1. University of Fribourg, Department of Biology, Unit of Ecology and Evolution, Chemin du musée 10, CH‐1700 Fribourg, Switzerland;
2. University of South Bohemia, Faculty of Science, Department of Botany, Branišovská 31 CZ‐37005 České Budějovice, Czech Republic;
3. University of Reading, Centre for Agri‐Environmental Research, Earley Gate, PO Box 237, Reading RG6 6AR, UK;
4. Institute of Botany CAS CZ, Dukelská 135, 379 01 Třeboň, Czech Republic;
5. Laboratory of Biogeography and Ecology, University of the Aegean, Department of Geography, University Hill, GR‐81100 Mytilene, Greece;
6. Netherlands Institute of Ecology (NIOO‐KNAW), PO Box 40, 6666 ZG Heteren, the Netherlands