Abstract: Vegetation construction is the most effective way to control erosion by wind and water in the arid and semiarid regions of northern China. Reasonable vegetation construction needs to consider the vegetation carrying capacity of soil water. Based on published literatures of soil water change following revegetation in the arid and semiarid regions of northern China, this paper analyzed the influences of two kinds of vegetation construction (trees and shrubs) on soil water at different depths using a metaanalysis. The results showed that vegetation construction produced prominent negative effects on soil water in deep layers (below 40 cm, with an effect size of -0.40). Tree planting resulted in a significant decrease in soil water (effect size: -0.58), while shrub planting had a negative effect on soil water (effect size: -0.27) though no significant influence was found. According to the subgroup analysis, tree plantations in the zones with precipitation of more than 400 mm and with the stand ages of less than 20 years led to decline of soil water (effect sizes: -0.62 and -0.69, respectively). The results indicated that tree planting produced more negative influences on soil water environments than shrub planting, and shrub planting could improve soil wateruse efficiency in the arid and semiarid regions.

Key words: dew condensation time, dew occurrence frequency, loess hilly region, meteorological factors