Changes within the geoecosystem of a small lake catchment in the last three decades versus changes in land use and precipitation quality (Radomyskie Lake, upper Parsęta catchment)

Abstract

There are numerous ( though spread unevenly ) small run-off-free bodies of water in the Parseta basin as well as in the upper Parseta catchment. The geoecosystems of these non-run-off bodies serve various functions in the geographic environment ; they are particularly important in terms of shaping catchment retention and water circulation. They quickly react to environmental conditions, especially to changes in land use and land cover in the catchment and the supply of pollutants in waters. Radomyskie Lake is a small body of water in the upper Parseta catchment within which radical changes in land use and changes in the chemistry of the lake waters have taken place over the last 30 years. The concentration of ion components in the lake waters has become significantly reduced compared with that in the early 1980s. A comparison with Czarne Lake – a similar body of water in the upper Parseta catchment revealed that these ongoing changes have two causes : afforestation of agriculturally cultivated catchment areas around Radomyskie Lake and consequently reduced supply of fertilizer as well as a drop in precipitation mineral content, which had been noted by researchers for 20 years. Radomyskie Lake is experiencing the stage of re-naturalization and its evolution is moving towards a peat-bog geoecosystem.