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111.
Variation among sites and years in the local ecological outcome of interspecific interactions can generate a geographic mosaic of coevolution, as indicated by recent mathematical models. We evaluated whether local temporal dynamics of ecological outcome in the interaction between the moth Greya politella (Prodoxidae) and its host plant Lithophragma parviflorum (Saxifragaceae) are likely to mitigate or magnify geographic differences in ecological outcome found in earlier studies. The moths are highly host-specific pollinating floral parasites, and the mutualism can be swamped in some populations by the presence of effective co-pollinators. Hence, differing community contexts can shift the outcome of the interaction from mutualism to commensalism or antagonism. During each of four years, we evaluated the effect of Greya oviposition on seed development through a paired design that controlled for plant genotype and microenvironment. At Turnbull National Wildlife Refuge in Washington State, the interaction was significantly mutualistic in all four years. Mutualism in this population was indicated by a higher probability of development of capsules visited by ovipositing Greya than capsules not visited by Greya on the same plant. At Rapid River, Idaho, the interaction was commensalistic in three years and antagonistic in one year. Antagonism in this population was indicated by selective withering of capsules containing Greya eggs. Overall, the results suggest stable geographic differences in the range of ecological outcomes in this plant-insect interaction under different community contexts. 相似文献
112.
Khan AB Clark NN Thompson GJ Wayne WS Gautam M Lyons DW Hawelti D 《Journal of the Air & Waste Management Association (1995)》2006,56(10):1404-1419
Heavy-duty diesel vehicle idling consumes fuel and reduces atmospheric quality, but its restriction cannot simply be proscribed, because cab heat or air-conditioning provides essential driver comfort. A comprehensive tailpipe emissions database to describe idling impacts is not yet available. This paper presents a substantial data set that incorporates results from the West Virginia University transient engine test cell, the E-55/59 Study and the Gasoline/Diesel PM Split Study. It covered 75 heavy-duty diesel engines and trucks, which were divided into two groups: vehicles with mechanical fuel injection (MFI) and vehicles with electronic fuel injection (EFI). Idle emissions of CO, hydrocarbon (HC), oxides of nitrogen (NOx), particulate matter (PM), and carbon dioxide (CO2) have been reported. Idle CO2 emissions allowed the projection of fuel consumption during idling. Test-to-test variations were observed for repeat idle tests on the same vehicle because of measurement variation, accessory loads, and ambient conditions. Vehicles fitted with EFI, on average, emitted approximately 20 g/hr of CO, 6 g/hr of HC, 86 g/hr of NOx, 1 g/hr of PM, and 4636 g/hr of CO2 during idle. MFI equipped vehicles emitted approximately 35 g/hr of CO, 23 g/hr of HC, 48 g/hr of NOx, 4 g/hr of PM, and 4484 g/hr of CO2, on average, during idle. Vehicles with EFI emitted less idle CO, HC, and PM, which could be attributed to the efficient combustion and superior fuel atomization in EFI systems. Idle NOx, however, increased with EFI, which corresponds with the advancing of timing to improve idle combustion. Fuel injection management did not have any effect on CO2 and, hence, fuel consumption. Use of air conditioning without increasing engine speed increased idle CO2, NOx, PM, HC, and fuel consumption by 25% on average. When the engine speed was elevated from 600 to 1100 revolutions per minute, CO2 and NOx emissions and fuel consumption increased by >150%, whereas PM and HC emissions increased by approximately 100% and 70%, respectively. Six Detroit Diesel Corp. (DDC) Series 60 engines in engine test cell were found to emit less CO, NOx, and PM emissions and consumed fuel at only 75% of the level found in the chassis dynamometer data. This is because fan and compressor loads were absent in the engine test cell. 相似文献
113.
In recent years AT&T changed its focus on environmental policies from compliance to pollution prevention. Pollution prevention is an integrated program that includes design for the environment, “green” manufacturing, and a comprehensive program to reduce existing waste in production. The principles of Total Quality Management can be applied to pollution prevention as well as the more traditional manufacturing concepts. The project described in this article is one of several concurrent programs being conducted at AT&T'S Columbus Works to reduce overall waste produced by the facility by applying TQM practices. 相似文献
114.
Allen J. Bedrosian William O. Bennett James E. Berry Robert B. Ditton James W. Kolka Thomas W. Thompson 《Journal of the American Water Resources Association》1972,8(5):887-899
ABSTRACT. This paper outlines an approach to planning the management of a lake heavily used for recreation and of substantial importance to the tourist economy of Northeastern Wisconsin. A framework, utilizing a three dimensional matrix, is developed to analyze levels of public concern, management alternatives and action agencies. Structural and non-structural alternatives are examined and evaluated on the basis of social and economic criteria, long- and short-term environmental impact and legal-political feasibility. Data requirements which created the necessity for an interdisciplinary approach involving social, physical, and biological sciences are enumerated. The authors examine the role of universities in assisting communities with resource management planning and detail the attributes of academic institutions which desire to successfully attack resource planning problems. 相似文献
115.
Habitat restoration at a landscape scale is becoming increasingly important in environmental management. In this context, geographical information systems are well suited as they can store and integrate many of the abiotic and biotic criteria used to assess the ecological worth of a site. However, this capacity can be limited by the availability or suitability of spatial data sets. A classic example of the latter case is the National Soil Map of England and Wales, which groups soils of a varied nature into associations. Consequently the national soil map has proved to be a poor predictor of habitat suitability. Using polytomous logistic regression we put forward a method for separating soil associations into their constituent soils within the Chilterns Natural Area. This approach used soil association, aspect, slope and relative height as variables for this analysis. Whilst the model's performance is likely to have been limited by the accuracy of the soil association data set, a predictive accuracy of between 47 and 65% is sufficient to facilitate better targeting of habitat restoration when combined with other abiotic factors such as climate and topography. 相似文献
116.
Environmental auditing: Theory and applications 总被引:3,自引:0,他引:3
The environmental audit has become a regular part of corporate environmental management in Canada and is also gaining recognition
in the public sector. A 1991 survey of 75 private sector companies across Canada revealed that 76% (57/75) had established
environmental auditing programs. A similar survey of 19 federal, provincial, and municipal government departments revealed
that 11% (2/19) had established such programs. The information gained from environmental audits can be used to facilitate
and enhance environmental management from the single facility level to the national and international levels. This paper is
divided into two sections: section one examines environmental audits at the facility/company level and discusses environmental
audit characteristics, trends, and driving forces not commonly found in the available literature. Important conclusions are:
that wherever possible, an action plan to correct the identified problems should be an integral part of an audit, and therefore
there should be a close working relationship between auditors, managers, and employees, and that the first audits will generally
be more difficult, time consuming, and expensive than subsequent audits. Section two looks at environmental audits in the
broader context and discusses the relationship between environmental audits and three other environmental information gathering/analysis
tools: environmental impact assessments, state of the environment reports, and new systems of national accounts. The argument
is made that the information collected by environmental audits and environmental impact assessments at the facility/company
level can be used as the bases for regional and national state of the environment reports and new systems of national accounts. 相似文献
117.
Composted organic wastes have been shown to reduce emissions of N2O and CH4, but little is known about the release of these gases during the composting process. This research examined the emissions of N2O and CH4 during the composting of liquid swine manure and wheat straw at two operations, one with forced aeration and the other without. The lack of aeration increased CH4 emissions to 24 times that of composting with aeration, but had no significant effect on N2O production. When total N2O and CH4 emissions from composting were compared with liquid swine manure emissions, aerated composting was found to reduce emissions to as low as 30% of those from liquid manure storage, while non-aerated composting elevated emissions up to an estimated 330% of liquid manure storage. 相似文献
118.
Ian D. Thompson 《Environmental monitoring and assessment》2006,121(1-3):261-271
The general principles of scale and coarse and fine filters have been widely accepted, but management agencies and industry are still grappling with the question of what to monitor to detect changes in forest biodiversity following forest management. Part of this problem can be attributed to the lack of focused questions for monitoring including absence of null models and predicted effects, a certain level of disconnect between research and management, and recognition that monitoring can be designed as a research question. Considerable research from the past decade has not been adequately synthesized to answer important questions, such as which species or forest attributes might be the best indicators of change. A disproportionate research emphasis has been placed on community ecology, and mostly on a few groups of organisms including arthropods, amphibians, migratory songbirds, and small mammals, while other species, including soil organisms, lichens, bats, raptors, some carnivores, and larger mammals remain less well-known. In most studies of community ecology, the question of what is the importance, if any, of the regularly observed subtle changes in community structures, and causes of observed changes is usually not answered. Hence, our ability to deal with questions of persistence is limited, and demographic research on regionally--defined key species (such as species linked to processes, species whose persistence may be affected, species with large home ranges, species already selected as indicators, and rare and threatened species) is urgently needed. Monitoring programs need to be designed to enable managers to respond to unexpected changes caused by forest management. To do this, management agencies need to articulate null models for monitoring that predict effects, focus fine--scale monitoring on key species (defined by local and regional research) in key habitats (rare, declining, important) across landscapes, and have a protocol in place to adapt management strategies to changes observed. Finally, agencies must have some way to determine and define when a significant change has occurred and to predict the persistence of species; this too should flow from a well--designed null model. 相似文献
119.
De Rooij C Thompson RS Garny V Lecloux A van Wijk D 《Environmental monitoring and assessment》2004,97(1-3):3-22
This risk assessment on dichloromethane was carried out specifically for the marine environment, following methodology given in the EU risk assessment Regulation (1488/94) and Guidance Document of the EU New and Existing Substances Regulation (TGD, 1997). The study consists of collection and evaluation of data on effects and environmental concentrations from analytical monitoring programs in large rivers and estuaries in the North Sea area. The risk is indicated by the ratio of 'predicted environmental concentrations' (PEC) to 'predicted no-effect concentrations' (PNEC) for the marine aquatic environment. In total, 23 studies for fish, 17 studies for invertebrates and 6 studies for algae were evaluated. Both acute and chronic toxicity studies were taken into account and appropriate assessment factors used to define a PNEC value of 830 microg/l. Most of the available monitoring data apply to rivers and estuaries and were used to calculate PECs. The most recent data (1983--1995) support a typical PEC for dichloromethane lower than 0.2 microg/l and a worst case PEC of 13.6 microg/l. Dichloromethane is not a 'toxic, persistent and liable to bioaccumulate' substance sensu the Oslo and Paris Conventions for the Prevention of Marine Pollution (OSPAR-DYNAMEC). The calculated PEC/PNEC ratios give margins of 60 to 4000 between the PNEC and PEC, dilution within the sea would further increase these margins. It can be concluded that the present use of dichloromethane does not present a risk to the marine aquatic environment. 相似文献
120.
James G. Thompson Michael Parker William Templin Robert R. Reynolds 《Journal of the American Water Resources Association》1993,29(3):425-433
ABSTRACT: This paper reviews the processes that occurred during an application of the Metropolitan Water District (MWD)-MAIN water use forecasting system for the City of Salinas, California. The review includes an analysis of sources of available data, methods for estimating input data, calibration, and verification of the MWD-MAIN System, and an evaluation of the reliability of system output. We found that inexperienced users can have difficulty understanding the level of skill, knowledge, and amount of data that are required to produce reliable forecasts. Some of the issues associated with application of the MWD-MAIN System include the following:
- ? All input data needed for accurate forecasts simply are not available for many cities and towns.
- ? The data requirements are more extensive than many users anticipate.
- ? Substantial requirements for manipulation of input data produces opportunity for error that creates major time demands in troubleshooting.
- ? Calibration and verification for specific uses can be substantially more difficult than is readily apparent from the guidance manual.
- ? Independent validity checks need to be done to validate system output.
- ? If specified calibrating procedures do not produce reasonable results, reestimating slope coefficients is an option, but this requires resources and expertise that can easily exceed the limits of most users.