Temperature effect on erosion-induced disturbances to soil organic carbon cycling

Erosion exerts control on soil organic carbon (SOC) and both erosion and SOC are affected by climate. To what extent temperature controls the coupling between these erosion–C interactions remains unclear. Using 137Cs and SOC inventories from catchments spanning different climates, we find that increasing decomposition rates with temperature result in the efficient replacement of SOC laterally lost by erosion in eroding areas but lower preservation of deposited SOC in depositional areas. When combined at the landscape level, the erosion-induced C sink strength per unit lateral SOC flux increases with temperature from 0.19 g C (g C)−1 at 0 °C to 0.24 g C (g C)−1 at 25 °C. We estimated that the global C sink of 0.050 Pg C yr−1 induced by water erosion on croplands increases by 7% because of climate change. Our results reveal a negative feedback loop between climate change and erosion-induced disturbance to SOC cycling. The authors demonstrate the interacting impacts of warming on erosion and soil organic carbon (SOC) cycling. Under warming, they project increased replacement of SOC lost by erosion but lower preservation of deposited SOC, with an overall increase in the global C sink by erosion.