黄河孟津段河岸带土壤有机碳分布特征及影响因素分析

Distribution characteristics and influencing factors of soil organic carbon in the riparian zone of Mengjin Section of the Yellow River

【目的】探究黄河孟津段河岸带土壤有机碳空间分布差异及规律,为黄河河岸带土壤固碳和生态修复提供理论依据。【方法】以河岸带表层土壤为研究对象,采用克里金插值法和冗余分析对土壤有机碳空间分布及影响因素进行分析,探讨土壤有机碳含量与微地形、土壤物理性质及植被组合的相关关系。【结果】研究区土壤有机碳含量和土壤有机碳密度的平均值分别为1.94 g·kg^(-1)和0.11 kg·m^(-2),空间变异系数分别为69.9%和83.6%,均属于中等程度变异。研究区土壤有机碳含量在随垂直河流方向距离V1—V5样带的增加而增加,V5样带土壤有机碳含量显著高于V1—V3这3个样带。相关性分析和冗余分析中,研究区土壤有机碳含量与垂直河流距离、土壤含水率、土壤黏粒呈极显著正相关,与土壤砂粒呈极显著负相关,与植物群落、海拔无显著相关。【结论】河岸带土壤有机碳含量随垂直河流方向距离的增加而增加,空间自相关性强,河岸带微地形、土壤黏粒和土壤含水率显著影响土壤有机碳的空间分布。

【Objective】The purpose of this study is to investigate the differences in the spatial distribution of soil organic carbon in the riparian zone of the Mengjin section of the Yellow River,and to provide a theoretical basis for soil carbon sequestration and ecological restoration of the riparian zone of the Yellow River.【Method】The spatial distribution of soil organic carbon and its influencing factors were analysed using Kriging interpolation and redundancy analysis,and the correlations between soil organic carbon content and microtopography,soil physical properties and vegetation assemblage were investigated.【Result】The mean values of soil organic carbon content and soil organic carbon density in the study area were 1.94 g·kg^(-1)and 0.11 kg·m^(-2),respectively,with spatial coefficients of variation of 69.9%and 83.6%,which were of moderate variability.The soil organic carbon content in the study area increased with the increase of the distance from sample zones V1 to V5 in the vertical river direction,and the soil organic carbon content in sample zone V5 was significantly higher than that in the three sample zones V1 to V3.In the correlation and redundancy analyses,the soil organic carbon content in the study area was significantly positively correlated with the distance from the vertical river,soil water content,and soil clay,negatively correlated with soil sand,and not significantly correlated with plant community and altitude.【Conclusion】The soil organic carbon content in the riparian zone,with strong spatial autocorrelation,increases with the increase of vertical river distance.The riparian microtopography,soil clay and soil water content significantly affect the spatial distribution of soil organic carbon.