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ŠUMARSKI LIST 9-10/2017 str. 31     <-- 31 -->        PDF

(Table 2). With the average bark thickness of 3.05 cm, total average debarking cycle time was determined as 6.91 min/timber.
One-Way Anova analysis results for debarking studies using a chainsaw mounted debarking tool are given in Table 3. The results showed that different volume classes have a significant statistical effect (p<0.01) on the productivity. The average productivity (3.54 m3/hour) of low volume timbers was found to be higher than the medium (2.90 m3/hour) and high (2.39 m3/hour) volume classes.
The results of debarking activity using an axe showed that different volume classes have also a significant statistical effect (p<0.01) on the productivity. According to One-Way Anova analysis results, average productivity increased from low volume class (0.54 m3/hour), to medium (0.68 m3/hour) and high volume class (0.89 m3/hour) (Table 4). In contrast to debarking using a chainsaw mounted debarking tool, debarking activity with an axe was determined to be more productive in high volume timbers.
The correlation test results of debarking activities were given in Table 5. In both methods, it was determined that a significant relation (p=0.00, p<0.01) was determined at a confidence level of 95% between all the other variables in both methods. Based on the operational experiences, loggers tent to use chainsaw mounted debarking tool for relatively thinner barks during forest operation in the field. Therefore, average bark thicknesses were lower comparing with debarking activity using an axe.
R2 values of the regression models by using a chainsaw mounted debarking tool and an axe were found as 0.97 and 0.94, respectively. Also, the regression model gave a significant (p=0.00, p<0.01) result in both of the methods at a confidence level of 99%. Including the diameter (x1), bark thickness (x2) and volume (x3) in solution process, with the dependent variable of the total time (y), regression model parameters for both methods were evaluated (Table 6).
According to the results, it was found that total time is directly proportional to diameter, bark thickness, and volume in both methods (Figure 4). Increase in timber sizes caused the workers to spend more time for debarking activity. Besides, timbers with thicker barks took more debarking cycle time.