Abstract:

For analysing and evaluating the soil water features, the periodical soil water measurement and stand investigation were carried out during 1988—1992 in the experimental station of Beijing Forestry University, Ji County, Shanxi Province. The results showed that according to the vertical soil water variation, the soil profile could be divided into three layers, i. e. weak utilization layer, utilization layer and regulatinglayer, and according to the seasonal soil water veriation, the calendar year of soil water condition could be divided into four periods, i. e. consuming period, accumulating period, lowering period and stable period. From the study of soil water effectiveness, it is shown that eddectiveness of northern slope is better than that of southern slope, effectiveness of bare and shrub land is better than that of forest land. A multiple regression equation is proposed to present the relationship between soil water content, frequency of noneffective water and verious stand description factors of black locust and Chinese pine plantation.

Key words: Soil water variation, Soil water effectiveness, Soil water utilization and regulation, Protective forest ecosystem, Loess area