Foliar concentrations of volunteer willows growing on polluted sediment-derived sites versus sites with baseline contamination levels

Many alluvial soils along navigable waterways are affected by disposal of dredged sediments or overbank sedimentation and contain metal concentrations that are elevated compared to baseline levels. Uptake patterns for metals and other elements by several volunteer Salix species growing on these sites were determined during a growing season in field plots and compared with the same species growing on soils with baseline contamination levels. For Cd and Zn, foliar concentrations were clearly higher on dredged sediment landfills. Uptake patterns differed significantly between species. A high uptake of Mn and low uptake of Cu, K and S in S. cinerea was attributed to wetland soil chemistry. Site effects on metal uptake were evaluated in more detail for Salix cinerea and S. alba growing on different sediment-derived sites under field conditions. Foliar Cd concentrations were higher in S. cinerea than in S. alba. This appeared to be a genetic feature not influenced by soil chemical properties, as it was observed both on clean sites and polluted sediment-derived sites. For S. cinerea, soil chemistry was reflected in foliar concentrations, while foliar Cd concentrations and bioavailability were found to be independent of the thickness of the polluted horizon. Dredged sediment landfills and freshwater tidal marshes with comparable Cd soil pollution had significantly different foliar Cd concentrations.     

Growth and trace metal accumulation of two Salix clones on sediment-derived soils with increasing contamination levels

The growth and metal uptake of two willow clones (Salix fragilis 'Belgisch Rood' and Salix viminalis 'Aage') was evaluated in a greenhouse pot experiment with six sediment-derived soils with increasing field Cd levels (0.9-41.4 mg kg-1). Metal concentrations of eight elements were measured in roots, stems and leaves and correlated to total and soil water metal concentrations. Dry weight root biomass, number of leaves and shoot length were measured to identify eventual negative responses of the trees. No growth inhibition was observed for both clones for any of the treatments (max. 41.4 mg kg-1 Cd, 1914 mg kg-1 Cr, 2422 mg kg-1 Zn, 655 mg kg-1 Pb), allowing their use for phytoextraction on a broad range of contaminated sediments. However, dry weight root biomass and total shoot length were significantly lower for S. viminalis compared to S. fragilis for all treatments. Willow foliar Cd concentrations were strongly correlated with soil and soil water Cd concentrations. Both clones exhibited high accumulation levels of Cd and Zn in aboveground plant parts, making them suitable subjects for phytoextraction research. Cu, Cr, Pb, Fe, Mn and Ni were found mainly in the roots. Bioconcentration factors of Cd and Zn in the leaves were highest for the treatments with the lowest soil Cd and Zn concentration.     

The effect of hydrological regime on the metal bioavailability for the wetland plant species Salix cinerea

The hydrological conditions on a site constitute one of the many factors that may affect the availability of potentially toxic trace metals for uptake by plants. Bioavailability of Cd, Mn and Zn in a contaminated dredged sediment-derived soil under different hydrological regimes was determined by measuring metal uptake by the wetland plant species Salix cinerea, both in field circumstances and in a greenhouse experiment. Longer submersion periods in the field caused lower Cd concentrations in leaves and bark. The wetland hydrological regime in the greenhouse experiment resulted in normal Cd and Zn concentrations in the leaves, while the upland hydrological regime resulted in elevated Cd and Zn concentrations in the leaves. Field observations and the greenhouse experiment suggest that a hydrological regime that creates or sustains a wetland is a potential management option that reduces metal bioavailability to willows. This would constitute a safe management option of metal-polluted, willow-dominated wetlands provided that wetland conditions can be maintained throughout the full growing season.     

Determining eyeball surface area directly exposed to the effects of external factors

This article discusses determining the surface area of eyeballs of men and women exposed to the direct effects of external factors in the working environment. For one eye, the mean surface is 172–182?mm². The determined surface area can be used in formulas for calculating the exposure of eyeballs to harmful chemical substances in workplace air.     

Maturation of work attitudes: Correlated change with big five personality traits and reciprocal effects over 15 years

As employees grow older, do their attitudes regarding work change over time? Can such long‐term changes be understood from a personality development perspective? The present study addressed these fundamental questions by tracking 504 young professionals' work attitudes (i.e., job satisfaction and work involvement) and Big Five personality traits over the first 15 years of their professional career. We specifically investigated whether trait changes drive peoples' changing attitudes, a mechanism we called maturation of work attitudes. Latent change models first indicated significant associations between traits and attitudes at the beginning of the career, and mean‐level changes in Big Five traits (i.e., increases in Agreeableness and Conscientiousness and decreases in Neuroticism) in the direction of greater functional maturity. Although no significant mean‐level changes in work attitudes were observed, results regarding correlated change indicated that variability in attitude change was related to variability in trait change and that this indeed signaled a maturational process. Finally, reciprocal effect estimates highlighted bidirectional relations between personality and attitudes over time. It is discussed how these results (i) provide a better understanding of potential age effects on work‐related attitudes and (ii) imply a revision of the traditional dispositional approach to attitudes. Copyright © 2013 John Wiley & Sons, Ltd.     

Zero-valent iron particles for PCB degradation and an evaluation of their effects on bacteria,plants, and soil organisms

Two types of nano-scale zero-valent iron (nZVI-B prepared by borohydride reduction and nZVI-T produced by thermal reduction of iron oxide nanoparticles in H₂) and a micro-scale ZVI (mZVI) were compared for PCB degradation efficiency in water and soil. In addition, the ecotoxicity of nZVI-B and nZVI-T particles in treated water and soil was evaluated on bacteria, plants, earthworms, and ostracods. All types of nZVI and mZVI were highly efficient in degradation of PCBs in water, but had little degradation effect on PCBs in soil. Although nZVI-B had a significant negative impact on the organisms tested, treatment with nZVI-T showed no negative effect, probably due to surface passivation through controlled oxidation of the nanoparticles.

     

Trampling impact on vegetation of embryonic and stabilised sand dunes in Montenegro

Trampling is one of the human activities that are harmful for plant species and communities of sand dune ecosystems. The aim of this study was to compare the vegetation of embryonic and shifting Ammophila sand dunes with and without fencing to limit trampling. Fenced sand dunes appeared to be richer in species but differences were more prominent in embryonic sand dunes. Some species (Cakile maritima, Pancratium maritimum) were missing on trampled embryonic dunes. The positive impact of trampling exclusion on embryonic sand dunes was indicated by a lowered slope in a Whittaker graph as well as by rarefaction curves that showed higher species richness on the lower slope. Changes in the vegetation of more stabilised shifting Ammophila sand dunes due to trampling are not evident, although species composition is also impoverished. Fencing of parts of sand dunes proved to be an effective measure for vegetation conservation. In addition to physical exclusion of visitors, fences can also have symbolic value for raising public awareness.     

The sensitivity of current and future forest managers to climate-induced changes in ecological processes

Climate vulnerability of managed forest ecosystems is not only determined by ecological processes but also influenced by the adaptive capacity of forest managers. To better understand adaptive behaviour, we conducted a questionnaire study among current and future forest managers (i.e. active managers and forestry students) in Austria. We found widespread belief in climate change (94.7 % of respondents), and no significant difference between current and future managers. Based on intended responses to climate-induced ecosystem changes, we distinguished four groups: highly sensitive managers (27.7 %), those mainly sensitive to changes in growth and regeneration processes (46.7 %), managers primarily sensitive to regeneration changes (11.2 %), and insensitive managers (14.4 %). Experiences and beliefs with regard to disturbance-related tree mortality were found to particularly influence a manager’s sensitivity to climate change. Our findings underline the importance of the social dimension of climate change adaptation, and suggest potentially strong adaptive feedbacks between ecosystems and their managers.

Electronic supplementary material

The online version of this article (doi:10.1007/s13280-015-0737-6) contains supplementary material, which is available to authorized users.     

Storage mediums affect metal concentration in woodlice (Isopoda)

Terrestrial invertebrates are becoming widely established as tools to assess heavy metal pollution at contaminated sites. A practical and time saving method to sample terrestrial invertebrates consist of pitfall traps, often filled with a 4% formaldehyde solution and some detergent. The reliability of metal concentrations based on organisms captured and stored in this solution might however be questioned and we therefore tested the effect of formaldehyde on Zn, Cu, Cd and Pb concentration experimentally in three isopod species. Our results showed that in many cases, significant decreases in Cu concentrations compared to animals stored in a freezer were observed that could be as high as 40%, while Zn, Cd and Pb concentrations increased. A regression analysis of individual dry weight on individual size revealed that formaldehyde decreases the dry weight substantially and in that way causes increased measurements of Zn, Cd and Pb concentrations. We conclude that pitfall traps with formaldehyde should better not be used to collect animals in which concentrations of heavy metals or other toxic substances will be determined.     

Einflu? chemischer Kontaminanten (insbesondere Schwermetalle) auf die Bodenorganismen und ihre ?kologisch bedeutenden Aktivit?ten

Für die Vorsorge- und Sanierungsma?nahmen im Rahmen des Bodenschutzes ist es notwendig, Auswirkungen anthropogener Bodenbelastungen auf die im Boden lebenden Organismen und auf ihre ?kologisch bedeutenden Aktivit?ten zu kennen und voll zu berücksichtigen. Der vorliegende Aufsatz bringt eine übersicht insbesondere betreffend den Einflu? von Schwermetallen auf (a) die quantitative und qualitative Zusammensetzung der Population von Bodenorganismen; (b) die mikrobiellen Umsetzungen kohlenstoff- und stickstoffhaltiger Substrate; (c) die Enzymaktivit?ten im Boden; (d) den Abbau von Pflanzenrückst?nden; (c) die Resistenzerscheinungen bei Bodenmikroorganismen und (f) die Auswirkungen abiotischer Bodenfaktoren auf die biologische Wirksamkeit der Schadstoffe. Aus den zahlreichen durch Referenzen belegten Erkenntnissen werden Schlu?folgerungen gezogen, die auf die Eignung von Mikrobenpopulationen und ihrer Aktivit?ten für die Beurteilung der anthropogenen Bodenbelastungen hinweisen.