対数正規分布とその応用(第4報) : 混合対数正規分布の択伐林直径分布への応用

The mixed lognormal distribution was derived theoretically and proposed as a mathematical model to describe the diameter frequency distnbutions in selection forests. The assumptions of the model are that the diameter frequency distributions in selection forests are the composition of diameter distnbution on each age class, and that each diameter distribution can be described by the lognormal distribution. The model was applied to 4 observed diameter frequency distnbutions in Ate(Thujopsis dolabrata var. H0NDAI MAKIN0) selection forests. The agreement between the observed and the expect ed frequencies was tested by the chi-square test. The model achieved a good fit to every observed diameter frequency distribution. The mixed lognormal distribution may be useful for analyzing the diameter frequency distributions of selection forests.