Variation of Soil Moisture under Shrubs during Growing Season on the Western Loess Plateau

To provide theoretical evidence for vegetation recovery on the Western Loess Plateau,this paper analyzed variation of soil moisture,and tested the difference of soil moisture in different layers between shrubs by Brown-Forsythe method,taking shrubs as study object.The experimental plot of Laohutai in Lanzhou was selected as research site.The results show that variation of soil moisture is influenced by slope position,slope direction and shrub characteristics.The variation coefficient of soil moisture in the same soil layer is ranked in the descendant order of shaded,semi-shaded,semi-lighted,lighted slope.The variation coefficient of soil moisture in the central slope and lower slope are more stable than that on upper slope.The soil moisture in the depth of 20-80 cm varied obviously and the variation coefficient of soil moisture of most shrubs decreased as depth increased.Based on the soil water storage and water deficit degree of shrub,Caraganaopulens,Caragana roborovskyi,Lycium chinense,which consume less water,were more suitable to be planted on research field in plantation recovery process.