Volume 13 (2014) Pages 20-40
This study examined the effects of a new subsidy system, stand conditions, and forest road network on annual supply potentials and available amounts of timber and logging residues. Excepting a few municipalities, available amounts of logging residues with the new subsidy system were smaller than those with the old subsidy system because the subsidy in the new system was received for the thinning operations with more than 5 ha operation site areas and more than 10 m³/ha extracted volumes. Therefore, available amounts are expected to increase as a result of adapting forestry operation site areas and operation systems to the new subsidy system. According to stand conditions, final felling operations with Japanese cypress, larger supply potentials, gentle terrains, road sides, and shorter transporting distances led to a higher ratio of profitable sub-compartments. Larger areas are expected to have an increased ratio of profitable sub-compartments. However, almost all profitable sub-compartments were less than 4 ha because forwarding distances were estimated as average distances from the landings to all grids within the sub-compartments in this study, and larger areas tended to have longer forwarding distances and subsequently, higher forwarding costs. Since forest road networks were relatively well established in Tochigi prefecture, 73% of supply potentials and almost all available amounts of logging residues were within 100 m from existing roads.