1. a ZALF , Institute of Microbial Ecology and Soil Biology , Müncheberg, 15374 Phone: Fax: E-mail:
2. b Institute of Soil Landscape Research
3. c Institute of Land Use Systems and Landscape Ecology
4. d Research Station Eberswalde , a — d ZALF Centre for Agricultural Landscape and Land Use Research , Eberswalder Str. 84, Müncheberg, D‐15374
5. e Federal Research Centre of Agriculture (FAL) , Institute of Production Engineering , Bundesallee 50, Braunschweig, D‐38116, Germany