This work is licensed under the Creative Commons Attribution-NonCommercial-NoDerivatives 3.0 License.
Michał Brach
Warsaw University of Life Sciences, Faculty of Forestry, Department of Forest Management Planning, Geomatics and Forest Economics, Nowoursynowska 159, 02-776 Warsaw, Poland
Dariusz Górski
Regional Directorate for Environmental Protection in Bydgoszcz, Dworcowa 63, 85-950 Bydgoszcz, Poland