1. Faculty of Agriculture, University of Miyazaki, 1-1 Gakuenkibanadainishi, Miyazaki 889-2192, Japan
2. Graduate School of Agricultural Science, Tohoku University, 232-3 Aza-yomogida, Naruko Onsen, Osaki, Miyagi 989-6711, Japan
3. Kuju Grassland Ecomuseum, 5-4-67-101 Ozasa, Chuo-ku, Fukuoka 810-0033, Japan