Speciation of trace elements in the sediment of a meromictic Piaseczno Lake (inundated opencast sulphur mine, southern Poland) with permanently anoxic monimolimnion was studied. A 6-step sequential extraction procedure was applied to determine operationally defined phases: exchangeable (FI), carbonate (F2). easily reducible (F3), moderately reducible (F4), organic/sulphides (FS). and residual (F6) in the sediment. The differences in trace elements (except Mn) speciation in the littoral sediment with the respect of lake depths were not found Considerable difference in the trace elements speciation between the littoral sediment and permanently anoxic profundal one was found.

Climate change, manifested by long term periods of drought to heavy rainfall, may remarkably modify river flow regimes. We hypothesize that flow prevailing in a given year determines water chemistry of the Carpathian Raba River above and below Dobczyce Reservoir (southern Poland), used for drinking purposes. Based on the mean annual river flow for years 1991‒2017, hydrologically dry (HD), hydrologically average (HA)and hydrologically wet (HW) years were distinguished. We found significant differences in the values of most studied physicochemical parameters of river water above and below the reservoir between studied hydrological years (for a period of April‒November). In HD years, the water above the dam had significantly higher temperature and values of conductivity (point pollution source, groundwater inflow), while lower ones of nutrients NO3- and P-tot (diffuse pollution) compared to those in HA and/or HW years. The best GLM models for mean monthly flows above and below the dam include 3‒5 factors among which conductivity and NO3- concentration were always present. The reservoir in different ways influences the water chemistry below the dam in HD, HA and HWyears. The impact of flow on the water quality in hydrologically varied years is discussed. The obtained results are important for appropriate management in catchment basins of mountain rivers and the protection of dam reservoirs against the eutrophication processes in changing climate and flow regime.

Physicochemical parameters of water and phytoplankton composition were studied in the dirnictic, submountain Dobczyce Reservoir (southern Poland) affected by summer storrnflow, which took place in September 2007. During summer (except September) temperature, pH, dissolved oxygen, and carbonates showed vertical differentiation. Stormwater flow through the system had a destabilizing effect on summer stratification. It diluted the concentrations of salts (sulphate and chloride) and slightly increased the concentration of nutrients in the reservoir. In phytoplankton some changes in the dominant species among the Cyanobacteria group were noted.

Antarctica is perceived as one of the most pristine environments on Earth, though increasing human activities and global climate change raise concerns about preserving the continent’s environmental quality. Limited in distribution, soils are particularly vulnerable to disturbances and pollution, yet lack of baseline studies limits our abilities to recognize and monitor adverse effects of environmental change. To improve the understanding of natural geochemical variability of soils, a survey was conducted in the fellfield environments of Edmonson Point (Victoria Land). Soil samples were analyzed for six major (Fe, Ca, Mg, Na, K and Ti) and 24 trace elements (As, Ba, Be, Bi, Cd, Co, Cr, Cs, Cu, Ga, Li, Mn, Mo, Ni, Pb, Rb, Sn, Sr, Tl, U, V, Y, Zn and Zr). Relationships among element concentrations in the samples and local bedrock were analyzed to identify their origin and similarities in geochemical cycles. Element concentrations in the soils were highly variable but generally within the lowest values reported elsewhere in Antarctica. Though values of Cd, Mn, Ni and Zn were relatively high, they are consistent with those in the local soil-forming rocks indicating an origin from natural sources rather than anthropogenic contamination. Chemical composition of soils vs. rocks pointed to alkali basalts as the lithogenic source of the soil matrix, but also indicated considerable alteration of elemental composition in the soil. Considering local environmental settings, the soil elemental content was likely affected by marine-derived inputs and very active hydrological processes which enhanced leaching and removal of mobilized elements. Both of these processes may be of particular importance within the context of global climate change as the predicted increases in temperature, water availability and length of the summer season would favor mineral weathering and increase geochemical mobility of elements.