Kazuki Nanko, Forestry & Forest Products Research Institute, Ibaraki, Japan, Delphis F Levia Jr, University of Delaware, Departments of Geography and Plant & Soil Sciences, Newark, DE, United States, Shin'ichi Iida, Forestry & Forest Products Research Institute, Department of Disaster Prevention, Meteorology and Hydrology, Ibaraki, Japan, Xinchao Sun, Tianjin University, Tianjin, China, Yoshinori Shinohara, University of Miyazaki, Miyazaki, Japan and Naoki Sakai, National research institute for Earth Science and Disaster Resilience, Tsukuba, Japan