Soil water properties in a recently established forest as affected by grazing in a semiarid valley

Abstract

In arid and semiarid areas, soil water deficit is a major constraint to vegetation establishment (Zhang 1992). While climatic conditions can be a constraint to soil water supply, other factors can be extremely important in determining forest survival. One of the key factors leading to tree death is livestock grazing in the early growth stage of forest establishment (Li 1995). Braunack & Walker (1985) found that after 16 years without grazing, the surface soil properties of a semiarid woodland still showed evidence of prior damage by grazing sheep. Infiltration rates can still increase many years after grazing has ceased (Gifford & Hawkins 1978).Greenwood et al. (1998) reported that there were significant increases in unsaturated hydraulic conductivity in the ungrazed treatments compared with the grazed controls after 2.5 years without livestock. The purpose of this study was to quantify the changes in soil water properties in a recently established forest as affected by grazing in a semiarid climate.