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ŠUMARSKI LIST 9-10/2017 str. 32     <-- 32 -->        PDF

Average percentage values according to total time of the debarking studies with chainsaw mounted debarking tool and axe working stages are seen in Table 7. When the working stages are compared to their percentages, while debarking stage took more time than the others, preparation stage took less time. The bark thickness, where the chainsaw mounted debarking tool was used, was thinner compared to other diameters where axe was preferred. It was determined that turning the timber with debarking tool took much more time than with axe. The reason for this is that the worker’s ability of movement is limited due to weight of the chainsaw. In a similar study by Eker et al. (2011), it was reported that debarking stage using chainsaw mounted debarking tool carried out in a Turkish red pine stand took a plenty of time (89.7%), while preparation stage (3.7%) took the least time.
According to obtained results, it was determined that hourly average productivity with a chainsaw mounted debarking tool and an axe was 3.36 m3/hour and 0.64 m3/hour, respectively. It was also found that while productivity of debarking with axe increases by volume classes, it was just the opposite in the case of using a chainsaw mounted debarking tool. This is because bark thickness increases relatively with the increase of volume.
It was determined that hourly productivity was five times higher when chainsaw mounted debarking tool was used, compared to axe. In a study conducted by Eker et al. (2011), it was also found that hourly productivity was about five times higher when compared to debarking with axe. In a similar study carried out by Eker and Acar (2004) in a Turkish red pine stand, it was determined that using a chainsaw mounted debarking tool was three times more productive than using an axe.
While productivity increases in studies where the chainsaw debarking tool is used and the bark thickness reaches up to 2.5 cm, it remains constant where the bark thickness pass over 2.5 cm. In case of studies where axe is used and the bark thickness reaches up to 2.5 cm, productivity remains constant, but an increase was observed when the bark thickness passed over 2.5 cm. (Figure 5). That is why maximum bark thickness was determined as 2.5 cm in order to use the chainsaw debarking tool efficiently. Also, when the bark thickness was over 2.5 cm, axe was preferably used as a debarking alternative.
Even though debarking methods that are subject to this study are thought to be the optimum method for the current conditions in Turkey, using highly mechanized debarking techniques (chain flail debarker, harvester head for debarking and etc.) or using oriented processor (delimbre-debarker-chipper) at harvesting unit might be more productive. Economic value of the tree species can be considered as one of the most important factors in determination of optimum method (Spinelli et al. 2009; Magagnotti et al. 2011). However, debarking with chainsaw tools and axe are still more common in Turkey because logging residuals are not used as an economic product and usually left in the forests.
Even though debarking stage that is carried out inside the cutting area is not the primary stage of the logging operation,