Comparison of the beech (Fagus orientalis Lipsky) saplings characteristics in unmanaged and single tree-selection cutting compartments

The single tree selection method was applied in the Hyrcanian forests of northern Iran to imitate nature and enhance the ecosystem characteristics and functions such as biodiversity, flexibility, and adaptability. However, the effectiveness of this imitation and the changes in the forest stand characteristics were unclear. This research compared the regeneration characteristics of tree species in canopy gaps larger than 100 m2 in a beech (Fagus orientalis Lipsky) stand in the Hyrcanian forests that underwent single tree selection in 2013 with an unmanaged beech forest as a reference. The abundance of seedlings and saplings of all tree species was recorded in each microplot (with an area of 4 m2) in the center and four edges of each gap. The height, collar diameter, crown width, health, stem form, and mode of branching of beech saplings were also measured in each sample microplot and compared. The results indicated that the mean collar diameter (26.6±2.2 mm), height (270.4±23.6 cm), and frequency of orthotropic beech saplings (0.3±0.06) in the managed compartment were significantly higher than the unmanaged compartment (p < 0.05). The average frequency of regeneration in the managed and unmanaged compartments was 7.9 and 6.3 per microplot, respectively. The frequency of beech regeneration in the managed compartment was higher in large gaps, while it was higher in medium gaps in the unmanaged compartment. Although the low harvesting in the studied forest improved the growth conditions for beech seedlings, the abundance of dead trees should be considered. Moreover, the presence of Hedera pastuchovii Woron. exGrossh. in these forests should be examined and managed accordingly.