Abstract
Since 1972, an experimental management system for Japanese oak (Quercus mongolica var. grosseserrata) has been studied in a natural Japanese oak forest approximately 200 ha in area in the Kyushu University Forest in Hokkaido. The management system was imposed by clearcutting in tongue-shaped blocks surrounded by shelterbelts; rotations were 150 years. The silvicultural process to which the natural oak forest has been subjected was designed to produce high-quality timber. For the 20 years between 1973 and 1992, the number of first-year oak seedlings established by the silvicultural process averaged 61,000 per ha per year. For the 20 years between 1972 and 1991, the area managed averaged 8.64 ha per year. For the 20-year period, the timber volume derived from thinning and final cutting averaged 240 m^3 per year. The average revenue obtained by selling this timber was 1,169,000 yen per year. The average cost of silvicultural management was 600,000 yen per year, excluding the management costs for staff members and related factors on the Kyushu University Forest. Thus, the average net revenue per year was 569,000 yen for the 20-year period.
