Truck Transportation and Chipping Productivity of Whole Trees and Delimbed Energy Wood in Finland

Nacrtak The present study aims to evaluate the competitiveness of various supply systems of smalldiameter wood harvested from young stands for fuel. Trees were harvested for the cost com­ parison either as (i) multi-stem delimbed shortwood or (ii) as whole trees or (iii) the harvesting was based on bundle-harvesting using the Fixteri II bundle harvester. The cutting of whole trees and multi-stem delimbed shortwood was carried out using a conventional harvester head equipped with multi-tree-handling accessories. Forwarding was carried out using a standard medium-sized forwarder. The comparison of procurement costs was done at stand level as a function of breast height diameter (5–13 cm) and on-road transportation distance (5–160 km). The harvested wood was chipped either at a roadside landing or at a terminal using a trailermounted drum chipper. The comparison of the supply systems was done using recently pub­ lished productivity parameters and data obtained from complementary field studies reported herein. According to the cost assessment, whole-tree harvesting and chipping at the roadside landing was almost invariably the most cost-efficient supply system. The cost of whole-tree and multistem delimbed shortwood chips was at the same level when the breast height diameter of the harvested trees was 11 cm (pine) or more. The cutting of whole trees is cheaper, but the cost difference diminished as a function of tree size. The productivity of forwarding, transportation and chipping of multi-stem delimbed shortwood was significantly higher compared to that of whole trees. When applying roadside chipping in Finnish conditions with small and sparsely located forest holdings, acquiring large enough concentrations of wood for profitable production is a great challenge. Machine relocations can be reduced by transporting raw material to terminals or the end-use facility to be chipped. However, the low bulk density of the initial material restricts the operation radius unless the wood biomass is pre-processed. According to the results of our study, harvesting of multi-stem delimbed shortwood is a promising way to simplify operations and to reduce transportation and chipping costs. In the case of whole-tree bundling, savings in transportation and chipping costs did not offset the high felling and compaction costs, and the bundling system was the least competitive alternative.