A Native Species with Invasive Behaviour in Coastal Dunes: Evidence for Progressing Decay and Homogenization of Habitat Types

A new species has recently invaded coastal dune ecosystems in North West Europe. The native and expansive inland grass, Deschampsia flexuosa, progressively dominating inland heaths, has recently invaded coastal dunes in Denmark, occasionally even as a dominant species. A total of 222 coastal locations with 5,000 random sample plots have been investigated. These findings are in contrast to historical records, and D. flexuosa has never been considered belonging to coastal dune ecosystems. The occurrence of the typical inland grass in the coastal dunes is a strong indication of increase in nutrient level and that human influences may cause a native species to be invasive in new ecosystems. This could be a radical example of change in species composition due to a long lasting exceedance of critical load of nitrogen. The investigation also showed a general increase in cover of the most dominant species.     

Status of nanoremediation and its potential for future deployment: Risk‐benefit and benchmarking appraisals

NanoRem (Taking Nanotechnological Remediation Processes from Lab Scale to End User Applications for the Restoration of a Clean Environment) was a research project, funded through the European Commission's Seventh Framework Programme, which focuses on facilitating practical, safe, economic, and exploitable nanotechnology for in situ remediation of polluted soil and groundwater, which closed in January 2017. This article describes the status of the nanoremediation implementation and future opportunities for deployment based on risk‐benefit appraisal and benchmarking undertaken in the NanoRem Project. As of November 2016, NanoRem identified 100 deployments of nanoremediation in the field. While the majority of these are pilot‐scale deployments, there are a number of large scale deployments over the last five to 10 years. Most applications have been for plume control (i.e., pathway management in groundwater), but a number of source control measures appear to have taken place. Nanoremediation has been most frequently applied to problems of chlorinated solvents and metals (such as chromium VI). The perception of risk‐benefit balance for nanoremediation has shifted as the NanoRem Project has proceeded. Niche benefits are now more strongly recognized, and some (if not most) of the concerns, for example, relating to environmental risks of nanoremediation deployment, prevalent when the project was proposed and initiated, have been addressed. Indeed, these now appear overstated. However, it appears to remain the case that in some jurisdictions the use of nanoparticles remains less attractive owing to regulatory concerns and/or a lack of awareness, meaning that regulators may demand additional verification measures compared to technologies with which they have a greater level of comfort.     

Road dust emissions from paved roads measured using different mobile systems

Very few real-world measurements of road dust suspension have been performed to date. This study compares two different techniques (referred to as Sniffer and Emma) to measure road dust emissions. The main differences between the systems are the construction of the inlet, different instruments for recording particulate matter (PM) levels, and different loads on the wheel axes (the weight of Sniffer was much higher than that of Emma). Both systems showed substantial small-scale variations of emission levels along the road, likely depending on-road surface conditions. The variations observed correlated quite well, and the discrepancies are likely a result of variations in dust load on the road surface perpendicular to the driving direction that cause variations in the measurements depending on slightly different paths driven by the two vehicles. Both systems showed a substantial influence on the emission levels depending on the type of tire used. The summer tire showed much lower suspension than the winter tires (one nonstudded and one studded). However, the relative importance of the nonstudded versus studded tire was rather different. For the ratio of studded/nonstudded, Emma shows higher values on all road sections compared with Sniffer. Both techniques showed increased emission levels with increasing vehicle speed. When the speed increased from 50 to 80 km hr(-1), the relative concentrations increased by 30-170% depending on the tire type and dust load. However, for road sections that were very dirty, Sniffer showed a much higher relative increase in the emission level with the nonstudded tire. Sniffer's absolute concentrations were mostly higher than Emma's. Possible reasons for the differences are discussed in the paper. Both systems can be used for studying relative road dust emissions and for designing air quality management strategies.     

A GIS Approach to Model Sediment Reduction Susceptibility of Mixed Sand and Gravel Beaches

The morphological form of mixed sand and gravel beaches is distinct, and the process/response system and complex dynamics of these beaches are not well understood. Process response models developed for pure sand or gravel beaches cannot be directly applied to these beaches. The Canterbury Bight coastline is apparently abundantly supplied with sediments from large rivers and coastal alluvial cliffs, but a large part of this coastline is experiencing long-term erosion. Sediment budget models provide little evidence to suggest sediments are stored within this system. Current sediment budget models inadequately quantify and account for the processes responsible for the patterns of erosion and accretion of this coastline. We outline a new method to extrapolate from laboratory experiments to the field using a geographical information system approach to model sediment reduction susceptibility for the Canterbury Bight. Sediment samples from ten representative sites were tumbled in a concrete mixer for an equivalent distance of 40 km. From the textural mixture and weight loss over 40 km tumbling, we applied regression techniques to generate a predictive equation for Sediment Reduction Susceptibility (SRS). We used Inverse Distance Weighting (IDW) to extrapolate the results from fifty-five sites with data on textural sediment composition to field locations with no data along the Canterbury Bight, creating a continuous sediment reductions susceptibility surface. Isolines of regular SRS intervals were then derived from the continuous surface to create a contour map of sediment reductions susceptibility for the Canterbury Bight. Results highlighted the variability in SRS along this coastline.     

ASsessment Of Alcohol Ethoxylate Surfactants And Fatty Alcohols Mixtures In River Sediments And Prospective Risk Assessment

A feasible and relatively readily available analytical method was adapted for the assessment of alcohol ethoxylates (AE) and fatty alcohols (FA) in sediments. This study illustrates the simultaneous measurement of 38 of 114 possible alcohol ethoxylate ethoxymers (AE) and fatty alcohols (FA) found in commercially important AE products. We predicted toxicity for all identified fractions, as well as the total mixture toxicity, relative to three exposure scenarios via sewage treatment plants (STP) for these widely used chemicals in consumer products and hence generate a preliminary environmental risk screening for AE and FA in sediments. The method is based on derivatization of solvent or solid-phase extracts with 2-fluoro-N-methylpyridinium p-toluenesulfonate (Pyr+). The derivatized extracts were analyzed with liquid chromatography/mass spectrometry (LC/MS) operating in the positive ion electrospray mode. The extraction efficiency of AE and FA in three different sediments of varying composition was evaluated with spike-recovery studies, ranging from 64% to 80%. The detection limits for individual ethoxymers typically ranged from 1 to 5ngg⁻¹on a dry weight basis. The mean limit of detection (LOD) was 6ngg⁻¹and the median LOD was 3ngg⁻¹. AE and FA in sediments were found to be stable for two weeks if preserved with 3% (v/v) formalin and stored at 4–6^∘C. Based on equilibrium partitioning, background concentrations of AE and FA were predicted to be below concentrations known to elicit chronically toxic effects. Total worst case mixture toxicities for all AE ethoxymers combined with FA were predicted to result in a risk quotient less than 0.6. Activated sludge treatment (STP) significantly reduced the release of total AE and FA by four-fold, suggesting that the total mixture risk quotient would be < 0.15 for sediment dependent organisms.     

Toxicity, uptake and metabolism of 4-n-nonylphenol in root cultures and intact plants under septic and aseptic conditions

4-Nonylphenol, a compound with estrogenic activity, has been shown to occur in sewage sludges and effluents of sludge treatment. This, as well as its use in the formulation of pesticides, may result in the contamination of crop plants and may therefore have an impact on the quality of food or feedstuff. The toxicity, uptake and metabolism of 4-n-nonylphenol (4-n-NP) were investigated as¹⁴C-labeled 4-n-NP in root cultures under septical and aseptical conditions and with intact plants grown in containers with soil and aseptically grown in nutrient media. 4-n-NP was toxic to all plant systems tested. The presence of microorganisms and the developmental state of the plant material appeared to have an influence on the EC₅₀ values. 4-n-NP was taken up by the roots and a metabolism to polar compounds was observed in the cases where sufficiently high uptake rates. With intact plants a transport from roots to the shoots was evident. Metabolism in roots changed quantitatively in the presence of microorganisms. The mineralization of 4-n-NP to₁₄CO₂ only occurred with microorganisms.     

Effect of surrounding landscape on driving behaviour: A driving simulator study

This paper examines how three Swedish landscape types (open, forested, and varied) affect driver behaviour. The study was carried out in 2007 under controlled conditions in the VTI Driving Simulator III, Linköping, Sweden. Qualitative (questionnaires) and quantitative (simulator measurement) data were used. Eighteen subjects were selected, nine men and nine women aged 25–65 years, all licensed to drive for at least five years. Two hypotheses were established based on previous research: 1) landscape character (open, forested, or varied) affects driving behaviour (average speed, variation in lateral vehicle position, and steering wheel grasping frequency); and 2) landscape character affects driver perception of the driving situation. The first was tested in the driving simulator and the second via questionnaires concerning the simulator drive. The results indicate that the driver is affected by different landscape types. In the open landscape, subjects drove faster, did not drive as close to the centre of the road, and grasped the steering wheel more often while simultaneously experiencing less stress. Landscape also appears to be relevant to traffic safety, which has implications for choosing new routes when planning new roads and for maintaining existing roads.     

Heavy metal load and dominance hierarchy in juvenile willow tits during winter

Possible links between plasma testosterone levels, heavy metal loads and dominance in juvenile male willow tits (Parus montanus) are studied during winter conditions in Norway. Dominant individuals have better access to food resources, significantly higher cadmium content in the liver and higher plasma testosterone level compared to subordinates. A positive correlation was also found between plasma testosterone level and content of cadmium in the liver. Although the results in our study shows only a limited difference in testosterone level of dominant and subordinate juvenile male willow tits, possible small changes in behaviour might have crucial effects on winter survival of these birds.     

Effects of preference heterogeneity among landowners on spatial conservation prioritization

The participation of private landowners in conservation is crucial to efficient biodiversity conservation. This is especially the case in settings where the share of private ownership is large and the economic costs associated with land acquisition are high. We used probit regression analysis and historical participation data to examine the likelihood of participation of Danish forest owners in a voluntary conservation program. We used the results to spatially predict the likelihood of participation of all forest owners in Denmark. We merged spatial data on the presence of forest, cadastral information on participation contracts, and individual‐level socioeconomic information about the forest owners and their households. We included predicted participation in a probability model for species survival. Uninformed and informed (included land owner characteristics) models were then incorporated into a spatial prioritization for conservation of unmanaged forests. The choice models are based on sociodemographic data on the entire population of Danish forest owners and historical data on their participation in conservation schemes. Inclusion in the model of information on private landowners’ willingness to supply land for conservation yielded at intermediate budget levels up to 30% more expected species coverage than the uninformed prioritization scheme. Our landowner‐choice model provides an example of moving toward more implementable conservation planning.