伏牛山区陶湾流域森林土壤有机碳的深度分布格局研究

Distribution Pattern of Soil Organic Carbon in Depth of Soil in Forests of Taowan Watershed of Funiu Mountain Area

选取栓皮栎林、油松林、混交林、灌木林等主要林地类型的165个土壤采样点,研究了伏牛山区陶湾流域林地土壤有机碳SOC含量变化规律和分布模型。结果表明:0～20cm深度,栓皮栎林、油松林、混交林、灌木林SOC密度平均为7.92,8.42,8.14和9.67kg·m-2,灌木林与栓皮栎林、油松林、混交林SOC密度差异显著(P<0.05),4类植被类型SOC密度值均随土壤深度的增加而急剧下降。0～20cm层SOC密度与植被类型、郁闭度、粘粒含量、砂粒含量相关性均显著,与海拔相关性不显著;用0～100cm层碳密度来描述区域SOC储量时,估计值偏低。若考虑0～150cm深度土壤有机碳的分布,与0～100cm的深度相比,研究流域4种树种有机碳密度将增加2.0%～3.6%,若考虑0～200cm的深度,有机碳密度将增加3.9%～7.0%。

165sampling plots covering Quercus variabilis,Pinus tabulaeformis,mixed forest and shrub forest in Taowan watershed were selected to determine the SOC content and construct a depth distribution model of SOC for4species.The results showed that the SOC density of the Quercus variabilis forest,Pinus tabulaeformis forest,mixed forest and shrub forest was7.92,8.42,8.14and9.67kg·m^-2at the depth of0~20cm,respectively.Significant difference of SOC between shrub and Quercus variabilis,Pinus tabulaeformis and mixed forest(P<0.05)were observed.SOC density values of the four types of vegetation decreased sharply with the increase of soil depth.The correlation between SOC density and vegetation types,canopy density,clay content and sand content was significant in0~20cm layer,and the correlation with altitude was not significant.When using0~100cm layer carbon density to describe regional SOC storage,it always had the lower estimated values.Considering the depth of0~150cm,the organic carbon density of the four tree species in the study watershed will increase by2.0%~3.6%compared with the depth of0~100cm.If the depth of0~200cm is considered,the SOC storage will increase by3.9%~7.0%.