1. Geographical Institute “Jovan Cvijić”, Serbian Academy of Sciences and Arts, Djure Jakšića 9, 11000 Belgrade, Serbia
2. Department of Geography, Faculty of Sciences and Mathematics, University of Niš, Višegradska 33, 18000 Niš, Serbia
3. Faculty of Biology, University of Belgrade, Studentski Trg 16, 11000 Belgrade, Serbia