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181.
Since 2005, a dramatic decline of the Arctic sea-ice extent is observed which results in an increase of shipping activities. Even though this provides commercial and social development opportunities, the resulting environmental impacts need to be investigated and monitored. In order to understand the impact of shipping in arctic areas, the method described in this paper determines the travel time, fuel consumption and resulting exhaust emissions of ships navigating in arctic waters. The investigated case studies are considering ship particulars as well as environmental conditions with special focus on ice scenarios. Travel time, fuel consumption and exhaust gas emission were investigated for three different vessels, using different passages of the Northern Sea Route (NSR) in different seasons of years 1960, 2000 and 2040. The presented results show the sensitivity of vessel performance and amount of exhaust emissions to optimize arctic traffic with respect to efficiency, safety and environmental impact. 相似文献
182.
Lack of sufficiently detailed data often limits the applicability of complex transport-reaction models for estimating potential herbicide loss to surface waters. Therefore, there is also a need for simple models that are easy to apply but still capture the main features of the underlying processes.In this study, a simple regression model was developed to assess the vulnerability of catchments in the Swiss Plateau to diffuse herbicide loss to surface waters. The model is designed as a screening tool to rank the catchments in a relative sense and not to calculate Predicted Environmental Concentrations (PEC) of pesticides. The main goal is to capture two dominating factors controlling diffuse herbicide transport into streams and rivers. These factors are herbicide application and fast flow processes that are mainly responsible for herbicide transport. In a first step vulnerability of sites to herbicide loss is estimated based on site-specific conditions irrespective of actual herbicide application. In the second step, this vulnerability assessment is combined with actual herbicide application data to estimate the potential herbicide loss.The fast flow index (FFI), derived from discharge data using a base flow separation method, was applied as a proxy for the amount of fast flow occurring. The influence of catchment attributes (including topographic, climatic and soil data) on the FFI was analyzed using a multiple regression approach based on data from 57 catchments of the Swiss Plateau. By combining regression analysis with mechanistic knowledge, a two factor non-linear model based on river density and soil permeability as dominant input factors was selected as the best model for FFI prediction given the available data. Higher dimensional models had to be excluded because the strong correlation between the potential input factors led to unrealistic dependences while only minimally improving the quality of the fit.The spatial pattern of the predicted FFI as a measure for the vulnerability to diffuse herbicide losses shows a clearly increasing trend from the western to the eastern part of the Swiss Plateau and towards the pre-alpine/alpine regions in the south.In general the pattern of herbicide use corresponds to site conditions typical of a low FFI. However, the spatial analysis revealed exceptions, namely areas in which high actual herbicide use coincides with a high FFI.Despite the uncertainties in the model, this simple approach seems to be useful for supporting site-adapted agricultural practice whenever the higher accuracy of more detailed models is not required or too expensive to achieve. In addition, in combination with data on actual herbicide application, it can support the design of monitoring strategies by identifying critical areas of actual herbicide loss. 相似文献
183.
Christian Coff 《Journal of Agricultural and Environmental Ethics》2013,26(4):813-825
The aim of this paper is to explore how food can be analyzed in terms of signs and codes of everyday life, and especially how food can be used to express ethical concerns. The paper investigates the potential of a semiotic conceptual analysis: How can the semiotic approach be used to analyze expressions of ethics and food ethics in everyday life? The intention is to explore from a theoretical point of view and with constructed cases, how semiotics can be used to analyze the role of food as an expression of ethics in everyday life among families, friends, and colleagues: How do foodstuffs function as signs of ethics in everyday life? How is food used to send signals about care and concern? How are the signs of food ethics perceived? It is concluded that analyzing ethical considerations with respect to food with the help of the semiotic model can show us perspectives that otherwise would be difficult to see and thus we can address everyday food ethical issues that otherwise might not be noted. The semiotic approach to food ethics in everyday life is a conceptual framework that can be used to draw attention to certain domains and fields of food ethical behavior that otherwise would tend to remain implicit and unspoken. 相似文献
184.
Christian C. Voigt Gerald Heckel Frieder Mayer 《Behavioral ecology and sociobiology》2005,57(5):457-464
We investigated how morphological traits of territorial males in the polygynous bat Saccopteryx bilineata were related to their reproductive success. Because of the frequency of aerial courtship displays and defence manoeuvres, and the high energetic costs of flight, we expected small and symmetric males to be better able to court females on the wing and to monopolize copulations with females in their harems. We predicted that small and symmetric males would sire more offspring within the colony and a larger portion of the young born within their harem than large or asymmetric males. We measured size and fluctuating asymmetry of 21 territorial males and analysed their reproductive success in 6 offspring cohorts (n=209 juveniles) using 11 microsatellite loci. As predicted, small and symmetric males had, on average, a higher reproductive success in the colony than large and asymmetric males. The percentage of young sired by males within their harem increased as males decreased in size, but was not influenced by fluctuating asymmetry. As fluctuating asymmetry of males correlated with their reproductive success within the colony but not within their harems, we infer that fluctuating asymmetry is probably related to female choice, whereas male size is probably important for harem defence on the wing.Communicated by G. Wilkinson 相似文献
185.
The mining industry has been one of the backbones of the socialist countries of Eastern Europe, not only in economic, but also in political, terms. Three years after the beginning of economic reforms, the mining industry in all the Eastern European countries is facing dramatic changes. Most mines are mining ores below acceptable cut-off grades, and there is no hope of finding new, richer deposits. Downstream metallurgical industries will need to replace their former suppliers. In addition, the social contract that had been maintained under the socialist governments is about to be undone and a new form of internal organization must be found. The success of the economic reforms in Eastern Europe depends upon the capacity to develop new industrial relations: the large mining combinates will have to be transformed into competitive capitalist enterprises and the role of the state must be redefined. Prospects for this transformation vary greatly, from metal to metal and from country to country. Finally, restructuring in Eastern Europe will also affect European and world markets, both on the supply and demand sides. The integration of the Eastern European mining industries into the international mining community should be the medium-term goal of all the participants . 相似文献
186.
Dynamics of Bacterial Abundance,Biomass, Activity,and Community Composition in the Oligotrophic Traunsee and the Traun River (Austria) 总被引:1,自引:0,他引:1
Klammer Susanne Posch Thomas Sonntag Bettina Griebler Christian Mindl Birgit Psenner Roland 《Water, Air, & Soil Pollution: Focus》2002,2(4):137-163
The holomictic Traunsee is the deepest and second largest lakein Austria. The special characteristic of this ecosystem isthe fact that local salt and soda industries presumably alterthe lake by the discharge of waste materials. Since thebeginning of the 20th century salt and soda works areannually releasing up to 50,000 tons of solid wastes and up to150,000 tons of chloride into Traunsee. To assess potentialeffects of these anthropogenic impacts on the bacterioplanktonthree sampling sites, influenced as well as not influenced bythe industrial discharge, were chosen for comparison andsampled monthly from November 1997 to October 1998. Bacterialabundance ranged between 0.4 to 3.0 × 106 cells ml-1 with decreasing numbers along the depth profile. Theproportion of actively respiring bacteria, i.e. INT [2-(4-iodophenyl)-3-(4-nitrophenyl)-5-phenyltetrazolium chloride]reducing cells, never exceeded 10% of DAPI (4',6'-diamidino-2-phenylindole) stained cells. Fluorescence in situ hybridization (FISH) was used to examine the seasonal and spatial distribution of dominant phylogenetic groups of thebacterioplankton. Up to 84% of bacteria detected with DAPIcould be detected via FISH applying the universal bacterialprobe EUB338. Percentages of alpha- and beta-Proteobacteriaand members of the Cytophaga-Flavobacterium cluster did notexceed 60% of DAPI-stained cells.Beta-Proteobacteriaappeared to be the most abundant group, not only in Traunsee butalso in two reference lakes, Attersee and Hallstättersee. No significant differences in any of the bacterial parameters couldbe detected between the three sampling sites and all measurementswere found in the range reported for oligotrophic lakes. The highdischarge of the Traun River, resulting in a lake water renewaltime of only one year, may diminish possible effects of industrial waste discharge in the pelagic zone. 相似文献
187.
Benjamin Hofmann Karin Ingold Christian Stamm Priska Ammann Rik I. L. Eggen Robert Finger Samuel Fuhrimann Judit Lienert Jennifer Mark Chloe McCallum Nicole Probst-Hensch Ueli Reber Lucius Tamm Milena Wiget Mirko S. Winkler Lucca Zachmann Sabine Hoffmann 《Ambio》2023,52(2):425
Calls for supporting sustainability through more and better research rest on an incomplete understanding of scientific evidence use. We argue that a variety of barriers to a transformative impact of evidence arises from diverse actor motivations within different stages of evidence use. We abductively specify this variety in policy and practice arenas for three actor motivations (truth-seeking, sense-making, and utility-maximizing) and five stages (evidence production, uptake, influence on decisions, effects on sustainability outcomes, and feedback from outcome evaluations). Our interdisciplinary synthesis focuses on the sustainability challenge of reducing environmental and human health risks of agricultural pesticides. It identifies barriers resulting from (1) truth-seekers’ desire to reduce uncertainty that is complicated by evidence gaps, (2) sense-makers’ evidence needs that differ from the type of evidence available, and (3) utility-maximizers’ interests that guide strategic evidence use. We outline context-specific research–policy–practice measures to increase evidence use for sustainable transformation in pesticides and beyond. 相似文献
188.
We wanted to test the hypothesis that forest exposure to phytotoxic gases indirectly affects their carbon uptake. We estimated that the reduction of photosynthesis may have reached 20 to 30% at a site located 9 km (test site) from the Horne copper smelter in Rouyn-Noranda, which is a point source of SO2. Twenty-one spruce trees older than 100 yr were selected from seven sites at various distances from the smelter to evaluate conditions prior to and during the periods of smelter operation. The carbon isotope results obtained from spruce tree rings at our test site reveal an unprecedented and abrupt shift of +4/1000 after the onset of smelter operations. This large and permanent shift exceeds natural variations in regional pre-smelter series or in the series at a remote control site. All trees up to 116 km downwind from the smelter show delta13C positive shifts following the onset of operations. There is also a clear inverse relationship between the amplitude of the first-order trends and distance from the smelter. Those delta13C trends indicate that trees exposed to high levels of SO2 decrease their level of CO2 uptake through activation of stomatal closure. This is strongly supported by the significant departure of the Rouyn-Noranda trends from those measured for trees from non-industrialized areas of the Northern Hemisphere, or calculated using global atmospheric conditions. Considering the large number of SO2 point sources in North America, our results imply that CO2 uptake by the boreal forest in the vicinity of these sources may be lower than previously thought. 相似文献
189.
Rainer Brüggemann Gerhard Ginzel Christian Steinberg 《Environmental Sciences Europe》1997,9(6):339-343
Conflict are frequently observed when drinking water protection areas are to be defined and when many variants of how to protect these area are to be found. Using ten potential scenarios, a method is presented here which shows how such conflicts concerning these variants may be handled in a systematic manner. The technique is derived from the use of partially ordered sets and their visualization by Hasse diagrams. The first step is to define rankings of different variants according to each aim of protection. A further step is to define an appropriate relationship of order. It is then possible to visualize the extent of consensus and of dissension through the use of a Hasse diagram. The final step is to quantify the importance of each protection aim and the initialization of an iteration. Should a complete consensus be found, this would result in a chain of (connected) variants. Should a complete dissension be found on the other hand, an antichain would then result (i.e. where all variants are isolated). 相似文献
190.
We conducted breeding bird surveys in Minnesota, Wisconsin, and South Dakota in 12 hybrid poplar plantations and surrounding landscapes from 1992 to 1994. Plantations varied in age, shape, composition of surrounding landscape, and internal vegetative heterogeneity. Numbers of breeding bird individuals and species in plantations were lower than in surrounding forest/shrub habitat, but higher than in row crops. Numbers of individuals observed within several bird groups based on migratory status and habitat preference also differed among plantations and surrounding land-use types. Most differences were between numbers in plantations and row crops. Year-to-year changes in bird species composition in plantations were more likely in plantations between ages 2 and 4 years than in younger or older plantations. Correlative evidence from canonical correspondence analysis illustrated that plantation bird communities were related to habitat in surrounding landscapes, plantation age, size, latitude, and longitude. Additionally, more heterogeneous plantations had more species, individuals, and numbers of long-distance migrants. Plantations will likely not support bird communities that are comparable to natural forests in either species composition or species diversity. A goal would be to position them in the landscape to minimize impacts on regional biodiversity. This could be accomplished by maintaining structural diversity of plantations by creating a broad range of successional stages (ages) throughout plantations within a region. Size and connectivity of existing forest fragments may be increased by plantations, but fragmentation of natural open areas should be avoided. 相似文献