1. Department of Earth Sciences, Physical Geography; Freie Universität Berlin; Malteserstraβe 74-100, Haus H 12249 Berlin Germany
2. Department of Agronomy and Land Management; University of Florence; Piazzale delle Cascine 14 I-50144 Florence Italy
3. Heidelberg Academy of Sciences and Humanities; ROCEEH; c/o University of Tübingen, Rümelinstr. 19-23 72070 Tübingen Germany