1. Periglacial Research Section; Alfred Wegener Institute Helmholtz Centre for Polar and Marine Research; Potsdam 14473 Germany
2. Institute of Earth and Environmental Science; University of Potsdam; Potsdam 14476 Germany
3. Institute of Natural Sciences; North-Eastern Federal University of Yakutsk; Yakutsk 677000 Russia
4. Melnikov Institute of Permafrost SB RAS; Yakutsk 677000 Russia
5. GFZ German Research Centre for Geosciences; Telegrafenberg Potsdam 14473 Germany
6. Department of Plant Ecology and Nature Conservation; Institute of Biochemistry and Biology; University of Potsdam; Potsdam 14467 Germany
7. Berlin-Brandenburg Institute of Advanced Biodiversity Research (BBIB); Berlin D-14195 Germany
8. ZALF; Leibniz-Centre for Agricultural Landscape Research; Eberswalder Str. 84 Müncheberg D-15374 Germany