1. State Key Laboratory of Vegetation and Environmental Change; Institute of Botany, Chinese Academy of Sciences; No. 20 Nanxincun, Xiangshan, Beijing 100093 China
2. College of Land and Environment; Shenyang Agricultural University, Dongling Rd; Shenyang 110866 China
3. University of Chinese Academy of Sciences; No. 19A Yuquan Road, Shijingshan District, Beijing 100049 China