Volume 16 (2016): Issue 3 (September 2016)

Analyses were conducted concerning the accumulation of four metals representing the group of macroelements, i.e. sodium, potassium, calcium and magnesium in two ponds located in the city of Słupsk. Water samples for chemical analyses were collected from the surface microlayer using a Garrett net. At the same time subsurface water samples were collected. Concentrations of metals were determined using a mass spectrometer. Generally, amounts of sodium, potassium, calcium and magnesium were similar in surface microlayer and subsurface water. Only in the case of potassium and calcium was low enrichment observed in the surface microlayer in one pond, while the greatest extent for magnesium enrichment was observed in the spring period.

The study relates to the use of the ²¹⁰Pb method for determining sedimentation rates, sedimentation accumulation rates and identifying post-depositional processes. The analysis was based on seven cores of recent sediments collected from different parts of Lake Raduńskie Górne, which is a typical channel lake with diverse bottom morphology. We used alpha spectrometry to determine ²¹⁰Pb activities in sediment samples and a CF:CS dating model to obtain mean sediment accumulation rates. The results show significant differences between coring sites with highest values in the deepest part of the lake and lowest within the shallow and flat bottom areas. The reason for such a large diversity is the lake basin morphology, e.g. steep slopes and complex configuration of the lake bottom, most probably responsible for the post-depositional sediment replacements.

The article presents the results of experimental research on evapotranspiration and transpiration of a common reed bed. The study was conducted in 2014–2015 on Lake Raduńskie Górne (Kashubian Lakeland) in the summer half-year from 1 May to 31 October. In the experiment two sets of standard evaporimeters GGI-3000 were used. One of the evaporimeters was filled with water, while the second additionally contained common reed. During the experiment medium reed bed density was 240 shoots per square metre. The results of the study showed that during the research period the average daily common reed transpiration was 3.9 mm, and the daily maxima reached 12.1–12.5 mm. Average monthly transpiration totals ranged from 42.8 (October) to 208.5 mm (August). During the growing season, the loss of water to transpiration reached 872–971 mm. The average transpiration rate, determined in the conditions of already well developed reed bed (June-September), was 1.83 dm³ m⁻² d⁻¹. The values of the ratios T_h/E_O and ET_h/E_O, determined during the experiment, were within the ranges reported in most previous research. The average ratio T_h/E_O was 1.6, and the ratio ET_h/E_O was 2.0. These values indicate that during the vegetation period common reed transpiration is higher by 60% from open water evaporation, and the total water losses from the common reed bed to evapotranspiration are twice as high as water loss in open water evaporation.

The main objective of this study was to characterize the muddy bottom sediments of three hydrologically different old river beds of the lower Vistula, located in the vicinity of Toruń: Port Drzewny, Martwa Wisła and Przybysz. Samples were taken at monthly intervals from April to November 2015 from two (Martwa Wisła and Przybysz) or three sampling sites (Port Drzewny) located in the central parts of the reservoirs. The bottom sediments of these water bodies were characterized by a low water content and organic matter content expressed as a percentage of dry weight, high organic matter content expressed in units of weight, as well as a high sediment oxygen demand. The most distinct reservoir was Martwa Wisła, most likely due to the lack of a connection with the River Vistula.

Lakes along with their surroundings are an attractive landscape component that play an important role in recreation and relaxation. In Poland, the Great Masurian Lakeland, visited by a million tourists every year, is considered to be the most attractive lake area. However, tourist pressure has several negative effects which cause degradation of the water environment. The aim of this study was to determine the trophic state of Lake Mikołajskie which is a hub for sailing and motorboating traffic. Values of the trophic status index were calculated from the content of total phosphorus, chlorophyll a and Secchi disc visibility, according to the data from the Voivodeship Inspectorate for Environmental Protection. In summer, the concentration of total phosphorus was 0.019–0.042 mg dm⁻³ in 2013 and 0.022–0.055 mg dm⁻³ in 2014. The concentration of chlorophyll a was in the range of 8.3–45.0 μg dm⁻³ in 2013 and 8.9–22.0 μg dm⁻³ in 2014. The maximum visibility of Secchi disc reached 2.0 m (2013) and 1.8 m (2014). Based on the calculated, Lake Mikołajskie can be classified as a eutrophic lake. In order to protect lakes from degradation tourists should be educated about the rational use of surface waters and the surrounding catchment. However, it is not only the massive influx of tourists, but also the activity of residents (dictated by economic reasons) that contribute to the pollution of lakes. Therefore, the development of tourism and the economy of the whole region should be harmonious and balanced so that the natural resources can serve us and future generations for as long as possible.

The aim of this study is to reconstitute the changes in the local water cycle and plant habitats occurring in wetlands under anthropic influence. The selected area for the study in this paper is the swamp of Pobłockie Peatbog, located in the catchment area of the river Łeba in northern Poland. The fieldwork was performed in October of 2013. Using ArcMap the hydrographic network of the study area in the years 1837, 1918, 1936, 1976 and 2000 were digitized and represented. Using a LIDAR image, the terrain model for the swamp of Pobłockie Peatbog was generated in ArcMap. This was then used to create a map showing the location of runoff pathways from the waterlogged areas. Long-term drainage and the construction of new drainage ditches have led to the encroachment of bog woodland on the originally treeless swamp of Pobłockie Peatbog.

Due to its inaccessibility (in winter), Lake Czarny Staw pod Rysami (Black Lake below Mount Rysy) has no series of continuous observations concerning ice phenomena. For the purpose of supplementing knowledge in this scope, ice corings were performed in the years 2010–2015. They permitted the determination of the variability of ice cover thickness on the lake’s surface. A high degree of similarity was determined in the distribution of ice cover thickness in the analysed winters (in contrast to the nearby Lake Morskie Oko). Moreover, a correlation was determined according to which the thicker the snow cover overlying the ice, the thinner the ice cover. It was determined that the mean thickness of the ice cover of Lake Czarny Staw pod Rysami is higher by approximately a dozen cm than that on Lake Morskie Oko located around 200 m lower.