The structure of natural oriental beech (Fagus orientalis) forests in the Caspian region of Iran and potential for the application of the group selection system

Abstract

In the Caspian region of northern Iran, research was carried out into the structure of pure and mixed stands of natural oriental beech (Fagus orientalis Lipsky) and the presence of regeneration in natural gaps of differing sizes. Results showed that beech stands usually occurred naturally in small groups of a similar age, whereas the age structure of larger areas (>1 ha) was more uneven. The total volume of stands investigated ranged from 480 m3 in the pure stand to 600 m3 in the mixed stand. Only one-third of total trees were classed as large timber (>55 cm diamater at breast height), which in turn accounted for two-thirds of total stand volume. Although beech regeneration within the large gaps (>0.1 ha) showed the best growth characteristics, more well-formed saplings were found within medium-sized gaps (0.02-0.05 ha). From the results, it was concluded that the group selection system, with the removal of two to four main trees, could be a suitable method for managing oriental beech stands.