1. Landscape Ecology and Environmental Systems Analysis; Institute of Geoecology; Technische Universität Braunschweig; Langer Kamp 19c D-38106 Braunschweig Germany
2. Institute of Earth and Environmental Science; University of Potsdam; Karl-Liebknecht-Strasse 24-25 D-14476 Potsdam-Golm Germany
3. Plant Ecology and Nature Conservation; University of Potsdam; Am Mühlenberg 3 D-14476 Potsdam-Golm Germany
4. Landscape Ecology Group; University of Oldenburg; D-26111 Oldenburg Germany
5. Berlin-Brandenburg Institute of Advanced Biodiversity Research BBIB; Altensteinstrasse 6 D-14195 Berlin Germany