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Biological assessment of aquatic ecosystems is widely employed as an alternative or complement to chemical and toxicity testing due to numerous advantages of using biota to determine ecosystem condition. These advantages, especially to developing countries, include the relatively low cost and technical requirements. This study was conducted to determine the biological impacts of aquaculture operations on effluent-receiving streams in the Ashanti Region of Ghana. We collected water, fish and benthic macroinvertebrate samples from 12 aquaculture effluent-receiving streams upstream and downstream of fish farms and 12 reference streams between May and August of 2009, and then calculated structural and functional metrics for biotic assemblages. Fish species with non-guarding mode of reproduction were more abundant in reference streams than downstream (P?=?0.0214) and upstream (P?=?0.0251), and sand-detritus spawning fish were less predominant in reference stream than upstream (P?=?0.0222) and marginally less in downstream locations (P?=?0.0539). A possible subsidy-stress response of macroinvertebrate family richness and abundance was also observed, with nutrient (nitrogen) augmentation from aquaculture and other farming activities likely. Generally, there were no, or only marginal differences among locations downstream and upstream of fish farms and in reference streams in terms of several other biotic metrics considered. Therefore, the scale of impact in the future will depend not only on the management of nutrient augmentation from pond effluents, but also on the consideration of nutrient discharges from other industries like fruit and vegetable farming within the study area.  相似文献   
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Geochemical mapping of soils and selected plant species has been carried out in the Mole National Park, Ghana. The distribution of the essential nutrients: cobalt, copper and manganese is largely controlled by bedrock geology, while the geochemical dispersion of Ca, I, Fe, Mg, Mo, P, K, Se, Na and Zn has been modified by soil and hydromorphic processes. From selective extraction experiments, Fe, Mn and Co are found to be largely fixed in the soil mineral fraction. Larger proportions of Cu, I, Mo, Se and Zn are EDTA extractable and have a high chelation potential.Cobalt, Cu and Mn were preferentially concentrated in grass species while molybdenum and selenium are concentrated in browse plants. Copper uptake is antagonistic to Fe, Mo and Zn accumulation in all plant and grass samples. Similarly, Se and Mn appear antagonistic and Fe uptake is antagonistic to Co, Cu, Mn, Mo and Zn.The low concentration of P points to a potential dietary deficiency of this element throughout the park. Cobalt deficiency may also occur due to a love extractability of these elements in the soils and low concentration in plants. However, the lack of data on the elemental requirements of wildlife allows only tentative conclusions to be drawn.  相似文献   
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The focus of this paper is to present a discussion of the role of the private sector in response to the need for climate change adaptations. The study, which was conducted through a literature review, investigates the concept of the green economy and climate change, as well as businesses’ commitment to advance climate actions in ways that build resilience in vulnerable communities in developing countries. The paper calls on companies with national, regional, and/or global reach to adopt or develop strategies that improve resource efficiency, reduce greenhouse gas emissions, and reduce the loss of biodiversity. Businesses can accelerate this transition by aligning their investments with climate change adaptation opportunities, and thus, “green” the economy. In addition, green growth could be achieved through tactical public and private investments in mitigating climate change. The paper concludes that the private sector is a key sector in addressing the challenges of vulnerable communities, and it has much to contribute to the planning, development, and implementation of climate adaptation strategies, including sector‐specific expertise, technology, efficiency, financing, and entrepreneurship. Finally, some social conditions and environmental boundaries have been highlighted in this paper to attract the attention of business leaders who are trying to build initiatives and advance climate actions that will reduce socio‐community risks from climate change. Also, comprehensive initiatives and strategies have been recommended to private companies seeking to address climate vulnerabilities.  相似文献   
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As part of the Ghanaian government's efforts to revive the national economy a series of measures were instituted. They included devaluation of the local currency, reduction of budget deficits and the rehabilitation of basic infrastructure. The mining industry plays an important role in the national economy and special measures were also introduced to encourage its rehabilitation and development. A new licensing system was introduced and a new fiscal regime was established which inter alia allows mining companies to retain part of their export earnings offshore. The response of the private investment community to those changes has been excellent and investment in the mining industry has increased substantially.  相似文献   
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