牦牛放牧强度对小嵩草草甸两季轮牧草场植物群落数量特征的影响  

Effects of yak grazing intensity on quantitative characteristics of plant community in a two-seasonal rotation pasture in Kobresia Parva meadow

作　　者：董全民[1] 赵新全[2] 马玉寿[1] 施建军[1] 王彦龙[1] 李世雄[1] 杨时海[1] 盛丽[1] 

机构地区：[1]青海省畜牧兽医科学院,西宁810016 [2]中国科学院西北高原生物研究所,西宁810001

出　　处：《生态学杂志》2011年第10期2233-2239,共7页Chinese Journal of Ecology

基　　金：国家"十一五"科技支撑计划重大项目(2006BAC01A-02);国家"十一五"科技支撑计划项目(2007BAC30B04;2009BAC61B02);国家自然科学基金项目(30960074);青海省科技厅重点项目(2009-N-502)资助

摘　　要：基于小嵩草(Kobresia parva)草甸连续2年的牦牛放牧控制试验,研究了暖季和冷季放牧草场植物群落数量特征的变化。结果表明:在2年的放牧期内,小嵩草草甸2季草场优良牧草的盖度随放牧强度的提高呈降低趋势,而杂草的盖度呈增加趋势;2季草场对照、轻度放牧和中度放牧组的优势种均为小嵩草和垂穗披碱草,但暖季草场重度放牧下主要优势种变为鹅绒委陵菜和阿拉善马先蒿,冷季草场重度放牧下小嵩草和鹅绒委陵菜为主要优势种;放牧强度之间的差异越大,2季草场各放牧处理间群落的相似性程度越低,说明放牧强度是引起群落差异的主要原因,也是群落变化的主导因子。2季草场各放牧处理的物种丰富度、多样性指数、均匀度指数在对照组最低,中度放牧组最高,其指数排序为:对照<轻度放牧<重度放牧<中度放牧,这一结果支持"中度干扰理论"。A two-year yak grazing trial was conducted in a two-seasonal grazing pasture in Kobresia parva meadow to study the variations of the quantitative characteristics of plant community in the pasture in warm season and cold season.Within the grazing periods of the two years,the coverage of high quality forage in the pasture decreased with increasing grazing intensity,while the coverage of weeds had an increasing trend.The dominant plant species under no grazing,light grazing,and moderate grazing in both warm and cold seasons were K.parva and Elymus nutans;whereas the dominant species under heavy grazing were Potentilla anserine and Pedicularis alaschanica in warm season,and K.parva and P.anserine in cold season.The larger the difference in grazing intensity,the lower the similarity of the community in the two seasons,indicating that grazing was the major factor leading to the difference in the community,and the predominant factor inducing the community change.The species richness,diversity index,and evenness index of the plant community in warm and cold seasons were all the lowest under no grazing,and the highest under moderate grazing,with the order of no grazing light grazing heavy grazing moderate grazing,which supported the ＇hypothesis of medium disturbance＇.

关 键 词：放牧强度 盖度 优势度 相似性系数 多样性指数 

分 类 号：S812[农业科学—草业科学]