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

1972年4月，日本栎树(Quercus mongolica var.)在北海道九州大学森林内的一片面积约200公顷的天然日本橡树林中建立。这种管理制度是由被防护林包围的舌形街区的割草制实施的。轮伐期为150年，并设置了每年交错采伐的插条块。包含这些积木的天然林分已经通过森林培育过程进行管理，旨在用日本橡木生产高质量的木材。从1972年到2001年的30年(第一、第二和第三阶段)所获得的结果如下：1)通过更新过程建立的第一年每公顷橡树幼苗的数量差别很大--从5,000株(2001年)到133,000株(1974年)；平均为55,500株。这种差异是由于日本橡树天然林种子产量的显著差异造成的。2)当通过更新过程…建立林分时更接近15年生的林分，在冠层中以与上述已建立的林分相同的方式区分垂直分层。3)在15~22年生的林分中，上层栎树的树高似乎略低于变异较大的上层乔木。4)在15~29年生林分更新过程中，上层树的胸径在15~21年生之间变化，而在21~29年生林分中，胸径生长量几乎是恒定的(每年约5 mm)。5)在35~57年生的林分中，上层林木蓄积量似乎随着林龄的增加而增大，且变异较大。6)30年间的年平均净收入为33.5万日元，这一数字是用年平均成本(55.7万日元)减去年平均收入(892,000日元)来计算的。要调查这一应用管理系统的盈利能力并改进其不足之处，需要长期继续进行这一实验。较少

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