1. Department of Geography; University of Bonn; Bonn Germany
2. Institute of Geoecology and Geoinformation; Adam Mickiewicz University; Poznan Poland
3. Department of Biological Sciences; Ecosystem and Biomedical Lab; University of Alaska Anchorage; Anchorage AK USA
4. Department of Physical Geography and Ecosystem Science; Lund University; Lund Sweden
5. Center for Permafrost (CENPERM); Department of Geosciences and Natural Resource Management; University of Copenhagen; Copenhagen Denmark