Plant Biodiversity under Impact of Slope Position in Managed and Unmanaged Beech Forest of Asalem-Gilan

This study was carried out in managed and unmanaged Fagus orientalis L. (beech) stands in the Asalem beech forest in order to compare the composition and diversity of plant species. Three V-shaped catena landforms were selected for each stand. Then, large quadrats, 400 m2 area, with selective method and within each of them, small quadrats, 4 m2 area, were established along each catena and slope position (summit, shoulder, backslope, footslope, topeslope) to study the density and species diversity of trees, composition and species diversity of regeneration and herbaceous species, respectively. Simpson, Margalef and Camargo indices were employed for diversity, richness and evenness analysis. The result showed that beech had the highest crown cover and regeneration density. Slope position analysis showed that significant differences in Simpson diversity and Camargo's evenness indices in trees and Simpson diversity and Margalef richness in herbs. There was no significant difference between indices regarding to regeneration. Dryopteris filix-mass L. and Asperula odorata L. exposed the highest frequency in managed and unmanaged stands, respectively. Considering the dominant form of land in north forest habitats of Iran is catena landform; it is necessary to implement silviculture's plans (protection, restoration, development and utilization) with particular attention to catena management.