1. Institute of Geological Sciences, University of Wrocław, Wrocław, Poland;
2. Faculty of Earth Sciences, University of Silesia, Sosnowiec, Poland;
3. Poltegor-Institute, Institute of Opencast Mining, Wrocław, Poland;
4. Department of Forest Protection, Forest Research Institute, Raszyn, Poland;
5. Faculty of Agriculture and Biology, Warsaw University of Life Sciences, Warszawa, Poland