关键词: 林型, 土壤物理性质

Abstract: Through a study on the effects of different types of natural forest in two districts of the Loess Plateau on physical properties of soil, research results indicated that (1) in both districts, average contents of coarse sand (1.0—0.5mm in diameter), medium (0.5—0.25mm) and fine (0.25—0.05mm) in the top layer of the soil showed the following sequnce: forest land>bush land>farm land; similar sequnce also obtained on the soil profile despite varying with soil depth; (2) average contents of coarse silt in the top layer of the soil were appeared in the following order: bush land>forest land, young stands>middle-aged stands>mature stands while the total contents of medium and fine silt were adversely; (3) average contents of physical particales of clay in the top layer of the soil were in the order of forest land>bush land, mature forest stands>middle-aged stands>young stands; (4) the contents of soil moisture were arranged in the following sequnce: forest land>bush land>farm land.

Key words: Forest type, Soil preperty