The Study of Some Important Measurement Characteristics of Orientalis Beech by Statistical Models (Case study: Siyahkalforests)

In order to study the fit circumstances of some important measurement characteristics of Orientalis Beech such as diameter at breast height, total height by statistical models (Distributions).To meet this objective,the parcell 704 was selected with a 51 hectare measurement that contains Beech trees in different heights and age classes and healthy stand in SiyahkalShenroud forests. In this parcel the inventory net with a dimension of 100×200 meters with a randomsystematic method was selected and 20 circle sample pieces with a 10 R(1000 m2) measurement were made. In each sample piece the diameter and height of all trees with diameter more than 7.5 cm were measured. In this study Beta, Normal, Johnson SB, Exponential one and two parameter, Gamma two and three parameter, lognormal two and three parameter, weibull two and three parameter statistical distributions were used. The results obtained from the goodness fit tests showed that the statistical distributions fit power weren’t eaqual in a way that for the description of Beech tree diameter two parameter Gamma distribution is suitable and Beta distribution also has caused a suitable fit for explaining Beech trees height.