Botanical Institute of the University of Cologne, Gyrhofstr. 15, 50931 Cologne, GERMANY Geographic Inistitute of the University of Bonn , Meckenheimer Allee, 53115 Bonn, GERMANY Geographic Institute of the University of Cologne, Otto-Fischer-Str. 4, 50674 Cologne, GERMANY Geological Institute of the University of Bonn, Nussallee 8, 53115 Bonn, GERMANY  Institute for Food and Resource Economics of the University of Bonn, Nussallee 21, 53115 Bonn, GERMANY Institute for Geophysics und Meteorology of the University of Cologne, Kerpener Str. 13, 50923 Cologne, GERMANY Institute for Medical Microbiology and Hygiene of the University of Cologne, Goldenfelsstr. 21, 50935 Cologne, GERMANY Institute for Agronomy und Crop Science of the University of Bonn, Auf dem Hügel 6, 53121 Bonn, GERMANY Department of Plant Nutrition of the University of Bonn, Karlrobert-Kreiten-Str. 13, 53115 Bonn, GERMANY   Institute for Virology of the University of Cologne, Fürst-Pückler-Str. 56, 50935 Cologne, GERMANY Institute for Ethnology of the University of Cologne, Albertus-Magnus-Str., 50923 Cologne, GERMANY Meteorological Institute of the University of Bonn, Auf dem Hügel 20, 53121 Bonn, GERMANY