龄级和密度变化对黔东南杉木人工纯林结构及有机碳密度的影响

Influence of Age and Density Classes on Forest Structure Indicators and Organic Carbon Density of Cunninghamia lanceolata Plantation in Southeastern Guizhou Province,China

采用空间替代时间、野外样地调查和室内分析相结合的方法,研究了黔东南杉木人工纯林结构及有机碳密度随龄级和密度变化的规律。结果表明,随杉木林龄增大和密度降低:1林分平均胸径和高度值升高、密度值降低,龄级及密度级内的相应指标值差异显著。2除Pielou指数值外,草本层植物多样性指数增加。灌木层植物多样性指数值随林龄增大而增加、随密度降低而减小。不同龄级及密度级灌木层植物Pielou指数值差异显著。草本层植物Gleason指数值在龄级间差异不显著、密度级间差异显著,Pielou指数值在龄级间差异显著、密度级间差异不显著。3土壤密度值增大、土壤有机碳含量等其它理化指标降低。土壤密度值在龄级间差异显著、密度级间差异不显著,土壤有机碳含量等其它理化指标值在龄级及密度级间差异不显著。4乔木、灌木、凋落物和土壤-植被层有机碳密度值增加,草本和土壤层有机碳密度值在龄级间降低、密度级间升高。乔木层植物有机碳密度值在龄级间差异显著、密度级间差异不显著。5林龄和密度对乔木层植物有机碳密度值的贡献率分别为99.06%、0.94%。土壤有机碳密度受土壤层部分指标影响,植被有机碳密度受植被-土壤部分指标综合影响。6培育大径级林和增加土壤有机碳含量是提高杉木人工林有机碳密度的有效途径。

Using the space instead of time and the combining method of field sample plot survey and indoor analysis,this article studied the structural indicators and organic carbon density changes of different age and density classes of artificial pure forest of Cunninghamia lanceolata in southeast Guizhou province,China.Results showed that with the age increase and density decrease of Chinese fir plantation：（1）Values of average diameter at breast height and height increased and density reduced,corresponding parameter values within the age or density classes were difference significantly.（2）Beside Pielou index,another herb plant diversity indices increased.Shrub plant diversity indices values increased with forest age increasing and decreased with density reducing.Pielou index values of shrub layer had significant difference in the different age or density classes.Gleason index values had no significant difference in the age classes and significant difference in the density classes,and Pielou index values had significant difference in the age classes and no significant difference in the density classes of herb layer.（3）Soil density increased,soil organic carbon content,etc,decreased.Soil density value was significant difference in age classes and no significant difference in density classes,soil organic carbon content,etc,had not significant difference in age or density classes.（4）Organic carbon density values of tree layer,shrub layer,litter layer and soil-vegetation layer increased,and organic carbon density values of herb layer and soil stratum（0-40cm）went down in the age classes and went up in the density classes.Organic carbon density values of tree layer were significant difference in age classes and no significant difference in the density classes.（5）Age and density contribution rates for organic carbon density of tree layer were 99.06% and 0.94%,respectively.Soil organic carbon density was influenced by some factors of soil stratum.Vegetation organic carbon density was influenced comprehensively by part factors of vegetation-soil.（6）To foster large diameter and increase soil organic carbon content is an effective way to improve the organic carbon density of Chinese fir plantation.