Sciences Recovery of acidified Finnish lakes: trends, patterns and dependence of catchment characteristics

• Main Authors: Hydrology, J. Vuorenmaa, M. Forsius
• Other Authors: The Pennsylvania State University CiteSeerX Archives
• Format: Text
• Language: English
• Published: 2008
• Subjects: North Finland
• Online Access: http://citeseerx.ist.psu.edu/viewdoc/summary?doi=10.1.1.371.7099; http://hal.archives-ouvertes.fr/docs/00/30/51/49/PDF/hess-12-465-2008.pdf

Abstract. The regional-scale trends (south, central and north Finland) in key acidification parameters over the period 1990–2003 were studied in lakes used for monitoring of acidification (157 lakes), and the catchment characteristics that best discriminate between lakes showing recovery (significant increase in alkalinity) and those not showing recovery (no significant increase) were determined. A significant decline in sulphate concentrations occurred in 82–98% of the lakes, depending of the region. Base cation (BC) concentrations decreased for most lakes, but to a lesser extent than those of SO4. Consequently, a significant increase in Gran alkalinity occurred in 40–92 % of the lakes. The recovery from acidification has been strongest in lakes in south Finland, where both levels and decrease of S (and N) deposition have been higher compared to other regions. A significant