1. Faculty of Biology and Environmental Protection, Nicolaus Copernicus Univ. in Toruń, Lwowska 1; PL-87-100 Toruń Poland
2. Faculty of Mathematics and Informatics, Nicolaus Copernicus Univ. in Toruń; Toruń Poland
3. Dept of Soil Science and Landscape Management; Nicolaus Copernicus Univ.; Toruń Poland
4. European Commission Joint Research Centre, Inst. for Environment and Sustainability; Ispra Italy
5. Dept of Biology; Univ. of Vermont; Burlington VT USA