Response Characteristics of Soil Water in Vegetated Slopes to Spring Rainfall Under Different Covers

Spring is the optimal season for the ecological restoration of slopes. Addressing the response of soil water to spring rainfall is crucial to constructing a suitable hydrothermal environment for plant growth. In this study, three model slopes under different vegetation covers were constructed to measure soil water content during the spring. The accumulated increment in soil water (AISW), the growth rate of the soil water content rate (GRSW), the soil water recharge amount (∆SW), and the response time (Tr) of soil water were introduced to analyze its response to different spring rainfall events. The effects of vegetation and rainfall intensity were discussed. The results indicate that Cynodon dactylon mainly regulates surface soil water (0–20 cm), with a rapid and significant response in shallow soil. Magnolia multiflora is more effective in regulating deeper soil water (40–100 cm), especially during heavy rainfall, where shrubs enhance water infiltration into deeper layers. This study further demonstrates that increased rainfall intensity exacerbates the differences in water distribution between vegetation types. The combined effect of the canopy and root structure is crucial for water redistribution.