1. Department of Environmental Systems Science, ETH Zurich, Weinbergstr. 56/58, CH-8092 Zurich, Switzerland
2. Institute of Ecology and Landscape, University of Applied Sciences Weihenstephan-Triesdorf, Hans-Carl-von-Carlowitz-Platz 3, D-85354 Freising, Germany
3. Department of Soil and Climate, Bavarian State Institute of Forestry, Hans-Carl-von-Carlowitz-Platz 1, D-85354 Freising, Germany