1. German Centre for Integrative Biodiversity Research (iDiv) Halle-Jena-Leipzig; Deutscher Platz 5e 04103 Leipzig Germany
2. Institute of Biology; Leipzig University; Johannisallee 21 04103 Leipzig Germany
3. Metapopulation Research Centre; Department of Biosciences; University of Helsinki; PO Box 65, 00014 Helsinki Finland
4. Center for Macroecology, Evolution and Climate Change; Natural History Museum of Denmark; University of Copenhagen, Universitetsparken 15; København Denmark
5. Center for Forest Ecology; University of Minnesota; St. Paul MN USA
6. Département de Biologie; Université de Sherbrooke; Sherbrooke QC Canada
7. Department of Fisheries, Wildlife, and Conservation Biology; University Of Minnesota; 2003 Upper Buford Circle Suite 135 St. Paul MN 55108 USA
8. Department of Natural Resources; Cornell University; Ithaca New York USA
9. Faculty of Forestry; University of Toronto; Toronto ON Canada
10. Schoodic Institute at Acadia National Park; Forest Ecology Program; Winter Harbor ME USA
11. Department of Botany and Plant Pathology; Purdue University; West Lafayette IN USA
12. Département des sciences biologiques; Université du Québec à Montréal; Montréal QC Canada
13. Department of Biological Sciences; Northern Kentucky University; Highland Heights KY USA
14. Department of Natural Resource Ecology and Management; Oklahoma State University; Stillwater OK USA
15. Natural Area Consultants; 1 West Hill School Road Richford NY USA
16. Warnell School of Forestry and Natural Resources; University of Georgia; Athens GA USA
17. College of Natural Resources; University of Wisconsin - Stevens Point; Stevens Point WI USA
18. Plant Biology and Conservation; Northwestern University; Evanston IL USA
19. Department of Plant Science; Chicago Botanic Garden; Glencoe IL USA