Abstract:

In order to understand the effect of land cover change from abandoned land to Caragana korshinskii forest land on soil water resources, the dynamics of soil water content with time in the soil layers from 0－400 cm in both of caragana forest land and wasteland was measured simutaneously with neutron probe in fixed positions, and effect of the land cover change on soil water resources was quantitatively analyzed. The results showed that there was a negative effect of the land cover change on soil water resources during the observed years (2002—2006), with the exception year in 2003 in which there was a positive effect of the land cover change on soil water resources because it was a wet year. The influenced degree of the land cover change on the annual averaged soil water content, soil water storage in the soil profile was exacerbated with plant age. The difference of soil water content and soil water storage between the two kinds of land cover type was increased with plant age. Because the precipitation is the only resource of soil water in the semiarid loess region, some proper measures should be taken at the fifth year of C. korshinskii forest to control its growth in order to reduce soil water consumption,prevent deep soil from desiccation and realize the sustainable use of soil water resources and vegetation resources.

Key words: semiarid loess hilly region, land cover change, soil water resources, effect