1. Graduate School of Agriculture, Kyoto University, Kitashirakawa Oiwake Cho, Sakyo District, Kyoto 6068502, Japan
2. Institute of Ecology, College of Urban and Environmental Sciences, and Key Laboratory for Earth Surface Processes of the Ministry of Education, Peking University, 5 Yiheyuan Road, Haidian District, Beijing 100871, China
3. Uryu Experimental Forest, Hokkaido University, Moshiri, Uryu 0740741, Japan
4. Kasuya Research Forest, Kyushu University, 394 Sasaguri, Kasuya 8112415, Japan
5. Field Science Center for Northern Biosphere, Hokkaido University, Kita 9, Nishi 9, Kita District, Sapporo 0600809, Japan