Survey Slenderness Coefficient of Beech Mixed Trees in Hajikola Tirankoli Area- Sari

Beech is one of the richest, most important, and most economical forest types of Iran. Total height variable is one of the main forest morphometric variables. The height variable of trees is used in forest biometrics: determining volume, height curve drawing, and computation Slenderness coefficient of trees. One of the crucial factors in calculating the diameter at breast height is the size of tree. The forest of 90 trees of Hajikola Mazandaran forest was selected for this research; five samples per class were randomly chosen to evaluate Slenderness coefficient beech. Accelerators increase the height of beech trees until they reach 40 cm in diameter, higher. The minimum average height of 19.20 meters in diameter classes 30-50 cm & maximum average 27.55 meters a height diameter classes 100-120 cm. The average Slenderness coefficient 34.58 stability was witnessed as accepted. Slenderness coefficient in the increase of tree diameter shows a decreasing trend. Reducing the Slenderness coefficient of beech tree at a young age is because of the competition for crown which results in height growth and low diameter growth. And thereafter, the increased diameter growth and decreased height growth occur. Age and diameter growth increase the stability of the tree.