Effects of different vegetation restoration types on soil hydro-physical properties in the hilly region of the Loess Plateau, China

Context. Severe soil erosion in the Chinese Loess Plateau and the resulting high sediment yield of the Yellow River have been important research topics. Aims. Understanding the impacts of vegetation types on soil hydro-physical properties is essential for understanding regional runoff-sediment changes, soil and water conservation, and revegetation. Methods. Three main plantation covers of the study area [natural restoration grassland (NG), artificial Prunus armeniaca forest (AP), and artificial Hippophae rhamnoides shrubland (AH) with 15 years of restoration] and Sorghum bicolor agricultural land as control (CK), were selected to compare their soil hydro-physical properties and infiltration capacity in the soil profile. Key results. The bulk density was lower, and soil organic matter (SOM), the proportion of macro-aggregates (>5 mm), mean weight diameter (MWD) of water-stable aggregates, and the initial infiltration and stable infiltration rate were higher in the AH plot compared to CK and the other two plots. The impacts of vegetation restoration on soil properties were mainly in the 0-60 cm layer. Infiltration rates changed mainly within 5 h and basically stabilised within 10 h, with even shorter times to reach stable infiltration in CK. The initial and stable infiltration rates were significant positively correlated (P < 0.05) with macro-aggregate content, MWD, and SOM. Conclusions. The AH and AP had greater impacts on soil hydro-properties than NG. The AH had the greatest positive effect on soil hydro-properties and soil and water conservation functions. Implications. This study provides practical references for vegetation restoration measures assessment on the Loess Plateau or other similar regions.