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Deborah F. Shmueli 《Geoforum》2008,39(6):2048-2061
When applied to environmental concerns, framing offers a rigorous conceptual and analytic approach with potentially practical significance for dealing with complex issues relevant to geography. The purpose of this article is to introduce framing concepts, typology and modes of analysis to address issues which geographers commonly treat: disputes over land ownership and uses, competition for water resources, cultural clashes over control of territory and resources and the impact of spatial patterns and structures when siting noxious sites. Framing analysis is applied to three cases of environmental conflict in Israel and, more generally, for understanding conflicts revolving around the management of human habitats in relation to the physical environment.  相似文献   
3.
Variations in sulfur mineralogy and chemistry of serpentinized peridotites and gabbros beneath the Lost City Hydrothermal Field at the southern face of the Atlantis Massif (Mid-Atlantic Ridge, 30°N) were examined to better understand serpentinization and alteration processes and to study fluid fluxes, redox conditions, and the influence of microbial activity in this active, peridotite-hosted hydrothermal system. The serpentinized peridotites are characterized by low total sulfur contents and high bulk δ34S values close to seawater composition. Low concentrations of 34S-enriched sulfide phases and the predominance of sulfate with seawater-like δ34S values indicate oxidation, loss of sulfide minerals and incorporation of seawater sulfate into the serpentinites. The predominance of pyrite in both serpentinites and gabbros indicates relatively high fO2 conditions during progressive serpentinization and alteration, which likely result from high fluid fluxes during hydrothermal circulation and evolution of the Lost City system from temperatures of ∼250 to 150 °C. Sulfate and sulfide minerals in samples from near the base of hydrothermal carbonate towers at Lost City show δ34S values that reflect the influence of microbial activity. Our study highlights the variations in sulfur chemistry of serpentinized peridotites in different marine environments and the influence of long-lived, moderate temperature peridotite-hosted hydrothermal system and high seawater fluxes on the global sulfur cycle.  相似文献   
4.
The sources and distribution of organic matter (OM) in surface waters and sediments from Winyah Bay (South Carolina, USA) were investigated using a variety of analytical techniques, including elemental, stable isotope and organic biomarker analyses. Several locations along the estuary salinity gradient were sampled during four different periods of contrasting river discharge and tidal range. The dissolved organic carbon (DOC) concentrations of surface waters ranged from 7 mg l−1 in the lower bay stations closest to the ocean to 20 mg l−1 in the river and upper bay samples. There was a general linear relationship between DOC concentrations and salinity in three of the four sampling periods. In contrast, particulate organic carbon (POC) concentrations were significantly lower (0.1–3 mg l−1) and showed no relationship with salinity. The high molecular weight dissolved OM (HMW DOM) isolated from selected water samples collected along the bay displayed atomic carbon:nitrogen ratios ([C/N]a) and stable carbon isotopic compositions of organic carbon (δ13COC) that ranged from 10 to 30 and from −28 to −25‰, respectively. Combined, such compositions indicate that in most HMW DOM samples, the majority of the OM originates from terrigenous sources, with smaller contributions from riverine and estuarine phytoplankton. In contrast, the [C/N]a ratios of particulate OM (POM) samples varied significantly among the collection periods, ranging from low values of 5 to high values of >20. Overall, the trends in [C/N]a ratios indicated that algal sources of POM were most important during the early and late summer, whereas terrigenous sources dominated in the winter and early spring.In Winyah Bay bottom sediments, the concentrations of the mineral-associated OM were positively correlated with sediment surface area. The [C/N]a ratios and δ13COC compositions of the bulk sedimentary OM ranged from 5 to 45 and from −28 to −23‰, respectively. These compositions were consistent with predominant contributions of terrigenous sources and lesser (but significant) inputs of freshwater, estuarine and marine phytoplankton. The highest terrigenous contents were found in sediments from the river and upper bay sites, with smaller contributions to the lower parts of the estuary. The yields of lignin-derived CuO oxidation products from Winyah Bay sediments indicated that the terrigenous OM in these samples was composed of variable mixtures of relatively fresh vascular plant detritus and moderately altered soil OM. Based on the lignin phenol compositions, most of this material appeared to be derived from angiosperm and gymnosperm vascular plant sources similar to those found in the upland coastal forests in this region. A few samples displayed lignin compositions that suggested a more significant contribution from marsh C3 grasses. However, there was no evidence of inputs of Spartina alterniflora (a C4 grass) remains from the salt marshes that surround the lower sections of Winyah Bay.  相似文献   
5.
The first estimates of uptake kinetic parameters for NH4+, NO3, and urea in the Ross Sea, Antarctica were measured on three cruises during austral late winter–early spring 1996 (pre-bloom), late spring 1997 (bloom development), and summer 1997 (bloom decline). Nitrogen (N) uptake experiments were conducted with water collected at the 50% light penetration depth using trace-metal clean protocols and 15N tracer techniques. At all sites, ambient NO3 concentrations ranged from 5.8 to 30.5 μg-at N l−1 and silicic acid concentrations were greater than 62.0 μg-at Si l−1. The following trends were observed. First, based on maximum uptake rates (Vmax), apparent N utilization followed the order NO3>NH4+>urea during the pre-bloom and bloom development cruises. During the summer cruise, as the bloom was declining, the apparent order of utilization was NH4+>NO3>urea. Second, evidence for possible repression of NO3 uptake by elevated NH4+ concentrations was only observed at one site. Third, the kinetic parameters of NH4+ uptake rates corrected for isotope dilution were compared with the kinetic parameters determined from uncorrected rates. In this comparison, the measure of substrate affinity, α (α=Vmax/Ks) increased by an average of 4.6-fold when rates were corrected for isotope dilution, but values of Vmax remained unchanged. Fourth, using bacterial production data, the magnitude of bacterial N uptake was estimated. Assuming that all bacterial N demands were met with NH4+, the estimated bacterial portion of NH4+ uptake ranged from <1%, when the ratio of bacteria to autotrophic biomass was low, to 35%, when bacterial abundance and biomass were highest. Finally, dramatic changes in NH4+ uptake capacity were observed at one station (Stn. O), where kinetic parameters were measured during all three cruises. We hypothesize that a mutualistic relationship exists between phytoplankton and heterotrophic bacteria, and that the creation of microzones of high NH4+ concentrations contributed to the changes seen at this station.  相似文献   
6.
Although commonly utilized in continental geothermal work, the water-hydrogen and methane-hydrogen isotope geothermometers have been neglected in hydrothermal studies. Here we report δD-CH4 and δD-H2 values from high-temperature, black smoker-type hydrothermal vents and low-temperature carbonate-hosted samples from the recently discovered Lost City Hydrothermal Field. Methane deuterium content is uniform across the dataset at − 120 ± 12‰. Hydrogen δD values vary from − 420‰ to − 330‰ at high-temperature vents to − 700‰ to − 600‰ at Lost City. The application of several geothermometer equations to a suite of hydrothermal vent volatile samples reveals that predicted temperatures are similar to measured vent temperatures at high-temperature vents, and 20-60 °C higher than those measured at the Lost City vents. We conclude that the overestimation of temperature at Lost City reflects 1) that methane and hydrogen are produced by serpentinization at > 110 °C, and 2) that isotopic equilibrium at temperatures < 70 °C is mediated by microbial sulfate reduction. The successful application of hydrogen isotope geothermometers to low-temperature Lost City hydrothermal samples encourages its employment with low-temperature diffuse hydrothermal fluids.  相似文献   
7.
Developing ecotourism in First World, resource-dependent areas   总被引:1,自引:0,他引:1  
Deborah Che 《Geoforum》2006,37(2):212-226
Ecotourism, an economic diversification tool most commonly applied in the Third World as a means to protect ecosystems, preserve local cultures, and spur economic development, has recently been applied in First World resource-dependent areas. While ecotourism has traditionally focused on Third World ‘undisturbed’ protected lands, it has also been developed in their First World equivalents (i.e., old-growth forests) as well as in First World sites of past resource extraction and in places where current agricultural practices maintain cherished cultural landscapes. Forest County, Pennsylvania, a timber-dependent area, sought to diversify its economy by developing ecotourism based on its unique Allegheny hardwood forests, which are produced by timber harvesting. This ecotourism would encourage amenity-based, locally-driven economic development and maintain timber harvesting. While government and foundation supported ecotourism development efforts in areas dependent on resource extraction have incorporated some of ecotourism’s ideals, these operations have had mixed success. Such isolated areas, which have traditionally drawn visitors independently engaging in traditional outdoor recreation activities, have not been able to draw enough customers willing to pay for natural and cultural history tours. If ecotourism is to be successful, such areas may need further government support and destination branding to increase name recognition in order to counter the global orientation of the nature tour industry. For true community development, local collaborative efforts including resource and environmental interests are also required in which primary production is connected to processing and consumers through value-added and service sector activities such as tourism.  相似文献   
8.
As part of a broader process of inter-urban competition, city governments have increasingly sought to 'position' themselves as centres of creativity. In these branding initiatives, culture is viewed as a tool of urban regeneration and economic development. Our paper examines the case of Commerce Design Montréal, an annual design competition run by the City of Montréal, which aims to brand Montréal as a centre of design. Commerce Design Montréal is an example of a 'fast' policy initiated by the state, but carried out by business owners and citizens. As such, it represents a downloading of the responsibility for economic development to the private or individual scale and adopts only a partial view of the varied actors and uses that are implicated in the design process. The paper considers the opportunities and challenges that this model presents for promoting design as a form of urban regeneration in a neo-liberal context.  相似文献   
9.
Parameters affecting maximum fluid transport in large aperture fractures   总被引:1,自引:0,他引:1  
We present results of laboratory experiments to study the behavior of liquids moving in unsaturated wide-aperture fractures. A 5-mm-thick glass plate cut with a 1.7-mm aperture was used as a fractured rock analog to study behavior of film and capillary droplet flow modes. Flow rates ranged between 0.6 and 6.0 ml/min. Variability in the ambient barometric pressure, resulting from weather conditions, seemed to play a role in the natural selection of flow mode. For droplet mode, constant input conditions resulted in highly variable transport properties within the fracture. The advancing meniscus exhibited a dynamic contact angle that was a function of the droplet speed and much larger than the static contact angle. Flow rate was reduced due to the larger contact angle. Analytical expressions for droplet velocity and flow capacity are presented as a function of the dynamic rather than the static contact angle.  相似文献   
10.
We report the benthic fluxes of O2, titration alkalinity (TA), Ca2+, NO3, PO43−, and Si(OH)4 from in situ benthic flux chamber incubations on the Ceara Rise and Cape Verde Plateau and compare them to previously published results. We find within analytical uncertainty that the TA flux is twice the calcium flux, suggesting that dissolution/precipitation of CaCO3 is the principal mechanism controlling benthic TA and Ca2+ fluxes. At sites where the sediments contain significant (>35%) CaCO3 and the overlying waters are supersaturated with respect to CaCO3, the ratios of the total dissolution rate to the remineralization rate are significantly less than at all other study sites. We propose that these observations can be explained by precipitation of fresh CaCO3 at the supersaturated sediment surface followed by redissolution deeper in the sediments because of metabolically-produced CO2. A numerical simulation is presented to demonstrate the feasibility of this explanation. In addition, surface exchange reactions in high-CaCO3 sediments coupled with high rates of particle mixing may also impact rates of metabolic dissolution and depress chamber-derived estimates of carbonate alkalinity and calcium benthic fluxes. These results suggest that at supersaturated, high CaCO3 locations, previous models of sediment diagenesis may have overestimated the impact of metabolic dissolution on the preservation of CaCO3 deposited on the sea floor.  相似文献   
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