Abstract:In order to reveal the degradation of planted forest communities under human-induced disturbance,the influences of grazing disturbance on soil physical properties under planted Pinus tabulaeformis forest on the Loess Plateau were analyzed by spatial contrast method.Results showed that compared with the soil in the undisturbed area,with the increase of grazing disturbance intensity,sand content increased,and clay content decreased.Consequently,soil texture became coarse.Soil bulk density increased 0.09~0.39 g/cm3.The total porosity,capillary space,and non-capillary space decreased greatly with the increase of grazing disturbance intensity.Soil water content,water-holding capacity,and infiltration rate decreased due to grazing disturbance.Compared with undisturbed soil,soil water content and water-holding capacity on heavily disturbed land and moderately disturbed land decreased significantly.Compared with the undisturbed soil,with the increase of grazing disturbance intensity,the initial infiltration rate and the stable infiltration rate decreased,and the saturated infiltration rate decreasedtoo.