@article{oai:soar-ir.repo.nii.ac.jp:00011200, author = {中野, 達夫 and 朱, 建軍 and 徳本, 守彦 and 武田, 孝志}, journal = {信州大学農学部演習林報告}, month = {Mar}, note = {Based on current forest management practices, planting trees of karamatsu grow significantly fast in early stages, therefore, annual rings are extremely wide in early growth period, and after that, they are getting narrow gradually. Latewood width is constant in juvenile wood, and gets wide proportionally with ring width in mature wood. As the result, the percentage of latewood is very low at first, and becomes higher and higher gradually after that, and reaches stable at about 15 years. For this reason, the reduction of percentage of latewood with the increase of ring width appeared in juvenile wood can not be found in mature wood. From experimental results, it also can be found that the significant reduction of wood density, shrinkage, and bending strength with the increase of ring width did not appear in mature wood. The ring width of mature wood obtained from usual karamatsu plantation is not as wide as the ring width of juvenile wood, and even for the wider one, it is about 4~5 mm. Under this condition, it can be sure that increasing the growth rate can not decrease wood quality largely. The results presented here are only from 6 sample trees of the same site. In order to obtain more reliable results, it is necessary to study the wood from various districts. Moreover, the research here is only concerned to basic wood quality, and in order to be recognized as valuable wood for karamatsu, the subject of wood cutting, such as avoiding the low quality wood near pith according to demanded size as well as keeping less knots, are also needed to be further studied., Article, 信州大学農学部演習林報告 35: 101-110(1999)}, pages = {101--110}, title = {カラマツの成長と材質 : 手良沢山演習林産材の年輪構造,収縮率,曲げ強度}, volume = {35}, year = {1999} }