Response of soil moisture to landscape restoration in the hilly and gully region of the Loess Plateau, China

Vegetation restoration was conducted by the Chinese government over the past decades to reduce soil and water loss on the Chinese Loess Plateau. However, vegetation restoration was very blind in plant species selection and had no guidance. Field measurements were conducted from 2009 to 2014 to analyze the influence of land-use conversions from croplands to pastures, native grasslands and planted trees, shrubs and on runoff, soil water dynamics and water stresses in the semi-arid loess hilly area. Our research has led to the following major findings: (1) The soil water stored decreased from 2009 to 2014 among all land cover types. The soil water replenishment by rainfall during rainy seasons was not sufficient to fully recharge the soil water storage. Vegetation restoration by shrub could retain more soil water than other land cover types; (2) The ratio of ET/P (evapotranspiration/precipitation) ranked from high to low was Grassland (1.31) > Shrubland (1.29) > Cropland (1.28) > Alfalfa (1.26) > Woodland (1.20). The ET/P ratio of the pine plantation was the lowest among the five land cover types; (3) Woodlands and shrublands showed the higher infiltration rates and the wetting fronts of croplands and shrublands could reach greater depths than woodland and grassland.