PRODUCTIVITY AND COSTS OF FOREST CUTTING IN A PINE STAND UNDER TWO THINNING METHODS

Resumo

The need for higher value-added wood products and the high cost of mechanized operations stimulate the development of new thinning methods in order to provide gains in productive capacity of forest stands. In this context, the aim of this study was to analyze the effect of two thinning methods on productivity and costs of the forest harvesting in the generation of multi‐products. The study was carried out in a 10-year-old Pinus taeda stand under to two thinning methods: TH5 (harvester, with systematic harvesting of the fifth tree row and selective in adjacent rows); and TH7 (chainsaw and harvester, with systematic harvesting of the seventh tree row and selective in adjacent rows). We determined the working cycle times, productivity, and production costs through a time and motion study, with the averages of partial and total times being compared between thinning methods by the Wilcoxon-Mann-Whitney test (α ≤ 0.05). From the obtained results, it was found that the thinning methods directly affected the harvester’s partial and total times, with the largest time obtained in the TH7 thinning method due to the need to locate previously cut trees by chainsaw, with a consequent reduction in the productivity and an increase in the production costs when compared to the TH5 method. However, despite the higher production cost, the TH7 method showed potential with the use of mechanization in all activities, making it possible to increase selective thinning and contribute to gains in forest stand quality.