雅鲁藏布江中部流域沙地植被的分类和排序

CLASSIFICATION AND SORTING OF THE PSAMMOPHYTIC VEGETATION IN THE MIDDLE YARLUNG ZANGBO RIVER BASIN, TIBET

选用模糊聚类分析方法，利用群落组种的相对盖度作为优势度指标，将该区沙地植被划分为２２个群系，群系下又划分出了不同的群丛。同时，采用主分量分析（ＰＣＡ）模型，对１０个常见的群落类型进行了二维排序，比较直观和真实地反映了不同群落类型在土壤砾石化程度和土壤潜在肥力２个环境梯度上的分布情况。

The psammophytic vegetation in the Middle Yarlung Zangbo River Basin is divided into twenty two formations by using Fuzzy cluster analysis method. At the same time,using principal components analysis(PCA) model, two dimentional sorting was made for ten community types, which visually and really responsed the distribution of these types on the two environmental gradients of potential soil fertilities and soil coarsening degrees.