1. Freshwater Centre Finnish Environment Institute Latokartanonkaari 11 FI‐00790 Helsinki Finland
2. Geography Research Unit University of Oulu P.O. Box 3000 FI‐90014 Oulu Finland
3. Departamento de Ecologia Universidade Federal de Goiás Goiânia GO 74690‐900 Brazil
4. Key Laboratory of Watershed Geographic Sciences, Nanjing Institute of Geography and Limnology Chinese Academy of Sciences 73 East Beijing Road 210008 Nanjing China
5. Biodiversity Centre Finnish Environment Institute Latokartanonkaari 11 FI‐00790 Helsinki Finland
6. Department of Biological and Environmental Sciences University of Jyväskylä P.O. Box 35 FI‐40014 Jyväskylä Finland
7. Department of Aquatic Sciences and Assessment Swedish University of Agricultural Sciences Box 7050 750 07 Uppsala Sweden
8. School of Natural Resources University of Nebraska–Lincoln Lincoln NE 68583‐0984 U.S.A.