福建省土壤有机碳储量估算、时空分布特征及其影响因素

基于福建省多目标区域地球化学调查所获得的土壤有机碳数据,采用单位土壤碳量计算方法,按照7种不同分类方式,统计了福建省土壤有机碳储量和平均碳密度等特征参数,并与福建省第二次土壤普查结果、国内其他地区及中国典型地区平均水平对比。结果表明:福建省表层土壤(0~0.2 m)有机碳储量和平均碳密度分别为427.5 Mt和3 446.8 t/km²,中层土壤(0~1.0 m)分别为1 495.0 Mt和12 052.9 t/km²,深层土壤(0~1.5 m)分别为1 986.8 Mt和16 017.5 t/km²,高于中国典型地区平均水平,具有较高的有机碳储量和碳密度。土壤平均有机碳密度呈现出随海拔高度增高而变大,内陆地区高于沿海地区的区域空间变化规律。近30年来,表层土壤有机碳储量总体呈下降趋势。影响表层土壤有机碳密度分布特征的主要因素为地貌景观、气候环境、植被发育状况、土壤质地及理化、生态系统稳定性、人类活动等。

Reserve Estimation,Spatiotemporal Distribution and Its Influencing Factors of Soil Organic Carbon in Fujian Province,China

Based on achievement of multi-purpose regional geochemical survey (1∶250 000) in Fujian pro-vince, reserve estimation and average density of soil organic carbon were calculated in seven different focus using unit soil carbon calculation method. Comparison was made by the computation result above, the second soil census result of Fujian, result of other regions in China, and the result of the typical areas of China. The results showed that the reserve and average density of topsoil(0-0.2 m) organic carbon were 427.5 Mt and 3 446.8 t/km², respectively. The middle soil (0-1.0 m) was 1 495.0 Mt and 12 052.9 t/km², respectively. The deep soil (0-1.5 m) was 1 986.8 Mt and 16 017.5 t/km², respectively. It was higher than the average level in the typical areas of China and had higher organic carbon reserves and carbon density. Furthermore, the average density of soil organic carbon increased with the increase of altitude, and was higher in inland areas than in coastal areas. In recent 30 years, the organic carbon storage of topsoil was decreased. The main influencing factors of topsoil organic carbon density distribution can be consider as geomorphic landscape, climate, vegetation, soil texture, physical and chemical properties of soil, ecosystem stability, human activities, etc.