The concentrations of Cu, Mn, Ni and Zn in the soil and litterfall, as well as influx of the elements to the soils with litterfall were studied in a mixed beech-pine-spruce stand in northern Poland during the years 2007–2009. Annual influx of litterfall to the soil amounted from 3.234 to 4.871 t/ha. Beech, pine and spruce litterfall contributed in total litterfall in 50.8−70.1%, 11.4−11.9% and 1.6−24.0% respectively. The following average annual concentrations of heavy metals in total litterfall during the 3-year study period were noticed: 2469.3–3469.2 mg Mn/kg, 153.6–160.8 mg/kg Zn, 8.0–14.3 mg Ni/kg and 5.0–6.8 mg Cu/kg. In general, the concentrations of Mn and Cu were higher in beech litterfall in comparison to pine and spruce. The contents of Zn and Ni in beech, pine and spruce litterfall were comparable. Annual influx of metals to the soil with litterfall was: 10341.6–14422.4 g/ha Mn, 460.3–748.1 g/ha Zn, 37.4–66.6 g/ha Ni and 20.2–31.8 g/ha Cu. The fluxes were higher for Mn, Zn and Ni, and comparable for Cu in relation to those observed in other beech, pine, spruce and mixed stands in northern Europe.

The oxygen and thermal conditions in Lake Ińsko were examined in years 1999-2000. Lake Ińsko is one of a dynamictic type and its waters are mixed twice a year. This lake has a strong thermal and oxygen stratification. The oxygen conditions in the lake are very good because the total deficiency of oxygen appears only in summer, on the depth below 30 m, and only in the areas where the influence of town of Ińsko is the strongest. During autumn and winter circulation the concentration of oxygen near the bottom reaches 5 mg O2 dm-3. The concentration of oxygen in the water reflects favorable conditions of biomass production, including primary production of phytoplankton in epilimnion of Lake Ińsko. The intensive development of algas has considerably influenced the transparency of water. On the background of vertical thermal and oxygen differences during the summer there were also differences in the reactions of water.

The paper presents the results of study on heavy metals in needles of Pinus sylvestris in selected pine forests in Słowiński National Park. It was evidenced that heavy metal contents (Zn, Cu, Mn and Fe) in needles of Pinus sylvestris varied depending on the metal, the age of the needles and the humidity of a forest complex. Variation coefficients of such metals remained at the level of: 13-30% (Zn), 3-6% (Cu), 13-34% (Mn) and 12-30% (Fe) depending on the age of the needles. In the case of Zn, Mn and Fe higher concentrations of researched metal were found in the 2-year-old needles than in 1 year old needles, and in the case of Cu in 1 year old needles than in 2-year-old needles. The increase of zinc concentration found in 1-year-old needles after rainfall sums was (Bw, r = 0.67, p < 0.05, n = 24) and (Bśw, r = 0.39, p < 0.05, n = 24) in 2-year-old needles. The content of the above mentioned metals in needles of dry coniferous forests (Bs), fresh coniferous forests (Bśw) and humid coniferous forests (Bw) of the ground cover constitute the following decreasing series: Mn(323.8) > Fe(103.4) > Zn(65.5) > Cu(5.9).

This paper presents the results of study on heavy metals in soil and in herbaceous plants in selected pine forests in Słowiński National Park. The heavy metals, such as Zn, Cu, Mn and Fe were studied. Concentrations of zinc in tested soil are strongly and very strongly related to manganese and copper content (r = 0.57 do r = 0.98, p < 0.05). Moreover, the soil moistening has vital impact on copper content in the plants of the ground cover. It was also found that moss in comparison to other forest plants captures higher volume of zinc and copper. The content of the above mentioned metals in the plants of dry coniferous forests (Bs), fresh coniferous forests (Bśw) and humid coniferous forests (Bw) of the ground cover constitute the following decreasing series: Mn(438.1) > Fe(98.6) > Zn(35.2) > Cu(3.5).