Environmental Impact Assessment of Forest Harvesting to Residual Stand (Case Study: in Kheyrud Forest)

Forest operations aims at delivering plans and operations that is technically feasible, economically viable, environmentally sound, and institutionally acceptable. Reducing the impact of harvesting on residual stand and regeneration is very important, considering the use of close-to-nature forestry for Hyrcanian forest management and the low cutting volume distribution of this method. This research was carried out in compartment no. 221 in Namkhaneh district of Kheyrud Forest. The Objects of this study were to evaluate damages to the residual stand. To investigate the effect of damages on residual trees and regeneration in felling areas, 100% inventory was used. Considering the results of all felling areas in sample plots showed that 1.2 percent of trees were damaged because of felling operation. 73% of damaged trees were Beech, 25% Hornbeam and 2% other species like Acer, Oak and Alder. Most damages were on trees with less than 40 cm (d.b.h) diameter. This study showed that the most damages to regeneration groups in felling areas were large sapling with 19.7% and least damages of 10.8% were to seedling. Evaluation of quality of scars on the trunk of tree stand in felling areas with regards to position of scars showed that most scars were present at 2 m heights and were mostly superficial scars (no bark removed and damages to cambium). Training of tree cutting crews is the most important factor for decreasing residual stand damage after harvesting. The residual stand damage from a cutting operation was studied in an uneven-aged mixed forest to examine the main factors (i.e. tree species, location, size, and type) affecting stand damages. Directional tree felling in a forest stand and using some helping instrument could be useful for decreasing the residual stand damage.