1. Key Laboratory for Forest Resources Conservation and Utilisation in the Southwest Mountains of China, Ministry of Education; Southwest Forestry University; Yunnan 650224 China
2. Key Laboratory of Forest Disaster Warning and Control of Yunnan Province; Southwest Forestry University; Kunming Yunnan 650224 China
3. Department of Pathology, Bacteriology and Avian Diseases, Faculty of Veterinary Medicine; Ghent University; Salisburylaan 133 Merelbeke 9820 Belgium
4. Nanjing Institute of Environmental Sciences; Ministry of Environmental Protection of China; Nanjing Jiangsu 210042 China