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411.
The U.S. Environmental Protection Agency (EPA) performed a reservoir diagnosis and developed low-cost recommendations to improve drinking water quality for the city of Nizhnii Tagil, Russia. Despite widespread regional pollution, water quality within the drinking water supply source can be summarized as generally good. Sampling and analysis efforts did not reveal appreciable amounts of hazardous chemicals or metals. The major water quality problem stems from an abundance of blue-green algae during the summer months, causing drinking water taste and odor problems and filter clogging at the water treatment plant. City water treatment officials also frequently experience difficulties with maintaining an effective disinfection residual in the distribution system because it spans more than 30 kilometers in length. Regrowth of microorganisms in the distribution system often causes coliform bacteria counts to exceed standards. The implementation of a watershed protection and management program, and the installation of a new disinfection system, to purify drinking water and to reduce bacterial growth in the distribution system should improve drinking water quality for the city residents. 相似文献
412.
The endangered Mauna Kea silversword (Argyroxiphium sandwicense ssp. sandwicense) has experienced a severe decline in distribution and abundance because of predation by alien ungulates. By the late 1970s only a small remnant natural population persisted on the Mauna Kea volcano on the Island of Hawaii. The Hawaii Department of Land and Natural Resources, Division of Forestry and Wildlife, initiated an outplanting program in the 1970s to promote recovery of A. sandwicense ssp. sandwicense. Intermittent outplanting since 1973 has generated an outplanted population of over 450 plants on Mauna Kea, but the program has unintentionally resulted in a major population bottleneck. All plants in the outplanted population appear to be first- or subsequent-generation offspring of only two maternal founders from the natural population. Genetic variation in the natural and outplanted populations was assessed for 90 random amplified polymorphic DNA loci. Eleven loci were detectably polymorphic in the natural population, whereas only three loci were detectably polymorphic in the outplanted population. Thus, the population bottleneck has been accompanied by a 73% reduction in the level of detectable polymorphism. In addition, for eight loci, the population bottleneck has resulted in the loss of the marker allele in the outplanted population. A management strategy involving manual pollen transfer has recently been implemented to incorporate additional founders from the natural population into the outplanting program. As a supplement to the outplanting program, the strategy also includes a program promoting direct seedling establishment following manual pollen transfer. Incorporating additional founders may serve to overcome the legacy of the population bottleneck, especially if founder representation can be equalized. 相似文献
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Robert S. Kandel 《Environment international》1979,2(4-6)
In this survey the earth is viewed from the astrophysical perspective, i.e. using global mean values of environmental parameters. The role of carbon dioxide is described in the processes of energy transfer from the earth's surface to space, which determine “global climate” as measured by the mean surface temperature. Analogies and differences between the problems of the terrestrial atmosphere and those of the solar and stellar atmospheres are examines, both in the computation of model atmosphere and in remote sensing of atmospheric temperature and composition. Subsequently, the temporal astrophysical perspective, with a review of the evolution of CO2 abundance and climate on astrophysical or geological time scales, on earth as on Venus (the runaway greenhouse) and on Mars is introduced. Variation of CO2 may have been critical to the maintenance of an environment in which life could originate and evolve, and may itself have been affected by life. On human time scales, the recent and continuing increase in atmospheric CO2 raises new problems, which are briefly surveyed. It is argued, that the differential greenhouse effect of increased CO2 in the earth's atmosphere is essentially identical to the “blanketing effect” of spectral lines on the temperature structure of stellar atmospheres. The methods used by astrophysicists in such studies are reviewed and compared with those used to evaluate the differential greenhouse effect of CO2 in radiative-convective models of the earth's atmosphere. The latter methods remain relatively crude, but recent results by different authors are in reasonably good agreement; however, the astrophysical perspective, i.e. the use of one-dimensional global mean models, remains a gross simplification of the real complexity of the earth's climate system, which is also true in stellar atmospheres. 相似文献
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Six varieties of wheat, tolerant or susceptible towards chlortoluron, a photosynthesis-inhibiting herbicide, were submitted to a 24-hour herbicide treatment. Fluorescence induc tion kinetics of whole leaves were recorded during the six following days. Recovery of photosynthetic electron transfer was found in tolerant varieties only. Ratios of I and P levels of induction kinetics appeared as the most reliable parameter for quantitative evaluation of detoxification rates. 相似文献
418.
Robert Mendelsohn 《Journal of Environmental Economics and Management》1984,11(3):202-207
A model of environmental regulation under uncertainty is developed to compare the effect of price versus quantity rules upon technical change. Quantity rules tend to encourage more efficient levels of technical change. 相似文献
420.
Summary The Dominican Republic and other Caribbean countries face serious challenges to their natural resource base. In recent years
the government of the Dominican Republic has taken major steps toward the development and implementation of a comprehensive
plan for national natural resources management. This plan is called Plan Sierra. An important component of this plan is the
outline of actions for carrying out an environmental education programme within the country. This demonstrates a commitment
to fulfill Recommendation No. 96 of the Stockholm Conference in a way that could become a model for other Latin American nations.
Clinton L. Shepard is Assistant Professor in the Division of Environmental Education, School of Natural Resources, The Ohio
State University. Dr Shepard holds a Bachelor of Science degree in Zoology from the University of Kentucky and graduate degrees
from The Ohio State University in Natural Resources/Environmental Education and Education-Foundations and Research. He has
worked as an interpreter and Environmental Education Coordinator for the State of Ohio Department of Natural Resources, a
research associate for ERIC—Science, Math, and Environmental Education Clearinghouse, and College instructor in interpretive
methods, environmental education methodology, resident outdoor programming, and natural resources development. He is also
involved in international research and development, especially in the Caribbean Basin.
Robert E. Roth is Chairman/Professor in the Division of Environmental Education, School of Natural Resources, The Ohio State
University. Dr Roth received a Bachelor's degree in Wildlife Management, a Bachelor's degree in Secondary Science Education,
a Master's degree in Conservation Education from The Ohio State University, and his Ph.D. in Environmental Education from
The University of Wisconsin. he came to OSU in 1969 and since that time has designed and institutionalized the only academic
unit in the US that offers both well developed undergraduate and graduate programmes in Environmental Communications, Education
and Interpretation and has published over 40 works in the field. He has been instrumental in implementing a growing international
environmental education research and development emphasis in the wider Caribbean, he continues as an Executive Editor of theJournal of Environmental Education. 相似文献