Assessment of Structural Diversity of Beech Forest Stands in North of Iran

Stand structure is a key principle in stand biodiversity. High biodiversity was associated with the stands that have different trees species with different dimension. In this regard, for evaluation Structural diversity in different diameter and height classes and also their changing procedure of beech stands in north of Iran, 30 modified Whittaker plots by systematic random system were located. The heterogeneity indices of Shannon–Wiener, number of equally common species and evenness indices of Simpson and smith-Wilson were using for the quantitative data. In order to understand the diversity condition in horizontal and vertical composition of stand further, the diameter divided in 10-cm classes and method of Mohajer and the height divided in 10-m height classes and dominant height. Then diversity of each class was extract by ecological methodology software. Results showed the most diversity of trees and shrubs is in low height and diametrical classes. Thus, the study of biodiversity changes in different diameter and height category cause ecologically precise perspective in management of forest stands.