Temporal variation of fluoride concentration in antlers of roe deer (Capreolus capreolus) living in an area exposed to emissions from iron and steel industry, 1948-2000

Temporal changes of environmental fluoride concentration in the industrialized area of Siegen, western Germany were assessed by studying the fluoride content of antlers (n=116) collected between 1948 and 2000 from the resident roe deer (Capreolus capreolus) population. During the analyzed period, major fluoride emission sources in the study area have been iron- and steelworks. Fluoride concentrations in the antlers ranged between 118 and 5428 mg/kg of bone ash. There was an overall increase in antler fluoride content from the late 1940s/early 1950s to the late 1950s/mid-1960s. Thereafter, antler fluoride levels overall steadily declined. For statistical analysis, the data were grouped into five periods (1948–1959, 1960–1969, 1970–1979, 1980–1989, and 1990–2000). Geometric mean fluoride concentrations of the samples ranged from 323 (period 1990–2000) to 2096 mg/kg of bone ash (period 1960–1969). Sample means for the periods 1980–1989 and 1990–2000, respectively, were always significantly lower than those of older samples. The decrease in antler fluoride concentrations during recent decades suggests a drop of ambient fluoride levels, that is hypothetically attributed to a reduction in the number of emission sources in the area and a decline of fluoride discharges from both local and more distant sources due to improved emission control measures. Comparison with antler fluoride data for other roe deer populations from western Germany further suggests that the roe deer from the Siegen area were recently exposed to an only moderate additional fluoride load from industrial sources. Studying antler fluoride concentrations is a convenient and cost-effective method of monitoring temporal changes in ambient fluoride levels.     

Modelling the fate of organic chemicals in the soil plant environment: Model study of root uptake of pesticides

The fate of organic chemicals in the soil-plant-atmosphere environment and the governing processes were studied with a coupled dynamic soil transport and plant compartment model. Scenarios with applications of pesticides on sand and loam soils with chemical uptake in barley and wheat were used in the model calculations. Root uptake and concentrations in the plant compartments stem, leave and fruit were calculated for the pesticides terbuthylazine, isoproturon and carbofuran.

The effectivity of uptake from soils with different soil sorption coefficients had been shown for sand and loam soils. The processes degradation in plant and volatilization from leaves to atmosphere are especially effective for carbofuran and terbuthylazine. Although the concentrations in corn at harvest are lower than the maximum allowed concentrations, the peak concentrations in the course of the vegetation period are significantly higher (factor ≤ 200).     

The life history responses of the abalone pest,<Emphasis Type="Italic"> Terebrasabella heterouncinata</Emphasis>, under natural and aquaculture conditions

The sabellid, Terebrasabella heterouncinata, is a small (<5 mm) intratubular brooder that lives in burrows within the hosts shell matrix. It is a semi-continuous breeder and despite producing small numbers of large eggs, infestation by this animal has reached epidemic proportions on local abalone farms. The present study compared the morphometrics and reproductive characteristics of worms from farmed and wild abalone, in the Walker Bay area of the south Western Cape Province of South Africa, to gain insights into why this animal has become so successful under aquaculture conditions. The farms designated farm A and farm B each had one on-farm site, and two wild sites, while farm C had two on-farm sites and two wild sites. The wild sites were natural abalone habitats located within 2.5 km of the farms. Our results conclusively showed that environmental conditions prevalent on the farms enhanced the reproductive success of these worms relative to that observed in its natural environment. At farms B and C, worms occurred in significantly higher densities at the on-farm sites than in the corresponding wild samples, but at farm A, density was equally low at the three sites. At all three farms, a greater proportion of the population was reproductively active in the on-farm samples than in the wild samples. Worms on farmed abalone had a higher instantaneous fecundity, brooded more clutches simultaneously and were larger than their conspecifics from the wild. There was a positive correlation between adult size and brood size and the number of clutches brooded simultaneously. Within the three on-farm sites there was a negative correlation between egg volume and brood size, indicating a trade-off between these traits. However, such a trade-off was not apparent between sites, with brood size being higher at the on-farm sites than at the wild sites, irrespective of egg size. This suggests that the stable nutrient-enriched environment on the farm led to an increase in fecundity without compromising the size (and implicitly the quality) of the eggs. Worm density did not have a significant effect on body size or any other reproductive traits at most sites, and the density of T. heterouncinata was unaffected by the density of other shell-infesting polychaetes. The results suggest that the farm environment has selected for larger, more fecund worms that breed rapidly with high recruitment success as a consequence of abundant nutrients, high host density, habitat stability and a possible lack of predation and interspecific competition.Communicated by J.P. Thorpe, Port Erin     

How global conditions impact regional agricultural production and nitrogen surpluses in the German Elbe River Basin

Agricultural land use has shifted towards more intensified production because the prices of agricultural products have increased during the past years. Just a few years ago, voluntary area set-aside was a lucrative alternative in some regions. But nowadays, land is re-cultivated again, inter alia with biomass crops. Consequently, this affects the soil and nutrient balances in agriculture. The global changes on the world markets influence agricultural production and thus the water cycle at the regional scale. In this paper, the regional developments and policy alternatives are discussed for the Elbe River Basin. The paper concludes that on average, no substantial effects of nitrogen surpluses are expected for the Elbe River Basin due to a continuing decline in animal herds. However, at the county level, nitrogen surpluses are likely to exceed the maximum threshold of 60 kg nitrogen per hectare (stipulated in the German Fertiliser Regulation) due to regional concentrations of animal production. A halving of the threshold to 30 kg per hectare shows that the marginal costs of nitrogen surplus reduction regionally exceeded 10 Euros per kilogram nitrogen.     

A universal method to assess the potential of phosphorus loss from soil to aquatic ecosystems

Background, aim, and scope  

Phosphorus loss from terrestrial to the aquatic ecosystems contributes to eutrophication of surface waters. To maintain the world's vital freshwater ecosystems, the reduction of eutrophication is crucial. This needs the prevention of overfertilization of agricultural soils with phosphorus. However, the methods of risk assessment for the P loss potential from soils lack uniformity and are difficult for routine analysis. Therefore, the efficient detection of areas with a high risk of P loss requires a simple and universal soil test method that is cost effective and applicable in both industrialized and developing countries.     

Insights from years of performance that are shaping injection‐based remediation systems

Research and field experience from the past 15 years has allowed remediation professionals to purposefully design injection‐based remediation systems with a high potential for success. Industry professionals can now claim a number of achievements that were unthinkable just a few years ago: (1) we have demonstrated that maximum contaminant levels (MCLs) can be achieved for multiple contaminants; (2) we have successfully targeted dense nonaqueous‐phase liquid (DNAPL) source zones; (3) we have expanded our understanding of injection hydraulics to treat large plumes; and (4) we have collected sufficient data on rates of treatment to be more predictive regarding outcomes. The next decade will continue to evolve the design and execution of these types of systems for application to more complex problems. At this point on the timeline, questions regarding the mechanisms of treatment have largely been addressed, allowing a shift in focus to operational enhancements. Specific operational insights arising from the body of work to date that arguably will continue to shape and influence the design and execution of injection‐based remediation systems include: (1) the fact that delivery does not always equal distribution, (2) treatment optimization requires aquifer tuning, and (3) life‐cycle costs can be reduced with remedy‐optimized investigation. The number of examples that support these concepts and their ramifications to future technology refinement is already increasing, demonstrating how the refinements that can be made around these areas of focus will enhance our ability to effectively tackle larger and more complicated plumes, and do so with maximum efficiency. © 2011 Wiley Periodicals, Inc.     

Single- and dual-porosity modelling of flow in reclaimed mine soil cores with embedded lignitic fragments

Lignitic mine soils represent a typical two-scale dual-porosity medium consisting of a technogenic mixture of overburden sediments that include lignitic components as dust and as porous fragments embedded within a mostly coarse-textured matrix. Flow and transport processes in such soils are not sufficiently understood to predict the course of soil reclamation or of mine drainage. The objective of this contribution is to identify the most appropriate conceptual model for describing small-scale heterogeneity effects on flow on the basis of the physical structure of the system. Multistep flow experiments on soil cores are analyzed using either mobile–immobile or mobile–mobile type 1D dual-porosity models, and a 3D numerical model that considers a local-scale distribution of fragments. Simulations are compared with time series' of upward infiltration and matric potential heads measured at two depths using miniature tensiometers. The 3D and the 1D dual-permeability models yielded comparable results as long as pressure heads are in local equilibrium; however, could describe either the upward infiltration or the matric potential curves but not both at the same time. The mobile–immobile type dual-porosity model failed to describe the data. A simultaneous match with pressure heads and upward infiltration data could only be obtained with the 1D dual-permeability model (i.e., mobile–mobile) by assuming an additional restriction of the inter-domain water transfer. These results indicate that for unsaturated flow conditions at higher matric potential heads (i.e., here >− 40 hPa), water in a restricted part of the fragment domain must be more mobile as compared to water in the sandy matrix domain. Closer inspections of the pore system and first neutron radiographic imaging support the hypothesis that a more continuous pore region exists at these pressure heads in the vicinity of the lignitic fragments possibly formed by fragment contacts and a lignitic dust interface-region between the two domains. The results suggest that the small-scale structure is too complex as to be represented by weighted contributions of individual components alone.