Impacts of forestland vegetation restoration on soil moisture content in humid karst region: A case study on a limestone slope

Forestland vegetation restoration changes the state of soil water storage and consumption, leading to changes in soil water content. Many scholars have conducted research on the soil water content of restored forestland vegetation in different climatic regions. However, due to the uniqueness of the karst environment, the research findings from other humid regions may not be indicative of the impacts of forestland vegetation restoration on the soil water content in humid karst regions. In this work, the soil water content of four sample plots with different restoration durations in a karst region was examined. The results showed that the soil water contents of the sample plots with different restoration durations differed significantly. As the restoration process of the forestland vegetation progressed, the soil water content decreased, but the range of reduction was small. There was a significant negative correlation between forestland vegetation restoration duration and soil water content (P < 0.01), and the Spearman correlation coefficient between the two was −0.621. At different soil depths and in different seasons, the soil moisture content also decreased with increased restoration duration. Compared with humid non-karst regions, the karst environment bedrock possessed thin soil layers and strong water permeability, which further amplified the effect of vegetation restoration on the reduction of soil moisture content.