1. Ecosystem Ecology Lab; College of Resources and Environmental Sciences; Nanjing Agricultural University; Nanjing 210095 China
2. Department of Ecology, Evolution, and Organismal Biology; Iowa State University; Ames IA 50011 USA
3. State Key Laboratory of Vegetation and Environmental Change; Institute of Botany; Chinese Academy of Sciences; Beijing 100093 China
4. Department of Entomology & Plant Pathology; North Carolina State University; Raleigh NC 27695 USA