率与优良牧草的盖度和地上现存量之间呈极显著的线性回归关系,而与杂草的盖度和地上现存量之间呈显著的二次回归关系;在暖季草场,放牧率与各植物类群盖度和地上现存量之间呈极显著的线性回归关系。Effects of stocking rates on plant community diversity,aboveground present biomass and its composition in Kobrecia parva alpine meadow had been studied for two year.The results showed that the coverage and ratio of high quality forage reduced, and ones of weeds increased with increase of stocking rates,and dominant varieties of plants lied in difference,dominant varieties of the light and heavy grazing did not change,but the moderate grazing changed.In cold season pasture,the relationship between stocking rate and diversity index(H′),evenness index(J′) and composing species of plant community was notable second degree polynomial regression(R2=0.8876,P<0.05; R2=0.9077,P<0.05;R2=0.9932,P<0.001),and in summer pasture,there was a significant linear regression relationship between stocking rates and diversity index(H′),evenness index(J′) and composing species of plant community respectively(R=0.9840,P<0.01;R=0.9986,P<0.01;R=-0.8660,P<0.05).The change of aboveground present biomass was basically'S'shape,and with the increase of stocking rates,the aboveground present biomass was reduced.There was a significant linear regression relationship between stocking rates and the coverage and aboveground present biomass of high quality forage(P<0.05),and a greatly notable relationship of the second degree polynomial regression relationship between stocking rate and the coverage of weeds in cold season pasture(P<0.01).But in warm pasture,it was a greatly notable relationship of linear regression between stocking rate and the coverage and aboveground present biomass of the different plant groups(P<0.01).

关 键 词：牦牛 放牧率 高寒草甸 植物群落多样性 地上现存量 

分 类 号：S812.43[农业科学—草业科学]