1. Ministry of Education Key Laboratory for Earth System Modeling; Center for Earth System Science; Tsinghua University; 100084 Beijing China
2. Joint Center for Global Change Studies (JCGCS); Beijing 100875 China
3. Cornell Laboratory of Ornithology; Cornell University; Ithaca NY 14850 USA
4. Institute of Botany; Department of Invasion Ecology; The Czech Academy of Sciences; CZ-252 43 Průhonice Czech Republic
5. Department of Ecology; Faculty of Science; Charles University in Prague; CZ-128 44 Prague Czech Republic
6. Centre for Invasion Biology; Department of Botany and Zoology; Stellenbosch University; 7602 Matieland South Africa
7. College of Forestry; Beijing Forestry University; 100083 Beijing China
8. Northern Research Station; c/o SUNY ESF; Syracuse NY 13210 USA
9. Department of Environmental Science, Policy, and Management; University of California; Berkeley CA 94720 USA