2007 Volume 6 Pages 19-28
In this study, we estimated critical wind speed causing overturning and stem breakage with special focus on linking a mechanistic wind risk model, GALES, with growth and yield models for sugi (Cryptomeria japonica (L.f.) D.Don) and hinoki (Chamaecyparis obtuse (Sieb. Et Zucc.) Endl.). We found that lower initial planting density tended to increase the stability to the wind. In addition, stands with lower top tree height were more likely to be overturned than broken. To reduce wind damage, thinning would be recommended before the critical top tree height of sugi reaches 12m and that of hinoki reaches 14m. After this height, thinning might increase risk of wind damage. Although there were some limitations in the models developed for Japanese forests, the results indicated the most suitable timing to conduct thinnings, which could be utilized for long-term forest management in Japan.
