The beech Fagus orientalis Lipsky diameter frequency fit with probability distribution in Iran''s north forests

Abstract

In order to study the quality of the Beech tree diameter at breast height and its fit through the statistical distribution two one hectare sample pieces were randomly selected in a lozenge shape of Fagus orientalis Lipsky of natural stand forests in the northern slope of Iran's north forests. In these pieces all trees with more than 7.5 cm diameter were measured according to full callipering. The Beta, Gamma, Weibull, Normal, Lognormal, Exponential and Power statistical models were used in order to fit the data. The results obtained from chi-square test χ2 revealed that the Beta distribution in west and east directions and also exponential distribution in the west direction have produced a good fit for trees diameter distribution. But the other distributions didn't show much capability in explaining the studied trees diameter distribution

Keywords

• fit,statistical distributions,diameter,beech

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