1. Institute of Applied Ecology, Chinese Academy of Sciences, Shenyang 110015, People's Republic of China.
2. School of Science, Shenyang University of Technology, Shenyang 110023, People's Republic of China.
3. School of Ecology and Environment, Deakin University, Warrnambool, Vic. 3280, Australia.
4. Corresponding author: School of Ecology and Environment, Deakin University, P.O. Box 423, Warrnambool, Victoria, Australia 3280. Phone: 61 3 5563 3535; Fax: 61 3 5563 3143; E-mail: frankst@deakin.edu.au.
5. Centre for Eco-Environmental Modelling, Hohai University, Nanjing 210098, People's Republic of China.