1. Department of Aquatic Ecology, Eawag; Swiss Federal Institute of Aquatic Science and Technology; CH-8600 Dübendorf Switzerland
2. Institute of Integrative Biology; ETH Zurich; 8092 Zurich Switzerland
3. Department of Systematic and Evolutionary Botany; University of Zurich; 8008 Zürich Switzerland
4. Department of Ecosystem Research; Leibniz-Institute of Freshwater Ecology and Inland Fisheries; Müggelseedamm 301 12587 Berlin Germany
5. Department of Biology, Chemistry, and Pharmacy; Institute of Biology; Freie Universität Berlin, Königin-Luise-Strasse 1-3 14195 Berlin Germany