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ŠUMARSKI LIST 9-10/2017 str. 28     <-- 28 -->        PDF

1969). Debarking activities should be carried out in advance because hard objects like stone and sand that are stuck in barks can damage the saw tooth and decrease productivity during the timber process in sawmills. Also, blunts occurred on the debarking machine knives damage the heartwood, which reduces their quality (Watson et al. 1993).
In harvesting activities, which are usually performed in spring and summer months, unbarked products that are left in forests are confronted with the risk of bark beetles. Thus, one of the most important reasons of debarking is to prevent damages of bark beetles between the bark and the wood of harvested trees (FAO, 2011). Besides, debarking activities should be completed until the end of April at last, otherwise not only harvested trees but also the residual standing trees can be also damaged by these beetles (Gürtan, 1969).
The efficiency and productivity of debarking activity is affected by many factors such as the types of the equipment, physical structure of the workers, tree species and diameter, bark thickness, harvesting period, the time between felling and debarking, ground slope, and weather condition (Gürtan, 1969; Çoban, 1975). Debarking activities of coniferous trees in Turkey are performed by using axe or chainsaw mounted debarking tool.
Debarking with axe is performed by starting from the thicker part of the trunk to its thinner part (Yıldırım, 1989). Debarking of trees with thick barks is performed by removing barks as long strips. For debarking trees with relatively thinner barks, chainsaw mounted debarking tools are often preferred. These tools are located on the metal plates of the chainsaw and receive the power from the chainsaw engine (Eker and Acar, 2004; Gülci, 2014). During debarking with axe, workers mostly work by bending down, so in this case muscle power is heavily used. During debarking with a chainsaw mounted debarking tool, however, workers also work by bending down, but in this case they use engine power, and they complete the work by moving only back and forth (Eker et al., 2011).
Debarking tools used in debarking studies that are carried out with traditional and developed methods differ according to the tree species, location and economy. Nowadays, while countries with lack of mechanization in forestry use manual devices (like attachable apparatus for axe and chainsaw) for debarking, countries with various forestry mechanization options prefer different mechanical debarking tools (chain flail debarker, harvester head for debarking and etc.) (Watson et al., 1993; Eker et al., 2011; Murphy and Acuna, 2016).
There are various factors for choosing debarking method in forest harvesting, for certain. It is an important decision whether to remove the barks at the stump-site, or debark them in wood processing mills. Logging residuals (bark, leave, branch, etc) of economically valuable trees are evaluated as fuel in generating bio-energy, or thanks to their chemical content, bio-products are obtained from logging residuals to gain economic value (Magaggnotti et al. 2011).
The productivity of the equipment and techniques used during debarking activity are generally determined based on operation time. The most commonly used method for measuring the operation time is time study method (Yıldırım, 1987). Main material and tools used in time studies are timers (i.e. chronometer, palmtop, data loggers) and time study forms. In addition, devices for measuring distance and operation speed, camera, clinometer, steel tape, caliper are used in time study work in the field (Yıldırım, 1987; Gülci, 2014; Manavakun, 2014).
In this study, it was aimed to evaluate two common debarking methods using axe and chainsaw mounted debarking