Effects of land use patterns on slope soil water in the semiarid Loess Plateau, China

Land use patterns (LUPs) are the form in which various land use types are combined spatially, evidently impacting soil water. However, the influence mechanism by which LUPs form remains unclear. In this study, the soil water content (SWC) in the 0-160-cm soil depth was observed in shrubland (SL), mature forestland (MF), grassland (GL) and young forestland (YF) sites on four slopes with different LUPs in the Yangjuangou catchment of the Chinese Loess Plateau. The SWC in SL-YF-SL (13.28%) was significantly greater than that in YF-MF (9.93%), MF-GL-YF (10.38%) and SL-MF (10.83%) and was temporally stable during the study period. The spatial distribution of SWC along the slope differed among the four LUPs. Vegetation characteristics and soil texture mainly determined the spatial variations in SWC in the shallow soil layers (0-40 cm), while topographic factors were the determinants in the deep soil layers (60-160 cm) as well as in the entire soil profile (0-160 cm). The significance of SWC differences among the various land use patterns increased with decreasing precipitation during the growing seasons. YF-MF (77.8 mm) and SL-YF-GL (73.9 mm) required more rainwater than SL-MF (68.2 mm) and MF-GL-MF (67.5 mm) to compensate for the loss of soil water on the monthly scale during the rainy season. Therefore, vegetation restoration should consider land use patterns on hillslopes for soil water conservation.

Automated summary

Land use patterns have a significant impact on soil water content, with vegetation characteristics and soil texture mainly affecting shallow soil water content, while topographic factors play a decisive role in deep soil layers and the entire soil profile. The differences in soil water content among different land use patterns become more significant during periods of decreased precipitation.