1. Research Center for Engineering Ecology and Nonlinear Science North China Electric Power University Beijing 102206 China
2. Department of Life Sciences Imperial College London Silwood Park Campus, Buckhurst Road, Ascot Berkshire SL5 7PY UK
3. School of Electronic Engineering and Computer Science Queen Mary University of London Mile End Road London E1 4NS UK
4. Department of Ecosystem Science and Sustainability Colorado State University Fort Collins CO 80523 USA
5. Natural Resource Ecology Laboratory Colorado State University Fort Collins CO 80523 USA
6. Department of Biology and Marine Biology University of North Carolina Wilmington Wilmington NC 28403 USA
7. Duke Network Analysis Center Duke University Durham NC 27708 USA