1Department of Forest Protection and Ecology, Warsaw University of Life Sciences (SGGW),
Nowoursynowska 159, 02-776 Warsaw, Poland
2Institute for Agricultural and Forest Environment, Polish Academy of Sciences,
Field Station, Turew, Szkolna 4, 64-000 Kościan, Poland
Pol. J. Environ. Stud. 2012;21(6):1791–1795