Abstract:Taking three typical vegetation communities (Bothriochloa ischaemum, Artemisia gmelinii and Periploca sepium) in the loess hilly region as research objects, and the abandoned land for one year as the control (CK), the characteristics of soil preferential flow under different vegetation community patch patterns were analyzed based on in-situ dye-tracer and laboratory experiment methods, and the effects of plant roots and soil physicochemical properties on preferential flow were explored. The results showed that vegetation restoration improved the development of preferential flow in comparison with the CK. For each vegetation patch, the highest dye coverage (45.62%), maximum staining depth (30.30 cm), preferential flow proportion (39.76%) and the length index (475.90%) were found in A. gmelinii vegetation patch, followed by P. sepium and B. ischaemum. For the same vegetation community, the development degree of preferential flow was higher in vegetation patches than that in bare patches, except for the B. ischaemum community. Furthermore, the structural equation model indicated that the dyeing area ratio of preferential flow was directly affected by soil total porosity, aggregate stability, root mass density and soil organic matter content, and which could explain 70% of the total variance. Therefore, the natural vegetation restoration could affect soil properties through roots development, thereby improving the development degree of soil preferential flow and soil infiltration capacity.