Fragmentation of Landscape as a Cause for Genetic Subdivision in Bank Voles

Abstract: We studied the barrier effects of various roadways on the genetic subdivision of bank vole (Clethrionomys glareolus) populations. Allele frequencies, genetic variability, and genetic distances of natural populations were calculated based on polymorphism of seven microsatellite markers. We compared bank vole populations in control areas without such barriers with animals from both sides of a country road, a railway, and a highway. Using F and R statistics, we demonstrated significant population subdivision in bank vole populations separated by the highway, but not in populations on either side of the other roadways or in the control area. Correlations between geographic and genetic distances were revealed by an extended method based on a Mantel analysis. This allowed us to measure genetic barrier effects and express them as additional geographic distances. For instance, statistically significant differences in allele frequencies in all seven loci examined existed among populations in southern Germany and Switzerland, which are separated by the Rhine River and Lake Constance. The real geographic distance between bank vole populations in Konstanz and those in Lengwil, Switzerland, was 6 km. According to this analysis the genetic barrier effect of the Rhine could be defined as an additional distance of 7.7 km. This study shows for the first time that not only old geographic barriers but also more recent fragmentation of landscape by, for example, highways has an important effect on gene flow and the genetic substructuring of populations, which should be considered in future environmental impact assessments.     

Environmental accounting on a communal level: A tool to support environmental management and decision-making by communal executives

Starting from an ecological perspective of urban-industrial areas, environmental accounting is used to analyse and to evaluate which environmental impacts are the result of communal activities (e.g. the results of different kinds of water supply systems). Therefore, the anthropogenic fluxes, the changing quality of areas as well as the processes between the environmental fields are taken into account. The approach is based on methodical elements of te Life Cycle Analysis and the Environmental Impact Assessment. Looking at the ‘urban systems’ within the communal activities, ‘ecological modelling’ gives us a new and fuller picture of the spatial and temporal character of urban metabolism. The approach supports the perception of cumulative effects and the postponement of environmental problems and opens new horizons for process-oriented environmental planning within the community. Greater efficiency and a decrease in costs can be arrived at by leaving ‘end of the pipe’ strategies; opportunities for a better planning process and measures for different individuals and organisations can be drawn up. A data base which acts as a ‘support system’ implements the computer-aided approach to environmental accounting.     

Whole cell hybridisation for monitoring harmful marine microalgae

Fluorescence in situ hybridisation (FISH) is a powerful molecular biological tool to detect and enumerate harmful microorganism in the marine environment. Different FISH methods are available, and especially in combination with automated counting techniques, the potential for a routine monitoring of harmful marine microalgae is attainable. Various oligonucleotide probes are developed for detecting harmful microalgae. However, FISH-based methods are not yet regularly included in monitoring programmes tracking the presence of harmful marine microalgae. A limitation factor of the FISH technique is the currently available number of suited fluorochromes attached to the FISH probes to detect various harmful species in one environmental sample at a time. However, coupled automated techniques, like flow cytometry or solid-phase cytometry, can facilitate the analysis of numerous field samples and help to overcome this drawback. A great benefit of FISH in contrast to other molecular biological detection methods for harmful marine microalgae is the direct visualisation of the hybridised target cells, which are not permitted in cell free formats, like DNA depending analysis methods. Therefore, an additional validation of the FISH-generated results is simultaneously given.     

Entwicklung von Prüfwertempfehlungen für ausgewählte Schadstoffe zum Schutz des Bodens als Lebensraum für Bodenorganismen

Goal and Scope

In the German Federal Soil Protection and Contaminated Sites Ordinance there are no ecotoxicological trigger values for the protection of soil as a habitat for soil organisms. The objective of this study was to derive preliminary trigger values for the habitat function of soils. This was done by collecting data on the impact of priority pollutants on soil organisms and plants followed by the parallel use of the Factorial Application Method (FAME) and Distribution Based Extrapolation (DIBAEX) and a final verification of the plausibility of the calculated trigger values by means of an ecotoxicological test battery.

Methods

Data on the effects of pollutants on soil organisms and plants were recorded in a specific data base (Soil Value). Subsequently, we derived so-called ‘working trigger values’ using the extrapolation methods FAME (factorial application method) and DIBAEX (distribution based extrapolation). In the second phase of the project, we verified experimentally the plausibility of these values by means of an ecotoxicological test battery. Test substrate was a sandy soil with low sorption capacity and organic carbon content which was mixed with fresh pollutants (e.g. heavy metal salts) and polluted soil material from contaminated sites (aged contamination), respectively. Organisms tested were microorganisms, plants, earthworms, springtails and nematodes.

Results and Conclusions

We calculated working trigger values for 12 pollutants based on 900 datasets compiled in he data base. The laboratory investigations showed the freshly added contaminants to be less strongly adsorbed to the soil than those added by the use of contaminated soil material. Nevertheless, aged contaminations displayed often the same inhibitive effects as the freshly added chemicals. The results achieved in the second phase of the project were also recorded in the Soil-Value database. Based on the new data set, final trigger values were derived for the experimentally tested substances.

Outlook

The procedure described in this contribution exemplarily for copper can be used for the derivation of recommended trigger values for the pathway soil ? soil organisms. Besides copper, preliminary trigger values were derived for zinc, mercury, lead and HCH.     

Food 21: a research program looking for measures and tools to increase food chain sustainability

Food 21, an interdisciplinary research program encompassing the whole agro-food chain, was conducted in Sweden during 1997-2004. The challenges undertaken were to come up with environmental tools and solutions to existing nonsustainable practices along the entire food chain. This required close collaboration between the scientists and the food chain stakeholders. A set of goals characterizing sustainable food production is presented in this paper. Synthesis and systems analysis were the main tools used to analyze the sustainability of proposed changes. In this introduction we give an overview of the Food 21 concept and highlight some results. For example, we found that organic farming and organic products were not in general superior to conventional products and practices with respect to environmental impact and product quality. We also summarize the management experiences in this article, since we consider them to be rather unique and since they contributed to the overall success of the program.     

Gull eggs--food of high organic pollutant content?

A wide range and occasionally high levels of persistent organic pollutants (POPs) are reported in Arctic regions, especially among top predators. Polar bears (Ursus maritimus), arctic foxes (Alopex lagopus) and some gull species (Larus spp.) often have high levels of these fat-soluble pollutants. Gulls deposit significant levels of these contaminants in their eggs. In northern regions, gull eggs are part of the traditional human diet. In the present study we have investigated the levels of POPs in gull eggs in order to determine the tolerable weekly intake (TWI) for humans. Concentrations of polychlorinated biphenyls (PCBs), polychlorinated dibenzo-p-dioxins (PCDDs) and polychlorinated dibenzofurans (PCDFs) were measured in 214 gull eggs collected in the spring of 2001-02. The eggs were collected from four gull species (herring gulls (Larus argentatus), great black-backed gulls (L. marinus), lesser black-backed gulls (L. fuscus) and glaucous gulls (L. hyperboreus)) at 12 different locations in Northern Norway, on the Faroe Islands and on Svalbard. The pollutant levels in gull eggs were found to be 65.5 +/- 26.9 pg toxic equivalent (TE) for dioxin and PCB g(-1) wet weight. Based on these findings and the TWI-value determined by the EU Scientific Committee on Food it is advised that children, young women and pregnant and nursing women should not eat gull eggs. Other people should limit their intake of eggs to an absolute minimum, considering the health risks associated with gull egg intake.     

Are savannas patch-dynamic systems? A landscape model

Savannas are ecosystems characterized by the coexistence of woody species (trees and bushes) and grasses. Given that savanna characteristics are mainly formed from competition, herbivory, fire, woodcutting, and patchy soil and precipitation characteristics, we propose a spatially explicit model to examine the effects of the above-mentioned parameters on savanna vegetation dynamics in space and time. Furthermore, we investigate the effects of the above-mentioned parameters on tree–bush–grass ratios, as well as the degrees of aggregation of tree–bush–grass biomass. We parameterized our model for an arid savanna with shallow soil depth as well as a mesic one with generally deeper and more variable soil depths. Our model was able to reproduce savanna vegetation characteristics for periods of time over 2000 years with daily updated time steps. According to our results, tree biomass was higher than bush biomass in the arid savanna but bush biomass exceeded tree and grass biomass in the simulated mesic savanna. Woody biomass increased in our simulations when the soil's porosity values were increased (mesic savanna), in combination with higher precipitation. Savanna vegetation varied from open savanna to woodland and back to open savanna again. Vegetation cycles varied over ∼300-year cycles in the arid and ∼220-year cycles in the mesic-simulated savanna. Autocorrelation values indicated that there are both temporal and spatial vegetation cycles. Our model indicated cycling savanna vegetation at the landscape scale, cycles in cells, and patchiness, i.e. patch dynamics.     

Approach for detecting mutagenicity of biodegraded and ozonated pharmaceuticals, metabolites and transformation products from a drinking water perspective

Many pharmaceuticals and related metabolites are not efficiently removed in sewage treatment plants and enter into surface water. There, they might be subject of drinking water abstraction and treatment by ozonation. In this study, a systematic approach for producing and effect-based testing of transformation products (TPs) during the drinking water ozonation process is proposed. For this, two pharmaceutical parent substances, three metabolites and one environmental degradation product were investigated with respect to their biodegradability and fate during drinking water ozonation. The Ames test (TA98, TA100) was used for the identification of mutagenic activity present in the solutions after testing inherent biodegradability and/or after ozonation of the samples. Suspicious results were complemented with the umu test. Due to the low substrate concentration required for ozonation, all ozonated samples were concentrated via solid phase extraction (SPE) before performing the Ames test. With the exception of piracetam, all substances were only incompletely biodegradable, suggesting the formation of stable TPs. Metformin, piracetam and guanylurea could not be removed completely by the ozonation process. We received some evidence that technical TPs are formed by ozonation of metformin and piracetam, whereas all tested metabolites were not detectable by analytical means after ozonation. In the case of guanylurea, one ozonation TP was identified by LC/MS. None of the experiments showed an increase of mutagenic effects in the Ames test. However, the SPE concentration procedure might lead to false-positive results due to the generation of mutagenic artefacts or might lead to false-negative results by missing adequate recovery efficiency. Thus, these investigations should always be accompanied by process blank controls that are carried out along the whole ozonation and SPE procedure. The study presented here is a first attempt to investigate the significance of transformation products by a systematic approach. However, the adequacy and sensitivity of the methodology need to be further investigated. The approach of combining biodegradation and ozonation with effect-based assays is a promising tool for the early detection of potential hazards from TPs as drinking water contaminants. It can support the strategy for the evaluation of substances and metabolites in drinking water. A multitude of possible factors which influence the results have to be carefully considered, among them the selectivity and sensibility of the mutagenicity test applied, the extraction method for concentrating the relevant compounds and the biocompatibility of the solvent. Therefore, the results have to be carefully interpreted, and possible false-negative and false-positive results should be considered.     

Some heterocyclic aromatic compounds are Ah receptor agonists in the DR-CALUX assay and the EROD assay with RTL-W1 cells

Purpose  

Heterocyclic aromatic compounds containing nitrogen, sulfur, or oxygen heteroatoms (NSO-HET) have been detected in air, soil, marine, and freshwater systems. However, only few publications are available investigating NSO-HET using in vitro bioassays. To support better characterization of environmental samples, selected NSO-HET were screened for dioxin-like activity in two bioassays.     

KLUM@GTAP: Introducing Biophysical Aspects of Land-Use Decisions into a Computable General Equilibrium Model a Coupling Experiment

In this paper, the global agricultural land use model Kleines Land Use Model is coupled to an extended version of the computable general equilibrium model (CGE) Global Trade Analysis Project in order to consistently assess the integrated impacts of climate change on global cropland allocation and its implication for economic development. The methodology is innovative as it introduces dynamic economic land-use decisions based also on the biophysical aspects of land into a state-of-the-art CGE; it further allows the projection of resulting changes in cropland patterns on a spatially more explicit level. A convergence test and illustrative future simulations underpin the robustness and potentials of the coupled system. Reference simulations with the uncoupled models emphasise the impact and relevance of the coupling; the results of coupled and uncoupled simulations can differ by several hundred percent.