Acknowledgments
We thank Penglai Fan, Haochun Chen, Hanlong Chen, Ruoshuang Liu, Bo Zhang, Li Wei, Lang Lu and help collect data in the field. We thank Professor Tim Clutton-Brock and Dr Dieter Lukas for his constructive comments on this paper. This study was supported by Supported by the Strategic Priority Research Program of Chinese Academy of Sciences (XDB31000000), the National Natural Science Foundation of China (31870509, 31670397, 31821001),National Key R&D Program of China (2016YFC0503200) and the State Forestry Administration of China.