Decrease in Erosion-Induced Soil Organic Carbon as a Result of Vegetation Restoration in the Loess Plateau, China

Soil organic carbon (SOC) detachment and transport, especially in the eroded areas, has a profound influence on the global carbon cycling and climate. However, soil organic carbon erosion still has a high uncertainty on land C balance components for lack of a detailed capture of local topography and quantitative factors. Here, aimed at the Loess Plateau (LP) area with undulating terrain, we presented an unprecedentedly high resolution (90 x 90 m) soil erosion model, Revised Universal Soil Loss Equation and the contributions of vegetation to SOC erosion changes were quantified through factorial simulation. Our findings demonstrate soil organic carbon which induced a substantial lateral redistribution by soil erosion was 10.46 Tg C yr(-1) over the period 2000-2017, which was a decrease of 21% compared with that before 2000. In the fixed-NDVI scenario, after 2000, SOC erosion increased by around 7% compared with that before 2000. Agriculture and shrub are the primary source of regional soil erosion and SOC erosion. These findings highlight the importance of lateral transport of SOC as an important process in soil and carbon cycles for future regional carbon cycle assessment.