Ovaskainen, H., Palander, T., Jauhiainen, M., Lehtimäki, J., Tikkanen, L. and Nurmi, J. 2008. Productivity of Energywood Harvesting Chain in Different Stand Conditions of Early Thinnings.  Baltic Forestry 14(2):149-154

The objective of this study was to investigate the effects of stand conditions on the productivity of a harvesting machine chain in early thinning stands. The studied harvesting chain consisted of Pro Silva Ässä 810 harvester equipped with an accumulating Naarva-Grip 1600-40 felling head and Timberjack 810 forwarder. The study was implemented on two separate stands, which were divided into nine blocks; each with unique stand conditions. The stand densities of the studied blocks varied from 2,000 to 7,750 stems per hectare and average tree length on the blocks were between 5.3–9.9 meters. In these conditions the productivity in cutting varied between 4.7–8.5 m³/h. Average productivity in cutting was 5.8 m³/h. Forwarding productivity was 7.9 m³/h in average varying between 6.0–9.2 m³/h. The increase of stand density and decrease of average stem size reduced less cutting productivity than forwarding productivity compared to separate machine studies.

Key words: energy wood, multiple tree handling, accumulating felling head, whole tree harvesting, productivity