Annals of Biological Research
Abstract
Author(s): Sheykholeslami A. , Kia Pasha, Kh. and Kia Lashaki A.
Identification and estimation of quantitative characteristics of trees community are the initial
requirements of forest planning. By applying common probability distributions, it is possible to
predict the stand status in diameter class distribution. The aim of this study is providing the most
appropriate model for tree distribution in diameter classes in natural and uneven-aged forests.
To obtain this purpose, a control plot which has grown with minimal interference was selected.
At first, travel through the forest, a proper identification was obtained and considering that, this
parcel consists of three separable stands, in each parcel a plot of one hectare was measured to
study on selective sampling. One-hundred percent inventory was conducted in sample plots.
Inventory started in welts, from down a slope to up, and then after identification of spices, all the
trees having diameter more than 7.5 cm were measured for the diameter at breast height and
were recorded in related forms. Data were analyzed, then the Normal, Lognormal, Exponential,
Gamma, and Weibull distributions were fitted to diameter at breast height data. The results of
Chi-square( ) and Kolmogorov-Smirnov (k-s) tests showed that only Lognormal distribution
can determine the diameter distribution of trees, so it is appropriate.
