1. Institute of Biology; Freie Universität Berlin; Altensteinstr. 6 Berlin D-14195 Germany
2. Berlin-Brandenburg Institute of Advanced Biodiversity Research (BBIB); Berlin D-14195 Germany
3. Albrecht von Haller Institute of Plant Sciences; University of Göttingen; Untere Karspüle 2 Göttingen 37073 Germany
4. Geographic Institute; University of Bern; Hallerstr. 12 Bern 3012 Switzerland
5. Institute of Geography and Geoecology; Karlsruhe Institute of Technology; Kaiserstr. 12 Karlsruhe 76131 Germany