College of Geography and Environmental Science, Northwest Normal University, Lanzhou, 730070, Gansu, China.
State Key Laboratory of Cryosphere Science, Northwest Institute of Eco-Environment and Resources, Chinese Academy of Sciences, Lanzhou, 730000, China.
Environ Geochem Health. 2023 Jun;45(6):4071-4086. doi: 10.1007/s10653-022-01472-w. Epub 2023 Jan 10.
Accurate assessment of soil C storage patterns and control factors on a regional and global scale is essential for predicting and mitigating soil C feedback to global environmental change. We used soil samples collected in the Shiyang River Basin in 2018, combined with remote sensing data, climate and meteorological data, watershed hydrological data, and soil physical and chemical properties to discuss the change characteristics and influencing factors of soil organic carbon (SOC) under different soil depths in the Shiyang River Basin in an arid area and analyze the storage model and carbon sequestration potential of soil organic carbon in different geomorphic units. The research results show that, (1) in spatial distribution, the SOC content in the Shiyang River Basin shows an obvious regional difference, and the average content of SOC in the oasis area in the middle reaches significantly higher than that in the mountain area in the upstream and desert area in the downstream. In vertical distribution, the content of SOC in the whole watershed decreases with the soil depth increase. (2) Soil carbon sequestration potential decreased with the increase in soil depth, but there were regional differences. The Oasis area in the middle reaches of the Shiyang River Basin is a high-potential area. In contrast, most of the upper mountain areas and the lower reaches of the desert area are low-potential areas. Environmental factors such as vegetation cover, meteorological factors, and physical and chemical properties of soil are important factors that promote the spatial variability of SOC content. The decisive effect of environmental factors on the SOC content is most significant in the surface layer 0-20 cm.
准确评估土壤碳储量模式及其在区域和全球范围内的控制因素，对于预测和减轻土壤碳对全球环境变化的反馈至关重要。本研究利用 2018 年采集的石羊河流域土壤样本，结合遥感数据、气候气象数据、流域水文数据以及土壤理化性质，探讨了干旱区石羊河流域不同土壤深度下土壤有机碳（SOC）的变化特征及其影响因素，并分析了不同地貌单元土壤有机碳的储量模型和固碳潜力。研究结果表明：（1）SOC 含量在空间分布上呈现出明显的区域差异，中游绿洲区 SOC 平均含量显著高于上游山区和下游沙漠区；在垂直分布上，全流域 SOC 含量随土层深度的增加而降低。（2）土壤碳固存潜力随土层深度的增加而降低，但存在区域差异。石羊河流域中游绿洲区为高潜力区，相比之下，上游山区和下游沙漠区大部分地区为低潜力区。植被覆盖等环境因素、气象因素以及土壤理化性质是促进 SOC 含量空间变异性的重要因素，其中环境因素对 SOC 含量的决定性作用在表层 0-20cm 最为显著。
