1. Grup de recerca FEHM (Freshwater Ecology, Hydrology and Management), Departament de Biologia Evolutiva, Ecologia i Ciència Ambientals, Universitat de Barcelona, Avda Diagonal 643, 08028 Barcelona, Spain
2. Institute for Applied Ecology, University of Canberra, Australian Capital Territory 2601, Australia
3. Department of Quantitative Landscape Ecology, University Koblenz-Landau, Fortstr. 7, 76829 Landau, Germany