Recovery pattern from acidification of headwater Lakes in Finland

摘要

Acid sensitive headwater lakes (n=163) throughout Finland have been monitored during autumn overturn between 1987-1998. Statistically significant decline in sulphate concentration is detected in 60 to 80 percent of the lakes, depending on the region. Median slope estimates are from -1.1 μeq L~-1 in North Finland to -3.3 μeq L~-1 in South Finland. The base cation (BC) concentrations are still declining especially in southern Finland (slope -2.5μeq L~-1), where every second lake exhibits a significant downward trend.