1. Kansai Research Center, Forestry and Forest Products Research Institute, 68 Nagaikyutaroh, Momoyama, Fushimi, Kyoto 612-0855, Japan
2. School of Agriculture, Meiji University, Kawasaki, Kanagawa 214-8571, Japan
3. Sugadaira Research Station, Mountain Science Center, University of Tsukuba, 1278-294 Sugadaira-Kogen, Ueda, Nagano 386-2204, Japan