Potential acidification of soil and soil water: a monitoring study in the Janow Forest, southeastern Poland

Abstract A field study was established in the Janow National Forest south of Lublin to study the impact of acidic precipitation and dry deposition on soil and soil water in Poland. The sulphur deposition (about 2.7 g S m −2 yr −1 ) at the site is typical for large areas in Europe, but considerably less than in the most affected regions. Concentrations of all major ions have been determined in precipitation, throughfall, soil- and groundwater; in addition soils have been analysed. The soils are acidic with pH less than 4 in the upper layers and with aluminium saturation (AIS) above 80% in the illuvial (Bhs) horizon. The soil- and groundwater are quite acid; in groundwater pH is about 4.3, with concentrations of inorganic monomeric aluminium (Al i )5–6 mg/l. Deposition of basic components seems to mitigate effects of acid deposition.