Structural characteristics of Quercus macranthera forests in Arasbaran region, North west of Iran (Hatam Mashe Si, Meshgin-Shahr)

This study aimed to evaluate the structural characteristics of Quercus macranthera forests in the Arasbaran region, Hatam Mashe Si, Meshgin-Shahr. To achieve this, all trees and shrubs were full calipered in three one-hectare plots. Additionally, the structural characteristics were measured using the nearest neighbor’s method. To measure intensity of trees, several indices like nearest neighbor distance index (density of trees), uniform angle index and Clark and Evans index (variety of location), Mingling index and Shannon-Wiener index (tree diversity in diameter classes), diameter and height differentiation indices (dimensional differences of trees), and complex structural diversity index (tree diversity) were used. The results showed that Q. macranthera represented a relatively homogeneous structure in its main site, and the mean of distance to the neighbors was 2.59 m. The results of uniform angle and Clark and Evans indices showed that the spatial pattern of trees was regular. Mingling and Shannon-Wiener indices showed a low tendency of Q. macranthera to mix with other tree species so that the majority of trees were Q. macranthera. The height and diameter differentiation indices illustrated that the dimensions of the trees had a slight difference. According to complex structural diversity index, tree diversity was at the medium level. It can be concluded that the Q. macranthera communities have a homogeneous structure in a study region with a low mixture and single canopy layer. The information can provide the opportunity to monitor future changes in Q. macranthera communities in this region. To promote ecosystem stability, it is suggested to create heterogeneity of stand structure and support other tree species in this area.