Changes in soil water holding capacity and water availability following vegetation restoration on the Chinese Loess Plateau

Changes in land use type can lead to variations in soil water characteristics. The objective of this study was to identify the responses of soil water holding capacity (SWHC) and soil water availability (SWA) to land use type (grassland, shrubland and forestland). The soil water characteristic curve describes the relationship between gravimetric water content and soil suction. We measured the soil water characteristic parameters representing SWHC and SWA, which we derived from soil water characteristic curves, in the 0-50 cm soil layer at sites representing three land use types in the Ziwuling forest region, located in the central part of the Loess Plateau, China. Our results showed that the SWHC was higher at the woodland site than the grassland and shrubland, and there was no significant difference between the latter two sites, the trend of SWA was similar to the SWHC. From grassland to woodland, the soil physical properties in the 0-50 cm soil layer partially improved, BD was significantly higher at the grassland site than at the shrubland and woodland sites, the clay and silt contents decreased significantly from grassland to shrubland to woodland and sand content showed the opposite pattern, the soil porosity was higher in the shrubland and woodland than that in the grassland, the soil physical properties across the 0-50 cm soil layer improved. Soil texture, porosity and bulk density were the key factors affecting SWHC and SWA. The results of this study provide insight into the effects of vegetation restoration on local hydrological resources and can inform soil water management and land use planning on the Chinese Loess Plateau.