科尔沁沙质草甸草场不同牧压条件植物群落分异数量分析

QUANTIATIVE ANALYSIS OF PLANT COMMUNITY DIFFERENTIATION UNDER DIFFERENT GRAZING INTENSITY IN HORQIN SANDY MEADOW RANGELAND

本文用ＴＷＩＮＳＰＡＮ分类和ＰＣＡ及ＤＣＡ排序技术分析了沙质草甸草场放牧试验引起地植物群落分异的特征，主要结论为：放牧强度是引起群落分异的主要原因，群落的分异主要表现在高度和现存生物量上。放牧引起群落变化的动力主要是放牧强度。而无牧条件下群落变化的主要动力是植物间的相互作用。当地的放牧强度处于中牧与重牧之间，属于过度放牧。这是引起草场退化及沙漠化的主要原因之一。

In this paper,the differential Characteristics of the plant communities under grazing experi-ment in sandy meadow rangeland are analysed by the use of TWINSPAN classification,PCA andDCAORDINATION TECHNIQUES.The resu lts sbow that grazing intensity is the chief rea-son for community differentiation,which is manifested mainly in the aspect of hight and phy-tomass,Under grazing condition,the ehange of plant communities mainly induced by grazing in-tensity.Under no grazing condition,the change of commtinities is mainly caused through the in-teraction of plant species,Presently the local grazing intensity is between moderate grazing andheavy grazing,belongs to overgrazing,which is the main reason for rangeland degradation anddesertifiication.