1 Nature Conservation and Landscape Ecology, University of Freiburg, Freiburg im Breisgau, Germany; Senckenberg Biodiversity and Climate Research Centre, Frankfurt am Main, Germany. Electronic address: anne-christine.mupepele@biom.uni-freiburg.de.
2 Biometry and Environmental System Analysis, University of Freiburg, Freiburg im Breisgau, Germany.