1. Graduate School of Agriculture, Kyoto University, Kyoto 606‐8502, Japan
2. Graduate School of Environmental Studies, Nagoya University, Nagoya 464‐8601, Japan
3. Forestry and Forest Products Research Institute, Ibaraki 305‐8687, Japan
4. Kansai Research Center, Forestry and Forest Products Research Institute, Kyoto 612‐0855, Japan