1. Department of Biological Environment, Akita Prefectural University, Shimoshinjo-Nakano, Akita 010-0195, Japan
2. Seibu Landscape Co., Ltd, Tokorozawa Office, Tokorozawa, Saitama 359-0037, Japan
3. Tohoku Research Center, Forestry and Forest Products Research Institute, Morioka 020-0123, Japan
4. Institute of Forestry, Akita Prefectural Agriculture, Forestry and Fisheries Research Center, Akita 019-2611, Japan
5. Iwate Prefectural Forestry Technology Center, Yahaba, Iwate 028-3623, Japan