1. Institute of Grassland Science Key Laboratory of Vegetation Ecology of the Ministry of Education Jilin Songnen Grassland Ecosystem National Observation and Research Station Northeast Normal University Changchun 130024 China
2. Department of Biology University of New Mexico Albuquerque New Mexico 87131 USA
3. Jornada Basin LTER Program New Mexico State University Las Cruces New Mexico 88003 USA
4. College of Grassland Science Grassland Agri‐Husbandry Research Center Qingdao Agricultural University Qingdao 255109 China
5. Key Laboratory of Mollisols Agroecology Northeast Institute of Geography and Agroecology Chinese Academy of Sciences Harbin 150081 China