1. Department of Botany and Zoology; Masaryk University; Kotlářská 2 CZ-61137 Brno Czech Republic
2. Department of Biological; Geological & Environmental Sciences; University of Bologna; I-40126 Bologna Italy
3. Department of Ecology; Federal University of Rio Grande do Sul; Porto Alegre RS 91540-000 Brazil
4. Institute of Ecology and Earth Sciences; University of Tartu; 40 Lai St. Tartu EE-51005 Estonia