1. Central South University of Forestry and Technology, Changsha, Hunan 410004, China.
2. Forestry and Forest Products Research Institute, Tsukuba, Ibaraki 305-8687, Japan.
3. Guangxi Universities, Nanning, Guangxi 530004, China.
4. Faculty of Life and Environmental Sciences, University of Tsukuba, Tsukuba, Ibaraki 305-8572, Japan.