Impacts of ski resorts on water quality of boreal lakes : a case study in northern Finland

1) Oulanka Research Station and Thule Institute, Liikasenvaarantie 134, FI-93999 Kuusamo, Finland 2) Finnish Environment Institute, P.O. Box 35, FI-40014 University of Jyvaskyla, Finland 3) Department of Geography, P.O. Box 3000, FI-90014 University of Oulu, Finland 4) Metsahallitus Natural Heritage Services, Torangintaival 2, FI-93600 Kuusamo, Finland 5) current address: Finnish Forest Research Institute, P.O. Box 413, FI-90014 University of Oulu, Finland (*corresponding author’s e-mail: katja.kangas@metla.fi)