Beech tree (Fagus orientalis) is a species of Fagus genus and Fagaceae family. Beech forests are the most valuable forests in the northern part of Iran. These forests are economically very important, and knowing their status may help us to treat the problems of silviculture and forest management more knowledgeably. The Beech forests in Iran cover a tape of 700km in length and 40-50km in width on the north slope of Alborz Mountains (south of Caspian Sea) from Astara to Dareh Ziyarat (Ziyarat Valley) in Gorgan province. Its minimum and maximum altitudes are respectively about 600 and 2200m from the sea level. This research performed is in a section of Ramsar forests called "Beneshky beech forests". They begin at 900 m from the sea level and extend to 2100m. Their general slope is northern. This study mainly aims to describe the status of crown shape and determine the length of trunk without branch which is important parameters in forest improvement. To do this, the beech forests were divided into 6 altitude classes (as treatments): 900-1100, 1100-1300, 1300-1500, 1500-1700, 1700-1900, 1900-2100 meter from the sea level. Systematic Random Sampling was used as a method for sampling. In each class, 30 circular sample plots were selected (180 plots totally). Each sample had an area of 1000 m2 .In each sample parameters such as crown shape, stand density; diameter at breast height (d.b.h), height, and length of branchless trunk of beech trees were evaluated. The data analysis was done in SPSS format, using complete randomized design. The treatments were compared by Duncan's Multiple Range Test.The results show that, save the last altitude class (1900-2100 meter a.s.l), there is no significant difference in crown shape between other altitude classes. But the length of branchless trunk in altitude classes is different significantly. The highest length of branchless trunk is 11.9 meter in 1300-1500 class and the lowest is 2.2 meter in 1900-2100 class.
