1. Institute of Geography and Geoecology; Karlsruhe Institute of Technology; Karlsruhe 76131 Germany
2. Chair of Landslide Research; Technische Universität München; München 80333 Germany
3. Institute of Crop Science and Resource Conservation, Soil Science and Soil Ecology; University of Bonn; Bonn 53115 Germany
4. Department of Forest Sciences; University of Helsinki; Helsinki 00100 Finland