Abstract
Logging operations of private forest on a small scale forestry need efficient logging operation system. Analyses of logging operation systems on a small scale were performed according to Ehime Prefecture data that were about thinning operations from 1981 to 1990. Main operation systems were yarding mini-forwarder, human power, yarder and self-propelled carriages. The average of productivity was 1.10m^3/man・day. The highest productivity was yarding operation with self-propelled carriage, mini-forwarder, yarder and human power in order. Moreover, the average of production cost was 16,779 yen/m^3, and yarding operation with mini-forwarder was the cheapest cost of production, and then self-propelled carriage, yarder, human power respectively. A theory of quantification was applied and the factors which have an influences on logging operations were analyzed. The most influencing factor in logging operation was logging operation region, the next factors were difference of logging operation system, DBH, cutting ratio, average gradient (degree) and logging distance respectively.
