The authors gratefully acknowledge the financial support of the National Natural Science Foundation of China (Grant No: 21607176), the Natural Science Foundation of Hunan Province, China (Grant No. 2017JJ3516), the Research Foundation of Education Bureau of Hunan Province, China (Grant No. 16B274), the Open fund for key discipline of Forestry of Central South University of Forestry and Technology (Grant No. 2016ZD11), the Science and Technology Planning Project of Hunan Province, China (No. 2016SK2088), and the Youth Scientific Research Foundation of Central South University of Forestry and Technology (104|0329).