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201.
Abstract

The city of Missoula is located in a high mountain valley (elevation 3200 ft) in western Montana and contains one of the largest populations in the entire Rocky Mountain Region completely enclosed by mountains. During the 2000/2001 Missoula Valley Sampling Program, ambient levels of 61 semivolatile organic compounds (SVOCs) and 54 volatile organic compounds (VOCs) were originally quantified before refining the analytical program to 28 of the most prominent SVOCs and VOCs found in the Missoula Valley airshed. These compounds were measured over 24-hr periods at two locations throughout an entire year. This study provides the first, comprehensive appraisal of the levels of SVOCs and VOCs measured simultaneously throughout all four seasons at two locations in the Missoula Valley, including those levels measured during the 2000 Montana wildfire season. Generally, SVOC levels were comparable between both sides of the Missoula Valley. However, there were nearly double the amount of VOCs measured at the more urban Boyd Park site compared with the rural Frenchtown sampling site, a result of the greater number of automobiles on the eastern side of the Valley. SVOCs and VOCs were measured at their highest levels of the sampling program during the winter. Forest fire smoke samples collected during the summer of 2000 showed significant increases in SVOC phenolic compounds, including phenol, 2-methylphenol, 4-methylphenol, and 2,4-dimethylphenol. Although there were modest increases in some of the other SVOCs and VOCs measured during the fire season, none of the increases were as dramatic as the phenolics.  相似文献   
202.
The interactive effects of soil texture and type of N fertility (i.e., manure vs. commercial N fertilizer) on N(2)O and CH(4) emissions have not been well established. This study was conducted to assess the impact of soil type and N fertility on greenhouse gas fluxes (N(2)O, CH(4), and CO(2)) from the soil surface. The soils used were a sandy loam (789 g kg(-1) sand and 138 g kg(-1) clay) and a clay soil (216 g kg(-1) sand, and 415 g kg(-1) clay). Chamber experiments were conducted using plastic buckets as the experimental units. The treatments applied to each soil type were: (i) control (no added N), (ii) urea-ammonium nitrate (UAN), and (iii) liquid swine manure slurry. Greenhouse gas fluxes were measured over 8 weeks. Within the UAN and swine manure treatments both N(2)O and CH(4) emissions were greater in the sandy loam than in the clay soil. In the sandy loam soil N(2)O emissions were significantly different among all N treatments, but in the clay soil only the manure treatment had significantly higher N(2)O emissions. It is thought that the major differences between the two soils controlling both N(2)O and CH(4) emissions were cation exchange capacity (CEC) and percent water-filled pore space (%WFPS). We speculate that the higher CEC in the clay soil reduced N availability through increased adsorption of NH(4)(+) compared to the sandy loam soil. In addition the higher average %WFPS in the sandy loam may have favored higher denitrification and CH(4) production than in the clay soil.  相似文献   
203.
Runoff from turf environments, such as golf courses, is of increasing concern due to the associated chemical contamination of lakes, reservoirs, rivers, and ground water. Pesticide runoff due to fungicides, herbicides, and insecticides used to maintain golf courses in acceptable playing condition is a particular concern. One possible approach to mitigate such contamination is through the implementation of effective vegetative filter strips (VFS) on golf courses and other recreational turf environments. The objective of the current study was to screen ten aesthetically acceptable plant species for their ability to remove four commonly-used and degradable pesticides: chlorpyrifos (CP), chlorothalonil (CT), pendimethalin (PE), and propiconazole (PR) from soil in a greenhouse setting, thus providing invaluable information as to the species composition that would be most efficacious for use in VFS surrounding turf environments. Our results revealed that blue flag iris (Iris versicolor) (76% CP, 94% CT, 48% PE, and 33% PR were lost from soil after 3 mo of plant growth), eastern gama grass (Tripsacum dactyloides) (47% CP, 95% CT, 17% PE, and 22% PR were lost from soil after 3 mo of plant growth), and big blue stem (Andropogon gerardii) (52% CP, 91% CT, 19% PE, and 30% PR were lost from soil after 3 mo of plant growth) were excellent candidates for the optimization of VFS as buffer zones abutting turf environments. Blue flag iris was most effective at removing selected pesticides from soil and had the highest aesthetic value of the plants tested.  相似文献   
204.
205.

In 1995 the Progressive Conservative Party (PC) defeated the New Democratic Party (NDP) to form the government in the province of Ontario, Canada. These parties represent different positions regarding the management, regulation and control of environmental affairs. The effects of provincial legislation on the environment are typically felt at the local level and hence we argue that this study has relevance for those interested in local environments. One policy paper regarding the environment for each party is analysed using a formal discourse analysis technique called textual analysis computing tools (TACT). The rationale for using TACT is included, as is a brief commentary on previous studies that have used discourse analysis to examine environmental issues. The results of the analysis indicate the different ways that the NDP and the PC express their philosophical positions as applied to environmental policy making in Ontario. The shift in 1995 from the social democratic and interventionist stance of the NDP with respect to environmental policy making toward the more corporate, free-market privatisation regime of the PC is demonstrated. Close attention is paid in the discourse analysis to the use of words like 'cost', 'economy' and 'environment' in the two documents analysed. The use of language in a government position paper creates meaning and significance to citizens in the context of their local environment. En 1995 el Partido Conservador Progresista (PC) vencio al Nuevo Partido Democratico (NDP) para formar el gobierno en la provincia de Ontario, Canada. Estos partidos representan diferentes posiciones con respecto al manejo, regulación y control de los asuntos ambientales. Los efectos de la legislación provincial en el ambiente son sentidos típicamente a nivel local y por lo tanto nosotros argumentamos que este estudio tiene relevancia para los interesados en ambientes locales. Un documento de cada partido de politicas concernientes al medio ambiente es analizado usando una técnica de análisis de discurso formal llamada TACT. La razón para usar TACT es incluida yá que es un leve comentario sobre estudios previos que han usado análisis de discurso para examinar temas ambientales. Los resultados del análisis indican las diferentes formas que el NDP y el PC expresan su posiciones filósoficas como aplicación a la creación de politicas ambientales en Ontario. El cambio en 1995 de la actitud intervencionista y social-democrata del NDP con respecto a la creación de politicas ambientales hacia una postura mas corporativa de regimen de privatización de mercado libre del PC es demostrado. En los dos documentos analizados se presta una detenida atención en el análisis de discurso al uso de palabras como 'costo', 'economía', y 'ambiente'. El uso del lenguaje en un documento de la posición del gobierno crea sentido y significado a los ciudadanos en el contexto de su ambiente local.  相似文献   
206.
Abstract

Defining and putting into practice sustainable land use is a complex, systemic problem. Systems models and techniques were used in a study of Herefordshire to clarify the situation and identify the potential for a more locally focused, learning-based approach to land use. Issues included: (i) uncertainty about the boundary of a ‘system of sustainable Herefordshire land use’; (ii) the complexity of economic flows in the county and the absence of some critical data; (iii) the importance of the Herefordshire landscape to tourism and the role of agriculture as a determinant of the state of that landscape; (iv) weakness of the institutional linkage between tourism and agriculture; (v) the current lack of inclusion of many relevant stakeholders in concerted action. Factors favouring a learning approach included a strong local identity, local food-related developments, and educational initiatives. Barriers to such an approach included questions of power and landholding, government policies, and attitudes and skills within organizations. These findings are considered in relation to the wider debate over approaches to sustainability.  相似文献   
207.
208.
209.
Climate change exposes economic systems to numerous risks, including reduced agricultural production and electric power supply shortages. The interdependent nature of economic systems causes disruptions in any sector to cascade to other sectors via forward and backward linkages. This work develops an optimization model with which allocation of scarce goods or resources can be optimized; the model uses an overall index of satisfaction of fuzzy economic output goals under conditions of scarcity caused by climatic disruptions. The proposed model includes a vulnerability measure that integrates information elicited from expert judgment. A case study based on a scenario of drought-induced electricity shortage in the Philippine economy is examined. Results show that trade, transportation and service-oriented industries suffer losses in gross domestic product in the Philippine case.  相似文献   
210.
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