1. Department of Ecology and Evolution; Plant Ecology Group; University of Tübingen; 72076 Tübingen Germany
2. Mitrani Department of Desert Ecology; Swiss Institute for Dryland Environmental and Energy Research; Jacob Blaustein Institutes for Desert Research; Ben-Gurion University of the Negev; 84900 Midreshet Ben-Gurion Israel
3. Department of Molecular Biology and Ecology of Plants; Faculty of Life Sciences; Tel Aviv University; Tel Aviv 69978 Israel