بررسي دستيابي به منحني تعادل در راشستانهاي ناهمسان شمال كشور در مازندران

Determining of equilibrium state in uneven - aged oriental beech forests of Northern - Iran.

This paper aimed to study the frequency distribution of tree number, basel area and volume in the uneven-aged oriental beech which are importent factors for determining of equilibrium state. For this purpose, six sample plots each covering one ha (100* 100m) were established in different beech stands of Neka region in Mazandaran province at the Caspian forests. All trees with dbh more than 7.5cm were measured and the number of trees in the first diameter class (Nio), as well as number of standing and marked trees for cutting were assesed. The results showed that the Nio of the plots varied between 7 and 74 per ha. The mean annual diameter increment calculated to 2.7mm. The basel area varied between 26 and 42.7 m^2 ha^-1 , while the volume varied between 388 and 509 m^3 ha^-1. A combination of datas showed that the equilibrium state would be expected, where the comulative basel area of the stand varies between 21 and 25 m^2 ha^-1 with a least N10 of 120 ha^-1. Considering the red rot, the target diameter for harvesting of trees could be fixed between 80 and 85cm.