Numerical examination of the optimal bucking method to maximize profits applied in Nasu town, Tochigi Prefecture, Japan

Abstract

In this study, the optimal bucking methods were numerically applied to Nasu town, and the factors of effects on profitability of commercial thinning operations and feasibility of extracting small sized logs were discussed. As a result, commercial thinning operations could be conducted on 18% (818 ha) and 54% (2427 ha) of 35 and 45 years old forests, respectively. On the other hand, pre-commercial thinning operation would be conducted on 81% (3666 ha) and 46% (2089 ha) of 35 and 45 years old forests. This shows current situation of Japanese forestry where nearly all the thinning operations conducted were pre-commercial. Stands with extracting small sized logs accounted for approximately ten percent of the total forest area. Extracted small sized logs from 35 years old forests were more than those from 45 years old forests although saw logs from 35 years old forest were less than those from 45 years old forests. The areas of stands with extracting small sized logs were increased according to the more gentle slope and shorter forwarding distances. Thus, it was clear that the reduction of forwarding distances by establishing forest road networks were effective in order to increase stands with extracting small sized logs.