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61.
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WISCONSIN AND THE WAIKATO: A COMPARISON OF DAIRY FARMING IN THE UNITED STATES AND NEW ZEALAND: Gordon R. Lewthwaite, Annals of the Association of American Geographers , Vol. 54, No. 1, March 1964, pp. 59–87.  相似文献   
63.
Recent work in political geography has emphasised how scale plays a role in constituting relationships and identities. Historically, the Canadian federal government has taken responsibilities for social services for First Nations people on reserves, leaving this responsibility to provinces for First Nations people in cities. This constitutes First Nations women as individuals with Aboriginal rights only on reserves, and as part of mainstream society in urban areas. First Nations women have challenged the definitions of their identities embedded in these scales of service provision. In presenting alternative geographies for organising the provision of services, they demonstrate the importance of paying attention to the diversity of women’s everyday geographies in the city. This is a phrase from Vicki English’s (1993) presentation to the Royal Commission on Aboriginal Peoples, where she argues that treaty rights to housing, education, medicare and other services should not be confined to the boundaries of reserves. I use the term “First Nations” to refer to people who identify themselves as such, including people who are and are not registered pursuant to the Indian Act. By “Aboriginal peoples” I mean the descendants of the indigenous people in Canada, including First Nations people, Métis and Inuit. The Census of Canada uses the term “North American Indian” to refer to First Nations people, and I employ this terminology for clarity in some cases.
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64.

De Beers kimberlite mine operations in South Africa (Venetia and Voorspoed) and Canada (Gahcho Kué, Victor, and Snap Lake) have the potential to sequester carbon dioxide (CO2) through weathering of kimberlite mine tailings, which can store carbon in secondary carbonate minerals (mineral carbonation). Carbonation of ca. 4.7 to 24.0 wt% (average = 13.8 wt%) of annual processed kimberlite production could offset 100% of each mine site’s carbon dioxide equivalent (CO2e) emissions. Minerals of particular interest for reactivity with atmospheric or waste CO2 from energy production include serpentine minerals, olivine (forsterite), brucite, and smectite. The most abundant minerals, such as serpentine polymorphs, provide the bulk of the carbonation potential. However, the detection of minor amounts of highly reactive brucite in tailings from Victor, as well as the likely presence of brucite at Venetia, Gahcho Kué, and Snap Lake, is also important for the mineral carbonation potential of the mine sites.

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65.
Coastal wetlands, among the most productive ecosystems, are important global reservoirs of carbon (C). Accelerated sea level rise (SLR) and saltwater intrusion in coastal wetlands increase salinity and inundation depth, causing uncertain effects on plant and soil processes that drive C storage. We exposed peat-soil monoliths with sawgrass (Cladium jamaicense) plants from a brackish marsh to continuous treatments of salinity (elevated (~?20 ppt) vs. ambient (~?10 ppt)) and inundation levels (submerged (water above soil surface) vs. exposed (water level 4 cm below soil surface)) for 18 months. We quantified changes in soil biogeochemistry, plant productivity, and whole-ecosystem C flux (gross ecosystem productivity, GEP; ecosystem respiration, ER). Elevated salinity had no effect on soil CO2 and CH4 efflux, but it reduced ER and GEP by 42 and 72%, respectively. Control monoliths exposed to ambient salinity had greater net ecosystem productivity (NEP), storing up to nine times more C than plants and soils exposed to elevated salinity. Submersion suppressed soil CO2 efflux but had no effect on NEP. Decreased plant productivity and soil organic C inputs with saltwater intrusion are likely mechanisms of net declines in soil C storage, which may affect the ability of coastal peat marshes to adapt to rising seas.  相似文献   
66.
Using high-resolution measures of aquatic ecosystem metabolism and water quality, we investigated the importance of hydrological inputs of phosphorus (P) on ecosystem dynamics in the oligotrophic, P-limited coastal Everglades. Due to low nutrient status and relatively large inputs of terrestrial organic matter, we hypothesized that the ponds in this region would be strongly net heterotrophic and that pond gross primary production (GPP) and respiration (R) would be the greatest during the “dry,” euhaline estuarine season that coincides with increased P availability. Results indicated that metabolism rates were consistently associated with elevated upstream total phosphorus and salinity concentrations. Pulses in aquatic metabolism rates were coupled to the timing of P supply from groundwater upwelling as well as a potential suite of hydrobiogeochemical interactions. We provide evidence that freshwater discharge has observable impacts on aquatic ecosystem function in the oligotrophic estuaries of the Florida Everglades by controlling the availability of P to the ecosystem. Future water management decisions in South Florida must include the impact of changes in water delivery on downstream estuaries.  相似文献   
67.
The capture and geological storage of CO2 can be used to reduce anthropogenic greenhouse gas emissions. To assess the environmental impact of potential CO2 leakage from deep storage reservoirs on the abundance and functional diversity of microorganisms in near-surface terrestrial environments, a natural CO2 vent (>90% CO2 in the soil gas) was studied as an analogue. The microbial communities were investigated using lipid biomarkers combined with compound-specific stable carbon isotope analyses, the determination of microbial activities, and the use of quantitative polymerase chain reactions (Q-PCR). With this complementary set of methods, significant differences between the CO2-rich vent and a reference site with a normal CO2 concentration were detected. The δ13C values of the plant and microbial lipids within the CO2 vent demonstrate that substantial amounts of geothermal CO2 were incorporated into the microbial, plant, and soil carbon pools. Moreover, the numbers of Archaea and Bacteria were highest at the reference site and substantially lower at the CO2 vent. Lipid biomarker analyses, Q-PCR, and the determination of microbial activities showed the presence of CO2-utilising methanogenic Archaea, Geobacteraceae, and sulphate-reducing Bacteria (SRB) mainly at the CO2 vent, only minor quantities were found at the reference site. Stable carbon isotopic analyses revealed that the methanogenic Archaea and SRB utilised the vent-derived CO2 for assimilatory biosynthesis. Our results show a shift in the microbial community towards anaerobic and acidophilic microorganisms as a consequence of the long-term exposure of the soil environment to high CO2 concentrations.  相似文献   
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