Entwicklung und Anwendung von Pflanzenschutzmitteln: Wirtschaftliche Aspekte

The development of new active ingredients and formulations is increasingly influenced by costs and regulations in the frame of pesticide registration procedures. Lawmakers and administrators therefore take over more responsibility, not only for the subject of regulation, but also for fair and balanced rules which can be predicted in the long-term. There are, however, deficiencies in the choice of certain quality standards — like in the European drinking water directive — which are not risk-related and which are susceptible to giving misleading guidance. Testing requirements should be scrutinized for efficiency, i.e. whether the increase in knowledge and safety is in reasonable proportion to the invested resources.     

Morphologie,Entwicklung und Ökologie digener Trematoden-Larven der StrandschneckeLittorina littorea

More than 6000 individuals of the snailLittorina littorea L., from 6 different localities on the coast of the German Bay (North Sea), were examined for larval trematodes by crushing their shells, an additional 6000 by isolation in small quantities of sea water. Six species of larval trematodes were found inL. littorea and described: Notocotylid larva —Cercaria lebouri Stunkard, 1932; Cercaria ofHimasthla elongata (Mehlis, 1831); Cercaria ofPodocotyle atomon (Rudolphi, 1802); Cercaria ofRenicola roscovita (Stunkard, 1932) n. comb.; Metacercaria ofMicrophallus pygmaeus (Levinsen, 1881); Cercaria ofCryptocotyle lingua (Creplin, 1825). Considering the large number of investigated snails, the trematode fauna ofL. littorea in this area is assumed to be completely known. The life cycles ofHimasthla elongata andRenicola roscovita are described. Larvae of the different trematode species show differential preferences for distinct size groups of snail hosts. Juvenile snails are not infected. No correlation exists between infection rates and sex of the hosts. Quantitative aspects of multiple infections are calculated and discussed. The incidence of larval trematodes in the investigated localities differs. Information is presented on seasonal variations of infestations and their possible causes.     

Störungen der Entwicklung und Funktion des männlichen Reproduktionssystems

Various recently published studies indicate increases in disorders of development and function of the male reproductive system during the last decades. This refers to reports on a decline in sperm count and increased incidences of testicular cancer, cryptorchidism and hypospadias. While the results of studies on the increase in (geographically varying) incidences of testicular cancer are unequivocal, data on changes in rates of cryptorchidism and hypospadias are rather limited. Meanwhile, numerous retrospective studies on changes in sperm concentrations in the ejaculate of normal men have been published. However, at present it is not possible to draw generally valid conclusions since results from some countries or geographic regions indicate a significant decline while in others either no changes or even slight increases have been reported. According to the so-called “Estrogen hypothesis”, the common cause of these disorders shall be an increased prenatal exposure to estrogens. Concerning exogenous estrogens, synthetic estrogens, phyto and mycoestrogens, and chemicals with estrogenic activity could play a role. A search in the available literature has revealed that at present more than 100 chemical compounds from different classes are known to possess estrogenic activity. This, however, is not the only way in which chemicals may be endocrinically active. Ubiquitously distributed compounds from the classes of polychlorinated dibenzodioxins/furans and biphenyls exhibit an antiestrogenic potential, while chemicals like p,p′-DDE, Linuron and Vinclozolin being competitive androgen receptor antagonists may act as antiandrogens. Concerning the very limited current knowledge, the estrogen hypothesis at present only represents an interesting basis for discussion. Most questions that would have to be answered in order to accept, reject or modify tis hypothesis are either completely open or only partially understood. Thus, there is an urgent need to initiate research efforts to clarify the toxicological significance for ecosystems and humans of chemicals with endocrine activity.     

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.     

Nachhaltige Entwicklung von Managementstrategien

In order to support evaluation and decision processes with respect to sustainability of management strategies, different mathematical methods can be applied. In this paper, the fundamentals of these so-called multi-criteria evaluation and decision-support instruments are presented. Moreover, advantages and disadvantages are worked out using an example data set of strategies of sustainable water management. It is shown that particularly transparency, objectivity and the degree of participation of stakeholders are the main characteristics: Whereas the Hasse diagram technique is directed to the scientifically given data matrix, and therefore yields an objective and transparent evaluation and data analysis, concordance analysis, utility function theory, PROMETHEE and AHP (analytical hierarchy process) have their preferences as participants or stakeholders in the decision process.     

Seeufer 2003 — Ökologie, Bewertung, Nachhaltige Entwicklung

This report of an international conference about the problems around lakeshores, their evaluation and the possibilities to improve the situation for lake shores, continues the series ‘Lake shores, a forgotten ecotone’ as article 4. Five main topics were discussed: (1) applied ecology of lakeshores, (2) human impact, (3) ecological assessment, (4) protection and restoration, (5) sustainable development and use of lake shores.     

Zur Entwicklung der Kolloblasten von Pleurobrachia pileus (Ctenophora)

Electron microscopic investigation of young Pleurobrachia pileus has shown that the colloblasts develop from ciliated cells containing rich endoplasmic reticulum. The cilium is connected with the cell-body by means of a thin strand of cytoplasm; the cilium grows spirally around the basal part of the cell and undergoes several modifications; its rootlet forms the star-shaped body; an electron-dense cylinder arises outside the microtubules, the microtubules then degenerate. Basally, the cilium exhibits special anchoring structures.