Effects of vegetation rehabilitation on soil saturated hydraulic conductivity in Ziwuling Forest Area Effect of raindrop impact on nutrient losses under different near -surface soil hydraulic conditions on black soil slope Study on optimum forest coverage for water conservation: a case study in Pingtonghe watershed (Pingwu section) Effects of Stocking Rate on Soil Saturated Hydraulic Conductivity and Its Spatial Variation Effect of lucerne-crop rotations on soil physical properties in the semiarid Loess Plateau of Central Gansu Physical degradation characteristics and mechanism of orchard soil in Weibei Region