抄録
This study investigated the commercial thinning operation with normal bucking at the Takahara Forest Owners' Cooperative, near the Nakagawa sawmill, Tochigi prefecture, Japan. The productivity and net profit of 3-m bucking were estimated based on investigations of normal bucking, to examine the possibility of extending 3-m bucking and fixed-price business to all logs. The recovery rate with 3-m bucking was estimated at 85%―a significant increase over that with normal bucking (38%); therefore, recovered volumes with 3-m bucking were also significantly higher, at 148 m3/ha, compared to that with normal bucking (67 m3/ha). Productivity regarding strip-road construction, felling, and processing with 3-m bucking were higher, in line with higher recovered volumes, whereas productivity regarding bunching, forwarding, and transportation with 3-m bucking were assumed to be identical to those with normal bucking. The total costs per cubic meter with 3-m bucking were lower, whereas total costs per hectare with 3-m bucking were higher, in line with higher recovered volumes. Recovered volumes of grade-A, B, and C wood with normal bucking were estimated at 40, 20, and 7 m3/ha; revenues were estimated at JPY10,000/m3. With 3-m bucking, recovered volumes of grade-A, B, and C wood were estimated at 59, 44, and 44 m3/ha; revenues per cubic meter were lower, at JPY8,400/m3. Generally, net profit per cubic meter with 3-m bucking was lower, in line with higher volumes of lower-quality logs, whereas net profit per hectare with 3-m bucking was twice as high, in line with higher recovered volumes.
