1. Dep. of Soil Science, Faculty of Natural Sciences; Comenius Univ.; Mlynska dolina B-2 842 15 Bratislava Slovak Republic
2. Dep. of Geography; Univ. of Wales Swansea; Singleton Park Swansea SA2 8PP UK
3. CSIRO Land & Water; GPO Box 1666 Canberra ATC 2601 Australia
4. Institute of Chemistry, Slovak Academy of Sciences; Dubravska cesta 9 845 38 Bratislava Slovak Republic
5. Institute of Landscape Ecology, Slovak Academy of Sciences; Stefanikova 3 81499 Bratislava Slovak Republic
6. GEA- Grupo de Edafología Ambiental, Dep. of Agrochemistry and Environment; Univ. Miguel Hernández; Avda de la Universidad s/n E-03202 Elche Alicante Spain