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161.
Our objectives were to collect information on contaminant levels and productivity of wading birds at the Drum Island heronry in Charleston Harbor, South Carolina, before diversion of the Cooper River took place in 1985. The diversion was expected to reduce water flow by 80% into the Harbor, thereby concentrating industrial effluents near the heronry with potentially harmful effects. Hatching success of white ibises (Eudocimus albus) in 1984 averaged 66% and 1.0 chick per nest survived to three weeks post-hatch. Fresh eggs collected from a sample of nests contained only background levels of DDT, DDE, and Dieldrin; no PCBs, diphenyl ethers, or styrenes were detected. Pesticide residues in eggs were not correlated (P>0.05) with productivity in corresponding nests. Heavy metals and selenium in tissues of wading bird chicks were also representative of background levels. Follow-up studies after the diversion of the Cooper River were not feasible because the heronry was abandoned beginning in 1985. However, our baseline results will be useful in determining potential contaminant effects due to diversion of the Cooper River should wading birds return to Drum Island in the future.  相似文献   
162.
Summary Environmental education is essential to the success of Agenda 21. Yet currently it is without focus and effectively side-lined. This paper supplies a strategy and accompanying methodology for establishing environmental education as a major force for implementing Agenda 21. The author proposes the establishment of an Education 21 programme and the designation of the educational community as a new Rio major group. Recommendations are made to appropriate competent bodies.Trevor Harvey is the Director of Studies in the Department of Environmental Management at Farnborough College of Technology. An earlier version of this paper was presented at the International Academic Conference on the Environment entitled, Towards a Sustainable future: Promoting Sustainable Development. Which was in Manchester, UK Part of Global Forum, June 1994.  相似文献   
163.
Congenital bronchopulmonary malformations detectable on prenatal ultrasound include cystic adenomatoid malformation (CAM), lobar sequestration, and upper airway atresia. We describe three fetuses with prenatally detected intrathoracic lesions in which the associated pulmonary hyperechogenicity disappeared before delivery. In the first case of pulmonary sequestration, the infant was asymptomatic after birth. However, in a case of CAM and another with laryngeal atresia, respiratory distress developed after delivery, despite recent scans showing apparently normal lung fields. This experience suggests that ultrasonic resolution of hyperechogenic lung lesions in utero does not necessarily indicate resolution of the underlying pathology.  相似文献   
164.
1IntroductionMcHargssuitabilityevaluationapproachtoalanduseplanningknownas“ecologicalplanning”haspracticedinsomecountriesofE...  相似文献   
165.
A distinction should be made betweentwo types of ethical problems. A Type I ethicalproblem is one in which there is no consensusas to what is ethical. A Type II ethicalproblem is one in which there is a consensus asto what is ethical, but incentives exist forindividuals to behave unethically. Type Iethical problems are resolved by making,challenging, and reasoning through moralarguments. Type II ethical problems areresolved by changing the institutionalenvironment so that people do not haveincentives to behave unethically. Type Isolutions, however, will not be effective insolving Type II problems. Examples inagriculture and elsewhere show howdistinguishing between Type I and Type IIethical problems will help in theidentification of solutions to ethical issuesin agriculture.  相似文献   
166.
Phylogeny, niches, and relative abundance in natural communities   总被引:3,自引:0,他引:3  
Kelly CK  Bowler MG  Pybus O  Harvey PH 《Ecology》2008,89(4):962-970
Community structure refers to the number of species in a community and the pattern of distribution of individuals among those species. We use a novel way of representing community structure to show that abundance within closely related pairs of co-occurring tree species in a highly diverse Mexican forest is more equitable than is abundance within more distantly related pairs. This observation is at odds with the fundamental assumption of neutral models of community structure, i.e., that species are interchangeable. The observed patterns suggest niche apportionment, in which interaction is focused pairwise between congeners but falls away from the phylogenetic structure above the genus level. Thus niche processes may significantly affect community structure through regulating relative abundance in a substantial proportion of species, which in turn potentially enhances community stability. One such mechanism of stable coexistence has already been shown to be active in this forest.  相似文献   
167.
SUMMARY

The increase in the number of golf courses around the world has been phenomenal, particularly since the 1990s where an estimated 350 new courses were added annually to the more than 25 000 existing ones. In terms of recreational sports spaces, golf arguably uses the greatest amount of land. Using the case study of Singapore, it is argued that the continual expansion of golf courses runs counter to the broad ideal of urban sustainability. The arguments that support golf course expansion viz. reducing the issue to a matter of supply and demand and extolling golfs economic benefits pay scant attention to principles of equity and sustainability. Although existing green spaces risk being converted into golf courses, golf course maintenance itself can be ecologically benign. However, the elitist nature of golf in Singapore ultimately imposes greater and unnecessary demands on resources in general. Given Singapore's land scarcity, golf course expansion is opposed not so much because of its ecological impacts but because of how it compromises spatial equity.  相似文献   
168.
Since 1972, the Parties (United States and Canada, 1987) to the Great Lakes Water Quality Agreement have been working collaboratively to achieve the purpose of the Agreement “to restore and maintain the chemical, physical and biological integrity of the waters of the Great Lakes Basin Ecosystem”. Billions of dollars and countless person – hours have been expended towards this end, but have the Parties, and their numerous collaborators at the state, provincial, and municipal levels, along with industry and citizen activists achieved meaningful results? This paper will examine the information provided through various monitoring programs and will assess the success of the Parties' programs, and will also discuss the continuing threats to achieving the purpose of the Agreement.  相似文献   
169.
Hill H  Wiener J  Warner K 《Disasters》2012,36(2):175-194
This paper describes a method for reducing the economic risks associated with predictable natural hazards by enhancing the resilience of national infrastructure systems. The three-step generalised framework is described along with examples. Step one establishes economic baseline growth without the disaster impact. Step two characterises economic growth constrained by a disaster. Step three assesses the economy's resilience to the disaster event when it is buffered by alternative resiliency investments. The successful outcome of step three is a disaster-resistant core of infrastructure systems and social capacity more able to maintain the national economy and development post disaster. In addition, the paper considers ways to achieve this goal in data-limited environments. The method provides a methodology to address this challenge via the integration of physical and social data of different spatial scales into macroeconomic models. This supports the disaster risk reduction objectives of governments, donor agencies, and the United Nations International Strategy for Disaster Reduction.  相似文献   
170.
The devastation of Hurricane Katrina and the federal levee failures facilitated the unprecedented proliferation of non-profits in some areas of the city. While the short- and moderate-term experiences of non-profits in the aftermath of Katrina have been examined, their long-term successes and failures remain unknown. In this paper we look at how race and nativism hindered the success of non-profits in rebuilding New Orleans. We likewise seek to demonstrate how the reactions on the part of non-profits to being the racial other or that of an outsider often further impeded the effectiveness of non-profits. The three authors, using data from participant observation, interviews, and ethnography, over a four-year period, describe generalisable lessons learned from rebuilding New Orleans’ communities, including the recognition of competing racial discourses in redevelopment; the valuing of local knowledge; and coming to terms with the paradoxes of the affect economy.  相似文献   
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