Sizeable net export of base cations from a Carpathian flysch catchment indicates their geogenic origin while the 26Mg/24Mg, 44Ca/40Ca and 87Sr/86Sr isotope ratios in runoff are indistinguishable from atmospheric input.

Nutrient imbalances may negatively affect the health status of forests exposed to multiple stress factors, including drought and bark beetle calamities. We studied the origin of base cations in runoff from a small Carpathian catchment underlain by base-poor flysch turbidites using magnesium (Mg), calcium (Ca) and strontium (Sr) isotope composition of 10 ecosystem compartments. Our objective was to constrain conclusions drawn from long-term hydrochemical monitoring of inputs and outputs. Annual export of Mg, Ca and Sr exceeds 5-to-15 times their atmospheric input. Mass budgets per se thus indicate sizeable net leaching of Mg, Ca and Sr from bedrock sandstones and claystones. Surprisingly, δ26Mg, δ44Ca and 87Sr/86Sr isotope ratios of runoff were practically identical to those of atmospheric deposition and soil water but significantly different from bedrock isotope ratios. We did not find any carbonates in the studied area as a hypothetical, easily dissolvable source of base cations whose isotope composition might corroborate the predominance of geogenic base cations in the runoff. Marine carbonates typically have lower δ26 Mg and 87Sr/86Sr ratios, and silicate sediments often have higher δ26Mg and 87Sr/86Sr ratios than runoff at the study site. Mixing of these two sources, if confirmed, could reconcile the flux and isotope data.

Accumulation and within-mushroom distribution of elements in red cracking bolete (Xerocomellus chrysenteron) collected over the extended period from compositionally contrasting substrates.

We conducted a study of elemental compositions of Xerocomellus chrysenteron samples accompanied by samples of related substrate soils. All samples were collected during the harvesting seasons 2021 and 2022 from three forested sites almost unpolluted by recent human activities and underlain by contrasting bedrock (granite, amphibolite, and serpentinite). Elements such as Ag, Cd, K, P, Rb, S, Se, and Zn were the main elements enriched in the mushroom's fruiting bodies relative to the substrate. Concentrations of most elements in mushrooms were not site-dependent, with only Ag, As, Rb, and Se concentrations significantly depending on the bedrock composition. Some elements analyzed in mushrooms displayed temporal features, but such features were not systematic and varied for each element. Most analyzed elements were distributed unevenly within the mushroom's fruiting bodies, with apical parts generally enriched in mobile elements. Mushrooms influenced concentrations of Ag, Cd, K, and Rb and a few other elements in the substrate via uptake, but such influence was very limited and can be responsible for only 2.5-11.5% of total depletion of the affected substrate in the named elements.

Spatial and temporal trends in δ66Zn and 206Pb/207Pb isotope ratios along a rural transect downwind from the Upper Silesian industrial area: Role of legacy vs. present-day pollution.

Transect sampling is an under-exploited tool in isotope studies of atmospheric pollution. Few studies have combined Zn and Pb isotope ratios to investigate whether atmospheric pollution at a receptor site is dominated by a different anthropogenic source of each of these toxic elements. It has been also unclear whether pollution abatement strategies in Central Europe have already resulted in regionally well-mixed background isotope signature of atmospheric Zn and Pb. Zinc and lead isotope ratios were determined in snow collected along a rural transect downwind from the Upper Silesian industrial area (southern Poland). Spatial and temporal gradients in δ66Zn and 206Pb/207Pb ratios at four sites were compared with those of ore and coal collected in eight Czech and Polish mining districts situated at distances of up to 500 km. Snow pollution was extremely high 8 km from Olkusz in 2011 (1670 µg Zn L-1; 240 µg Pb L-1), sharply decreased between 2011 and 2018, and remained low in 2019-2021. Snow pollution was lower at sites situated 28-68 km from Olkusz. Across study sites, mean δ66Zn and 206Pb/207Pb ratios of snow were -0.13‰ and 1.155, respectively. With an increasing distance from Olkusz, the δ66Zn values first increased and then decreased, while the 206Pb/207Pb ratios first decreased and then increased. The δ66Zn values in snow plotted closer to those of Upper Silesian ores (-0.20‰) than to the δ66Zn values of Upper Silesian stone coal (0.52‰), showing predominance of smelter-derived over power-plant derived Zn pollution. The 206Pb/207Pb ratios of Upper Silesian coal (1.171) and Upper Silesian ores (1.180) were higher compared to those of snow. A206Pb/207Pb vs.208Pb/207Pb plot identified legacy pollution from leaded gasoline as the low-radiogenic mixing end-member. Across the transect sites, only the last sampling campaign exhibited a high degree of isotope homogenization for both Zn and Pb.

Translocation of elements and fractionation of Mg, Cu, Zn, and Cd stable isotopes in a penny bun mushroom (Boletus edulis) from western Czech Republic.

Boletus edulis mushroom behaved as an accumulating biosystem with respect to Ag, Rb, Zn, and K. The mushroom was not an efficient accumulator of toxic As, Pb, and Cr, but Se and Cd displayed much higher concentrations in the mushroom than in the substrate samples. Other elements were bioexclusive. Different elements had different within-mushroom mobilities. The highest mobilities were displayed by Zn and Ag, and the lowest by Ti. The mushroom's fruiting body preferentially took up lighter Mg, Cu, and Cd isotopes (Δ26MgFB-soil = -0.75‰; Δ65CuFB-soil = -0.96‰; Δ114CdFB-soil = -0.63‰), and the heavier 66Zn isotope (Δ66ZnFB-soil = 0.92‰). Positive within-mushroom Zn isotope fractionation resulted in accumulation of the heavier 66Zn (Δ66Zncap-stipe = 0.12‰) in the mushroom's upper parts. Cadmium displayed virtually no within-mushroom isotope fractionation. Different parts of the fruiting body fractionated Mg and Cu isotopes differently. The middle part of the stipe (3-6 cm) was strongly depleted in the heavier 26 Mg with respect to the 0-3 cm (Δ26Mgstipe(3-6)-stipe(0-3) = -0.73‰) and 6-9 cm (Δ26Mgstipe(6-9)-stipe(3-6) = 0.28‰) sections. The same stipe part was strongly enriched in the heavier 65Cu with respect to the 0-3 cm (Δ65Custipe(3-6)-stipe(0-3) = 0.63‰) and 6-9 cm (Δ65Custipe(6-9)-stipe(3-6) = -0.42‰) sections. An overall tendency for the upper mushroom's parts to accumulate heavier isotopes was noted for Mg (Δ26Mgcap-stipe = 0.20‰), Zn (Δ66Zncap-stipe = 0.12‰), and Cd (Δ114Cdcap-stipe = 0.04‰), whereas Cu showed the opposite trend (Δ65Cucap-stipe = -0.08‰).

Comparison of vertical and horizontal atmospheric deposition of nitrate at Central European mountain-top sites during three consecutive winters.

Nitrogen (N) deposition, a key process of atmospheric self-cleaning, represents an important pathway for nutrients and pollutants to ecosystems. Enhanced N deposition flux contributes to acidification, eutrophication and loss of biodiversity. N-NO3- concentrations in rime and snow were measured at 10 Czech plots situated in borderline mountains in 2009-2011 winters. The results were put in context with data-driven geostatistical modelling results of annual wet vertical and horizontal deposition. Our hypotheses were that: (i) rime and snow would be more polluted in the highly industrialized north than in the south, (ii) the N-NO3- concentrations would differ in the three winters studied, and (iii), that N-NO3- rime deposition is not negligible in Central European mountain ranges. Our results indicated that winter N-NO3- concentrations were significantly higher in rime than in snow and that there were much larger between-site differences in N-NO3- concentrations for rime than for snow. Relatively large differences were found between individual years. Atmospheric input of N-NO3- in winter was dominated by vertical deposition, i.e., snow. Modelled results showed that mean winter rime deposition corresponded to about 6-25 %, and mean winter snow deposition made up 25-72.5 % of mean annual N-NO3- wet-only deposition. Model N-NO3-occult deposition estimated from throughfall and total (wet and dry) deposition is highly uncertain, however: N throughfall is not a relevant proxy for estimation of realistic total N deposition due to N exchange between the tree canopy and atmosphere.

Atmospheric deposition and trajectories of antimony in Central Europe.

Antimony (Sb) concentrations were measured in wet atmospheric deposition at 10 high-elevation sites in the Czech Republic (Central Europe) during three winter seasons (2009-2011). Soluble and insoluble Sb forms were quantified in snow (vertical deposition) and rime (horizontal deposition) on mountain summits located equidistantly near the Czech borders with Austria, Germany and Poland. The highest Sb concentrations were found in the soluble form in rime (0.47 µg L-1), while the lowest Sb concentrations were those in the insoluble form in snow (0.017 µg L-1). The estimated average Sb deposition rate in Central Europe amounted to 1.3. 10-4 g m-2 yr-1. Most Sb was deposited in the soluble form in snow (7.9. 10-5 g m-2 yr-1), followed by the soluble form in rime (3.5. 10-5 g m-2 yr-1). The corresponding insoluble fraction contained less Sb, namely 1.2. 10-5 g m-2 yr-1 in snow and 2.3. 10-6 g m-2 yr-1 in rime. The average Sb deposition in Central Europe, measured at an altitude of 1000 m a.s.l., was by six orders of magnitude higher compared to Sb deposition in the Arctic (7. 10-10 g m-2 yr-1), and by four orders of magnitude lower compared to Sb deposition in a Sb-Hg mining district in China (7 g m-2 yr-1). Using the HYSPLIT model, backward trajectories of air masses indicated that the Sb sources were predominantly situated in Upper and Lower Silesia.

Catchment Runoff in Industrial Areas Exports Legacy Pollutant Zinc from the Topsoil Rather than Geogenic Zn.

In highly industrialized, densely populated parts of Central Europe, mobilization of legacy Zn pollution from forest ecosystems may negatively affect the quality of water resources. To test this hypothesis, we determined the 66Zn/64Zn isotope ratios of 15 Zn reservoirs and fluxes in an acidified, spruce die-back affected mountain-slope catchment in northern Czech Republic. The δ66Zn values of precipitation, organic horizon, and runoff were statistically indistinguishable. In contrast, δ66Zn values of bedrock orthogneiss and mineral soil were significantly different from δ66Zn values of runoff. The magnitude of within-site Zn isotope fractionations appeared to be relatively small. Despite the large potential source of Zn in bedrock, runoff exported mostly young pollutant Zn that had been temporarily stored in the organic horizon. This conclusion was corroborated by comparing Zn input-output mass balances in the polluted northern catchment and in a relatively unpolluted catchment situated 250 km to the south. Seven-times higher Zn export via runoff at the northern site was controlled by a combination of 10-times higher atmospheric Zn input and five-times higher DOC leaching, compared to the southern site. In industrial areas, atmospherically deposited Zn is leached from headwater catchments in a direct analogy to leaching of highly toxic pollutant Pb.

Winter arsenic pollution in 10 forest ecosystems in the mountainous border regions of the Czech Republic.

Arsenic (As) concentrations and deposition fluxes were measured in snow and rime at 10 mountain-top sites near the borders between the Czech Republic and Austria, Germany, Poland, and Slovakia during three consecutive winter seasons (2009-2011). Our study was performed at a time following several decades of sharply decreasing regional atmospheric pollution and following the 2006 implementation of stricter air quality standards across Europe. Our objective was to compare vertical and horizontal depositions of soluble and insoluble As forms throughout the Czech Republic and define a recent Central European As pollution gradient. Arsenic soluble in weak nitric acid contributed 83 to 85% to the total As deposition, with the remaining 17-15% bound to stable particulate forms. The highest As deposition rates were recorded in the eastern Czech Republic near the borders with Poland and Slovakia. Complementary hydrochemical monitoring in four mountain-slope catchments situated near selected main study sites revealed a further decrease in open-area As deposition by the end of 2018 in the east of the country. In contrast, spruce canopy throughfall flux did not change significantly between 2009-2011 and 2016-2018. The site-specific relative roles of coal-burning-derived and ore-smelting-derived atmospheric As are discussed.

Controls on δ26Mg variability in three Central European headwater catchments characterized by contrasting bedrock chemistry and contrasting inputs of atmospheric pollutants.

Magnesium isotope ratios (26Mg/24Mg) can provide insights into the origin of Mg pools and fluxes in catchments where Mg sources have distinct isotope compositions, and the direction and magnitude of Mg isotope fractionations are known. Variability in Mg isotope compositions was investigated in three small, spruce-forested catchments in the Czech Republic (Central Europe) situated along an industrial pollution gradient. The following combinations of catchment characteristics were selected for the study: low-Mg bedrock + low Mg deposition (site LYS, underlain by leucogranite); high-Mg bedrock + low Mg deposition (site PLB, underlain by serpentinite), and low-Mg bedrock + high Mg deposition (site UDL, underlain by orthogneiss). UDL, affected by spruce die-back due to acid rain, was the only investigated site where dolomite was applied to mitigate forest decline. The δ26Mg values of 10 catchment compartments were determined on pooled subsamples. At LYS, a wide range of δ26Mg values was observed across the compartments, from -3.38 ‰ (bedrock) to -2.88 ‰ (soil), -1.48% (open-area precipitation), -1.34 ‰ (throughfall), -1.19 ‰ (soil water), -0.99 ‰ (xylem), -0.95 ‰ (needles), -0.82 ‰ (bark), -0.76 ‰ (fine roots), and -0.76 ‰ (runoff). The δ26Mg values at UDL spanned 1.32 ‰ and were thus less variable, compared to LYS. Magnesium at PLB was isotopically relatively homogeneous. The δ26Mg systematics was consistent with geogenic control of runoff Mg at PLB. Mainly atmospheric/biological control of runoff Mg was indicated at UDL, and possibly also at LYS. Our sites did not exhibit the combination of low-δ26Mg runoff and high-δ26Mg weathering products (secondary clay minerals) reported from several previously studied sites. Six years after the end of liming at UDL, Mg derived from dolomite was isotopically undetectable in runoff.

Retraction Statement: Comparison of nitrogen inputs and accumulation in 210 Pb-dated peat cores: Evidence for biological N2 -fixation in Central European peatlands despite decades of atmospheric N pollution.

"Comparison of nitrogen inputs and accumulation in 210 Pb-dated peat cores: Evidence for biological N2 -fixation in Central European peatlands despite decades of atmospheric N pollution" https://doi.org/10.1111/gcb.14505, by Martin Novak, Melanie A. Vile, Jan Curik, Bohuslava Cejkova, Jiri Barta, Marketa Stepanova, Ivana Jackova, Frantisek Buzek, Leona Bohdalkova, Eva Prechova, Frantisek Veselovsky, Marie Adamova, Ivana Valkova and Arnost Komarek. The above article, first published online in Wiley Online Library (wileyonlinelibrary.com) in Global Change Biology, has been retracted by agreement between the authors, the journal Editor-in-Chief, Stephen P. Long, and John Wiley & Sons Ltd. Since publication of the above article, it was brought to the attention of the authors that the peat accretion rates violate reasonable ranges of peatland C/N/P stoichiometry, placing the quantitative conclusions of the article in serious error. The authors apologize for any inconvenience the publication of this work may have caused our readers. REFERENCE Novak, M., Vile, M. A., Cejkova, B., Barta, J., Stepanova, M., Jackova, I., Buzek, F., Bohdalkova, L., Prechova, E., Veselovsky, F., Adamova, M., Valkova, I., & Komarek, A. (2018). Comparison of nitrogen inputs and accumulation in 210 Pb-dated peat cores: Evidence for biological N2 -fixation in Central European peatlands despite decades of atmospheric N pollution. Global Change Biology.. https://doi.org/10.1111/gcb.14505.

Cu-Zn isotope constraints on the provenance of air pollution in Central Europe: Using soluble and insoluble particles in snow and rime.

Copper (Cu) and zinc (Zn) isotope ratios can be used to fingerprint sources and dispersion pathways of pollutants in the environment. Little is known, however, about the potential of δ65Cu and δ66Zn values in liquid and solid forms of atmospheric deposition to distinguish between geogenic, industrial, local and remote sources of these potentially toxic base metals. Here we present Cu-Zn deposition fluxes at 10 mountain-top sites in the Czech Republic, a region affected by extremely high industrial emission rates 25 years ago. Additionally, we monitored isotope composition of Cu and Zn in vertical and horizontal atmospheric deposition at two sites. We compared δ65Cu and δ66Zn values in snow and rime, extracted by diluted HNO3 and concentrated HF. Cu and Zn isotope signatures of industrial pollution sources were also determined. Cu and Zn deposition fluxes at all study sites were minute. The mean δ65Cu value of atmospheric deposition (-0.07‰) was higher than the mean δ65Cu value of pollution sources (-1.17‰). The variability in δ65Cu values of atmospheric deposition was lower, compared to the pollution sources. The mean δ66Zn value of atmospheric deposition (-0.09‰) was slightly higher than the mean δ66Zn value of pollution sources (-0.23‰). The variability in δ66Zn values of atmospheric deposition was indistinguishable from that of pollution sources. The largest isotope differences (0.35‰) were observed between the insoluble and soluble fractions of atmospheric deposition. These differences may result from different sources of Cu/Zn for each fraction. The difference in isotope composition of soluble and insoluble particles appears to be a promising tool for pollution provenance studies in Central Europe.

Common occurrence of a positive δ53Cr shift in Central European waters contaminated by geogenic/industrial chromium relative to source values.

Carcinogenic effects of hexavalent chromium in waters are of concern in many countries worldwide. We explored Cr isotope systematics at 11 sites in the Czech Republic and Poland. Geogenic Cr pollution was associated with serpentinite bodies at former convergent plate margins, while anthropogenic Cr pollution resulted from electroplating, tanning, and the chemical industry. Cr(VI) concentration in geogenic waters was less than 40 ppb. Anthropogenic waters contained up to 127,000 ppb Cr(VI). At both geogenic and anthropogenic sites, where known, the source of pollution had a low δ53Cr (<1‰). δ53Cr of geogenic and anthropogenic waters was up to 3.9 and 5.8‰, respectively. At both serpentinite-dominated and industrial sites, δ53Cr(VI)aq was shifted toward higher values, compared to the pollution source. At the industrial sites, this positive δ53Cr shift was related to Cr(VI) reduction, a process known to fractionate Cr isotopes. At geogenic sites, the origin of high δ53Cr(VI)aq is tentatively ascribed to preferential release of 53Cr during oxidation of soil Cr(III) and its mobilization to water. δ53Cr(VI) of industrially contaminated waters was significantly higher (p<0.001) compared to δ53Cr of waters carrying geogenic Cr(VI), implying that either the effective fractionation factor or process extent was greater for Cr(VI) reduction than for Cr(III) oxidation.

The fate of atmospherically derived Pb in Central European catchments: insights from spatial and temporal pollution gradients and Pb isotope ratios.

Soils in polluted regions are generally regarded as a delayed, long-lasting source for Pb contamination of aquatic systems. Lead deposited on topsoil is slowly transported downward with particulate and colloidal organic matter, driven by infiltrating precipitation. Then, Pb is tightly retained in mineral soil. Lead export from catchments is extremely low and decoupled from the atmospheric input. We tested this hypothesis in 11 small catchments, differing in pollution levels. Input/ouput Pb fluxes were monitored for 14-15 years in an era of decreasing industrial Pb emission rates. Between 1996/1997 and 2010, Pb deposition fluxes decreased significantly, on average by 80%. At the beginning of the monitoring, Pb export constituted 2 to 58% of Pb input. At the end of the monitoring, Pb export constituted 2 to 95% of Pb input. Highly polluted sites in the northeast exported significantly more Pb than less polluted sites further south. The (206)Pb/(207)Pb isotope ratios of runoff (1.16) were identical to those of topsoil and present-day deposition, and different from mineral soil and bedrock. Lead isotope systematics and between-site flux comparisons indicated that a portion of the incoming Pb had a relatively short residence time in the catchments, on the order of decades.

Experimental evidence for mobility/immobility of metals in peat.

The biogeochemical cycles of most toxic metals have been significantly altered by anthropogenic activities. Anaerobic, rain-fed organic soils are believed to record historical changes in atmospheric pollution. Suspected postdepositional mobility of trace elements, however, hinders the usefulness of peat bogs as pollution archives. To lower this uncertainty, we quantified the mobility of six trace metals in peat during an 18-month field manipulation. A replicated, reciprocal peat transplant experiment was conducted between a heavily polluted and a relatively unpolluted peatland, located 200 km apart in the Czech Republic (Central Europe). Both peatlands were Sphagnum-derived, lawn-dominated, and had water table close to the surface. A strikingly different behavior was observed for two groups of elements. Elements of group I, Fe and Mn, adjusted their abundances and vertical patterns to the host site, showing an extremely high degree of mobility. In contrast, elements of group II, Pb, Cu, Zn, and Ti, preserved their original vertical patterns at the host site, showing a high degree of immobility. Our experimental results suggest that not just lead, but also copper and zinc concentration profiles in peat are a reliable archive of temporal pollution changes within a wide pH range (2.5-5.8).

Origin of lead in eight Central European peat bogs determined from isotope ratios, strengths, and operation times of regional pollution sources.

Lead originating from coal burning, gasoline burning, and ore smelting was identified in 210Pb-dated profiles through eight peat bogs distributed over an area of 60,000 km2. The Sphagnum-dominated bogs were located mainly in mountainous regions of the Czech Republic bordering with Germany, Austria, and Poland. Basal peat 14C-dated at 11,000 years BP had a relatively high 206Pb/207Pb ratio (1.193). Peat deposited around 1800 AD had a lower 206Pb/207Pb ratio of 1.168-1.178, indicating that environmental lead in Central Europe had been largely affected by human activity (smelting) even before the beginning of the Industrial Revolution. Five of the sites exhibited a nearly constant 206Pb/207Pb ratio (1.175) throughout the 19th century, resembling the "anthropogenic baseline" described in Northern Europe (1.17). At all sites, the 206Pb/207Pb ratio of peat decreased at least until 1980; at four sites, a reversal to more radiogenic values (higher 206Pb/207Pb), typical of easing pollution, was observed in the following decade (1980-1990). A time series of annual outputs for 14 different mining districts dispersing lead into the environment has been constructed for the past 200 years. The production of Ag-Pb, coal, and leaded gasoline peaked in 1900, 1980, and 1980, respectively. In contrast to other European countries, no peak in annual Pb accumulation rates was found in 1900, the year of maximum ore smelting. The highest annual Pb accumulation rates in peat were consistent with the highest Pb emission rates from coal-fired power plants and traffic (1980). Although maximum coal and gasoline production coincided in time, their isotope ratios were unique. The mean measured 206Pb/207Pb ratios of local coal, ores, and gasoline were 1.19, 1.16, and 1.11, respectively. A considerable proportion of coal emissions, relative to gasoline emisions, was responsible for the higher 206Pb/207Pb ratios in the recent atmosphere (1.15) compared to Western Europe (1.10). As in West European countries, the gasoline sold in the Czech Republic during the Communist era (1948-1989) contained an admixture of low-radiogenic Precambrian lead from Australia.