Fine roots benefit soil physical properties key to mitigate soil detachment capacity following the restoration of eroded land

Background and aims Trait-based approaches are increasingly used to improve ecological restoration in degraded ecosystems. The aim of this study was to evaluate how vegetation controls soil detachment capacity (D-c) by concentrated flow based on the linkages between root traits and soil physics. Methods We selected 60 plots along a land degradation gradient caused by long-term water erosion in a small catchment, central China. These plots consisted of woodlands, scrublands, grasslands and bare lands. And soil physical properties, root traits and D-c were measured in each plot. Results Fine roots (0.2 mm < diameter < 2 mm) accounted for 51-93% of total root length in topsoil. Roots explained most of the soil variations in noncapillary porosity, aggregate stability and shear strength. Furthermore, our prediction model (R-2 = 0.88, NSE = 0.85) showed that fine roots length density and soil shear strength were the primary factors reducing D-c. Conclusions Vegetation restoration improves multiple soil physical properties key to mitigating D-c, and the root functional traits play a substantial role in this relationship. These findings could provide the basis for soil conservation, and for expanding the pool of species of interest, which can be used to provide erosion mitigation services in degraded ecosystems.