1. Institute for Agricultural and Forest Environment, Polish Academy of Sciences, Bukowska 19, 60–809 Poznań, POLAND
2. Institute of Nature Conservation, Polish Academy of Sciences, Al. A. Mickiewicza 33, 31–120 Kraków, POLAND
3. Institute of Environmental Biology, University of Wrocław, Kanonia 6/8, 50–328 Wrocław, POLAND