1 Center for Ecological Research, Northeast Forestry University, Harbin 150040, China, 2 Forest Dynamics, Swiss Federal Institute for
Forest, Snow and Landscape Research WSL, CH-8903 Birmensdorf, Switzerland, 3 Erguna Forest-Steppe Ecotone Research Station, CAS
Key Laboratory of Forest Ecology and Management, Institute of Applied Ecology, Chinese Academy of Sciences, Shenyang 110016,
China, 4 Key Laboratory of Geographical Processes and Ecological Security in Changbai Mountains, Ministry of Education, School of
Geographical Sciences, Northeast Normal University, Changchun 130024, China, 5 East China Coastal Forest Ecosystem Long-term
Research Station, Research Institute of Subtropical Forestry, Chinese Academy of Forestry, Hangzhou 311400, China, 6 Key Laboratory of
Sustainable Forest Ecosystem Management-Ministry of Education, Northeast Forestry University, Harbin 150040, China