Abstract
We reviewed articles on thinning and selective cutting published between 1994 and 1998. We used their information on high performance forest vehicles to analyze the relationship between the thinning method (including selective cutting) and production conditions. High performance forest vehicles were used for thinning on slopes with inclinations of less than 20 degrees. At felling, the method of thinning (line thinning, qualitative thinning, or selective cutting) depended on stand density. There were also clear differences in bucking (at the felling site or in the landing area) and hauling (skidding, forwarding, and hauling by grapple loader) depending on differences in stand density and skidding distance. Based on this analysis, we used stand density and skidding distance to evaluate the logging systems. The productivity of the logging systems considered to be optimal, which was affected by the inclination of the cutting area, ranged from 10-17m^3 person^<-1> day^<-1> for slopes under about 10 degrees to 6-10m^3 person^<-1> day^<-1> for slopes over about 10 degrees. In contrast, the productivity of the other systems was only 2-6m^3 person^<-1> day^<-1>. These results show that it is important to select the proper logging system for optimal production conditions.
