Application Study on Forest Management System and Silvicultural Process for High Quality Timber Production of Japanese Oak

1972年4月，在北海道九州大学森林面积约200公顷的天然日本栎林中建立了日本栎（Quercus mongolica var. grosseserrata）试验管理系统。管理制度是在被防护林包围的舌状街区内实行的切密制度。轮流150年，并设立了每年交错切割的切割块。包含这些块的自然林分通过造林过程进行管理，旨在生产高质量的日本橡木木材。1972 - 2001年30年（第一、二、三期）的研究结果如下：1)每公顷新生栎树幼苗数量变化很大，从2001年的5000棵到1974年的133000棵不等；平均为55500。这种变化是由于日本橡树天然林种子作物大小的显著变化。2)当更新过程建立的林分进一步发展到15年林分附近时，林冠内的垂直分层与上述建立的林分相同。(3)在15 ~ 22年生林分中，上栎树的高度似乎略低于上栎树的高度，且变化较大。4)在15 ~ 29年更新的立地林分中，15 ~ 21年林分的林分胸径变化较大，而21 ~ 29年林分的林分直径增长基本不变（约为5 mm /年）。5)在35 ~ 57岁林龄中，随着林龄的增加，上层乔木的林分体积呈增加趋势，且变化幅度较大。6) 30年间的平均年净收益为33.5万日元，这是平均年收益（89.2万日元）减去平均年成本（55.7万日元）的结果。调查这一应用管理系统的盈利能力并改进其不足之处，需要在很长一段时间内继续进行试验。少

In April 1972, an experimental management system for Japanese oak (Quercus mongolica var. grosseserrata) was established in a natural Japanese oak forest, approximately 200 ha in area, in the Kyushu University Forest in Hokkaido. The management system was imposed by dear-cutting system in tongue-shaped blocks surrounded by shelterbelts. Rotations were 150 years and cutting blocks for staggered annual cutting were set up. The natural stands containing these blocks have been managed by a silvicultural process designed to produce high-quality timber from Japanese oak. The results obtained for 30 years between 1972 and 2001 (the first, second and third periods) are follows;.1) The number of first-year oak seedlings established by regeneration process per ha varied widely-from 5,000 (in 2001) to 133,000 (in 1974); it averaged 55,500. Such variation was due to noted variations in size of seed crop for natural forests of Japanese oak. 2) When the stands established by the regeneration process … More developed into near the 15-year-old stand, vertical stratifications were distinguished in the canopy on the same manner as the above established stands. 3) In the 15- to 22- year-old stand, the height of the upper oak trees seemed to be somewhat lower than the one of the upper trees progressing with wide variations. 4) In the established stands by the regeneration process from 15- through 29-year-old, whereas the DBH of the upper trees was varied between the 15- and 21-year-old stand, the diameter growth was nearly constant (approximately 5 mm per year) in the 21- through 29-year-old stands. 5) In the 35- to 57-yearold stand, the stand volume of the upper trees seemed to increase with an increase in stand age progressing with wide variations. 6) The average net annual revenue for the 30-year period was 335,000 yen, an amount calculated by subtracting the average cost per year (557,000 yen) from the average revenue per year (892,000 yen).Investigating the profitability of this applied management system and improving its shortcomings will require that the experiment be continued over a long period. Less