The influence of wind erosion on soil organic carbon pool and an assessment in China
风蚀作用下的土壤碳库变化及在中国的初步估算

Due to the tremendous soil organic carbon pool and the high carbon content on surface soil, even a trivial disturbance in surface soil can easily induce great changes of the whole soil organic carbon pool. On the other hand, as a universal geological process on earth, wind erosion has strong capacities to entrap, transport and redistribute the surface soil. Naturally, wind erosion then has important influences on the evolution of soil organic carbon pool. In eroded area, surface soil is eroded and the soil organic carbon pool decreases; in transportation process, soil organic carbon is further transformed and carbon dioxide (CO 2) is emitted; in deposition area, the changes of soil organic carbon pool are more complicated and the carbon pool increases at least in a short term. The redistribution of soil organic carbon over landscape and the emission of CO 2 react on the terrestrial ecosystem and finally affect the carbon budget. Such processes can be modeled by a series of equations based on the mass balance principle. Using the Arc/Info GRID data derived from the 2nd Chinese national remote sensing based soil erosion investigation and the 2nd Chinese national soil investigation, the spatial patterns of the top 20cm soil organic carbon content and wind erosion intensity are described in detail firstly. Soil organic loss and corresponding carbon flux are then estimated supported by GIS techniques. The total soil organic carbon loss induced by wind erosion is about 59.76 10 6t C/yr, including creeping materials of 14.34 10 6t C/yr, saltating materials of 44.82 10 6t C/yr and suspending materials of 0.60 10 6t C/yr. The emitted carbon dioxide (CO 2) is about 29.88 10 6t C/yr, ranging from 11.95 10 6t C/yr to 41.83 10 6t C/yr. The affected areas mainly lie in the Northwest China. The uncertainties in our research depend on the estimation of the eroded soil mass, the ratio of different erosion fluxes and the oxidizing ratio of SOC during transportation.