1. Centre for Ecology and Hydrology; Bangor; LL57 2UP; UK
2. Areal COV Horovice; Horovice; 268 01; Czech Republic
3. Department of Applied Environmental Science; Stockholm University; Stockholm; 106 91; Sweden
4. Department of Ecosystem Biology; University of South Bohemia; Branisovska 31; Ceske Budejovice; 370 05; Czech Republic
5. Department of Ecology; Section of Soil Ecology; Swedish University of Agricultural Sciences; Box 7044; Uppsala; 750 07; Sweden
6. Institute of Systems Biology and Ecology; Academy of Sciences of the Czech Republic; Na Sadkach 7; Ceske Budejovice; 370 05; Czech Republic
7. Department of Environmental Geochemistry and Biogeochemistry, Czech Geological Survey; Klarov 3; Prague; 118 21; Czech Republic