1. Department of Botany and Biodiversity Research, University of Vienna , Rennweg14, A -1030 Vienna , Austria
2. Instituto de Investigaciones en Biodiversidad y Medioambiente (INIBIOMA-CONICET-Universidad Nacional del Comahue), Quintral 1250, R8400FRF Bariloche , Río Negro , Argentina
3. Papanin Institute for Biology of Inland Waters, Russian Academy of Sciences , Borok, Yaroslavl Region, 152742 , Russia
4. Arctic Research Station, Institute of Plant and Animal Ecology, Urals Branch of Russian Academy of Sciences , Labytnangi, 629400 , Russia
5. WSL Swiss Federal Research Institute, Zürcherstrasse 111, CH-8903 Birmensdorf , Switzerland
6. Icelandic Institute of Natural History (Náttúrufræðistofnun Íslands), Borgir vid Nordurslod, 600 Akureyri , Iceland
7. Kharkevich Institute for Information Transmission Problems, Russian Academy of Sciences, Bolshoi Karetnyi Str. 19–1, 127051 , Moscow , Russia