Changes of soil quality induced by different vegetation restoration in the collapsing gully erosion areas of southern China

Abstract

Understanding the influence of collapsing gully management restoration on soil quality and function is essential to the protection of the regional ecological environment in the collapsing gully erosion area. The primary objective of this study was to construct soil quality index (SQI) to assess the influence of different vegetation restoration types on soil quality in collapsing gully restoration. The influence of five vegetation restoration types on soil properties was investigated by using a path analysis, a comprehensive soil quality index (SQI), and a general linear model (GLM). Vegetation restoration was shown to significantly increase the saturated hydraulic conductivity (Ks), mainly due to the effect of the physical parameters of bulk density, soil cohesion, and soil water content. Meanwhile, pH, Ks, soil organic matter (OM), and sand content were revealed as reasonable indicators to evaluate the influence of vegetation restoration on soil quality. Moreover, vegetation restoration was found to significantly improve the soil quality, with the highest SQI value for natural restoration mixed forest (NF), followed by replanted arboreal forest (RA) and replanted scrubland (RS), which were all significantly higher than the SQI value of the erosion area (EA) in the collapsing gully. Additionally, vegetation type explained the most substantial proportion of total variability (46.41%), and restoration time showed a positive correlation with SQI. The results of this study can provide a reference for the restoration and protection of the regional ecological environment in the collapsing gully area.