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41.
Reforestation with black locust (Robinia pseudoacacia) is considered a successful technique that is often used for the reclamation of open-cast mine areas. An alternative reclamation technique could be the natural regeneration of vegetation with spontaneous grass species. In this study, we compared the concentrations of chemical and biochemical variables in soil samples taken under black locust canopy to those from sites covered by spontaneous grass vegetation (control samples) in a time sequence of spoil deposition (0–10 years), in order to assess which of the two reclamation techniques yields higher soil quality. Soil quality refers here to the ability of soils to function ecologically. This has a special interest since the main question for the restored soils is their capacity to perform a range of ecological functions under stress or disturbance. Furthermore, we aimed at identifying the effect of vegetation type on soil ecological succession. The effect of vegetation type on primary succession becomes apparent after 2 years of reclamation. R. pseudoacacia as a nitrogen-fixing plant enriched soil with organic and inorganic nitrogen and organic matter to a greater extent than the natural grasses. It also increased the amount of soil microbial biomass and the activity of alkaline phosphatase. However, the fact that black locust failed to enhance dehydrogenase activity and actually decreased the activity of urease, activities that represent specialized niche functions and therefore, are more vulnerable to stress or disturbance, suggests that the development of an indigenous grass community in combination with organic supplements might often be more appropriate for the reclamation of similar kinds of mine areas.  相似文献   
42.
Agricultural wastes (AW) are often characterized by varying pH and substantial contamination potential, which are mainly related to their high organic load, thus affecting—when improperly disposed of—soils, living organisms, and water bodies. Composting of AW is the most commonly used management option and results in the production of soil improver that enhances crop growth and contributes to agricultural sustainability. This study aims to present the framework for assessing human and ecosystem risk when compost produced from AW is applied on soil. In order to develop this framework, issues such as origin, composition and pre-treatment of AW, application rates on soils, bioavailability and mobility of contaminants present in compost, exposure routes and rates as well as determination of the fate of contaminants in soil, air, and water, should be taken into consideration.  相似文献   
43.
Environmental education and financial support of nature conservation are considered among the primary components of the environmentalist dimension of ecotourism. The potential of environmental education calls for enhancing visitor environmental knowledge and prompting change of visitor behavior. The present study addressed the evaluation of the environmentalist dimension of ecotourism in the Dadia Forest Reserve. The first objective of the research was to study the influence of variables determined prior to the visit, namely, visitor and visit characteristics, visitor environmental information sources, visitor pro-environmental behavior, and visitation goals, on variables determined during the visit, that is, visitor participation in and satisfaction from ecotourism activities. The second objective was to study the effect of selected variables on visitor knowledge and behavior intentions. Visitor participation in and satisfaction from ecotourism activities were primarily controlled by visit characteristics. Levels of visitor knowledge were quite satisfactory; however, coherence among knowledge items was rather loose. On the other hand, behavior intention items revealed the highest possible degree of coherence, which should be attributed to the pervasive influence of visitor satisfaction from watching birds at the Bird Observatory within the Dadia Forest Reserve. Ecotourism activities, during which the main part of environmental knowledge was offered, exerted no effect on visitor knowledge; all the same, they significantly influenced visitor behavior intentions. Overall, visitor behavior intentions revealed a considerable potential of financing environmental protection and providing voluntary work in the frame of the environmental management of the Dadia Forest Reserve.  相似文献   
44.
Background arctic aerosol properties generally observed during the summer were studied at Ny-Ålesund, Svalbard in a six-week campaign where the aerosol size distribution and chemical composition were measured. The results presented here demonstrate the marked difference between the background arctic aerosol composition in comparison to the aged aerosol arriving in the area by long-range transport from southern latitudes. It is found that sulphate is the major water-soluble component of background aerosol followed by sea salt. Aged aerosol arriving in the Arctic from polluted areas is recognised by an increase in black carbon and in the refractory aerosol fraction.  相似文献   
45.
The operational designing of Environmentally Sustainable Economic Development (ESED) emerges as an urgent and demanding task. Even though ESED has paved the way for thought-provoking and constructive scientific dialogue, appeal for designing an operational ESED is still lagging behind the needs of contemporary societies, leaving much to be desired. With this in mind, the present paper will aim at delineating principles for the operational application of ESED. First, the preservation of crucial properties of environmental functions and ecosystems, emerges as a prime condition of ESED. The second condition concerns the provision of the economic process with sufficient natural inputs; in this context, the paper intends to trace certain operational tenets governing the use of natural resources. Finally, the appropriate institutional settings for the operational design of ESED are traced. Readers should send their comments on this paper to BhaskarNath@aol.com within 3 months of publication of this issue  相似文献   
46.
Carbonyl sulfide is found as a major sulfur compound in anodic gases of commercial aluminium electrolysis. Recent spectroscopic measurements on industrial aluminium smelters found typical CO/COS ratios between 80 and 200. This results in specific COS emissions of between 1 and 7 kg/t(Al) if all COS is released into the atmosphere. In 1993 aluminium production would have been responsible for between 0.02 and 0.14 Tg of COS emissions. Currently, aluminium production does not seem to influence the total atmospheric COS budget to an extent beyond its natural variability. If recent growth rates of global aluminium production are sustained, however, COS emissions would quadruple until 2030. Together with increasing aircraft emissions into the stratosphere, an increase of the sulfate background aerosol is to be expected that could significantly enhance ozone depletion. The use of inert anodes is recommended to reduce aluminium production emissions of COS and CF4, C2F6, CO2, and CO at the same time.  相似文献   
47.
The influence of pH on adsorption of dye-containing effluents with three different bentonites was studied. One dye of each of the basic, acid and direct categories were studied. A considerable increase of dye adsorption degree was observed in different pH.  相似文献   
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