1. Subtropical Field Science Center, Faculty of Agriculture, University of the Ryukyus, Okinawa, Japan
2. Department of Agro-environmental Sciences, Faculty of Agriculture, Kyushu University, Fukuoka, Japan
3. Department of Forest and Forest Products Sciences, Faculty of Agriculture, Kyushu University, Fukuoka, Japan
4. Department of Production and Environment Science, Faculty of Agriculture, Niigata University, Niigata, Japan