Epiphytische Flechten im Wandel von Immissionen und Klima • Ergebnisse einer Vergleichskartierung 1989/2007 in Nordwestdeutschland

Epiphytic lichens as indicators for changes in air pollution and climate. Results of a comparative survey 1989/2007 in north-west Germany Background, aim, and scope Lichens growing on tree bark (epiphytic lichens) respond very sensitively to environmental effects such as chemical substances and air temperature. Therefore, they are used as biomonitors for atmospheric pollution in environmental assessments. Based on a survey of epiphytic lichens in 1989, a repetition was performed in an intensively-used agricultural area of north-west Germany in 2007. The objective of this study was to assess possible changes in air pollution and climate. Materials and methods The study is based on a comparative inventory of epiphytic lichens, growing on 335 trees at 45 monitoring sites. A simplified half quantitative survey technique of the first survey was used. Results Indeed, major changes to the epiphytic lichen flora were found. Overall, nearly all monitoring points showed an increase in the level of lichen species. A sharp decrease in acidophileous species and a sharp increase in basidophileous and nitrophileous species were detected. In addition, an increase in thermophileous species which are mainly inhabitants of southern European countries was observed, combined with decreases in boreo-montanic species. Discussion These trends correspond with supra-regional observations. They are primarily attributed to changes in air pollution involving a decrease in SO₂ and an increase in NH₃ concentrations. Clear effects from climate change are evident as well. Conclusions Changes to epiphytic lichens over a 18-year period could be demonstrated using a relatively low-cost investigation. They are relevant for assessing the changing environmental situation, which is of great importance for other organism groups and ecosystems. Recommendations and perspectives Using standardized techniques epiphytic lichens are suitable bioindicators for obtaining different types of information about the air pollution in urban areas and in intensively-used agricultural regions. Furthermore they are obviously good indicators of temperature changes in their environment. More research is needed about the suitability of epiphytic lichens for a biomonitoring of climate changes.     

The Moral Foundation of the Precautionary Principle

The Commission's recentinterpretation of the Precautionary Principleis used as starting point for an analysis ofthe moral foundation of this principle. ThePrecautionary Principle is shown to have theethical status of an amendment to a liberalprinciple to the effect that a state only mayrestrict a person's actions in order to preventunacceptable harm to others. The amendmentallows for restrictions being justified even incases where there is no conclusive scientificevidence for the risk of harmful effects.However, the liberal tradition has seriousproblems in determining when a risk of harm isunacceptable. Nevertheless, reasonable liberalarguments in favor of precaution can be basedon considerations of irreversible harm andgeneral fear of harm. But it is unclear whenthere considerations can be overridden.Within the liberal framework, the Commissionadvocates a so-called proportional version ofthe Precautionary Principle. This should beclearly distinguished from a welfare-basedapproach to precaution based on risk-aversiveweighing up of expected costs and benefits.However, in the last resort, the Commissiondoes seem to make a covert appeal to suchconsiderations.     

Schnelle vor-ort-analytik zur untersuchung von rüstungsaltlasten

Field screening methods for the analysis of explosives (for which commercial test kits are generally available) are reviewed. These techniques include immunoassays, photometric methods, bio and chemical sensors as well as thin layer chromatography. Basic aspects of these techniques are discussed, their validation is presented and their application to water and soil samples from hazardous ammunition waste is described. An evaluation of field studies with commercial test kits demonstrates that these techniques can be applied successfully for both the exploration of suspected contaminated sites and their sanitation. These methods are used on-site. In general, they allow short analysis times and a high sample throughput, thus leading to a significant reduction of the number of samples to be analysed in the laboratory and the costs.     

“Conflict over Risks in Food Production: A Challenge for Democracy”

When it comes to conflict over risk management priorities in food production, a number of observers, including myself, have called for some sort of public deliberation as a means of resolving the moral disagreements underlying such conflicts. This paper asks how, precisely, such deliberation might be facilitated. It is shown that representative democracy and the liberal regulation that most Western democracies adhere to place important constraints on public deliberation. The challenge is to find forums for public deliberation that can operate within these constraints while still making a constructive contribution.