Moosmonitoring als Spiegel der Landnutzung?

Goal, Scope and Background

The study was conducted to test the hypothesis that the regional variability of nitrogen (N) and metal accumulations in terrestrial ecosystems are due to historical and recent ways of land use. To this end, in two regions of Central Europe the metal and N accumulations in both regions should be examined by comparative moss analysis. The regions should be of quantitatively specified representativity for selected ecological characteristics of Europe. Within both regions these characteristics should be covered by the sites where the moss samples were collected. The number of samples should allow for geostatistical estimation of the measured nitrogen and metal loads.

Methods

The two regions of investigation were selected according to an ecological land classification of Europe which was computed by classification trees. Within each of both research areas the sampling points were localized according to the areas occupied by the ecologically defined land classes. The sampling and chemical analysis of mosses was conducted in accordance with an appropriate UNECE guideline by means of ICP-MS (metals) and combustion analysis (N). The quality of measurements was assured using certified reference materials. The differences of deposition loads were tested for statistical significance with regard to time and space. Variogram analysis was used to examine and model the spatial autocorrelation function of the measurements. Ordinary kriging was then applied for surface estimations.

Results

By use of the ecological regionalisation of Europe the Weser-Ems Region (WER) and the Euro Region Nissa (ERN) were selected for investigation. The sampling sites represent quite well the natural landscapes and the land use categories of both regions. The measurement values corroborate the decline of metal accumulation observed since the beginning of the European Mosses Monitoring Survey in 1990. The metal loads of the mosses in the ERN exceed those in the WER significantly. The opposite holds true for the N concentrations: those in the WER are significantly higher than those in the ERN.

Discussion

The decrease of heavy metal emissions is correlated with lowered deposition and accumulation rates in terrestrial ecosystems. The accumulation of nitrogen in the biosphere is not following this trend.

Conclusions

The technique of moss analysis is adequate for spatially valid biomonitoring of spatial and temporal trends of metals and nitrogen in terrestrial ecosystems. By this, it enables to prove the efficiency of environmental policies.

Recommendations and Perspectives

The accumulation of N in ecosystems is still a serious environmental problem. Related ecological impacts are the eutrophication of aquatic ecosystems like ground waters, lakes, rivers and oceans as well as the biocoenotic changes in terrestrial ecosystems. Thus, a statistically valid exposure analysis must encompass both, accumulation of metals and N bioaccumulation. Further, the bioaccumulation of persistent organic pollutants should be monitored. Finally, environmental biomonitoring should be conducted in much closer contact with human health aspects.     

(Persistent) Organic pollutants in Germany: results from a pilot study within the 2015 moss survey

Background

Since 1990, every 5 years, moss sampling is conducted within the European moss monitoring programme to assess the atmospheric deposition of airborne pollutants. Besides many other countries, Germany takes regularly part at these evaluations. Within the European moss monitoring 2015, more than 400 moss samples across Germany were taken according to a harmonized methodology for the assessment heavy metal and nitrogen input. In a pilot programme, eight of these sites were chosen for additional investigations on a broad range of organic contaminants to evaluate their accumulation in moss and thereby their presence in atmospheric deposition in Germany. Target compound classes comprised polycyclic aromatic hydrocarbons (PAH), polychlorinated dibenzodioxins and –furans (PCDD/F), dioxin-like and non-dioxin-like polychlorinated biphenyls (dl-PCB, ndl-PCB), polyfluorinated alkyl substances, classical flame retardants as well as emerging chlorinated and brominated flame retardants. In total, 120 target compounds were analysed. For some analytes, comparisons of accumulation in moss and tree leave samples were possible.

Results

Except for certain flame retardants, PFAS, and ndl-PCB, substances of all other compound classes could be quantified in moss samples of all sites. Concentrations were highest for PAH (40–268 ng g^?1) followed by emerging flame retardants (0.5–7.7 ng g^?1), polybrominated diphenyl ethers (PBDE; 0.3–3.7 ng g^?1), hexabromocyclododecane (HBCD; 0.3–1.2 ng g^?1), dl-PCB (0.04–0.4 ng g^?1) and PCDD/F (0.008–0.06 ng g^?1).

Conclusions

Results show the widespread atmospheric distribution and deposition of organic contaminants across Germany as well as the suitability of moss as bioaccumulation monitor for most of these compound classes. Compared to nearby tree leaf samples, accumulation potential of moss appeared to be higher for pollutants of high octanol–air partition coefficient (K_OA) and octanol–water partition coefficient (K_OW).

     

Metallakkumulation in Moosen: Standörtliche und regionale Randbedingungen des Biomonitoring von Luftverunreinigungen

Goal and Scope

Several studies show that the concentration of metals in mosses depends not only on metal deposition but also on factors such as moss species, canopy drip, precipitation, altitude, distance to the sea and the analytical technique used. However, contrasting results have been reported and the interpretation of the spatial variability of the metal accumulation in mosses remains difficult. In the presented study existing monitoring data from the European Heavy Metals in Mosses Surveys together with surface data on precipitation, elevation and land use are statistically analysed to assess factors other than emissions that have an influence on the metal accumulation in the mosses.

Main Features

Inference statistics and Spearman correlation analysis were applied to examine the association of the metal accumulation and the distance of the monitoring sites to the sea as well as the altitude. Whether or not significant differences of the metal loads in the mosses exist at national borders was examined with help of the U-test after Mann and Whitney. In order to identify and rank the factors that are assumed to have an influence on the metal uptake of the mosses Classification and Regression Trees (CART) were applied.

Results

No clear tendency could be derived from the results of the inference statistical calculations and the correlation analyses with regard to the distance of the monitoring site to the sea and the altitude. According to the results of the CART-analyses mainly the moss species, potential emission sources around the monitoring sites, canopy drip and precipitation have an effect on the metal bioaccumulation. Assuming that each participating country followed strictly the manual for sampling and sample preparation the results of the inference statistical calculations furthermore suggest that in most cases different techniques for digestion and analysis bias the measurements significantly.

Discussion

For the first time a national monitoring data base consisting of measurement data and metadata as well as surface information on precipitation, land use and elevation was applied to examine influence factors on the metal bioaccumulation in mosses. The respective results mirror existing knowledge from other national studies to a large extend, although further analyses are necessary to affirm the findings. These analyses should include data from other national monitoring programmes and should additionally be carried out with other decision tree algorithms than CART.

Conclusions

The local variability in the metal concentration in mosses can be uncovered in terms of predictors or underlying hidden causes by using CART. Ideally, such an approach should be applied across the whole of Europe. This will only be feasible if all participating countries provide additional information about site characteristics as currently is done in for example the German moss surveys.

Recommendations

The UNECE Metals in Mosses Survey experimental protocol should be improved in order to reduce the observed influences, to enhance standardisation, and to strengthen the quality control. This implies the integration of sampling site describing metadata into the assessment. Furthermore, basis research is needed to test the hypothesis concerning moss species-specific accumulation of depositions.

Perspectives

Provided that the presented results hold true in further analyses correction factors should be applied on the moss data in order to get the depicted spatial patterns and temporal trends of metal bioaccumulation unbiased. Such factors should be calculated for natural landscape units or ecoregions that are homogeneous with regard to climate, vegetation and altitude.     

Vergleich der Raumgliederung Europas mit bestehenden Raumgliederungen – Teil 3

Background, aim and scope The first two articles of this series (Hornsmann et al. 2008; Weustermann et al. 2009) comprised how the Ecological Land Classification of Europe (ELCE) was calculated. Moreover several ecological classes were described exemplarily. In this part 3 of the series the ELCE is compared with two European ecoregionalisations at several levels of differentiation. These are the Digital Map of European ecological regions (DMEER) and the Environmental Stratification of Europe (EnS). In addition the ELCE was opposed to the ecoregionalisation of Germany. The alignment was carried out both functionally and statistically and served as a basis for the examination of the functional consistency of the ELCE. Materials and methods The ecological land classifications were described concerning their input data, the method of derivation and the intended use. The ELCE and the selected three ecoregionalisations were intersected in a GIS and crosstabulated with regard to the acreage of each polygon. These cross tabulations were performed by listing the percentage of ecoregions of e.?g. DMEER to the ecological classes of the ELCE (EC) and vice versa. The similarity of the compared ecoregions was estimated by means of statistics. Results The comparisons show high rates of similarity of the ELCE to the European land classifications. The mean overlap of the EC with the classes of the DMEER is 84 and 69?% vice versa. The EC are covered by the strata of the EnS with 67 and 72?%, respectively. In Germany, ELCE reflects the most important ecological conditions. The mean overlap of the ecoregions in this case is 75 and 80?% vice versa. Discussion The classes of the DMEER show a better overlap of the EC as vice versa due to their larger spatial extent. The main difference between the ELCE and the EnS is based on the procedure of the derivation of the regionalisations. While the classes of the EnS are more differentiated in the South of Europe, the ecoregions of ELCE are smaller and more subdivided in the middle of Europe. The high overlap between the ELCE and the ecoregionalisation of Germany can be indicative for the good account of the ecological structures of the ELCE in the European dimension. Conclusions The ELCE is functionally plausible and a useful complement to the existing land classifications of Europe. Nevertheless, it cannot substitute land classifications on the national level calculated with more detailed input data. The ELCE can be used testing the representativity of environmental monitoring networks in Europe. Recommendations In future, the ELCE should be compared with other national landscape classifications. A new calculation of ELCE would only be useful after the development of a highly powerful derivation method and on the basis of more detailed input data. Moreover, due to the observed climate change in the past 20 years, up-to-date data on climate should be used for the calculations. Perspectives The ELCE could be proven to be functionally consistent. Therefore the fourth article will focus on the investigation of the landscape representativity of environmental monitoring networks on the basis of the ELCE.     

REP-LECOTOX: an example of FP 6 INCO project to strengthen ecotoxicological research in WBC (Western Balkan countries)

Background

In order to map exceedances of critical atmospheric deposition loads for nitrogen (N) surface data on the atmospheric deposition of N compounds to terrestrial ecosystems are needed. Across Europe such information is provided by the international European Monitoring and Evaluation Programme (EMEP) in a resolution of 50 km by 50 km, relying on both emission data and measurement data on atmospheric depositions. The objective of the article at hand is on the improvement of the spatial resolution of the EMEP maps by combining them with data on the N concentration in mosses provided by the International Cooperative Programme on Effects of Air Pollution on Natural Vegetation and Crops (ICP Vegetation) of the United Nations Economic Commission for Europe (UNECE) Long-range Transboundary Air Pollution (LTRAP) Convention.

Methods

The map on atmospheric depositions of total N as modelled by EMEP was intersected with geostatistical surface estimations on the N concentration in mosses at a resolution of 5 km by 5 km. The medians of the N estimations in mosses were then calculated for each 50 km by 50 km grid cell. Both medians of moss estimations and corresponding modelled deposition values were ln-transformed and their relationship investigated and modelled by linear regression analysis. The regression equations were applied on the moss kriging estimates of the N concentration in mosses. The respective residuals were projected onto the centres of the EMEP grid cells and were mapped using variogram analysis and kriging procedures. Finally, the residual and the regression map were summed up to the map of total N deposition in terrestrial ecosystems throughout Europe.

Results and discussion

The regression analysis of the estimated N concentrations in mosses and the modelled EMEP depositions resulted in clear linear regression patterns with coefficients of determination of r ² = 0.62 and Pearson correlations of r _p = 0.79 and Spearman correlations of r _s = 0.70, respectively. Regarding the German territory a nationwide mean of 18.1 kg/ha/a (standard deviation: 3.49 kg/ha/a) could be derived from the resulting map on total N deposition in a resolution of 5 km by 5 km. Recent updates of the modelled atmospheric deposition of N provided a similar estimate for Germany.

Conclusions

The linking of modelled EMEP data on the atmospheric depositions of total N and the accumulation of N in mosses allows to map the deposition of total N in a high resolution of 5 km by 5 km using empirical moss data. The mapping relies on the strong statistical relationship between both processes that are physically and chemically related to each other. The mapping approach thereby relies on available data that are both based on European wide harmonized methodologies. From an ecotoxicological point of view the linking of data on N depositions and those on N bioaccumulation can be considered a substantial progress.     

Bioakkumulation von Metallen und Stickstoff zwischen 1990 und 2005 in Niedersachsen

Background, aim, and scope Since 1990 the UN ECE Heavy Metals in Mosses Surveys provide data inventories of the atmospheric heavy metal bioaccumulation across Europe. In the survey 2005 the nitrogen accumulation was measured for the first time in most of the participating countries. In Germany, the surveys were conducted in close cooperation of the relevant authorities of both the Federal Republic and the sixteen states. Therefore, statistical evaluations of the moss survey data with regard to the whole German territory and single federal states are of interest. This article concentrates on Lower Saxony, dealing with the mapping of the spatiotemporal trends of metal accumulation from 1990 to 2005, the spatial patterns of nitrogen accumulation in 2005, and the spatial variability of bioaccumulation due to characteristics of the sampling sites and their surroundings. Materials and methods The bioaccumulation of up to 40 trace elements and nitrogen in mosses was determined according to a Europe-wide harmonised methodology. The according experimental protocol regulates the selection of sampling sites and moss species, the chemical analysis and quality control and the classification of the measured values for mapping spatial patterns. In Lower Saxony all sampling sites were described with regard to topographical and ecological characteristics and several criteria to be fulfilled according to the guideline. Together with the measurements this metadata was combined with other information regarding land use in the surroundings of the sampling sites in the WebGIS MossMet. The spatial structure of the metal bioaccumulation was analysed and modelled by variogram analyses and then mapped by applying different Kriging techniques. Furthermore, multi metal indices (MMI) were derived for both the sampling sites and raster maps with help of percentile statistics: The MMI_1990–2005 was calculated for As, Cd, Cr, Cu, Fe, Ni, Pb, Ti, V and Zn. The statistical association of the metal and nitrogen bioaccumulation, site specific characteristics as well as information on land use and emissions was analysed by bivariate nonparametric correlation analysis, contingency tables and Classification and Regression Trees (CART). Results The results of the quality controlled chemical analyses shows a significant decrease of the metal bioaccumulation in Germany from 1990 to 2000 for all elements but Zn. From 2000 to 2005 a further significant decrease can be stated for Cd, Hg and Pb, to most parts non significant increases can be observed for Cr, Cu, Fe, Sb and Zn. Cr thereby exhibits the highest accumulation in 2005 when compared to the results of 1990, 1995 and 2000. The MMI illustrates the temporal trend of the metal bioaccumulation as a whole: From 1990 to 2000 a continuous significant decrease can be observed. From 2000 to 2005 the median of the MMI increases, again significantly, from 3.4 to 4. The N concentration in mosses in Lower Saxony reaches from 1.1 to 1.9?% in dry mass. High N concentrations were detected in agriculturally intensively used areas. Highly significant bivariate correlations between the metal bioaccumulation and land use in the surroundings of the sampling sites were found reaching from 0.3 to 0.5. Other location criteria with similar correlation coefficients/Cramér’s V are moss species, altitude, distance to the North and Baltic Sea and the distance of the sampling site to the nearest tree crown. N only shows negative correlations to urban land use and the distance to the nearest tree. Exemplified for Sb multivariate correlations were furthermore detected by CART. It could be shown that the Sb bioaccumulation interacts with the moss species and the ratio of agriculture, forests and urban areas around the sampling site. Discussion The decrease of the continuously decrease of heavy metals reflects the improving air quality in the past 15 years. Compared to other environmental monitoring and modelling programmes the moss surveys registered increasing concentrations of toxic metal elements between 1990 and 2005, e.?g. Cr. High Cr loads in mosses were also registered in other European countries like in Switzerland. Further investigations are therefore necessary to investigate whether this is due to different emission conditions or biogenic effects (e.?g. as a result of increasing nitrogen depositions). Contrary to deposition measurements that exhibit a higher temporal resolution the moss surveys provide measurement data on a wide range of elements. Some of these elements are important with regard to human-toxicological aspects (e.?g. As, Al, Hg, Sb, V). Due to its ecotoxicological relevance nitrogen was monitored in the European moss survey 2005 for the first time. Compared to the metals regionally high emissions of nitrogen compounds into the atmosphere can be detected in Lower Saxony. The standardised biomonitoring of atmospheric pollution with mosses is an important link between the technical acquisition of depositions and the accumulation in biological material. To claim that the element concentrations in mosses should correlate to a high degree with measured or modelled depositions is not appropriate since these approaches are considering different biological or physical receptors. Nevertheless, the accumulation of air pollutants in terricolous mosses reflects the degree of air pollution which is permanently deposited and affects the system of plants and soils. The degree of correlation thereby depends on the boundary conditions of the physical processes, like regional and site-specific meteorological conditions within the accumulation period, the vertical and horizontal vegetation structure or land use conditions. Conclusions The moss surveys contribute to the heavy metal and the multi-component-model of CLRTAP because they prove on different spatial scales how air pollution control influences the accumulation of emitted substances in environmental subjects of protection like vegetation incl. arable crops. If environmental monitoring is seen as a continuous task and the applied methodology works well as an early warning system then environmental policy is enabled to act in preventative sense and to pursue unexpected developments. No other environmental monitoring programme provides such a wide range of ecotoxicologically relevant elements measured as spatially dense as the case for the moss surveys. The spatial distribution of environmental information is an essential criterion for their usability in terms of political measures for the federal states and the federation. Recommendations and perspectives Heavy Metals in Mosses Surveys are a positive example for environmental monitoring activities reaching across three spatial and administrative levels: regional (e.?g. federal state or natural landscape), nation wide (e.?g. Germany) and continental (e.?g. Europe). In Germany the harmonised and quality controlled moss data are made available via a WebGIS portal. Therefore the moss data may easily be accessed for environmental monitoring purposes and the control of environmental political actions. Hence, the continuous task of environmental monitoring can be met and carried on in the future.     

Schwermetalle in Regenwürmern Baden-Württembergs

Goal and Scope

Since 1984 the Environmental Protection Agency (LfU) of the State of Baden-Wuerttemberg has been investigating the heavy metal burden of earthworms from representative long-term forest observation plots. These investigations are aimed at elucidating and assessing adverse effects of pollutants on the soil biocenosis.

Methods

At first only lead and cadmium were measured in the worms; in repetitive measurements over the years further metals or metalloid elements such as aluminum, arsenic, chromium, cobalt, copper, manganese, mercury, nickel, thallium, vanadium, and zinc were added to the agenda.

Results and Conclusion

The frequency distribution of the metals in the earthworms was characterized statistically. For the first time state-wide background values, normal values and threshold values were established for all the elements measured. A comparable study with a similar range of parameters is known neither nationally nor internationally. Time trend studies have been available for lead and cadmium since 1985/86, and for zinc since 1987. The studies show a steady decrease of the heavy metals on a state-wide average and especially in the ‘Odenwald’ and ‘Black Forest’ hills with their formerly highly polluted earthworm habitats. Today, the level of these metals in the earthworms is low with few exceptions. This holds true for other heavy metals as well.

Recommendations and Perspectives

The state-wide decreasing very low heavy metal burden of forest observation plots far from known emission sources can be considered a success of air pollution abatement measures. Because of the ongoing atmospheric deposition of heavy metals, regular observation should continue in order to estimate time trends and to recommend the reduction of emissions when precautionary values (part 2) are exceeded.     

Biomonitoring von Stickstoffimmissionen

Background and aim

Air pollution caused by oxidized and reduced nitrogen is distributed over wide areas of Europe at a high level. As an alternative or complement to physical measurements and modelling calculations, biomonitoring with plants provides techniques to assess amounts and effects of pollution from oxidized and reduced nitrogen compounds (depositions and concentrations). Many of the previously implemented techniques are based on well-proven standardised methods, e.g. documented in VDI guidelines, modified more or less for a biomonitoring of atmospheric nitrogen pollution. This paper gives a review of the techniques for a biomonitoring of atmospheric nitrogen pollution, their possibilities as well as their limitations.

Main features

-diversity of the ground vegetation

-nitrogen accumulation in vascular plants

-exposure of vascular plants

-mapping of epiphytic lichens, bryophytes and algae

-nitrogen accumulation in lichens and bryophytes

-exposure of lichens and bryophytes

Results and Discussion

Important response parameters are nitrogen concentrations in plant tissue (shoot, needle, leave) and biodiversity of plant species. These responses of vascular plants in many cases are influenced by other local varying conditions, in particular the soil. The exposure of vascular plants over a short period provides a standardised quantification of the total atmospheric nitrogen input in a model ecosystem. The enrichment of nitrogen in the plant tissue of bryophytes and lichens from the ground vegetation is closely correlated with the amount of nitrogen deposition. The diversity of epiphytic lichens and the response of exposed Hypogymnia physodes is more sensitive to ammonia than to nitrous oxide, whereas with the diversity of epiphytic bryophytes or the abundance of algae no significant correlation with atmospheric N pollution were found.

Conclusions

Some bioindication techniques provide a causeeffect related, partly standardised biomonitoring of nitrogen pollution. In some cases varying experiences with some biomonitors like the biodiversity of the ground vegetation, exposure of lichens, moss bags and grass cultures stress the need for more research in this subject.     

Metalle und Stickstoff angereichert in Moosen Sachsens

Background, aim and scope Since 1990 the UN ECE Heavy Metals in Mosses Surveys provide data inventories of the atmospheric heavy metal bioaccumulation across Europe. In the survey 2005 the nitrogen (N) accumulation was measured for the first time in most of the participating countries. In Germany, the surveys were conducted in close cooperation of the relevant authorities of both the Federal Republic and the sixteen states. Therefore, statistical evaluations of the moss survey data with regard to the whole German territory and single federal states are of interest. This article concentrates on Saxony, dealing with the mapping of the spatiotemporal trends of metal accumulation from 1990 to 2005, the spatial patterns of nitrogen accumulation in 2005, and the spatial variability of bioaccumulation due to characteristics of the sampling sites and their surroundings. Exemplified for Cadmium (Cd), Mercury (Hg) and Lead (Pb) the metal loads in mosses are furthermore related to modelled deposition data provided from the European Monitoring and Evaluation Programme (EMEP). Materials and methods In Saxony Pleurozium schreberi (1990, 1995 most frequent moss species, thereafter second most), Hypnum cupressiforme (1990, 1995 second most, thereafter most frequent moss species), Scleropodium purum and Brachytecium rutabulum (1995, 2000) were sampled at up to 83 sites. All sampling sites were described with regard to topographical and ecological characteristics and several criteria to be fulfilled according to the guideline. Together with the measurements this metadata was combined with other information regarding land use in the surroundings of the sampling sites in the WebGIS MossMet. The spatial structure of the metal bioaccumulation was analysed and modelled by variogram analyses and then mapped by applying different kriging techniques. Furthermore, multi metal indices (MMI) were derived for both the sampling sites and raster maps with help of percentile statistics: The MMI_1990–2005 was calculated for arsenic (As), cadmium (Cd), chromium (Cr), copper (Cu), iron (Fe), nickel (Ni), lead (Pb), titanium (Ti), vanadium (V) and zinc (Zn). The statistical association of the metal bioaccumulation, site specific characteristics as well as information on land use and emissions was analysed by bivariate nonparametric correlation analysis, contingency tables and Classification and Regression Trees (CART). Results The results of the quality controlled chemical analyses show a decrease of the metal bioaccumulation in Saxony from 1990 to 2000. From 2000 to 2005?a significant increase can be stated for As, Cr, Cu, Fe, Ti and V. The element loads of Cd, Hg, Pb and Sb show a decreasing, although non significant, tendency. The MMI_1990–2005 decreased significantly from 1990 to 2000 and increased significantly from 2000 to 2005. The N concentration in mosses in Saxony reaches from 1.36 to 1.96?% in dry mass showing significant correlations to the agriculture density (+), the height of the surrounding trees (+), altitude (–) and the precipitation sum for the accumulation period (–). The ratios of forests around the monitoring sites show a negative correlation to all elements but for Pb, Sb and V. Unlike Cd the moss loads of As, Cr, Cu, Fe, Hg, Ni, Pb, Ti and V are positively correlated to the density of urban areas calculated from the Corine Landcover map 2000. The same holds true for Cr, Cu Fe and Ni regarding traffic density and Cd, Cu, Hg and Ni regarding agricultural density. The precipitation sum within the accumulation period is positively correlated with As, Cd, Cr (1990–2000), Ni, Pb, Sb und V, negatively with Cr (2005), Cu, Fe and Zn. Regarding altitude a similar tendency can be observed. The slope gradient shows significant association to Cd, Cu, Ni and Pb. Regarding the canopy effect negative correlation coefficients were calculated for As, Pb and Sb regarding the distance of the sampling site to the nearest tree crowns and positive correlations were calculated for Cd, Cr, Fe and Sb with respect to the height of the surrounding trees. The distance of the moss site to human settlements is significantly related to As, Cd, Cr, Hg, Ni, Pb and Sb. The impact of traffic becomes apparent for As, Cr, Cu, Ni, Pb, Sb, V and Zn which are all negatively correlated with the distance of the moss site to the nearest road. The multivariate statistical CART analysis identifies the urban land use density in a radius of 5?km around the sampling site as well as the height of surrounding trees as the statistically most significant factors for the Cu concentrations in mosses sampled in 2005. The modelled total deposition of Cd, Hg and Pb (EMEP) and the respective concentrations in Saxon mosses are correlated significantly (1995 Hg: r _s = 0.62, p = 0.004; 2005 Cd: r _s = 0.43, p = 0.07, Hg: r _s = 0.44, p = 0.06, Pb: r _s = 0.39, p = 0,099). Discussion Unlike in e.?g. Baden-Württemberg the metal accumulation in mosses in Saxony increased between 2000 and 2005, Cr thereby increased dramatically. For Cd, Hg and Pb it could be shown that the metal loads in mosses are significantly correlated to the modelled total deposition provided by EMEP. Nevertheless, this does not hold true for all elements in all campaigns. Taking this into account, it can be verified that positive relationships between the metal bioaccumulation and the deposition for Saxony exist. Conclusions Contrary to deposition measurements that exhibit a higher temporal resolution the moss surveys provide measurement data on a wide range of elements. Some of these elements are important with regard to human-toxicological aspects (e.?g. Al, As, Hg, Sb, V). The standardised biomonitoring of atmospheric pollution with mosses is an important link between the technical acquisition of depositions and the accumulation in biological material. To claim that the element concentrations in mosses and in the deposition should correlate to a high degree is not appropriate since both approaches are physically related but are not identical. The degree of correlation thereby depends on the boundary conditions of the physical processes, like regional and site-specific meteorological conditions within the accumulation period, the vertical and horizontal vegetation structure or land use conditions. Recommendations and perspectives The Heavy Metals in Mosses Surveys are a positive example for environmental monitoring activities reaching across three spatial and administrative levels: regional (e.?g. federal state or natural landscape), nation wide (e.?g. Germany) and continental (e.?g. Europe). It can therefore be claimed that the moss survey is the only environmental monitoring network that provides high density and surface covering information on the metal and N exposition of near-natural and agricultural ecosystems. The correlations of the metal bioaccumulation and the modelled deposition should therefore be used to complement the deposition measurement activities across Europe.     

Anreicherung atmosphärischer Depositionen von Metallen und Stickstoff in Moosen Mecklenburg-Vorpommerns von 1990 bis 2005

Background, aim and scope Since 1990 the UN ECE Heavy Metals in Mosses Surveys provide data inventories of the atmospheric heavy metal bioaccumulation across Europe. In the survey 2005 the nitrogen accumulation was measured for the first time in most of the participating countries. In Germany, the surveys were conducted in close cooperation of the relevant authorities of both the Federal Republic and the sixteen states. Therefore, statistical evaluations of the moss survey data with regard to the whole German territory and single federal states are of interest. This article concentrates on Mecklenburg-Western Pomerania, dealing with the mapping of the spatiotemporal trends of metal accumulation from 1990 to 2005, the spatial patterns of nitrogen accumulation in 2005, and the spatial variability of bioaccumulation due to characteristics of the sampling sites and their surroundings. Materials and methods The bioaccumulation of up to 40 trace elements in mosses was determined according to a Europe-wide harmonised methodology. The according experimental protocol regulates the selection of sampling sites and moss species, the chemical analysis and quality control and the classification of the measured values for mapping spatial patterns. In Mecklenburg-Western Pomerania all sampling sites were described with regard to topographical and ecological characteristics and several criteria to be fulfilled according to the guideline. Together with the measurements this metadata was combined with other information regarding land use in the surroundings of the sampling sites in the WebGIS MossMet. The spatial structure of the metal bioaccumulation was analysed and modelled by variogram analyses and then mapped by applying different kriging techniques. Furthermore, multi metal indices (MMI) were derived for both the sampling sites and raster maps with help of percentile statistics: The MMI_1990–2005 was calculated for As, Cd, Cr, Cu, Fe, Ni, Pb, Ti, V and Zn. The statistical association of the metal bioaccumulation, site specific characteristics as well as information on land use and emissions was analysed by bivariate nonparametric correlation analysis, contingency tables and Chi-square Automatic Interaction Detection (CHAID). Results The results of the quality controlled chemical analyses show a significant decrease of the metal bioaccumulation in Germany from 1990 to 2000 for all elements. However, in Mecklenburg-Western Pomerania the concentrations of Cr and Zn are even significantly higher than those found in 1990. From 2000 to 2005?a further non-significant increase can be stated for As, Cu, Ni and Ti. The concentrations of Cd and Pb decreased significantly throughout all four surveys. The MMI illustrates the temporal trend of the metal bioaccumulation as a whole: After a significant decrease from 1990 to 2000 it increased significantly till 2005. The N concentration in mosses in Mecklenburg-Western Pomerania reaches from 1.3 to 2.3?% in dry mass and is negatively correlated with the forest ratio in the surroundings of the moss sampling sites and to the same degree positively correlated with the area ratio of agricultural land uses. Except for Cd, Pb and Sb all metal concentrations in the mosses are negatively correlated with the forest ratio around the sampling sites. With the exception of Cr all metal concentrations are further negatively correlated with the precipitation sums of the accumulation periods. Only the Cu and Zn concentrations show no or rather a negative correlation with the tree height whereas all other elements exhibit positive correlations. Furthermore, all elements except Cr are significantly associated to the sampled moss species, the growth pattern and the frequency of occurrence of the mosses at the respective sampling sites. Exemplified for Cu multivariate correlations were furthermore detected by CHAID. It could be shown that the frequency of the mosses, the sampled moss species, the distance to motorways and the distance to the Baltic Sea are the statistically most significant boundary conditions of the Cu concentrations in the mosses sampled in Mecklenburg-Western Pomerania in 2005. No correlations were found between the modelled total depositions and the concentrations of Cd, Hg and Pb in the mosses at p < 0.1. For Pb in 1995?r is 0.52 at p = 0.012, for the other surveys no correlations at p < 0.05 could be found. Discussion The increase of the Cr bioaccumulation from 2000 till 2005 is particularly pronounced in Mecklenburg-Western Pomerania. This trend is confirmed with regional differences in the national average as well as in other participating countries like in Switzerland. Deposition measurements did not register this trend. In contrast to the UNECE area, the federal territory and several federal states no correlations were found between the modelled total depositions and the metal concentrations in the mosses. Conclusions The fact that no correlations were found between the modelled total depositions and the element concentrations in the mosses may be caused by the low spatial resolution (50?×?50?km) of the EMEP data. The moss surveys contribute to the heavy metal and the multi-component-model of CLRTAP because they prove on different spatial scales how air pollution control influences the accumulation of emitted substances in environmental subjects of protection like vegetation. In contrast to deposition measurement networks the moss monitoring identified a trend reversal in Mecklenburg-Western Pomerania: The continuous decrease of the metal bioaccumulation in mosses from 1990 till 2000 has changed to an increase of several metals between 2000 and 2005. This increase is significant for Cr and Zn. Recommendations and perspectives The spatial resolution of the EMEP deposition data should be enhanced based on the Europe-wide regression relationship between the element concentrations in the deposition and in the mosses. For regional studies the existing but so far not useable deposition measurement data of the federal states should be made available. It should further be investigated what caused the increase of the Cr concentrations above the level of 1990 – perhaps emissions or biogenic effects as a consequence of simultaneously increased nitrogen loads? The Heavy Metals in Mosses Surveys are a positive example for environmental monitoring activities reaching across three spatial and administrative levels: regional (e.?g. federal state or natural landscape), nation wide (e.?g. Germany) and continental (e.?g. Europe). In Germany the harmonised and quality controlled moss data are made available via a WebGIS portal. Therefore the moss data may easily be accessed for environmental monitoring purposes and the control of environmental political actions. Hence, the continuous task of environmental monitoring can be met and carried on in the future. It should further be considered to expand the moss monitoring on the survey of persistent organic pollutants and apply it in human-biomonitoring. This would facilitate the acquisition of indoor and outdoor pollution with the same receptor.     

Schwermetallbelastung von Dreissena polymorpha in Donau und Drau und ihre Bedeutung als Bioindikator

Goal and Scope

This study was undertaken to investigate the differences in heavy metal burden between the organisms and environmental compartments and to evaluate the role of Dreissena polymorpha as a bioindicator organism.

Methods

The concentrations of zinc, copper, cadmium and lead in whole soft body and selected tissues of D. polymorpha at two river habitats in Austria were examined using atomic absorption spectroscopy (AAS). Concentrations in organisms were compared to those in sediment and water.

Results and Conclusion

Zebra mussels of the river Drau showed generally higher heavy metal concentrations as compared to mussels of the river Danube and contained elevated zinc and cadmium levels as compared to metal concentrations found in soft tissues of zebra mussels from uncontaminated sites in Germany and The Netherlands. The essential metals zinc and copper were mainly accumulated in gills, foot and byssal gland tissue of the mussel, in contrast to the non-essential metals cadmium and lead which were found predominantly in the midgut gland. The heavy metal concentrations in both, sediments and mussel tissue, were higher than in water samples. There was no correlation between the concentrations in water and in the organisms except for zinc. In contrast, correlations were found between concentrations in sediments and mussel soft tissue.

Recommendation and Perspective

Further investigations should include the examination of sediments and consider the mechanism of food uptake to assess the role of D. polymorpha as a bioindicator organism.     

Trend der Schwermetall-Bioakkumulation 1990 bis 2005: Qualitätssicherung bei Probenahme, Analytik, geostatistischer Auswertung

Background, aim and scope Since 1990, the UN ECE Heavy Metals in Mosses Surveys provide data inventories of the atmospheric heavy metal bioaccumulation across national boundaries in Europe. The results prove how air pollution control in Germany and in all of Europe affected the bioaccumulation of metals in those ecosystems that are not directly influenced by nearby emission sources. This article focuses on the assessment of spatiotemporal patterns of the metal bioaccumulation in Germany since 1990. Furthermore, the spatial variance of the metal bioaccumulation is analysed with regard to sampling site-specific and regional land characteristics. Special focus hereby relies on the correlation of the metal concentration in mosses and in depositions. Hence, the moss surveys contribute to §?12 of the German Federal Nature Conservation Act as well as to the “Convention on Long-range Transboundary Air Pollution” (CLRTAP). Materials and methods The bioaccumulation of up to 40 trace elements in mosses was determined according to a European wide harmonised methodology. The according experimental protocol regulates the selection of sampling sites and moss species, the chemical analysis and quality control and the classification of the measured values for the mapping of spatial patterns. In Germany all sampling sites were described with regard to topographical and ecological criteria as well as other aspects seen as relevant in the mandatory guideline. Together with the measurements this metadata was combined with other information regarding emissions and land use in the surroundings of the sampling sites in the WebGIS MossMet. The spatial structure of the metal bioaccumulation was analysed and modeled by variogram analyses and then mapped by applying different kriging techniques. Furthermore, different multi-metal indices (MMI) were derived for both the sampling sites and raster maps with the help of percentile statistics: The MMI1990 aggregates the data for Cr, Cu, Fe, Ni, Pb, Ti, V and Zn determined in 1990. The MMI1995, MMI2000, MMI2005 furthermore include As, Cd, Hg and Sb for 1995, 2000 and 2005, respectively. Two other MMI allow for a time integrating view on the metal bioaccumulation in Germany: The MMI1990–2005 was calculated on behalf of all measured/geostatistically estimated data for Cr, Cu, Fe, Ni, Pb, Ti, V and Zn. Therefore the integrated assessment of the metal bioaccumulation in Germany from 1990 to 2005 is possible. The MMI1995–2005 furthermore includes the element-specific data of As, Cd, Hg and Sb therefore integrating 12 elements over the last three surveys. The statistical association of the metal bioaccumulation, site-specific characteristics as well as information on land use and emissions was analysed by bivariate correlation analysis and multivariate decision tree models (Classification and Regression Trees – CART, Chisquare Automatic Interaction Detection – CHAID). Results The results of the quality-controlled chemical analyses show a significant decrease of the metal bioaccumulation in Germany from 1990 to 2000. From 2000 to 2005 a further decrease can be stated for Hg, Pb and Ti. However, a significant increase for Cd, Cr, Cu, Sb and Zn can be observed. This especially holds true for Cr (+ 160?%) that almost reaches as high concentrations in mosses as in 1990. In 2005, the metal loads in mosses, except for Cr, show spatial distributions similar to those in 1990, 1995 and 2000. Hot spots are mostly found in the urbanised and industrially influenced Ruhr Area, the densely populated Rhine–Main region and in the industrially influenced regions of former East Germany (e.?g. Halle–Leipzig region). The spatial variance of the metal bioaccumulation can mainly be explained by site-specific (moss species, canopy drip effects) and site-surrounding (land use, depositions, emissions) characteristics. Discussion High Cr loads in mosses were also registered in other European countries like in Switzerland. Further investigation is therefore necessary to investigate whether this is due to different emission conditions or biogenic effects (e.?g. as a result of increasing nitrogen depositions). Compared to other environmental monitoring and modelling programmes the moss surveys registered increasing concentrations of toxic metal elements between 1990 and 2005. Contrary to deposition measurements that exhibit a higher temporal resolution the moss surveys provide measurement data on a wide range of elements. Some of these elements are important with regard to human-toxicological aspects (e.?g. Hg, Sb, As, Al, V). The standardised biomonitoring of atmospheric pollution by mosses is an important link between the technical acquisition of depositions and the accumulation in biological material. To claim that the element concentrations in mosses and in the deposition should correlate to a high degree is not appropriate since both approaches are physically related but are not identical. The degree of correlation thereby depends on the boundary conditions of the physical processes, like regional and site-specific meteorological conditions within the accumulation period, the vertical and horizontal vegetation structure or land use conditions. Conclusions The moss surveys contribute to the heavy metal and multi-component model of CLRTAP because they prove on different spatial scales how air pollution control influences the accumulation of emitted substances in environmental subjects of protection like vegetation. If environmental monitoring is seen as a continuous task and the applied methodology works well as an early warning system then environmental policy is enabled to act in preventative sense and to pursue unexpected developments. No other environmental monitoring programme provides such a wide range of ecotoxically relevant elements measured as spatially dense as the case for the moss surveys. The spatial distribution of environmental information is an essential criterion for their usability in terms of political measures for the federal states and the federation. Recommendations and perspectives The Heavy Metals in Mosses Surveys are a positive example for environmental monitoring activities reaching across three spatial and administrative levels: regional (e.?g. federal state or natural landscape), nationwide (e.?g. Germany) and continental (e.?g. Europe). In Germany the harmonised and quality-controlled moss data are made available via an internet-based webGIS portal. Therefore the moss data may easily be accessed for environmental monitoring purposes and the control of environmental political actions. Hence, the monitoring of Heavy Metals by Mosses Surveys is an important task among the European environmental observations, which should be continued in future for scientific and political reasons in its current extent.     

Polyzyklische aromatische Kohlenwasserstoffe aus diffusen Quellen

Goal and Scope

Polycyclic aromatic hydrocarbons (PAHs) are one group of persistent organic pollutants which are ubiquitous distributed in soils, even in rural areas. After their release into the atmosphere, transportation and deposition, they tend to accumulate in topsoils and sediments. Similar distribution pattern of PAHs in atmospheric deposition, soil samples as well as sediment samples indicate a close relationship between atmospheric input and accumulation of PAHs in the terrestrial environment. The intention of this paper was to estimate the time when precautionary values of the German law of soil protection will be exceeded in rural areas. Furthermore, current soil concentrations will be linked to the historical record of PAHs by means of enrichment factors.

Methods

The historical record of the atmospheric deposition rates of PAHs can be obtained from investigation of sediment cores. Based thereon, enrichment factors of PAHs in the environment were calculated. With these enrichment factors it was possible to estimate the recent PAH concentration in soils in rural areas from currently measured annual deposition rates. Furthermore, concentrations of PAHs in soils and deposition rates can be used to calculate the time when precautionary values will be reached.

Results and Conclusion

PAH deposition rates have been decreasing since about 1960 by a factor of 2–3, but stabilized during the last decade on a level high above pre-industrial time. Thus, further enrichment of PAH in topsoils has to be expected. Actual deposition rates in connection with historical enrichment factors allow to determine the median concentrations of PAHs in rural soils. The time when precautionary values will be reached was calculated to about 300 Years.

Outlook

The database to predict the further development of atmospheric deposition rates is very weak. There was a lack of validated methods concerning direct measurements of atmospheric POP deposition. Meanwhile, a national draft of a standard base on time-integrated passive sampling exists. This method can be implemented to establish a combined soil and deposition-monitoring program in order to assess the risk of further accumulation of POPs in soils.     

Mapping Soil Lead and Remediation Needs in Contaminated Soils

For the past two decades, the Taiwan Environmental Protection Administration has made a systematic investigation of As, Cd, Cr, Cu, Pb, Hg, Ni and Zn in agricultural soils to identify soil pollution from industrial production. The EPA has cooperated with local governmental agencies to establish a soil quality monitoring system that would upgrade the land recovery ability and prohibit polluted lands from being cultivated or turned over to other uses. Based on an island-wide soil survey, more than 1,000 hectares of arable soils in Taiwan were found to be considerably contaminated by heavy metals. One of the heavy metal contaminated sites, located near a ceramic product manufacturing factory in Nantou County, was identified as lead contaminated. According to the Nantou Environmental Protection Bureau, the lead content in contaminated sites showed a great variation of several mg Pbkg^–1 soil to several thousands mg Pbkg^–1 soil. Therefore, it is appropriate to estimate the lead spatial distribution through geostatistics such as Kriging. The soil lead concentration contour maps obtained by Kriging can help us to identify the pollution patterns and delineate the range of contaminated sites. The purpose of this study is to determine the Pb concentrations at each location by performing detailed soil sampling on those Pb contaminated sites and estimating the lead spatial distributions by Kriging. A total of 70 soils were sampled from different locations at two experiment sites. Lead contents were determined with 0.1M HCl extractable lead content of the soils. The results obtained by investigating the lead contents in each 15cm segment down to a 60cm depth, revealed that lead contents were greater in arable land near the ceramic products manufacturing factory, and lead concentrations decreased with depth. In addition, Pb concentrations in heavily contaminated soils showed heavy concentrations of Pb in specific locations. Results from Pb content spatial distributions indicated that the Kriging model is a useful tool and can provide decision-makers with critical information for delineating hazardous areas in heavy metal contaminated sites.     

Elbehochwasser 2002 — Ein Rückblick

Objective

Flood sediments were investigated due to the extreme flood situation around Dresden in August 2002

Method

The samples have been analyzed by screening inorganic and organic pollutants.

Results

It was observed that As, Pb, Cd, Zn, Cu, B and other heavy metals as well as DDT, PCB and Benzo [a] pyren were significantly enriched.

Conclusion

Depending on geogenic and anthropogenic impacts, the spatial distribution of these contaminants was different. Organic compounds were dislocated down stream from Czech Republic along the Elbe River. Because of the old ore mining, samples near the Mulde and Wei\eritz Rivers showed high metal pollution.

Perspective

More detailed and systematic investigations should be undertaken in the Elbe and Mulde river systems.