1. University of Kassel, Department of Ecological Chemistry and Ecotoxicology, Nordbahnhofstr. 1a, D-37213 Witzenhausen, Germany
2. University of Giessen, Department of Agricultural Ecology and Natural Resources Management, Senckenbergstr. 3, D-35290 Giessen, Germany
3. University of Dortmund, Institute of Environmental Research, Otto-Hahn-Str. 6, D-44221 Dortmund, Germany