The decline of tufa deposition in an alkaline fen ecosystem in East-Central Europe and its impact on biotic assemblages: Insights from monitoring and paleoecological data.

Protection and restoration of the CaCO3 depositing alkaline fens require an in-depth understanding of these unique and declining ecosystems. The present study investigates the development of the formerly heavy tufa depositing alkaline fen in East-Central Europe after CaCO3 precipitation markedly declined ca. 5400 cal yr BP. By combining palaeoecological and monitoring data, we aim to identify the limiting factors for tufa deposition and to recognise the vegetation and mollusc response to the change. Investigation of the current fen ecosystem included a botanical and malacological inventory and a monthly monitoring of the physicochemical properties of the groundwater emerging at the fen. It was also tested whether CaCO3 precipitates there. Transformations of the fen ecosystem since the mid-Holocene tufa decline were recognized by applying plant macrofossil and malacological analyses supplemented with organic matter and CaCO3 contents and the radiocarbon chronologies of the sediment cores. Although macroscopic tufa is currently not observed at the fen surface, the monitoring study revealed the microscopic calcite crystals at the glass slides during the spring and summer. A combination of cooling, gradual depletion of the Ca2+ pool, acidification of soils, and water table fluctuations was likely responsible for limiting tufa deposition in the mid-Holocene and maintaining this state during the late Holocene. Share of the calciphilous species' macrofossils (e.g. moss Tomentypnum nitens) declined following the sedimentary CaCO3 drop, whereas the contribution of species associated with high nutrient levels raised (e.g. Juncus articulatus). Inspection of the contemporary vegetation of the fen revealed that only Carex paniculata is associated with the calcium-rich substrate. The response of molluscs to the decline in tufa deposition remains unclear as mollusc shells did not preserve in CaCO3-depleted sediments, except for the youngest deposits. The present-day malacofauna consists of 21 species, including two rare and protected calciphilous species, namely Vertigo angustior and V. geyeri.

Causes of variations of trace and rare earth elements concentration in lakes bottom sediments in the Bory Tucholskie National Park, Poland.

The objective of this study was to analyse spatial variability of the trace elements (TEs) and rare earth elements (REEs) concentration in lake bottom sediments in Bory Tucholskie National Park (BTNP); Poland. The following research questions were posed: which factors have a fundamental impact on the concentration and spatial variability of elements in bottom sediments, which of the elements can be considered as indicators of natural processes and which are related to anthropogenic sources. The research material was sediments samples collected from 19 lakes. The concentrations of 24 TEs and 14 REEs were determined. The analyses were carried out using the inductively coupled plasma mass spectrometry (ICP-QQQ). Cluster analysis and principal component analysis were used to determine the spatial variability of the TEs and REEs concentrations, indicate the elements that are the indicators of natural processes and identify potential anthropogenic sources of pollution. The geochemical background value (GBV) calculations were made using 13 different statistical methods. However, the contamination of bottom sediments was evaluated by means of the index of geo-accumulation, the enrichment factor, the pollution load index, and the metal pollution index. The BTNP area is unique because of its isolation from the inflow of pollutants from anthropogenic sources and a very stable land use structure over the last 200 years. This study shows high variability of TE and REE concentrations in lake sediments. The values of geochemical indices suggest low pollution of lakes bottom sediments. It was found that TEs originated mainly from geogenic sources. However, the concentrations of Li, Ni, Sc, Se, Be, Se, Ag, Re, Tl, Cd, Sb and U may be related to the impact of point sources found mainly in the Ostrowite Lake. Almost all REEs concentrations were strongly correlated and their presence was linked to with geochemical processes. The elements allowing to identify natural processes and anthropogenic pollution sources were Cr, Co, Cu, Ag, Cd, Zn, Bi, Re, Ba, Al and Rb in TEs group and Nd, Gd, Yb, Lu, Eu, Dy and Ce in REEs group. The analysis shows high spatial variability of TE and REE concentrations in lake sediments. The values of geochemical indices point to low pollution of lakes sediments. The anthropogenic sources only for two lakes had an impact on concentrations of selected TEs and REEs. The analyses allowed to identify elements among TEs and REEs documenting geochemical processes and those indicating anthropogenic sources of pollution.

The Release of Antimony from Mine Dump Soils in the Presence and Absence of Forest Litter.

This study examined the changes in antimony (Sb) solubility in soils, using organic matter introduced with forest litter, in various moisture conditions. Soils containing 12.8⁻163 mg/kg Sb were taken from the top layers of dumps in former mining sites in the Sudetes, South-West Poland. Soils were incubated for 90 days either in oxic or waterlogged conditions, with and without the addition of 50 g/kg of beech forest litter (FL). Water concentrations of Sb in some experimental treatments greatly exceeded the threshold values for good quality underground water and drinking water, and reached a maximum of 2.8 mg/L. The changes of Sb solubility caused by application of FL and prolonged waterlogging were, in various soils, highly divergent and in fact unpredictable based on the main soil properties. In some soils, the application of forest litter prompted the release of Sb from soil solid phase, while in the others it acted contradictorily. Soil waterlogging resulted, in most cases, in the increased release of Sb compared to oxic conditions, and this effect was enhanced by the addition of forest litter. However, in two soils the presence of forest litter counteracted the effects of waterlogging and diminished the quantities of released Sb.

Tracking heavy metal contamination in a complex river-oxbow lake system: Middle Odra Valley, Germany/Poland.

Oxbow lakes have received much attention in recent years due to their ecological importance and vulnerability for contamination. Sediment cores collected from the floor of oxbow lakes indicate the increasing contamination of lakes with heavy metals (Cu, Cd, Pb, Zn, Ni, Cr) over the last fifty years, owing to the development of transport and industry. Little is known, however, about how various factors can enhance or impede the migration of metallic contaminants between the pollution source and lake ecosystems. To untangle these complex processes, the metal distribution was studied throughout the waters and sediments of an urban zone-river-oxbow lake system in the Middle Odra Valley, Germany/Poland. As expected the degree of metal contamination is highest (>10 enrichment) at low distance (<1km) from the human source of pollution. Using correlations with highly mobile in water Na+ and Cl- ions, we reveal, however, that due to hydrological factors some metals (Cu, Cd, and Pb) are up to >5 times enriched in the sediments of lakes even >10km distant from the nearest source of pollution. The lakes that are permanently connected with the Odra River or that are frequently flooded are most vulnerable for contamination. Although the metal concentrations are especially enriched in the smallest grain size fractions, this portion of metals seems to be less bioavailable with respect to that accumulated within the larger grain size fractions. Concentrations of metallic contaminants in the bottom sediments of the Middle Odra lakes are generally lower than in other oxbow lakes. Having untangled the variety of processes controlling metal migration in a complex river-oxbow lake system operating on these low metal concentrations, allows us to believe that our approach could become a paradigm for future trace element studies in a variety of similar lowland systems across the World.

Application of multivariate statistical approach to identify trace elements sources in surface waters: a case study of Kowalskie and Stare Miasto reservoirs, Poland.

The paper reports the results of measurements of trace elements concentrations in surface water samples collected at the lowland retention reservoirs of Stare Miasto and Kowalskie (Poland). The samples were collected once a month from October 2011 to November 2012. Al, As, Cd, Co, Cr, Cu, Li, Mn, Ni, Pb, Sb, V, and Zn were determined in water samples using the inductively coupled plasma with mass detection (ICP-QQQ). To assess the chemical composition of surface water, multivariate statistical methods of data analysis were used, viz. cluster analysis (CA), principal components analysis (PCA), and discriminant analysis (DA). They made it possible to observe similarities and differences in the chemical composition of water in the points of water samples collection, to uncover hidden factors accounting for the structure of the data, and to assess the impact of natural and anthropogenic sources on the content of trace elements in the water of retention reservoirs. The conducted statistical analyses made it possible to distinguish groups of trace elements allowing for the analysis of time and spatial variation of water in the studied reservoirs.

Environmental factors affecting soil metals near outlet roads in Poznan, Poland: impact of grain size, soil depth, and wind dispersal.

We determined the Cd, Cr, Cu, Ni, Pb, and Zn concentrations in soil samples collected along the eight main outlet roads of Poznan. Samples were collected at distances of 1, 5, and 10 m from the roadway edges at depth intervals of 0-20 and 40-60 cm. The metal content was determined in seven grain size fractions. The highest metal concentrations were observed in the smallest fraction (<0.063 mm), which were up to four times higher than those in sand fractions. Soil Pb, Cu, and Zn (and to a lesser extent Ni, Cr, and Cd) all increased in relation to the geochemical background. At most sampling sites, metal concentrations decreased with increasing distance from roadway edges and increasing depth. In some locations, the accumulation of metals in soils appears to be strongly influenced by wind direction. Our survey findings should contribute in predicting the behavior of metals along outlet road, which is important by assessing sources for further migration of heavy metals into the groundwater, plants, and humans.

Sr isotope tracing of multiple water sources in a complex river system, Notec River, central Poland.

Anthropogenic impact on surface waters and other elements in the environment was investigated in the Notec River basin in central Poland. The approach was to trace changes in the Sr isotope composition ((87)Sr/(86)Sr) and concentration in space and time. Systematic sampling of the river water shows a very wide range of (87)Sr/(86)Sr ratios, from 0.7089 to 0.7127. This strong variation, however, is restricted to the upper course of the river, whereas the water in the lower course typically shows (87)Sr/(86)Sr values around 0.7104-0.7105. Variations in (87)Sr/(86)Sr are associated with a wide range of Sr concentrations, from 0.14 to 1.32mg/L. We find that strong variations in (87)Sr/(86)Sr and Sr concentrations can be accounted for by mixing of two end-members: 1) atmospheric waters charged with Sr from the near-surface weathering and wash-out of Quaternary glaciogenic deposits, and 2) waters introduced into the river from an open pit lignite mine. The first reservoir is characterized by a low Sr content and high (87)Sr/(86)Sr ratios, whereas mine waters display opposite characteristics. Anthropogenic pollution is also induced by extensive use of fertilizers which constitute the third source of Sr in the environment. The study has an important implication for future archeological studies in the region. It shows that the present-day Sr isotope signatures of river water, flora and fauna cannot be used unambiguously to determine the "baseline" for bioavailable (87)Sr/(86)Sr in the past.

Thallium in fractions of sediments formed during the 2004 tsunami in Thailand.

Thallium is a highly toxic element. Its concentration in sediment fractions from the 2004 tsunami in Thailand was investigated. A modified BCR procedure was used for sequential extraction. Tl was determined by flow injection differential pulse anodic stripping voltammetry. It was found that the majority of thallium in the investigated tsunami sediments (86-97 percent) is entrapped in the alumosilicate parent matter i.e. it is entirely immovable. Only the total destruction of this residual fraction with hydrofluoric acid made this thallium available. The conclusion strongly supports the hypothesis that thallium is mainly entrapped in alumosilicate parent matter. Total thallium concentration in the investigated tsunami sediments was divergent in various samples from 0.37 to 1.13 µg g(-1) and significantly different from the reference area (0.05 µg g(-1)). Tsunami sediment fractions from different sampling points are divergent in terms of total thallium concentration and concentration of mobile thallium. Generally, mobile thallium concentration was growing in sequence: water soluble fraction

Heavy metals: their pathway from the ground, groundwater and springs to Lake Góreckie (Poland).

The migration pathways of heavy metals derived from an area previously in agricultural use was investigated in the Wielkopolski National Park (mid-western Poland). The heavy metals involved (Cd, Cu, Cr, Pb, Ni and Zn) were determined in groundwater, the springs that feed Lake Góreckie and the lake itself. In order to show how the heavy metals may be set free and what is their biological availability, soil and sediment samples were subjected to single-stage extraction, using 0.01 M CaCl(2), 0.02 M EDTA, 0.005 M DTPA, 0.1 M HCl, 1 M HCl and de-ionised water. Varying metal concentrations were recorded in the water samples during the study period (from November 2009 to July 2010), usually with higher values in winter and lower ones in summer. The seasonal changes may be ascribed to natural processes taking place in the ground- and surface waters of Lake Góreckie. On the other hand, the concentration levels (mostly of Cd, Pb and Cr) are indicative of anthropogenic activity. It should be mentioned in this context that the highest metal concentrations were found in the soil layer. The concentrations were also found to exceed both the Polish and the World Health Organization water-quality standards. It appears that the soils are highly contaminated, mostly with cadmium. The long-lasting effect of acid precipitation in the area makes it possible for immobile forms to become mobile, thus facilitating further migration into the environment.

Determination of aluminium in groundwater samples by GF-AAS, ICP-AES, ICP-MS and modelling of inorganic aluminium complexes.

The paper presents the results of aluminium determinations in ground water samples of the Miocene aquifer from the area of the city of Poznan (Poland). The determined aluminium content amounted from <0.0001 to 752.7 µg L(-1). The aluminium determinations were performed using three analytical techniques: graphite furnace atomic absorption spectrometry (GF-AAS), inductively coupled plasma atomic emission spectrometry (ICP-AES) and inductively coupled plasma mass spectrometry (ICP-MS). The results of aluminium determinations in groundwater samples for particular analytical techniques were compared. The results were used to identify the ascent of ground water from the Mesozoic aquifer to the Miocene aquifer in the area of the fault graben. Using the Mineql+ program, the modelling of the occurrence of aluminium and the following aluminium complexes: hydroxy, with fluorides and sulphates was performed. The paper presents the results of aluminium determinations in ground water using different analytical techniques as well as the chemical modelling in the Mineql+ program, which was performed for the first time and which enabled the identification of aluminium complexes in the investigated samples. The study confirms the occurrence of aluminium hydroxy complexes and aluminium fluoride complexes in the analysed groundwater samples. Despite the dominance of sulphates and organic matter in the sample, major participation of the complexes with these ligands was not stated based on the modelling.