Comparative analyses on the cycle time, productivity, and cost between commercial thinning and clear-cutting operations in Nasu-machi Forest Owners' Co-operative, Tochigi Prefecture, Japan

This study investigates clear-cutting operations on moderately and gently sloping sites. Cycle times, productivities, and costs of those operations are analyzed and compared with those of commercial thinning operations, to enable logging contractors to easily find trends of those three variables. Felling cycle times of clear-cutting were lower than those of commercial thinning operations. Processing cycle times of clear-cutting on the gently sloping site were lower than those of clear-cutting on the moderately sloping site and commercial thinning. However, processing cycle times of clear-cutting on the moderately sloping site were similar to those of commercial thinning. Forwarding cycle times of clear-cutting on the moderately sloping site were the lowest among the estimated forwarding cycle times. Costs of operation systems were the lowest with clear-cutting on the gently sloping site, followed by clear-cutting on the moderately sloping site, and then commercial thinning with mechanized and current operation systems according to forwarding distance, with extracted volume 0.5 m(3)/stem. Costs of the current thinning operation system were less than those with a mechanized thinning system below extracted volume 0.3 m(3)/stem, because of smaller machinery expenses.