Long-term impact evaluation of ground-based skidding on residual damaged trees (Case study: Tavir forest management plan)

The use of ground-based skidding is well accepted practice for the extraction of timber from the forest, but this has tended to cause the greatest environmental problems. We test the hypothesis that, over time, there was a statistically significant difference among the progressive decay and wound healing or closure in the residual trees of different species. The present study aims to address the following items: proportion of the remaining trees, how extensive is the spread of wound decay in individual stems by wound size and wound age. Long-term impact evaluation on residual damaged trees was carried out in the Tavir forest management plan in Aliabad-e-Katoul. Variation in wound infection frequency could be attributed to several factors, such as differences in size and age of wounds, position of wound on a tree. The results showed that there was a significant relationship between the species type and amount of healing. By increasing the diameter of the tree species, the ratio of healing decreased. By increasing the height of wound from the stump, wound-healing rate increased. The results showed that the deep wounds of the trunk will be healed later than superficial wounds. Regardless of the type species, by increasing the size of the wound, the wound healing significantly (in a logarithmic relationship) was reduced. The results showed that there was not a statistically significant relationship between scar closure and wound age. Damage to the residual stand might be reduced by proper planning and training the logging crews.