1 Institute of Soil Science and Land Evaluation, Univ. of Hohenheim, Emil-Wolff-Strasse 27, 70599 Stuttgart, Germany 2 Ludwig-Maximilians Univ., Dept. of Geography, Luisenstr. 37, 80333 Munich, Germany 3 Max-Planck-Institute for Biogeochemistry, Postfach 100164, 07701 Jena, Germany 4 Vegetation Ecology, Techn. Univ. of Munich, Am Hochanger 6, 85350 Freising, Germany 5 Helmholtz Center Munich, G...