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161.
Robert H. Kennedy G. Dennis Cook 《Journal of the American Water Resources Association》1982,18(3):389-395
ABSTRACT: Nutrient diversion does not always bring about prompt and sufficient reduction in lake phosphorus concentration due to recycling from nutrient rich sediments. Certain lakes and reservoirs may continue to experience nuisance algal blooms and require additional restorative steps. The phosphorus precipitation/inactivation technique is a procedure to remove phosphorus from the water column and to control its release from sediments in order to achieve P-limiting conditions to algal growth. Aluminum salts have been used in advanced waste water treatment to remove phosphorus and this technology was extended to lake rehabilitation. Guidelines for dose calculation and application are generally lacking, and are provided in this report. The dose determination suggested here allows maximum application of aluminum to bottom sediments and thus emphasizes long term control of phosphorus recycling. Dose can be calculated directly from the alkalinity of the water to be treated. Titration of lake water samples of Varying alkalinity allows the establishment of the relationship between residual dissolved aluminum, alkalinity, and dose which can then be employed for lake scale applications of alum to lakes and reservoirs. Application equipment and procedures are described. These depend on site characteristics and treatment objectives and include lakeside stores, a distribution pipe, and an application barge and manifold. Alum may also be used to meet other restoration objectives including the treatment of problem flows and the reduction of particulate concentrations. 相似文献
162.
Patricia M. Dooris Vance Ley Dean F. Martin 《Journal of the American Water Resources Association》1982,18(4):599-604
ABSTRACT: The choice of a lake rehabilitation technique can be assisted by laboratory experiments concerned with the composition and properties of the sediments. This work on Sawgrass Lake, Pinellas County, Florida, provides an example of the type of laboratory information that can be useful towards making decisions regarding the most effective restorative techniques. Experiments include chemical analysis of sediment (water content, organic content, pesticides, nutrients), rate of sediment compaction and rehydration at ambient conditions, and the effect of treatment with alum and other chemicals. 相似文献
163.
Alberto Pivato Stefano Vanin Luca Palmeri Alberto Barausse Giovanni Mangione Michele Rasera Monego Gianluca 《Waste management (New York, N.Y.)》2013,33(7):1607-1615
The Biopotentiality Index is a landscape ecology indicator, which can be used to estimate the latent energy of a given land and to assess the environmental impacts due to the loss of naturalness on a landscape scale. This indicator has been applied to estimate the effectiveness of the measures put in place to provide an environmental compensation for the revamping of a composting plant. These compensation measures are represented by a green belt with a minimum width of 25 m all around the plant, representing both a windbreak and a buffer zone, and by two wide wooded zones acting as core natural areas.This case-study shows that the compensation index could be used as a key tool in order to negotiate the acceptance of waste treatment plant with the population. 相似文献
164.
Abstract: Extinctions can leave species without mutualist partners and thus potentially reduce their fitness. In cases where non‐native species function as mutualists, mutualism disruption associated with species’ extinction may be mitigated. To assess the effectiveness of mutualist species with different origins, we conducted a meta‐analysis in which we compared the effectiveness of pollination and seed‐dispersal functions of native and non‐native vertebrates. We used data from 40 studies in which a total of 34 non‐native vertebrate mutualists in 20 geographic locations were examined. For each plant species, opportunistic non‐native vertebrate pollinators were generally less effective mutualists than native pollinators. When native mutualists had been extirpated, however, plant seed set and seedling performance appeared elevated in the presence of non‐native mutualists, although non‐native mutualists had a negative overall effect on seed germination. These results suggest native mutualists may not be easily replaced. In some systems researchers propose taxon substitution or the deliberate introduction of non‐native vertebrate mutualists to reestablish mutualist functions such as pollination and seed dispersal and to rescue native species from extinction. Our results also suggest that in places where all native mutualists are extinct, careful taxon substitution may benefit native plants at some life stages. 相似文献
165.
166.
循环经济的范式研究 总被引:1,自引:0,他引:1
冯之浚 《中国人口.资源与环境》2007,17(4):10-13
发展循环经济是落实科学发展观、实现经济增长方式根本性转变的重要途径。借鉴“范式”理论探讨和研究了循环经济范式替代末端治理范式的变革:①自然资源的价值得到重估。循环经济范式中将自然资源列为最重要的资源形式。认为它是人类社会最大的资源储备,提高资源生产率是解决环境问题的关键。②不同生态伦理得到整合、提升。循环经济的生态伦理基础强调“生态价值”的全面回归.主张在生产领域和消费领域向生态化转向,承认“生态位”的存在和尊重自然权利。它既包含了现代人类中心主义、生命中心主义和生态中心主义兰种生态伦理追求人类道德完善的合理成分。又补充了各自其不完善的方面o③生态阈值的研究得到深化。循环经济范式的基本前提之一是认为生态阈值是客观存在的。强调在生态阈值的范围内合理利用自然资源.从原来的仅对人力生产率的重视转向在根本上提高资源生产率。在尊重自然的基础上切实有力地保护生态系统的自组织能力。实现经济发展和环境保护的目的。④深层生态学的研究得到加强。循环经济范式是一种深层生态学。符合天人调谐的理念。它不仅强调技术进步.而且将制度、体制、管理、文化等因素通盘考虑,注重观念创新和生产、消费方式的变革.树立了人与自然和谐发展的价值观念。 相似文献
167.
Abstract: The effectiveness of rare plant conservation will increase when life history, demographic, and genetic data are considered simultaneously. Inbreeding depression is a widely recognized genetic concern in rare plant conservation, and the mixing of genetically diverse populations in restoration efforts is a common remedy. Nevertheless, if populations with unrecognized intraspecific chromosome variation are crossed, progeny fitness losses will range from partial to complete sterility, and reintroductions and population augmentation of rare plants may fail. To assess the current state of cytological knowledge of threatened and endangered plants in the continental United States, we searched available resources for chromosome counts. We also reviewed recovery plans to discern whether recovery criteria potentially place listed species at risk by requiring reintroductions or population augmentation in the absence of cytological information. Over half the plants lacked a chromosome count, and when a taxon did have a count it generally originated from a sampling intensity too limited to detect intraspecific chromosome variation. Despite limited past cytological sampling, we found 11 plants with documented intraspecific cytological variation, while 8 others were ambiguous for intraspecific chromosome variation. Nevertheless, only one recovery plan addressed the chromosome differences. Inadequate within‐species cytological characterization, incomplete sampling among listed taxa, and the prevalence of interspecific and intraspecific chromosome variation in listed genera, suggests that other rare plants are likely to have intraspecific chromosome variation. Nearly 90% of all recovery plans called for reintroductions or population augmentation as part of recovery criteria despite the dearth of cytological knowledge. We recommend screening rare plants for intraspecific chromosome variation before reintroductions or population augmentation projects are undertaken to safeguard against inadvertent mixtures of incompatible cytotypes. 相似文献
168.
建立内蒙古生态环境恢复补偿机制若干问题探讨 总被引:1,自引:0,他引:1
生态环境恢复补偿机制的建立是科学利用生态资源和保持良好生存环境的必然途径,内蒙古自治区是全国天然植被分布面积最广地区之一,天然植被在保持流域、区域生态平衡,防止和减轻自然灾害,确保地区生态安全方面的重要作用毋庸置疑,然而由于原因,长期困绕我区的生态环境问题,如:森林生态系统的水源涵养、土壤保持、生物多样性保护功能衰退,水土流失的加剧、沙地活化;草场退化等级愈来愈高;湿地面积缩小,河道断流问题依然存在。近年随着矿业经济的兴起,又出现了矿山用水与农业生产争水、污染地下水等问题。因此,继矿产资源开发热潮之后,迅速做出制度安排尤为重要,本文通过对生态恢复补偿机制建立背景、重点、难点若干的探讨,旨在提出一些结合实际的可操作的补偿措施建议和意见,为制定内蒙古生态恢复补偿管理办法提供参考、并为该领域制度的完善提出技术层面的支持。 相似文献
169.
The application of ecological concepts to the industrial setting has been touched upon by literature across several disciplines. Two emerging ecological planning approaches, landscape ecology and industrial ecology, are applied here to look at alternative ways of planning industrial parks. As an emerging field, landscape ecology provides different viewpoints from the traditional approach of natural conservation, which mainly focuses on the protection of nature. The approach of landscape ecology regards the environment as a land mosaic, a mixture of natural and urban environment, which concerns a manageable human-scale environment across one or two human generations. Industrial ecology, on the other hand, goes beyond the traditional “end of pipe” idea of pollution control and learns from the ecosystem concept. The current paper is an attempt to reconcile these two fields as an integrated approach to the planning of industrial areas. Using a case study of Singapore’s Jurong Island industrial park, two fundamental issues behind the idea of landscape ecology and industrial ecology are raised. If raw materials, energy and by-products are more easily replaced or reused by technology and management, then research on industrial ecology and related knowledge will be crucial for developing natural resource substitution by innovative technology and new ways of environmental management. Where it is difficult to substitute natural resources, the skills of planning and managing natural resources will take priority over other strategies. In this situation, the knowledge of landscape ecology needs to be applied to the prediction, design and evaluation of ecologically optimum resource uses, patterns and processes in the mixture of natural, urban and industrial environment. A new concept, “nurtured landscape”, is proposed for mediating between the natural ecosystem and the urban/industrial environment. The nurtured landscape provides a basis for the development of new ecological technology using landscape to ameliorate the polluting effects of the urban/industrial neighbourhood. The planning of Singapore’s Jurong Island industrial park provides a test of applying the principles of landscape ecology and industrial ecology to the possible transformation of an industrial area. 相似文献
170.
Implementing SDG 15: Can large‐scale public programs help deliver biodiversity conservation,restoration and management,while assisting human development?
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Among the Sustainable Development Goals (SDGs), the proposed SDG 15 promotes activities that, inter alia, “Protect, restore and promote sustainable use of terrestrial ecosystems”. An important potential contribution in achieving SDG 15 is through public programmes designed to jointly promote human development through poverty alleviation and improvement of human livelihoods and biodiversity conservation/management/restoration. An analysis of twenty public programmes with such joint objectives yielded twelve lessons learned. In addition to financial commitments, government and intergovernmental agency input for such public programmes includes ensuring political will and appropriate legal frameworks. Local communities and civil society provide input through traditional and indigenous ecological knowledge and stewardship. Appropriate shared inputs in development and the implementation of such public programmes, with communication between local community, broader civil society, the scientific community and governments will result in: better use and management of biodiversity; alleviation of poverty; security of livelihoods and better governance systems. The Ecosystem Approach of the Convention on Biological Diversity provides an ideal framework when planning and implementing new programmes. Application of the lessons learned to new public programmes will ensure that the answer to the question posed in the title is an emphatic “Yes”, and assist with the achievement of SDG 15. 相似文献