Effect of forest structure on operational efficiency of a bundle-harvester system in early thinnings

摘要: The objective of the study was to improve knowledge on effects harvested tree size and density undergrowth operational efficiency a bundle-harvester that produces 2.6 m long bundles, with ca. 60–70 cm diameter, in early fuel wood thinnings. In total 26 time plots were marked out 30 35 year old Scots pine dominated stands initial 2800–9300 trees/ha stem range 15–43 dm3. Ten units, randomly chosen, precleared trees (≤2.5 at breast height diameter) prior harvesting. There no significant differences between treatments (preclearing vs. preclearing) properties or remaining stands. average cut volume stems 7.4 16.2 dm3, respectively, average, 3554 removed. bundles had mean fresh mass 439 kg correlated proportion birch cut. productivity was, 3.1 OD t/PM0H (6.6 t/PM0H; 15.1 bundles/PM0H, where PM0H is productive machine hours, without delays) modeled (dm3) as single independent variable. provides complementary earlier studies system’s performance, especially for harvesting <30 Its limited by cutting could probably be significantly increased using felling bunching head accumulate during continuous boom movements. Thus, it would informative evaluate such system various thinning stand conditions, including assessments its manoeuvrability more difficult terrain.