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R. Haas I. Schreiber Petra Kopecz G. Stork 《Umweltwissenschaften und Schadstoff-Forschung》1991,3(2):70-73
Die Ergebnisse der Untersuchung von Wasserproben aus dem Einflu?ereich der Rüstungsaltlast „Dethlinger Teich“ bei Munster/Niedersachsen
werden dargestellt und bewertet. Von mehr als 50 untersuchten spezifischen Substanzen wurden Arsenkampfstoffe als Hauptkontaminanten
erkannt. Im Rahmen der Gef?hrdungsabsch?tzung wird hier erstmals eine Analysenmethode zur Unterscheidung zwischen anorganisch
und organisch gebundenem Arsen vorgestellt.
Groundwater analyses in the area of the former munitions depository (World War II) „Dethlinger Teich“ near Munster/Niedersachsen
were evaluated. Results from 50 different chemical substances showed that arsenic compounds are the main contaminating chemicals.
A new method has been developed to distinguish between morganically- and organically bound compounds. This differentiation
is required for risk assessment and evaluation. Also, the relationship of chemical structure and physiological effects in
organo arsenic compounds is described. 相似文献
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We present a new system for microscopic multicolour variable chlorophyll fluorescence imaging of aquatic phototrophs. The
system is compact and portable and enables microscopic imaging of photosynthetic performance of individual cells and chloroplasts
using different combinations of blue, green, red or white light. Automated sequential exposure of microscopic samples to the
three excitation colours enables subsequent deconvolution of the resulting fluorescence signals and colour marking of cells
with different photopigmentation, i.e., cyanobacteria, green algae, red algae and diatoms. The photosynthetic activity in
complex mixtures of phototrophs and natural samples can thus be assigned to different types of phototrophs, which can be quantified
simultaneously. Here, we describe the composition and performance of the new imaging system and present applications with
both natural phytoplankton and microalgal culture samples. 相似文献
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A Concentric Analysis of the Impact of Urbanization on the Threatened European Tree Frog in an Agricultural Landscape 总被引:4,自引:1,他引:4
Abstract: Pond-breeding amphibians are affected by site-specific factors and regional and landscape-scale patterns of land use. Recent anthropogenic landscape modifications (drainage, agriculture intensification, larger road networks, and increased traffic) affect species by reducing the suitable habitat area and fragmenting remaining populations. Using a robust concentric approach based on permutation tests, we evaluated the impact of recent landscape changes on the presence of the endangered European tree frog ( Hyla arborea ) in wetlands. We analyzed the frequency of 1 traffic and 14 land-use indices at 20 circular ranges (from 100-m up to 2-km radii) around 76 ponds identified in western Switzerland. Urban areas and road surfaces had a strong adverse effect on tree frog presence even at relatively great distances (from 100 m up to 1 km). When traffic measurements were considered instead of road surfaces, the effect increased, suggesting a negative impact due to a vehicle-induced effect. Altogether, our results indicate that urbanization and traffic must be taken into account when pond creation is an option in conservation management plans, as is the case for the European tree frog in western Switzerland. We conclude that our easy-to-use and robust concentric method of analysis can successfully assist managers in identifying potential sites for pond creation, where probability of the presence of tree frogs is maximized. 相似文献
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