Jakość wód gruntowych i powierzchniowych dwóch wybranych zlewni leśnych

The paper presents the investigation results of the influence of pine and spruce stand on the quality of groundwater and streamwater in forest ecosystems. The investigations were conducted in the Augustowska Primeval Forest (north-eastern Poland) in two catchments in the years 1998-2000, according to the monitoring methodology of the environment. The Augustowska Primeval Forest represents the region of the least deposit of atmospheric pollution in Poland. Groundwater and streamwater levels were measured in month intervals (fig. 1). Samples of waters to chemical analysis were taken once a month. The analysis contained measurement of: pH, electrolytic conductivity and the content of calcium, magnesium, potassium, sodium, aluminium, iron, manganese and ions of sulphate, chloride, ammonium, nitrate or phosphorus. In the years 1998-2000 the pH of water was alkaline in both of stands in groundwater and streamwater. The share of cations in the total sum of ions was the biggest in streamwater in the pine stand (fig. 2). But the share of anions in the total sum of ions was the biggest in groundwater in the spruce stand (fig. 3). The results showed that: 1. The participation SO42- in sum of ions in studied waters (except water in Święty Jan stream) amounted to almost 20%. This showed that acidification in two forest catchments was already initiated although the pH is still alkaline. 2. The participation SO42- in sum of ions in Święty Jan stream amounted to 5%. This showed that deposit of SO42- has only little importance in mould of chemical composition of this stream. 3. The comparison of chemical composition of soilwaters, groundwaters and streamwaters showed that acidification process is more intensive in the spruce forest than in the pine forest.