Determination of diameter growth of forest trees and shrubs (Beech), in VAZ experimental forest (Mazandaran province)

In order to find out the diameter growth rate of beech trees in Caspian Forest region, to randomize plots(each 0.5 ha) were chosen. Strees were selected in each diameter class. Qualitative characteristics were studied in each tree and also samples were made by increment borer. The main results could be summarized as following: 1- About 75% trees with best quality belongs to dominance layer. Which has the minimize branches. as well as healty and well developed crown. 2- The highest velume increament(3.25 silve/ha) belongs to dominance layers and the lowest velume increament(0.13 silve/ha) belongs to suppressed layer. 3- There is a positive relationship between crown velume and velume increament. 4-There is a linear regresion between dbh and crown diameter (Dbdh=0.921+0.122 Dc).