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81.
Demography and Population Viability of an Endangered Plant Species before and after Protection from Trampling 总被引:2,自引:0,他引:2
Land managers often suggest fencing to protect rare plant species from being trampled in heavily used recreation areas, but there are few documented examples of the efficacy of this strategy. In a 7-year demographic study we examined the reproduction, survival, and long-term viability of the endangered sentry milk-vetch (Astragalus cremnophylax var. cremnophylax) before and after protection from trampling. Demographic monitoring and population viability analyses indicated that the population has fluctuated during the 7 years. Before protection the population declined: 26% of individuals died, mortality surpassed natality, and age of first reproduction was significantly older than post-protection. Fifty-eight percent of the population was severely damaged. Population viability analyses of pre-protection years predicted that the population would go extinct within 100 years. Since protection, the population stabilized, grew, and declined again. Seedlings reached reproductive maturity more quickly. Recruitment increased and peaked in 1993 coincident with abundant precipitation, but again declined in 1994. The total numbers of undamaged plants surpassed the numbers of damaged plants. Models of the post-protection population predict stability. Multiple-linear regression analysis indicated that winter and spring precipitation were significantly correlated with lambda. Both "good" and "bad" climatic conditions occurred during the pre- and post-protection periods. Because of small population size and depauperate genetic diversity, climate will continue to influence population growth. Nevertheless, models indicate that where trampling and bad climatic conditions were coupled, extinction was accelerated. Recovery of sentry milk-vetch will depend on continued protection, augmentation, and environmental factors, although risk of extinction remains very high. 相似文献
82.
Social learning and sustainable communities: An interim assessment of research into sustainable communities projects in the UK 总被引:1,自引:0,他引:1
Joe Smith James Blake Robin Grove-White Elham Kashefi Sarah Madden Sue Percy 《Local Environment》1999,4(2):195-207
The delivery of many of the most pressing environmental issues will rely on changes in environmental attitudes and behaviour at community level. At a UN Special Session in 1997, the British Government highlighted its initiatives on Local Agenda 21 (LA21) and Going for Green (GFG) as significant advances. This paper adds a new perspective, drawing on the range of experiences of some of the research teams that have been working with local authorities on pilot Sustainable Community Projects (SCPs) in England and Scotland. It sheds light on three substantive themes: the tensions inherent in the implementation of internationally and nationally agreed goals through local action; the ambiguity of local agencies acting as facilitators of community ownership of processes, and the requirements for successful partnership between local authorities and higher education. 相似文献
83.
Sheya SA Glowacki C Chang MC Chow JC Watson JG 《Journal of the Air & Waste Management Association (1995)》2008,58(4):553-561
A study using two stack-sampling methodologies for collecting particulate matter (PM) emissions was conducted using a hot filter followed by a cold impinger sampling train and a dilution sampler. Samples were collected from ferrous iron metal casting processes that included pouring molten iron into a sand mold containing an organic binder, metal cooling, removal of the sand from the cooled casting (shakeout), and postshakeout cooling. The shakeout process contributed more to PM emissions than the metal pouring and cooling processes. Particulate matter less than 2.5 microm in aerodynamic diameter (PM2.5) mass emissions for the entire casting cycle ranged from 3.4 to 4.7 lb/t of metal for the hot filter/impinger method and from 0.8 to 1.8 lb/t of metal for the dilution method. Most of the difference was due to PM captured by the impingers, much of which was probably dissolved gases rather than condensable vapors. Of the PM fraction captured by the impingers, 96-98% was organic in nature. The impinger PM fraction contributed 32-38% to the total suspended particle mass and caused a factor of 2-4 positive bias for PM2.5 emissions. For the pouring and cooling processes only, the factor increased to over seven times. 相似文献
84.
85.
We report a case of severe intrauterine growth retardation (IUGR) and hypospadias in association with trisomy 22 diagnosed following chorionic villus sampling (CVS). Subsequent analysis of amniotic fluid cultures showed a normal male karyotype, 46,XY. As a previous case had been reported with similar abnormalities, in association with maternal uniparental disomy (UPD) 22, molecular studies were also performed. Microsatellite marker studies showed biparental inheritance. Follow-up studies after delivery showed a normal cell line in lymphocytes with the trisomy appearing to be confined to the placenta. The present case concurs with other earlier reports that maternal UPD for chromosome 22 has no impact on the phenotype. The features seen in the fetus are most likely the result of placental dysfunction due to trisomy, tissue-specific mosaicism and/or the effects of local growth restriction. Copyright © 2002 John Wiley & Sons, Ltd. 相似文献
86.
Industrialization has brought with it environmental problems and the consequences of pollution, which has been affecting the world for decades. Immediate action is required to raise industry's awareness of its social responsibilities toward the environment. However, experience shows that companies that have obtained International Organization of Standardization (ISO) 14001:2015 certifications in Malaysia occupy but a small niche among the country's businesses. The purpose of this study is to assess the list of barriers and challenges to implementing and obtaining certifications under the ISO 14001:2015 Environmental Management System (EMS) by Malaysian firms. In addition, this study will rank these factors relative to their importance. This study is aimed at EMS experts at the Scientific and Industrial Research Institute of Malaysia (SIRIM QAS International Sdn. Bhd.). The study uses mathematical pairwise comparisons to generate the list of critical challenges and barriers. Therefore, the study is expected to raise environmental awareness among Malaysia's industries regarding the adoption of ISO 14001:2015 standards. Furthermore, the study provides a guideline for Malaysia's industries and policy‐makers to provide them with a better understanding of the barriers and challenges that companies face in implementing ISO 14001:2015 EMS, and at the same time, help them understand the need to eliminate the difficulties of standard implementation. 相似文献
87.
Active pharmaceutical ingredients (APIs) from medications can enter the environment as trace contaminants, at individual concentrations generally below a part per billion (microg/L). APIs enter the environment primarily via the discharge of raw and treated sewage. Residues of unmetabolized APIs from parenteral and enteral drugs are excreted in feces and urine, and topically applied medications are washed from skin during bathing. These trace residues may pose risks for aquatic life and cause concern with regard to subsequent human exposure. APIs also enter the environment from the disposal of unwanted medications directly to sewers and trash. The relative significance of this route compared with excretion and bathing is poorly understood and has been subject to much speculation. Two major aspects of uncertainty exist: the percentage of any particular API in the environment originating from disposal is unknown, and disposal undoubtedly occurs from a variety of dispersed sources. Sources of disposal, along with the types and quantities of APIs resulting from each source, are important to understand so that effective pollution prevention approaches can be designed and implemented. Accumulation of leftover, unwanted drugs poses three major concerns: (i) APIs disposed to sewage or trash compose a diverse source of potential chemical stressors in the environment. (ii) Accumulated drugs represent increased potential for drug diversion, with its attendant risks of unintentional poisonings and abuse. (iii) Leftover drugs represent wasted healthcare resources and lost opportunities for medical treatment. This paper has four major purposes: (1) Define the processes, actions, and behaviors that control and drive the consumption, accumulation, and need for disposal of pharmaceuticals. (2) Provide an overview of the diverse locations where drugs are used and accumulate. (3) Present a summary of the first cataloging of APIs disposed by a defined subpopulation. (4) Identify opportunities for pollution prevention and source reduction. 相似文献
88.
We examined trends in sea ice cover between 1979 and 2002 in four months (March, June, September, and November) for four large (approximately 100,000 km2) and 12 small (approximately 10,000 km2) regions of the western Arctic in habitats used by bowhead whales (Balaena mysticetus). Variation in open water with year was significant in all months except March, but interactions between region and year were not. Open water increased in both large and small regions, but trends were weak with least-squares regression accounting for < or =34% of the total variation. In large regions, positive trends in open water were strongest in September. Linear fits were poor, however, even in the East Siberian, Chukchi, and Beaufort seas, where basin-scale analyses have emphasized dramatic sea ice loss. Small regions also showed weak positive trends in open water and strong interannual variability. Open water increased consistently in five small regions where bowhead whales have been observed feeding or where oceanographic models predict prey entrainment, including: (1) June, along the northern Chukotka coast, near Wrangel Island, and along the Beaufort slope; (2) September, near Wrangel Island, the Barrow Arc, and the Chukchi Borderland; and (3) November, along the Barrow Arc. Conversely, there was very little consistent change in sea ice cover in four small regions considered winter refugia for bowhead whales in the northern Bering Sea, nor in two small regions that include the primary springtime migration corridor in the Chukchi Sea. The effects of sea ice cover on bowhead whale prey availability are unknown but can be modeled via production and advection pathways. Our conceptual model suggests that reductions in sea ice cover will increase prey availability along both pathways for this population. This analysis elucidates the variability inherent in the western Arctic marine ecosystem at scales relevant to bowhead whales and contrasts basin-scale depictions of extreme sea ice retreats, thinning, and wind-driven movements. 相似文献
89.
Overexploitation and Species Extinctions 总被引:1,自引:0,他引:1
90.
William B. Samuels Phillip L. Taylor Paul B. Evenhouse Timothy R. Bondelid Paul C. Eggers Sue A. Hanson 《Journal of the American Water Resources Association》1991,27(6):939-956
ABSTRACT: The Environmental Display Manager, EDM, is a development system on an IBM 3090 mainframe at the U.S. EPA National Computer Center in Research Triangle Park, North Carolina. EDM provides mapping, display, analysis support, and information management capabilities to workstations located across the United States, and connected to EPA through federal, state, academic, and private communications networks. Through interactive software, EDM can quickly support analyses, create maps and graphics, and generate reports that integrate millions of pieces of environmental data. The concept of EDM is to provide easy access to environmental information, to provide automated environmental analyses and reports, and then to provide data, graphics, images, text, and documents that can be used by numerous output devices, software packages, and computers. The mapping cumponent works with an electronic version of the 54,000 7.5 minute quad sheets of the U.S. Geological Survey. The software also works with a hydrographic data base of the surface waters of the United States. With the maps, a user can look at the rivers in any state, can zoom in on a small pond, and can overlay and identify particular features such as industrial waste dischargers and factories. The hydrography allows routing for modeling programs, identification of upstream and downstream components, and linkage of environmental features associated with surface waters. Alternatively, users can query data based on latitude/longitude, city name, EPA permit number, state agency and station code, river name or number, and river cataloging unit. The maps can be overlaid with roads and environmental sites such as: municipal and industrial dischargers, Superfund sites, public drinking water supplies, water quality monitoring stations, stream gages, and city locations. Retrievals from related systems can be performed for selected sites creating graphics showing water quality trends, discharge monitoring reports, and permit discharge limits. 相似文献