1. Estación Experimental de Zonas Áridas; Consejo Superior de Investigaciones Científicas; Carretera de Sacramento s/n E-04120 La Cañada Almería Spain
2. Department of Evolutionary Biology and Environmental Studies; University of Zurich; Winterthurerstrasse 190 CH-8057 Zurich Switzerland
3. Department of Plant Ecology; Bayreuth Center for Ecology and Environmental Research; University of Bayreuth; 95440 Bayreuth Germany
4. Smithsonian Tropical Research Institute; Apartado 0843-03092 Balboa Ancon Republic of Panama
5. Max-Plank Institute for Biogeochemistry; Hans-Knöll-Str. 10 07745 Jena Germany
6. Plant Ecology; Albrecht von Haller Institute for Plant Sciences; University of Göttingen; UntereKarspüle 2 37073 Göttingen Germany
7. Institute of Systematic Botany and Ecology; Ulm University; Albert-Einstein-Allee 11 89081 Ulm Germany
8. German Centre for Integrative Biodiversity Research (iDiv) Halle-Jena-Leipzig; Deutscher Platz 5e 04103 Leipzig Germany
9. Department of Renewable Resources; University of Alberta; Edmonton AB T6G 2E3 Canada
10. Robert H. Smith Institute of Plant Sciences and Genetics in Agriculture; The Hebrew University of Jerusalem; PO Box 12 Rehovot 76100 Israel
11. Department of Earth and Planetary Science; Weizmann Institute of Science; Rehovot Israel
12. School of Biological Sciences; University of Auckland; Private Bag 92019 Auckland 1142 New Zealand