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231.
Susan J. Elliott Martin S. Taylor James R. Dunn Stephen Walter Aleck Ostry 《Journal of Environmental Planning and Management》2004,47(3):351-363
This paper reports the results of a comparative analysis of the psychosocial impacts of municipal solid waste disposal facilities (both landfills and incinerators) in six communities in the provinces of Ontario and British Columbia, Canada. Telephone surveys were administered to random samples of residents living around each facility between 1990 and 1995 (total n=1203). The results of logistic regression analyses show that type of facility was the strongest predictor of residents' awareness, concern, and actions taken in response to site concerns. Essentially, residents living in close proximity to a landfill had a higher probability of reporting awareness, concern or actions than residents living around an incinerator site. There was little evidence of differences in reactions between Ontario and British Columbia (BC) residents, despite variations in provincial policies on waste disposal. The effects of other predictors, with the exception of involvement in the local community, were not consistent, supporting previous findings that the determinants of facility impacts are outcome‐specific. It is essential that environmental managers take this constellation of factors into account in the operation of existing, or siting of new, facilities. 相似文献
232.
Feeding behavior in sexual and clonal strains of Poeciliopsis 总被引:1,自引:0,他引:1
Stephen C. Weeks Oscar E. Gaggiotti Russell A. Schenck Kurt P. Spindler Robert C. Vrijenhoek 《Behavioral ecology and sociobiology》1992,30(1):1-6
Summary Sexual and clonal fish of the genus Poeciliopsis occur together in desert streams of Sonora, Mexico. Their coexistence has been explained in terms of niche partitioning for food and space. We examined predatory behavior that might influence niche relationships, and found significant differences among two coexisting sperm-dependent clonal strains and their two sexual progenitors. Handling time and prey manipulation of free-swimming (Artemia) and benthic (chironomid larvae) prey differed significantly among sexual and clonal strains. Analyses of gut contents from field-collected fish revealed that the laboratory estimates of predatory efficiency were related to their feeding behavior in nature. Behavior differences, such as those described herein, contribute to our understanding of the mechanisms of unisexual/bisexual coexistence in Poeciliopsis.
Offprint requests to: R.C. Vrijenhoek 相似文献
233.
234.
This paper reviews methods for exploring the differences between alternative equations in complex ecosystem models. A factorial design is proposed as a method for exposing possible interactions between equation forms in their effect on model output as well as to clarify differences between the main candidate equations. A number of display methods arising from statistical analysis are used including normal Q-Q plots, linear rank plots and interaction diagrams. The methods were illustrated using a complex ecosystem model of Lake Ontario. We found the methods effective at illustrating major differences between equations although several difficulties arose due to the complexity of the models and the diffuse nature of the data supporting model validation. Questions of the method for standardization of equation forms so that the compared equations are in some way analogous, are important. These methods are probably most useful in cases where the data are of sufficient quality to indicate not only how different equation forms affect model output but also which are to be preferred. 相似文献
235.
236.
Development of food preferences: social learning by Belding's ground squirrels Spermophilus beldingi
Summary The mechanisms by which food selection behavior develops may constrain the evolution of optimal foraging, yet these mechanisms have received relatively little attention in recent optimal foraging studies. We used cafeteria-style feeding trials to examine the role of social learning in the development of food preferences by a generalist mammalian herbivore, Spermophilus beldingi. Naive young spent relatively little time feeding and showed no preferences among five plant species offered in their feeding trials. This random pattern persisted for one set of young during two subsequent trials in the absence of their mother. A second group of young squirrels was tested initially alone, once with their mothers, and then once more alone. These squirrels fed more than those in the control group during their final trials, and showed significant preferences among plant species. These paralleled the preferences of their mothers. These results suggest that social learning may be important in the development of feeding behavior in ground squirrels, and provide a possible mechanism for cultural differences in food preferences among populations. 相似文献
237.
Stephen D. Field Steven W. Effler 《Journal of the American Water Resources Association》1988,24(2):325-328
ABSTRACT: Seventy-three in situ primary productivity experiments over a six-month period in hypereutrophic Onondaga Lake near Syracuse, New York, demonstrated variations in the light saturation parameter, Ip, which in part describes the interaction between productivity and light. Substantial variations in Ip were observed (coefficient of variation = 60 percent). Variations in Ip were significantly correlated (greater than 99 percent confidence level) with temperature (°C). An Arrhenius-type relationship (Ip= 1.312 × 1.088 (T-20)) accounted for approximately 37 percent of the variation in Ip and may be appropriate for other systems dominated by green algae. 相似文献
238.
Summary The longitudinal survivorship of a group of free-ranging male and female rhesus monkeys from La Parguera, Puerto Rico, was analyzed. Males had lower age-specific survivorship than females. There were no differences in the survivorship of daughters of high- and low-ranking mothers and there was no correlation between total number of offspring born and maternal rank for females. However, the sons of low-ranking mothers had lower survivorship than the sons of high-ranking females. This sex-related difference in survivorship, in conjunction with other evidence, indicates that the average lifetime reproduction of sons of low-ranking females is lower than that of daughters and vice versa for offspring of high-ranking females. 相似文献
239.
Stephen R. Gliessman 《Environmental management》1992,16(6):681-689
Agroecology is the application of ecological concepts and principles to the design and management of sustainable agricultural
systems. An agroecological approach to agriculture has special importance in the humid tropics where agricultural development
and the preservation of tropical forests are most often in direct conflict. It is proposed that a more sustainable approach
to development is needed, where agroecosystems depend on low external inputs, function more on the use of locally available
and renewable resources, have benign impacts on the environment, and are based on the knowledge and culture of the local inhabitants.
Examples of traditional agroecosystem management in Mesoamerica that can provide this basis are presented. The preservation
of both biological and cultural diversity are integral to the long-term sustainable management of natural resources in the
tropics. 相似文献
240.
Intense interest in stress had led to a proliferation of coping measures. To aid researchers in choosing or developing coping measures applicable to job stress, this paper provides a conceptual evaluation framework. The framework serves to evaluate the extent to which coping measures are comprehensive (focus and method of coping) and specific (coping behaviors versus coping effectiveness, coping style, or coping resources; and stress management applications). Both theoretical and organizational stress management perspectives are incorporated. 相似文献