There are numerous ( though spread unevenly ) small run-off-free bodies of water in the Parsęta basin as well as in the upper Parsęta 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 Parsęta 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 Parsęta 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.

The paper seeks to present the exceptional qualities of closed basins commonly found in areas covered by the last Pleistocene glaciation. Such basins are a natural part of the landscape ; they occupy a large percentage of the area. The research was conducted in the Parsęta catchment over the course of several years. Two basic types of basins without outlets were analyzed absorptive basins : absorption basins, evapotranspiration basins. The geographic individuality of small landforms with no surface runoff was characterized on the basis of key morphometric indicators, lithology, soil distribution, and physical-chemical properties of surface and groundwaters. Closed basins are usually small concave landforms, roughly circular in shape, at the bottom of which organic sediments attain a great thickness. In the southern part of the Parsęta catchment, permeable sediments predominate, while those located in its middle part are predominantly retentive in nature. Typical features of the spatial distribution of soils in the small catchments of closed depressions are their ring-like pattern going down towards the bottom and a predominance of organic soils in the bottom. Surface and groundwaters in these catchments display a low and a medium level of mineralization, and the elements dominating in their chemical composition are those coming from the leaching of rocks, the chief source of which is chemical weathering, as well as biogenic components connected with the deposition of organic sediments in the bottoms.

The presented results constitute a summary of a five-year study conducted from 2009 to 2013 in the upper catchment of the Lewińska Struga stream. Weekly research on the physical and chemical properties of Lewińska Struga waters at the Domysłów profile was combined with seasonal hydrochemical studies conducted in the following five flow-through lakes : Warnowo, Rabiąż, Czajcze, Domysłowskie and Żółwińskie. Across young glacial areas of the Polish Lowland, a drainage network is often produced by a fluvial-lacustrine system, in which a river links subsequent lakes via short sections. In such cases, this fluvial transport of solutes is sometimes disturbed in lakes, which are both their source and deposition area. The main research strategy of the paper was aimed at determining the functioning of the fluvial-lacustrine system of Lewińska Struga stream on Wolin Island. This paper also discusses the dynamics of fluvial transport of solutes carried with Lewińska Struga waters.

Detailed research studies on the physical and chemical properties of waters were conducted within the Żarnowo channel head in West Pomerania. Samples were collected at regular measuring sites, which represent groundwater of the footslope zone, interstitial waters and rivulets. In order to identify the origin of ionic components in channel headwaters, the collected hydrochemical data were subjected to factor analysis using the principal component method. The main factors shaping the chemistry of waters : geogenic, anthropogenic, biogenic, and redox were identified. The study was designed to identify the determinants of the water chemistry of 1st-order streams.

The Gardno Lake catchment on Wolin Island is located within the Wolin Range micro-region. Its coastal location and early glacial terrain within the temperate climate zone are the distinguishing features of this catchment. The catchment is non-run-off in character, and its area is dominated by beech forests and affected by a small degree of human impact. In the Gardno Lake catchment, atmospheric precipitation undergoes both physical and chemical conversion during its permeation in the beech forest zone, and then during infiltration through the slope cover, percolation to aquifers and subsequent drainage down towards the lake. A pattern of increased mineral content and higher pH at subsequent stages of water circulation were also identified. In the period 2010 – 2014, on a monthly basis, waters at the atmospheric stage ( precipitation, throughfall, stemflow ), transitional stage ( throughflow ), and lithospheric stage ( groundwaters, lake waters ) were examined in the Gardno  Lake catchment. The research study described herein allowed to determine changes in water physical and chemical characteristics at individual stages of its cycle and discrete solute loads reaching the studied catchment area. The annual variability of water mineral content circulating in the Gardno Lake geoecosystem – presented in the paper – was calculated via the total concentration of biogenic ions (NO 3 – , NH 4 + , K +), denudation-originated ions ( SO4 2– , Ca 2+, Mg 2+), and ions resulting from a large supply of marine aerosols ( Cl –– Na + ).

The research sought to determine the range of conversion of the chemical composition of precipitation in a beech stand located in the Gardno Lake catchment ( Wolin Island ) and a pine stand in the Czarne Lake catchment ( Upper Parsęta catchment, West Pomerania Province ). The presented results cover three hydrological years : 2012, 2013 and 2014. The research focused on the chemical composition of bulk precipitation ( in the open ), throughfall and stemflow ( in a forest ). The obtained results confirm that after precipitation has had contact with plant surfaces there is an increase in its mineral content. This is due to the process of enrichment of throughfall and stemflow with elements leached out of needles and leaves ( K +, Mg 2+ ) and coming from dry deposition ( NH 4 +, Cl –, Na +, Mg 2+, SO 4 2– , NO 3 – ) washed out from plant surfaces. The research, based on the canopy budget model, indicates that in the case of potassium, its load leached out of needles and leaves accounted for 75.6 % and 73 %, respectively, of its total deposition on the forest floor. Calcium leaching was not detected in either of the two stands. In comparison with potassium, the range of magnesium leaching was smaller and amounted to 34 % under beech and 26.5 % under pine. As to loads of potassium and magnesium in the beech stand, they were more than twice as large as the ones observed in the pine stand. In spite of the fact that coniferous trees capture aerosols present in the air much more effectively, a higher mineral content was recorded in the beech stand. It applies primarily to ions of marine origin ( Cl –, SO 4
2– , Na +, Mg 2+ ). It was only when ammonium ions originated from agriculture that their higher concentrations and loads were found in the pine stand.