1. a Key Laboratory of Resources Remote Sensing and Digital Agriculture , MOA , Hulunber Grassland Ecosystem Observation and Research Station , Institute of Agricultural Resources and Regional Planning , Chinese Academy of Agricultural Sciences , Beijing 100081, PR China
2. b Key Laboratory of Regional Climate‐Environment Research for Temperate East Asia (RCE‐TEA) , Chinese Academy of Sciences , Beijing, 100029, PR China
3. c State Key Laboratory of Information Engineering in Surveying , Mapping and Remote Sensing , Wuhan University , Wuhan, 430079, PR China
4. d Graduate School of Agriculture , Hokkaido University , N‐9, W‐9, Kita‐ku, Sapporo 060‐8589, Japan