Impact of vegetation restoration on preferential flow and soil infiltration capacity in the hilly region of the Loess Plateau
Shuyu Zhang, Yuanhao Liu, Mingyue Yang, Peng Tian, Xingmin Mu, Guangju Zhao
Abstract
The Zhifanggou Watershed, a typical watershed in the hilly region of Loess Plateau in China. Assessing effects of various vegetation types on soil water infiltration facilitates understanding of soil hydrological processes and provides valuable references for reforestation in arid areas. Double-ring infiltrometers and dye tracing were employed across plots with various vegetation types and restoration durations to comprehensively investigate the impact of vegetation restoration on soil infiltration capacity, preferential flow, and their influencing factors. The results showed that the highest stable infiltration rate occurred in 30-year-old replanted monoculture forestland (0.57 cm min⁻¹), followed by 30-year-old replanted shrubland (0.42 cm min⁻¹). Monocultured forestland had slightly higher soil infiltration rates than mixed forestland, with macropore flow was dominant. Mixed forestlands exhibited the highest degree of preferential flow and the most preferential flow paths. Soil infiltration capacity and preferential flow paths increased with restoration years, and preferential flow was promoted in deeper soil layers. Soil macroporosity, clay content, and root length density predominantly influenced soil infiltration capacity and dye-stained characteristics parameters. Root characteristics were critical for the degree of preferential flow, with rock fragment and cracks also being not negligible factors. These findings could deepen our understanding of vegetation restoration in improving soil hydrological functions, and provide a reference for the management of vegetation restoration. • Vegetation restoration enhance soil infiltration capacity and preferential flow. • Increasing vegetation restoration years promote preferential flow in deeper soil layers. • Mixed forestland has the highest degree of preferential flow. • Soil macroporosity, clay content, and roots affect soil water movement.