Living in an oasis: Rapid transformations,resilience, and resistance in the North Water Area societies and ecosystems

Based on lake sediment data, archaeological findings, and historical records, we describe rapid transformations, resilience and resistance in societies and ecosystems, and their interactions in the past in the North Water area related to changes in climate and historical events. Examples are the formation of the polynya itself and the early arrival of people, ca. 4500 years ago, and later major human immigrations (different societies, cultural encounters, or abandonment) from other regions in the Arctic. While the early immigrations had relatively modest and localised effect on the ecosystem, the later-incoming culture in the early thirteenth century was marked by extensive migrations into and out of the area and abrupt shifts in hunting technologies. This has had long-lasting consequences for the local lake ecosystems. Large natural transformations in the ecosystems have also occurred over relatively short time periods related to changes in the polynya. Finally, we discuss the future perspectives for the North Water area given the many threats, but also opportunities.     

Municipal wastewater treatment cost

The cost of control for conventional pollutants at municipal wastewater treatment plants is examined. Empirical estimates of the effect of performance measures as well as the flow size of the waste stream are obtained for both the capital and the operation and maintenance components of total facility cost. These estimates are used to calculate the marginal cost per pound of pollution control over the range of effluent concentration beyond secondary treatment. The implications of the results for current environmental policy issues are outlined.     

Urbanization affects stream ecosystem function by altering hydrology, chemistry, and biotic richness.

Catchment urbanization can alter physical, chemical, and biological attributes of stream ecosystems. In particular, changes in land use may affect the dynamics of organic matter decomposition, a measure of ecosystem function. We examined leaf-litter decomposition in 18 tributaries of the St. Johns River, Florida, USA. Land use in all 18 catchments ranged from 0% to 93% urban which translated to 0% to 66% total impervious area (TIA). Using a litter-bag technique, we measured mass loss, fungal biomass, and macroinvertebrate biomass for two leaf species (red maple [Acer rubrum] and sweetgum [Liquidambar styraciflua]). Rates of litter mass loss, which ranged from 0.01 to 0.05 per day for red maple and 0.006 to 0.018 per day for sweetgum, increased with impervious catchment area to levels of approximately 30-40% TIA and then decreased as impervious catchment area exceeded 40% TIA. Fungal biomass was also highest in streams draining catchments with intermediate levels of TIA. Macroinvertebrate biomass ranged from 17 to 354 mg/bag for red maple and from 15 to 399 mg/bag for sweetgum. Snail biomass and snail and total invertebrate richness were strongly related to breakdown rates among streams regardless of leaf species. Land-use and physical, chemical, and biological variables were highly intercorrelated. Principal-components analysis was therefore used to reduce the variables into several orthogonal axes. Using stepwise regression, we found that flow regime, snail biomass, snail and total invertebrate richness, and metal and nutrient content (which varied in a nonlinear manner with impervious surface area) were likely factors affecting litter breakdown rates in these streams.     

Modelling algal blooms in the Dutch coastal waters by integrated numerical and fuzzy cellular automata approaches

In this paper, an integrated numerical and fuzzy cellular automata model was developed to predict possible algal blooms in Dutch coastal waters basing on the irradiance, nutrients and neighbourhood conditions. The numerical module used Delft3D-WAQ to compute the abiotic conditions, and fuzzy cellular automata approach was applied to predict the algal biomass that was indicated by chlorophyll a concentration. The simulated results of year 1995 were compared with that from BLOOM II model, and the advantages, disadvantages as well as future improvement were presented. In general, through this study, it is seen that the integrated modelling deserves more research inputs because: (1) the hydrodynamic processes and nutrients concentrations can be simulated in details by numerical method; (2) the irregular and sparse water quality and biological data, and the empirical knowledge from experts can be explored by the fuzzy logic technique; (3) the spatial heterogeneity, local interactions and the emerge of patchiness could be well captured through the cellular automata paradigm.     

Chlorcarbazole in Böden

Goal and Scope

In soil samples taken from several locations throughout Bavaria, the detection of p,p′-DDT by GC/MS was impeded by a superimposed peak. The authenticity of this compound, which has been identified as dichlorocarbazole by mass spectra databases, is confirmed and some characteristics of its occurrence in soils are described.

Methods

The authenticity of the unknown compound has been checked by comparing the low resolution mass spectra and chromatographic retention times with those of standard compounds. Some methodical studies concerning extraction and clean-up were also carried out.

Results and Conclusion

Mass spectra and retention of the unknown compound are identical with that of the 3,6-dichlorocarbazole standard compound; additionally, a second chlorocarbazole was found with mass spectrum and retention similar to 3-chlorocarbazole. In many topsoils (A-horizons) and subsoils (B-horizons) from 200 locations of different land-uses, the dichlorocarbazole could be detected. In contrast to PAH and other POPs, maximum concentrations occurred in the A- and upper B-horizons of forest soils rather than in the organic layers. Assuming the environmental distribution properties of the chlorocarbazoles to be similar to those of the PAH, this could indicate that the chlorocarbazoles are not deposited from the atmosphere as a result of anthropogenic activities but might be generated by natural processes in situ.

Recommendation and Perspective

To our knowledge, the occurrence of chlorocarbazoles in soils of unpolluted sites has not been previously described. Their widespread occurrence in relatively high concentrations and their detection using analytical standard procedures is surprising and requires further examination.     

Binding of manganese by Antarctic Phaeocystis pouchetii and the role of bacteria in its release

The growth of Antarctic Phaeocystis pouchetii and associated bacteria in culture, and the binding and release of manganese were investigated using cultures derived from three clonal isolates collected from Prydz Bay, Antarctica, in November and December 1982. The cultured strains accumulated manganese from the culture medium. The concentration of Mn²⁺ in the alga was up to 58 times that of the medium. The Mn²⁺ apparently binds to the mucilage secreted by the cells and gives the alga its characteristic brown colour. Oxidation or complexing of Mn²⁺ by P. pouchetii was also indicated. Bacterial growth on the mucilage is inhibited in rapidly growing cultures by acrylic acid produced in the mucilage. Once the growth of P. pouchetii and production of ccrylic acid slow, bacterial numbers increase, leading to the solubilization of the mucilage and the release of Mn²⁺. In cool-temperate, subpolar and polar seas where P. pouchetii may form dense blooms, the binding and subsequent release of manganese may have important consequences for competing phytoplankton.     

EFFECTS OF BEST MANAGEMENT PRACTICES ON FOREST STREAMWATER QUALITY IN EASTERN KENTUCKY1

ABSTRACT: Forest land managers are concerned about the effects of logging on soil erosion, streamflow, and water quality and are promoting the use of Best Management Practices (BMPs) to control impacts. To compare the effects of BMP implementation on streamwater quality, two of three small watersheds in Kentucky were harvested in 1983 and 1984, one with BMPs, the other without BMPs. There was no effect of clearcutting on stream temperatures. Streamflow increased by 17.8 cm (123 percent) on the BMP watershed during the first 17 months after cutting and by 20.6 cm (138 percent) on the Non-BMP watershed. Water yields remained significantly elevated compared to the uncut watershed 8 years after harvesting. Suspended sediment flux was 14 and 30 times higher on the BMP and Non-BMP Watersheds, respectively, than on the uncut watershed during treatment, and 4 and 6.5 times higher in the 17 months after treatment was complete. Clearcutting resulted in increased concentrations of nitrate, and other nutrients compared to the uncut watershed, and concentrations were highest on the non-BMP watershed. Recovery of biotic control over nutrient losses occurred within three years of clearcutting. The streamside buffer strip was effective in reducing the impact of clearcutting on water yield and sediment flux.     

Environmentally friendly production of thiobencarb (Bolero)

S-Alkyl thiocarbamates are commercially available and widely used for their herbicidal properties. Despite the numerous methods for synthesizing these compounds, most employ toxic reagents that are harmful to the environment. Within we report a novel efficient one-pot process for the formation of thiobencarb employing readily available reagents. This method makes use of a trichloroacetyl chloride adduct and requires no complex starting materials. Furthermore, this process is efficient, proceeds in high yields, and utilizes several recyclable reagents.