Distribution and availability of potentially toxic metals in soil in central area of Belgrade,Serbia

Belgrade, capital city of Serbia, has over 1,600,000 inhabitants and over 400,000 vehicles trafficking every day on its streets. The investigation of soil pollution was performed by sequential extraction analysis to investigate the availability of potentially toxic metals (Zn, Cd, Pb, Co, Ni, Cu, Cr and Mn) under different oxidation and pH conditions. All investigated metals were mainly extracted from soils with neutral or acidic extractants. Serious pollution was observed along roads and streets with high traffic frequency, but Pb and Ni pollution was the highest since their concentrations exceed both soil Serbian standard and Canadian guidance values and is characteristic for all investigated sites. Cd, Cu, Cr and Zn concentrations are moderately high since they are between Canadian guideline and Serbian standard.     

Suspended particulate matter dynamics in a particle framework

Suspended particulate matter (SPM) dynamics in ocean models are usually treated with an advection–diffusion equation for one or more sediment size classes coupled to the hydrodynamical part of the model. Numerical solution of these additional partial differential equations unavoidably introduces numerical diffusion, i.e. in the case of sharp gradients the possible occurrence of artificial oscillations and non-positivity. A Lagrangian particle-tracking model has been developed to simulate short-term SPM dynamics. Modelling individual sediment particles allows a straightforward physical interpretation of the processes. The tracking of large numbers of individual and independent particles (up to 25 million in total in a single sediment class) can be achieved on high performance computer clusters, due to efficient parallelisation of particle tracking. The movement of the particles is described by a stochastic differential equation, which is consistent with the advection–diffusion equation. Here, the concentration profile is represented by a set of independent moving particles, which are advected according to the 3D velocity field, while the diffusive displacements of the particles are sampled from a random distribution, which is related to the eddy diffusivity field. To account for erosion a new parameterisation is proposed. Three numerical particle tracking schemes (EULER, MILSTEIN and HEUN) are presented and validated in idealised test cases. Finally, the particle tracking algorithms are applied to a realistic scenario, a severe winter storm in the East Frisian Wadden Sea (southern North Sea). The comparison with observations and an Eulerian SPM transport model seems to indicate a somewhat better fidelity of the Lagrangian approach.     

Middle-Eocene artiodactyls from Shanghuang (Jiangsu Province,Coastal China) and the diversity of basal dichobunoids in Asia

A new assemblage of basal dichobunoid artiodactyls from the middle-Eocene Shanghuang fissure fillings includes the diacodexeid Jiangsudon shanghuangensis gen. and sp. nov., a new species of the lantianine dichobunoid Elaschitotherium, Elaschitotherium crepaturus sp. nov., and an indeterminate suoid which is presently the earliest record of this clade. Diacodexeids are also represented by two forms provisionally referred to cf. Diacodexis sp. and to an indeterminate Diacodexeidae, respectively. The occurrence of diacodexeids in Shanghuang contrasts with the early and earliest middle-Eocene chronological range of the family in Europe and North America and suggests that the stratigraphic range of the family in Asia extends up to the middle Eocene. This may reflect particular habitats in coastal China that may have been relatively stable during the early and middle Eocene, thus preserving forest-dwelling artiodactyls that became extinct in the other Holarctic regions. Compared to other supposedly coeval North American, European, and Asian faunas, the Shanghuang mammalian assemblage is most similar to early Uintan faunas of North America but is also remarkable in recording forms close to taxa that are characteristic of the Wasatchian and Bridgerian North American Land Mammal Ages. The Irdinmanhan age of the Shanghuang fauna is supported by the mammalian assemblage recovered from the fissure D, but an Arshantan age cannot be completely ruled out at this point. Although the Shanghuang assemblage is biased towards preservation of small components of the mammalian fauna, the Shanghuang fauna provide an important and unique window into the Eocene diversity and early evolution of cetartiodactyls in eastern Asia.     

Sex-specific fitness consequences of dispersal in Siberian jays

In most birds, natal dispersal is female-biased, but the selective pressures leading to this pattern have rarely been explored with comprehensive data on lifetime reproductive success. In territorial birds, the benefit of philopatry should be higher for males than for females when males establish territories for which knowledge about the local environment is important. As females may use male characteristics for mate choice, and hence indirectly for territory choice, the benefit from the direct knowledge of the local environment may be lower for females than males. We tested this hypothesis using data from a long-term study of group living corvids, the Siberian jays (Perisoreus infaustus). In this species, the socially dominant offspring delay dispersal while the sub-dominant offspring leave the family group directly after reaching independence. Our results show that natal dispersal distance (a proxy for local knowledge) was related to sex and dispersal timing (a proxy for “quality”): Females and early dispersers traveled further on average than males and delayed dispersers. Furthermore, dispersal distance and timing were negatively related to the number of recruits produced over an individual’s lifetime in males, but not in females. Hence, the results support the hypothesis that the female-biased natal dispersal found in this and other bird species may come about through higher lifetime reproductive success of philopatric males than females.     

Hovering guards of the stingless bee <Emphasis Type="Italic">Tetragonisca angustula</Emphasis> increase colony defensive perimeter as shown by intra- and inter-specific comparisons

Social insects need to defend their nest against robbery, parasitism and predation. The stingless bee Tetragonisca angustula is unique in that it has guards that hover near the nest entrance in addition to guards that stand at the entrance. We tested both the general hypothesis that hovering guards increase the effectiveness with which flying intruders are detected and the specific hypothesis that hovering guards improve the detection of workers of the obligate robber bee, Lestrimellita limao. In an intraspecific study comparing colonies, we found a strong positive relationship between the number of hovering guards and the distance at which a dummy robber bee or L. limao worker, experimentally moved towards the nest entrance, was detected. These results were mirrored in an interspecific study showing that four species of stingless bees with similar population colonies but which lacked hovering guards, detected L. limao only at the nest entrance, in contrast to T. angustula. In addition, we found that a greater number of attacks by guards occurred when dummies were impregnated with citral, a major component of L. limao mandibular gland odour. Our results support the hypothesis that T. angustula hovering guards increase the detection perimeter for flying intruders, especially L. limao.     

Chemical investigations of aquifers affected by pyrite oxidation in the Bitterfeld lignite district

In a large area around the former open-pit lignite mines near Bitterfeld, Germany, groundwater taken from wells was analyzed for the major cations, anions, and trace elements. Quaternary and Tertiary sediments were collected from aquifers exposed on the sides of the pits and from boreholes outside the mines and analyzed for major and trace elements, as well as for carbonate, pyritic sulfur and total organic carbon. The pH and electrical conductivity of the sediments in suspension were measured. Significant differences were determined between the Tertiary sediments of the aquifers that were exposed to atmospheric oxygen during the lowering of the groundwater table and those outside the cone of depression. The greatest differences were found in the pyrite content, the pH values, and the electrical conductivity. In order to map the degree to which the mining of the lignite has affected the quality of the groundwater in the study area, the water samples were divided into six classes on the basis of their sulfate content. The neutralization potential was calculated to estimate the potential for acidification. Prediction of future groundwater quality is based on both (i) the present composition of the groundwater, surface water, and Quaternary and Tertiary aquifer sediments and (ii) the present and future groundwater flow directions. These studies have shown which parameters are important for future groundwater monitoring.     

Heavy metal recovery from the fine fraction of solid waste incineration bottom ash by wet density separation

Journal of Material Cycles and Waste Management - This work is aimed at exploring the recovery of heavy metals from the fine fraction of solid waste incineration bottom ash. For this study,...     

Worldwide cases of water pollution by emerging contaminants: a review

Environmental Chemistry Letters - Water contamination by emerging contaminants is increasing in the context of rising urbanization, industrialization, and agriculture production. Emerging...     

Pesticide and agro-ecological transition: assessing the environmental and human impacts of pesticides and limiting their use

Environmental Science and Pollution Research -     

Do plant traits help to design green walls for urban air pollution control? A short review of scientific evidences and knowledge gaps

Environmental Science and Pollution Research - It is often claimed that green walls (GW) and living wall systems (LWS) have a positive effect on urban air pollution problems if their plants...