Residual trees injury assessment after selective cutting in broadleaf forest in Shafaroud

In the Shafaroud forest, logging operation is generally performed by using selective cutting methods. Chainsaw and cable skidder are two main forest machines for harvesting of this forest. However, forest harvesting operations result in serious residual stand damage during felling, winching and skidding operations in this forest. Residual stand damage resulting from selective cutting was assessed on Avardim district in the Shafaroud forest in the north of Iran. Logging operation was performed by chainsaw and cable skidder. To gain benefit of directional felling, Landing and skid trail was planned prior to felling. Study area was cruised using 14 random sampling plots centered on transect lines uniformly distributed throughout the harvested area. Study results indicate majority of the injuries that occurred belong to the skidding and winching stage and the bole portion of tree (> 1m). Beech trees were injured more than trees of other species, and the mean area of injury was 290.3 cm2. Investigation on felling error showed that 40% of felled trees were at an angle of about 45-70 degrees with skidding direction, therefore felling crew could not lead the felled trees toward the skid trails. Increase felling error made the remaining trees more susceptible to injuries. This research indicated that preliminary planning of skid trail prior to felling is not a sufficient measure to minimize residual stand damage but proper training of crew is essential to insure a good performance of the operation. Felling crew should be not only trained and experienced workers but also aware of the value of residual crop trees, and the importance of minimizing stand damage if uneven-aged stand management practices are to be successful