Spatial distribution of dried soil layers under different vegetation types at slope scale in loess region

To understand the characteristics of dried soil layer (DSL) under different vegetation types at slope, the spatial distribution patterns of DSL on a representative slope were studied. The results showed that the extent of DSLs ranged from 0 to 400 cm for orchard (13 years of Prunus armeniaca) and from 280 to 400 cm for shrubland (25 years of Caragana Korshinskii kom), respectively, while slope position significantly influenced distribution pattern of DSLs in the orchard. In vertical direction, the depletion of soil water was more severe in shrubland than that in orchard. Horizontally, distribution of orchard DSL demonstrated obvious fleck and sheet characteristics and decreased gradually along north-south direction of the slope. Spatial pattern of DSLs in the orchard was controlled by vegetation, rainfall, slope gradient and micro-terrain. In contrast, the distribution pattern of DSL in shrubland was homogeneous that deeper DSLs (381～400 cm) distributed widely and combined together, implying that this pattern was only dominated by vegetation type. The results are helpful for DSL control and/or reclaim in loess regions.