Untersuchungen zur Aufnahme von HCB und Pyren durch den KompostwurmEisenia fetida und ausgew?hlte Regenwurmwildarten

Zusammenfassung  Ziel der beschriebenen Untersuchungen war die praktische überprüfung eines Methodenentwurfs zur Erfassung der Bioakkumulation von Umweltchemikalien mitEisenia fetida, der Eignung vonE. fetida als Modellorganismus und des OECD-Kunstbodens als Standardsubstrat. Als Testorganismen wurden aus eigener Zucht der KompostwurmEisenia fetida und nach FeldentnahmeAllolobophora caliginosa, Allolobophora chlorotica, Allolobophora longa undLumbricus rubellus eingesetzt. Testb?den waren der OECD-Kunstboden und ein Boden vom Versuchsfeld der BBA in Berlin-Dahlem. Beiden B?den wurden die Testsubstanzen Hexachlorbenzol und Pyren in einer Konzentration von 10 mg/kg Bodentrockengewicht zugemischt. Die Expositionszeit der Regenwürmer betrug 4 Wochen bei w?chentlicher Bestimmung der Konzentrationen der Testsubstanzen in den Würmern und B?den. Die fürE. fetida sowie die Wildarten errechneten Anreicherungsfaktoren (AF) beliefen sich bei HCB in Abh?ngigkeit des verwendeten Bodens auf Werte zwischen 10 und 17 und bei Pyren auf Werte zwischen 0,9 und 1,7. Durch Umrechnung der Bodenkonzentrationen auf Gehalte in der Wasserphase und Ableitung der entsprechenden Anreicherungsfaktoren kann ein Vergleich mit BCF-Werten, die aus QSAR’S anderer Regenwurmarten und Fischen berechnet wurden, hergestellt werden. Die Ergebnisse lassen den Schluss zu, dass der Regenwurmtest mitE. fetida (OECD 1984, ISO 1998) für die Untersuchung der Bioakkumulation geeignet ist. OnlineFirst: 31. 05. 2002     

Perspectives on social capacity building for natural hazards: outlining an emerging field of research and practice in Europe

Social capacity building for natural hazards is a topic increasingly gaining relevance not only for so-called developing countries but also for European welfare states which are continuously challenged by the social, economic and ecological impacts of natural hazards. Following an outline of recent governance changes with regard to natural hazards, we develop a heuristic model of social capacity building by taking into account a wide range of existing expertise from different fields of research. Particular attention is paid to social vulnerability and its assessment, as well as to risk communication and risk education as specific strategies of social capacity building. We propose to distinguish between interventionist and participatory approaches, thus enabling for a better understanding of existing practices of social capacity building as well as their particular strengths and weaknesses. By way of conclusion, we encourage more research on social capacity building for natural hazards in the European context which at present is highly diverse and, at least in parts, only poorly investigated.     

Planning and governing nature-based solutions in river landscapes: Concepts,cases, and insights

Nature-based solutions (NBS), understood as actions that use ecosystem processes to address societal needs, can play important roles to future-proof river landscape development for people and nature. However, knowledge gaps exist how NBS can be planned and implemented at landscape scales. This Special Issue brings together insights and experiences from studies of assessing, planning, and implementing NBS in river landscapes in Europe and beyond. It addresses three research fields: (i) NBS effects, looking at the effectiveness of NBS to achieve ecological, social, and/or economic outcomes, (ii) NBS planning, focusing on approaches for planning and designing NBS, and (iii) NBS governance, relating to governance and business models for implementation. The twelve contributions deliver evidence on how NBS outperform conventional, rather technical solutions, provide guidance and tools to operationalize the NBS concept into practice, and showcase successful governance models of NBS in different contexts. The editorial ends with an outlook on further research needs.     

Development and modelling of realistic retrofitted Nature-based Solution scenarios to reduce flood occurrence at the catchment scale

Decentralized Nature-based Solutions such as Urban Green Infrastructures (UGI) are increasingly promoted to reduce flooding in urban areas. Many studies have shown the effectiveness of flood control of UGI at a plot or neighbourhood level. Modelling approaches that extrapolate their flood reducing impact to larger catchment scales are often based on a simplistic assumption of different percentages of UGI implementation. Additionally, such approaches typically do not consider the suitable space for UGI and potential implementation constraints. This study proposes a scenario development and modelling approach for a more realistic upscaling of UGI based on empirical insights from a representative neighbourhood. The results from this study, conducted in the metropolitan area of Costa Rica, show that upscaling the full potential for UGI could significantly reduce surface runoff, peak flows, and flood volumes. In particular, the permeable pavement has the highest potential for flood reducing in public space while cisterns perform best at the property level. These results can guide the formation of policies that promote UGI.Supplementary InformationThe online version of this article (10.1007/s13280-020-01493-8) contains supplementary material, which is available to authorized users.     

Fluvial levees in compound channels: a review on formation processes and the impact of bedforms and vegetation

Environmental Fluid Mechanics - Natural levees are wedge-shaped morphological features developing along the boundaries of mass flows. When they form in fluvial landscapes, they can have multiple...     

The origin of stable halogenated compounds in volcanic gases

BACKGROUND: Halogenated compounds in the atmosphere are of great environmental concern due to their demonstrated negative effect on atmospheric chemistry and climate. Detailed knowledge of the emission budgets of halogenated compounds has to be gained to understand better their specific impact on ozone chemistry and the climate. Such data are also highly relevant to guide policy decisions in connexion with international agreements about protection of the ozone layer. In selected cases, the relevance of specific emission sources for certain compounds were unclear. In this study we present new and comprehensive evidence regarding the existence and relevance of a volcanic contribution of chlorofluorocarbons (CFCs), hydrofluorocarbons (HFCs), hydrochlorofluorocarbons (HCFCs), halons (bromine containing halo(hydro)carbons), and fully fluorinated compounds (e.g. CF4 and SF6) to the atmospheric budget. METHODS: In order to obtain new evidence of a volcanic origin of these compounds, we collected repeatedly, during four field campaigns covering a period of two years, gases from fumaroles discharging over a wide range of temperatures at the Nicaraguan subduction zone volcanoes Momotombo, Cerro Negro and Mombacho, and analysed them with very sensitive GC/MS systems. RESULTS AND DISCUSSION: In most fumarolic samples certain CFCs, HFCs, HCFCs, halons, and the fully fluorinated compounds CF4 and SF6 were present above detection limits. However, these compounds occur in the fumarole gases in relative proportions characteristic for ambient air. CONCLUSION: This atmospheric fingerprint can be explained by variable amounts of air entering the porous volcanic edifices and successively being incorporated into the fumarolic gas discharges. Recommendation and Outlook. Our results suggest that the investigated volcanoes do not constitute a significant natural source for CFCs, HFCs, HCFCs, halons, CF4, SF6 and NF3.     

Passive sampling of herbicides combined with effect analysis in algae using a novel high-throughput phytotoxicity assay (Maxi-Imaging-PAM)

We propose to combine a passive sampler for polar organic compounds (POS) with a specific bioassay for phytotoxicity to assess the hazard of herbicidal compounds in surface waters. The POS consisted of an Empore disk coated with styrenedivinylbenzene deployed in a Teflon housing, which has relatively high sampling rates (e.g., approximately 1 L d(-1) for diuron). POS were deployed for 5 days in a small-scale field study in South East Queensland, Australia, in a relatively pristine environment and an urban environment to explore sensitivity towards herbicides and potential influences of non-herbicidal pollutants. Besides chemical analysis of 8 herbicides, a novel bioassay (Maxi-Imaging-PAM, IPAM) was employed to assess the phytotoxic effects of water samples and POS extracts. The IPAM allows rapid assessment of photosynthetic quantum yields of a large number of samples via chlorophyll-fluorescence imaging and the saturation pulse method. Sampling rates for several herbicides from laboratory calibrations were found to be applicable under field conditions. Toxic equivalent concentrations (with reference to the herbicide diuron) were computed from the concentrations determined by chemical analysis and the relative potency (also termed toxic equivalence factor) of the detected herbicides. There was good agreement between diuron equivalent concentrations from chemical analysis and diuron equivalent concentrations determined with the IPAM.