Norwegian Journal of Agricultural Sciences : lake acidification - a complex phenomenon elucidated by studies of fifteen lakes in Finnemarka, Southem Norway

Abstract

One neutral and 14 acid lakes have been investigated during 1970-82. Some reference lakes, not discernibly acid, have also been roughly studied, especially with respect to the sediments. The main lakes are typical soft-water lakes lying in an area underlain by granitic rocks with very shallow overburden, i.e. a so-called sensitive area with poor neutralizing capacity of the lakes and their catchments. The area has previously been used for animal grazing and associated activities which today have come to an end, as evidenced by the development of the vegetation in the catchments. Heathers, mosses and trees have invaded at the expense of grass species, especially in the vicinity of abandoned mountain farms. The lakes have shown varying morphometry, e.g. with land/water area ratios from 1.4 to 22.9, lake surface area from 1075 to 314000 m2 and maximum lake depth from 2.0 to 34.0 m.