Assessment of vegetation restoration impacts on soil erosion control services based on a biogeochemical model and RUSLE

Loess Plateau, China The potential soil erosion has commonly been estimated using the revised universal soil loss equation (RUSLE) under bare land conditions. In few studies, biogeochemical models have been employed to simulate natural vegetation dynamics and assess the effects of regional vegetation restoration on soil loss control. In this study, a biogeochemical Biome-BGC (BBGC) model was developed to simulate the potential vegetation dynamics. The soil erosion rate and erosion control indices under both the current land use/cover (A, ERI) and the potential vegetation conditions (A', ERI') were estimated using the RUSLE model and an index-based ecosystem service approach, respectively. The effects of vegetation restoration on erosion control services were ultimately evaluated. The BBGC model performed well in simulating the potential vegetation dynamics. The average annual soil retention increased by 84% after vegetation restoration since 1999. The increased erosion control services accounted for 62% of the Loess Plateau. Erosion control services increased to a high degree (ERI-ERI' >0.4) in the southeast. Our results demonstrated that vegetation restoration effectively improved the erosion control services on the Loess Plateau. The results could provide a guidance in quantifying the regional effects of vegetation restoration on ecohydrological services and protecting the soil conservation function of watershed ecosystems.