长白山西部不同林型土壤有机碳和全氮的分布特征

摘要

为准确估算长白山地区土壤C、N储量并为该地区森林碳汇经营提供部分理论依据,以长白山西部3种典型林分类型为研究对象,分析不同林分类型土壤有机碳和全氮质量分数、碳氮比、碳密度和氮密度的分布特征.结果表明,阔叶混交天然林在3种林分类型中各项指标均值都最大,其中,有机碳质量分数和碳密度差异显著(P＜0.05),有机碳质量分数变化范围为18.61～30.75 g·kg-1,碳密度均值范围16.28～27.64 kg· m-2.3种林分类型C/N值变化范围3.14～4.77.随着土层深度增加,土壤有机碳、全氮质量分数递减,土壤容重递增.3种林型土壤碳密度和氮密度的垂直分布规律与其质量分数的变化规律一致,且各个林型有机碳密度和氮密度均以表土层最大,碳密度变化范围8.39～9.87 kg·m-2,氮密度变化范围1.12～1.32 kg·m-2.%In order to accurately estimate soil carbon and nitrogen reserves in Changbai Mountain area,and to provide theoretical basis for forest carbon sequestration management in this area,3 typical types of forest stands were taken as the research objects,the distribution characteristics of soil organic carbon,total nitrogen,carbon nitrogen ratio (C/N),carbon density and nitrogen density in Western Changbai Mountain were examined.The results showed that natural mixed broad-leaved forest had the largest mean values of the indexes examined among the three forest types.Soil organic carbon content and carbon density were significantly different (P＜0.05),with the values varied from 18.61 to 30.75 g · kg-1 and from 16.28 to 27.64 kg · m-2,respectively.The C/N,an important index of soil nutrient balance,varied from 3.14 to 4.77 among the three forest types.The soil organic carbon content and nitrogen content generally decreased with soil depth.On the contrary,soil bulk density increased with soil depth.The vertical distributions of soil organic carbon density and nitrogen density were consistent with the changes of their contents in the three forest types,and the largest organic carbon density and nitrogen density of each forest type were found in the surface soil layer,the range of soil organic carbon density varied from 8.39 to 9.87 kg · m-2 and the range of soil nitrogen density ranged from 1.12 to 1.32 kg · m-2.