森林土壤的结构特征具有重要的水文生态功能，能影响土壤的水分物理性质和抗蚀性。于2002 年5 月用环刀和铝盒采集了位于长江上游支流大渡河水源地的贡嘎山东坡亚高山针叶林不同林型土壤表层（0-10cm）原状土样，室内常规方法测定容重、含水量、孔隙度、稳渗率、团聚体组成和颗粒组成，研究土壤团聚特征及其生态环境效应。结果如下：混交成熟林土壤结构性最好，水文生态功能最强；林木皆伐后最差；其他林型界于其间。研究结果对长江上游生态环境建设具有一定指导意义。

Structural properties of forest soils have important hydro-ecological function and can influence the soil water-physical characters and soil erosion. The experimental soil samples were obtained in surface horizon (0-10 cm) from different subalpine forest types on east slope of Gongga Mountain in the upriver area of Yangtze River China in May 2002. The soil bulk density, porosity, stable infiltration rate, aggregate distribution and particle-size distribution were analyzed by the routine methods in room, and the features and effects on eco-environment of soil aggregation were studied. The results showed that the structure of soil under mixed mature forest is in the best condition and can clearly enhance the eco-environmental function of soil, and the soil structure under the clear-cutting forest is the worst, the others are ranked between them. The study results can offer a basic guidance for the eco-environmental construction in the upper reaches of Yangtze River.