1. Key Laboratory of Forest Plant Ecology, Northeast Forestry University, Harbin 150040, China.
2. College of Biological Engineering, Da Qing Normal University, Daqing 163000, China.
3. Urban Forests and Wetlands Group, Northeast Institute of Geography and Agroecology, Chinese Academy of Sciences, Changchun 130102, China.
4. College of Wildlife Resources, Northeast Forestry University, Harbin 150040 China.