@article{oai:iwate-u.repo.nii.ac.jp:00015509,
 author = {國崎, 貴嗣 and 山崎, 遥},
 issue = {4},
 journal = {日本森林学会誌, Journal of the Japanese Forest Society},
 month = {Aug},
 note = {過密なスギ老齢人工林1林分における林齢134～175年の林分成長経過を，斜面区と平坦区別に調べた。斜面区では，本数率10％前後の極めて弱い伐採が数回実施されたため，過密状態を解消できず，枯死木が発生し続けた。しかし，継続的に伐採されたことで，込み合い度は緩やかに改善し，胸高直径成長量が増加することで，平均形状比は70未満まで低下し，林分材積純成長量は10 m3/ha/年以上に達した。平坦区では，林齢146年に本数率22％の下層間伐が実施されたことで，過密状態が解消され，枯死木発生が止まった。そして，胸高直径成長量が増加することで，平均形状比は70未満まで低下し，林分材積純成長量は20 m3/ha/年前後まで増加した。地位級1等で樹高成長が継続しているため，相対幹距15％を超える下層間伐を施せば，林分材積純成長量が20年近く，20 m3/ha/年前後になることが確認された。, The stand growth process of an overcrowded old-gowth plantation of Japanese Cedar (Cryptomeria japonica D. Don) was investigated for 41 years, beginning when the stand was 134 years old, in the slope and flat site. In the slope site, since very weak cutting of about 10％ in number ratio was carried out several times, overcrowding condition could not be eliminated and mortality continued. However, as the trees were continuously cut down, the degree of crowding gradually improved and DBH growth increased, average height: DBH ratio decreased to less than 70, and net increment in stand volume reached more than 10 m3/ha/year. In the flat site, the low thinning of 22％ in number ratio was carried out, when the stand was 146 years old, and overcrowding condition was eliminated and mortality stopped. As DBH growth increased, average height: DBH ratio decreased to less than 70 and net increment in stand volume increased to around 20 m3/ha/year. It was confirmed that since the tree height growth continues at first site class, the net stand volume increment would be around 20 m3/ha/year for about 20 years, if lower thinning is conducted to exceed 15％ of the relative spacing index.},
 pages = {285--290},
 title = {過密なスギ老齢人工林における41年間の林分成長経過},
 volume = {103},
 year = {2021}
}