Residual damage in different ground logging methods alongside skid trails and winching strips

Abstract

To assess the residual damage a 100% inventory method was employed in pre-hauling and post-hauling, alongside skid trails and winching strips. Inventory was executed within 6 m from each side of the skid trail or winching strip centreline (12 m width). Besides the data analysis to choose the best alternative depending on residual damage the Analysis of Multiple-criteria Approval (MA) was applied. In the winching strip, our results demonstrated that depending on the density of standing residual trees the most unfriendly alternative to standing trees was a short-length method (SLM) which damaged 27.9% of the total standing trees and the best alternative was a tree-length method (TLM) (11.89%). The most unfriendly alternative to regeneration in winching and skidding operations was SLM with damaged 21% and 9% of all seedlings, respectively. In the winching strip TLM is the best alternative depending on the number of damage trees but 72% damage degree was deep. Alongside the skid trails the highest number of damaged trees occurred in TLM (44 stems) and the lowest was in the long-length method (LLM) (10 stems); according to the density of trees also the greatest damage to trees occurred in TLM (16.73%) and the lowest was in LLM (3.13%). In addition (in winching and skidding operations), 14.31, 8.79 and 18.19% of residual trees and 9, 11 and 16% of individuals of regeneration were damaged in TLM, LLM and SLM, respectively. The results of data analysis (by SPSS and MA) indicated that the friendly alternative to residual stand in the north of Iran is a long-length method.