عنوان مقاله [English]
نویسندگان [English]چکیده [English]
Since tree stems are not cylindrical completely, an index called form factor is needed for estimating the real tree volume. The form factor is third effective component in determining the tree volume after diameter and high. The goal of the present study is to investigate the effects of tree growth stages and site components such as aspects and slope on form factors of Beech (Fagus Orientalis Lipsky). This study was carried out in the Shafaroud forests. In total 411 trees were sampled. These trees were sampled in 4 aspects (north, north- east, north -west and east) and also in the four slope class (<30, 30-45, 45-60 and > 60) with four growth stages. Normality and homogenity of variance were done using Kolmogorov-Smirnov and Levene tests, respectively. Mean comparisons were performed usingDuncantest for homogeneous variance and Dunnett for heterogeneous variance in 5 and 1 percent levels. Results showed that there is a significant difference between various form factors of tree. Dunnett test showed that there is no difference between real form factor of stem (0.5474) and Hohenadl (0.5446). Form factor values increased on north aspects.