Slope is a major factor affecting forest harvesting machine productivity. As ground-based harvesting methods are generally cheaper than the alternatives, forest managers need to know when ground-based harvesting equipment can be used on sloping sites.
This University of the Sunshine Coast study determined how the effect of slope on the productivity, cycle time and elemental times of a Valmet 450 FXL self-levelling processor processing a 24 year-old, unthinned radiata pine plantation previously felled and stacked by a feller-buncher. Trees were selected from areas predominantly in the hilly (12–19°) and steep (20–26°) slope classes, as these classes made up the majority of the site area.
In contrast to previous research, no significant differences were found between the processor productivity, cycle time and elemental times (moving/positioning, swinging and processing) between the slope classes.
This was believed to result from the processor working well within its capabilities processing the relatively small trees on the study site. Further research is needed to determine whether the processor productivity would be significantly lower when processing larger trees on steeper slopes.
