نوع مقاله : مقاله پژوهشی
1 استادیار، دانشکدۀ کشاورزی و منابع طبیعی اهر، دانشگاه تبریز، اهر
2 دانشیار، دانشکدۀ کشاورزی و منابع طبیعی، دانشگاه محقق اردبیلی، اردبیل
عنوان مقاله [English]
Natural reconstruction of forest structure is one of the most important processes in the evolution of forest stands. In order to investigate the process of natural reconstruction of the structure in beech stands in Eshkevarat Roodsar region, three one-hectare sample plots with different histories of conservation, including low-term, middle-term and reference forest area were selected, and the most important stand structural characteristic and eleven structural quantification indices in 45 structural groups were evaluated using the distance measurment methods. The analysis of the stand structural changes was performed based on three groups of stand structural characteristic including the spatial pattern of the structure, heterogeneity in the dimensions of the trees and structural complexity. The diameter mean, Clark Evans, Berger-Parker and uniformangle indexes showed a significant difference between in the three areas. The increasing trend for Gini coefficient, diameter and height differentiation indices, along with the transfer of trees to higher diameter and height layers in protected area, indicates an increase in heterogeneity and formation of vertical structure in the forest. In conclusion, forest conservation in the traditional way and exclosure method in this area has led to the reconstruction of the stand structure. It is recommended to create a long-term exclosure (more than 60 years) along with close to nature silvicultual interventions for natural reconstruction in this areas.