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61.
In the Kullu District, Himachal Pradesh, India, economic and urban growth, and diversification have increased pressure on forests and forest-based social-ecological systems. As in many Himalayan regions, livelihood sustainability is linked to forest resources, products and services. Recent development in the region, to which these systems may be vulnerable, brings into question environmental and livelihood sustainability. This paper examines the resilience of integrated systems of people and nature, or social-ecological systems, in the face of development pressures by evaluating a number of local and state-level institutional responses. Resilience, which describes the ability of the social-ecological systems to adapt to change by buffering shocks, improving self-organization and increasing capacity for learning, is an essential quality for sustainable development. Institutional responses which positively contribute to resilience and sustainability include the work of mahila mandals in forest management, adoption of Joint Forest Management (JFM) policies and practices, upholding rules, strengthening local institutions, establishing firewood depots and adopting alternative energy sources. Institutional failures brought about by the lack of rule enforcement and corruption erode resilience. The analysis of institutional responses helps to identify areas where capacity exists and areas in which capacity building is needed to produce resilient social-ecological systems and therefore, sustainable development. 相似文献
62.
Charles M. Buchanan Christy N. Boggs Debra D. Dorschel Robert M. Gardner Ron J. Komarek Thelma L. Watterson Alan W. White 《Journal of Polymers and the Environment》1995,3(1):1-11
A series of miscible blends consisting of cellulose acetate propionate (CAP) and poly(ethylene glutarate) (PEG) or poly(tetramethylene glutarate) (PTG) were evaluated in a static bench-scale simulated municipal compost environment. Samples were removed from the compost at different intervals, and the weight loss was determined before evaluation by gel permeation chromatography, scanning electron microscopy, and1H NMR. The type of polyester (PEG versus PTG) in the blend made no difference in composting rates. At fixed CAP degree of substitution (DS), when the content of polyester in the blend was increased, the rate of composting and the weight loss due to composting increased. When the CAP was highly substituted, little degradation was observed within 30 days and almost all of the weight loss was ascribed to loss of polyester. Although the polyester was still observed to degrade faster, when the CAP DS was below approximately 2.0, both components are observed to degrade. The data suggests that initial degradation of the polyester is by chemical hydrolysis and the rate of this hydrolysis is very dependent upon the temperature profile of the compost and upon the DS of the CAP. 相似文献
63.
James M. Walker Roy Gardner Elinor Ostrom 《Journal of Environmental Economics and Management》1990,19(3)
This paper examines group behavior in an experimental environment designed to parallel the conditions specified in noncooperative models of limited-access common-pool resources. Using experimental methods, we investigate the strength of theoretical models which predict that users of such resources will appropriate units at a rate at which the marginal returns from appropriation are greater than the marginal appropriation costs. Our results confirm the prediction of suboptimal accrual of rents and offer evidence on the effects of increasing investment capital available to appropriators. 相似文献
64.
Three different studies examine moderating effects of focus of attention at work on leader-follower relationships, using the typology developed by Howell, Dorfman, and Kerr (1986). Survey data were collected from over 1300 subjects. Results indicate that: (1) high focus on the supervisor while at work enhances leader behaviour-subordinate satisfaction and behaviour relationships, (2) high focus on off-job factors while at work enhances leader behaviour-subordinate satisfaction relationships, and (3) high focus on off-job factors while at work weakens leader behaviour-subordinate behaviour relationships. Theoretical implications for the study of organizational behaviour are discussed, as well as practical issues for enhancing leader behaviour effectiveness in work organizations. 相似文献
65.
66.
A widespread distrust in the significance of the observation of trisomy 20 mosaicism in amniotic fluid cultures has led to an increasing belief that this particular type of aneuploidy is of extra foetal origin and is clinically incosequential. The report presents an example of amnoitic fluid cell mosaicism for trisomy 20 which was ultimately confirmed in the foetus, and proposes that, in spite of the absence of obvious congenital malformation from the foetus, trisomy 20 mosaicism in amnoitic fluid cultures should be regarded with the same deference as mosaicism for any other autosome of unknown effect. 相似文献
67.
C. Liepert S. M. Gardner S. Rees 《Journal of Environmental Planning and Management》1993,36(3):283-293
Heather regeneration following controlled burning and cutting of young and old heather stands was measured on twelve plots within the North York Moors National Park, UK. Rapid regeneration primarily from heather shoots, occurred in young heather stands and no significant differences were recorded between the two management treatments. Regeneration occurred more slowly in old heather stands and seedling growth was more rapid on the burnt plots. The results suggest that cutting promotes vegetative regeneration and burning promotes regeneration from seed. The implications for heather management are discussed. 相似文献
68.
69.
Kathryn E. Gardner Robin L. Foster Sean O’Donnell 《Behavioral ecology and sociobiology》2007,61(5):783-792
Bumblebee colonies experience daily and seasonal fluctuations in ambient temperature, but proper brood development requires
a stable nest temperature. This study examined how adaptive colony responses to changing ambient temperature are achieved
through the in-nest workers’ behavioral plasticity. We studied three Bombus huntii colonies in the laboratory. In the first experiment, we manipulated ambient temperature and recorded brood cell incubation
and wing fanning by individually marked, known-age bees. The colonies maintained their nests closer to appropriate brood development
temperatures (28 to 32°C) when exposed to a range of ambient temperatures from 10.3 to 38.6°C. Incubation activity was greater
in cooler treatment conditions, whereas in the highest temperature treatment, some bees fanned and others moved off the brood.
As the ambient temperature dropped, workers increased the duration of their incubating bouts, but, except at the highest temperature,
the number of workers that incubated did not differ significantly among treatments. A subset of the bees incubated significantly
more than their nest mates, some of which never incubated. Worker body size, but not age, was a good predictor of incubation
rates, and smaller bees incubated at higher rates. In the second experiment, we removed the most actively incubating workers.
Immediately after removals, the total colony incubation effort was lower than pre-removal levels, but incubation effort rebounded
toward pre-removal levels after 24 h. The increased thermoregulatory demand after removals was met primarily by bees increasing
their rates of incubation rather than by bees switching from a different task to incubation. We conclude that some B. huntii workers specialize on nest thermoregulation, and that changes in work rates are more important than task switching in meeting
thermal challenges. 相似文献
70.
Dobson J Gardner M Miller B Jessep M Toft R 《Journal of environmental monitoring : JEM》1999,1(1):91-95
This paper reports an approach to the assessment of the validity of environmental monitoring data--a 'data filter'. The strategy has been developed through the UK National Marine Analytical Quality Control (AQC) Scheme for application to data collected for the UK National Marine Monitoring Plan, although the principles described are applicable more widely. The proposed data filter is divided into three components: Part A, 'QA/QC'--an assessment of the laboratory's practices in Quality Assurance/Quality Control; Part B, 'fitness for purpose'--an evaluation of the standard of accuracy that can be demonstrated by activities in (A), in relation to the intended application of the data; and Part C, the overall assessment on which data will be accepted as usable or rejected as being of suspect quality. A pilot application of the proposed approach is reported. The approach described in this paper is intended to formalise the assessment of environmental monitoring data for fitness for a chosen purpose. The issues important to fitness for purpose are discussed and assigned a relative priority order on which to judge the reliability/usefulness of monitoring data. 相似文献