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.