泥沙研究

为揭示水土保持措施作用下土壤有机碳组分空间分布特征，基于山西吉县森林生态系统国家野外科学观测研究站典型流域实测核素¹³⁷Cs和有机碳组分数据，分析了侵蚀-沉积区有机碳组分空间分布规律及其与侵蚀模数的相关性。结果表明：侵蚀区土壤总有机碳含量均值较低(5.45 g/kg),坡向是有机碳组分占比的主要影响因子；侵蚀区20～30 cm土层有机碳组分含量与侵蚀模数相关性最好，粗细颗粒态有机碳含量与侵蚀模数相关性显著(p<0.05),各有机碳组分的优先冲刷顺序差异较小；相比于侵蚀区，沉积区有机碳组分含量降低，泥沙来源和有机碳矿化对其影响较大。研究成果对认识自然-人为双源驱动下的土壤有机碳变化具有重要意义，可为以固碳效益提升的区域水土保持生态治理提供依据。

In order to reveal the spatial distribution characteristics of soil organic carbon components under the action of soil and water conservation measures, based on the measured data of nuclide ¹³⁷Cs and organic carbon components from typical watersheds at the National Field Scientific Observation and Research Station of Forest Ecosystems in Jixian County, Shanxi Province, the spatial distribution pattern of organic carbon components in the erosion-deposition area and its correlation with the erosion modulus has been analyzed. The results show that the average content of total organic carbon in the erosion area is relatively low(5.45 g/kg), and the slope orientation is the main influencing factor of the proportion of organic carbon components. After the implementation of soil and water conservation measures, the content of organic carbon components in the 20-30 cm soil layer is better correlated with the erosion modulus, with significant correction(p<0.05) of the coarse and fine particle organic carbon content and erosion modulus, and the difference of the organic carbon components is smaller. However, the organic carbon component content in the sedimentary area decreases, which is significantly influenced by the sources of sediment and the mineralization of organic carbon. The research findings are of great significance for understanding the changes in soil organic carbon driven by both natural and anthropogenic factors, and they provide a basis for ecological management on enhancing carbon sequestration benefits in soil and water conservation efforts.