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Knowing and conducting studies on size characters of trees can provide a good guidance for proper management as silvicultural purposes require. In Gorazbon district, a part of experimental forest (Faculty of
Natural Resources), totally 124 beech trees were selected and their diameter breast height (dbh), total height, diameter and height of crown were determined. The results indicated that there is statistical correlation
between some of these characteristcs of beech trees, so considering this, a statistic - mathematical relationship can be derived from such dependenceis, as following:
a- In the study area, all trees in category of 25 meters height or with 35 centemeters diameter, would have an appropriate slenderness factor (hd<80).
b- Between diameter of stump and dbh there is a linear relationship that can be used to estimate the diameter of the harvested trees.
c- An increasing parabolic relation exists between dbh and height of crown, but for trees with larger (dbh> 105) diameter, this parabolic relation turns to be decreasing type.
d- Between dbh and diameter of crown, there is a statistical correlation and this can be used to estimate one of these two characters if the other is known.