1. Department of Geobotany and Plant Ecology, University of Lodz, Lodz, Poland
2. Institute of Marine and Environmental Sciences, University of Szczecin, Szczecin, Poland
3. Białowieża Geobotanical Station, Faculty of Biology, University of Warsaw, Białowieża, Poland
4. Department of Environmental Management, West Pomeranian University of Technology, Szczecin, Poland