Effects of biological soil crust on soil physicochemical properties in water-wind erosion crisscross region, northern Shaanxi Province, China Soil water depletion and infiltration under the typical vegetation in the water- wind erosion crisscross region Evapotranspiration of three types of plants in water-wind erosion crisscross regions in the Loess Plateau Artificial Cultivation of Biological Soil Crust and its Effects on Soil and Water Conservation in Water-Wind Erosion Crisscross Region of Loess Plateau,China