1. Laboratory of Forest Environment and Resources, Graduate School of Bioagricultural Sciences, Nagoya University, Furo-cho, Chikusa-ku, Nagoya, Aichi 464-8601, Japan
2. Faculty of Agriculture, Utsunomiya University, 350 Mine-machi, Utsunomioya, Tochigi 321-8505, Japan
3. Fukushima Prefectural Forest Research Center, 2–16 Sugitsumacho, Fukushima, Fukushima 960-8670, Japan