DIGITALNA ARHIVA ŠUMARSKOG LISTA
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ŠUMARSKI LIST 7-8/2015 str. 57     <-- 57 -->        PDF

Morphological characteristics of trees also affect the productivity of mechanized cutting. We calculated the productivity of 7.36 m3 per PMH in the single-trunked stands. The average tree volume was 0.21 m3. This productivity was 25 % higher than in the stands with multi-trunked trees with a long crown.
The ratio between Work place time and Work time was 1: 1.62. This ratio is higher than ratios (1.39), which has been used for calculation of recommended standard times of CTL cutting with heavy harvesters on the Slovenian state level or the one recorded in Austria (1.35) (Stampfer, 2001). Spinelli and Visser (2008) also report lower coefficients. Explanation of this difference was not a specific subject of this study. However, the problem can be pointed out relating to work organization and delays which are connected with it (repairs, refueling, workers breaks, meal time etc.).
The time study of mechanized cutting and processing shows that the Main work time (when harvester head is in direct contact with the trunk), amounts to 63.4% of work time. In comparison to studies in the coniferous stands (Nurminen et al. 2006), it is closer to those at work in the final fellings, where the authors report 62 % share of Main work time (felling and processing) in the final felling and only 45 % main work time share in the mechanized thinning operation.
The presented findings are the results of study where the productivity was compared for both technologies (MM cutting vs. CTL technology in deciduous stands). Certainly we know that a comprehensive assessment which would analyze additional influential factors (the cutting intensity, environmental impact, ergonomic load, different technological solutions) – would be much more complex. Such a complex study would give different and more general relationships for suitability of forest operation technologies in hardwood stands.
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