Abstract: The cluster analysis and principal components analysis methods have been used to divide the degenerated successional series of the main grassland communities for grazing in the bongnen Plain of China, including Stipa baicalensis-Leymus chinesis, S.baicalensis, S.baicalensis-Filifolium sibiricum, L.chinesis and L.chinesis-forbs communities.The results showed that the successional series of each community might be divided into four stages, that are light grazing, moderate grazing, heavy grazing and over-grazing.With the changes of grazing intensity, the various changes in the dominants of major plant populations are obvious, which are closely related to their eco-biological characterstics and the grazing behavior of domestic animals.

Key words: Grassland community, Grazing successional stages, Cluster analysis, Principal components analysis

摘要： 本文采用聚类分析和主分量分析的方法对松嫩平原主要草地群落:贝加尔针茅(Stipa baicalensis)-羊草(Leymus chinesis)群落、贝加尔针茅群落、贝加尔针茅-线叶菊(Filifoliun sibiricum)群落、羊草群落和羊草-杂类草群落的放牧退化演替阶段进行划分。结果表明:每个群落的放牧退化演替过程均可划分为四个阶段,即:轻牧、中牧、重牧和过牧。随着放牧压梯度的变化,群落主要植物种的优势地位发生明显的替代变化,这与其生态生物学特性和动物的采食行为密切相关。

关键词: 草地群落, 放牧演替阶段, 聚类分析, 主分量分析