降雨-侵蚀条件下多因素交互作用对土壤有机碳流失及矿化的影响机制

水蚀所引起的土壤有机碳动态变化，对全球碳循环具有重要影响，成为全球变化研究的前沿领域之一。降雨径流侵蚀过程中土壤有机碳流失和矿化机制是受多因素综合影响的复杂过程，但目前关于多因素交互作用影响的土壤有机碳流失和矿化的机制研究相对薄弱。本研究以不同类型土壤（黄土、黑土、红壤、紫土）为研究对象，在室内模拟降雨条件下，开展不同因素（降雨强度、降雨历时、坡度、地面糙度）影响下的土壤有机碳流失和矿化正交试验和完全试验。旨在量化影响土壤有机碳流失的影响因素的交互作用及相对贡献，明晰不同类型土壤有机碳流失的水动力学机制，深化土壤母质、降雨强度、降雨后历时、土壤温度和含水量对侵蚀区土壤团聚体有机碳矿化的影响机制。预期结果可深化水蚀对土壤有机碳流失及矿化的影响机制，为完善陆地碳循环过程模型、准确评估区域碳平衡提供理论支撑，且对于深化土壤侵蚀机理、合理防治坡耕地土壤有机碳流失具有重要意义。

The dynamic changes of soil organic carbon caused by water erosion play an important role in the global carbon cycle, and has been one of the frontier research areas of global change. Relatively less attention has been given to the research on the mechanism of soil organic carbon loss and mineralization during rainfall runoff erosion processes which is a complex process affected by multiple factors. This study uses rainfall simulation experiments to examine the effects of different factors on organic carbon loss and mineralization, including soil type, rainfall intensity, rainfall duration, slope, surface roughness. Multi-factor orthogonal test and complete test are used. The research aims to quantify the interaction and relative contributions of influencing factors affecting soil organic carbon loss, clarify the hydrodynamic mechanism of organic carbon loss for different types of soil, and investigate the impacts of soil type, rainfall intensity, duration after rainfall events, soil temperature and water content on soil aggregate organic carbon mineralization in the eroded areas. The results would improve our understanding on the soil erosion mechanisms and the effects of water erosion on soil organic carbon loss and mineralization, provide theoretical support for building and improving the model of terrestrial carbon cycle and accurately assessing regional carbon balance, and are beneficial for the restoration strategies on controlling soil organic carbon loss on sloping farmland.