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291.
292.
Pascale M. Biron Thomas Buffin-Bélanger Marie Larocque Guénolé Choné Claude-André Cloutier Marie-Audray Ouellet Sylvio Demers Taylor Olsen Claude Desjarlais Joanna Eyquem 《Environmental management》2014,54(5):1056-1073
River systems are increasingly under stress and pressure from agriculture and urbanization in riparian zones, resulting in frequent engineering interventions such as bank stabilization or flood protection. This study provides guidelines for a more sustainable approach to river management based on hydrogeomorphology concepts applied to three contrasted rivers in Quebec (Canada). Mobility and flooding spaces are determined for the three rivers, and three levels of “freedom space” are subsequently defined based on the combination of the two spaces. The first level of freedom space includes very frequently flooded and highly mobile zones over the next 50 years, as well as riparian wetlands. It provides the minimum space for both fluvial and ecological functionality of the river system. On average for the three studied sites, this minimum space was approximately 1.7 times the channel width, but this minimum space corresponds to a highly variable width which must be determined from a thorough hydrogeomorphic assessment and cannot be predicted using a representative average. The second level includes space for floods of larger magnitude and provides for meanders to migrate freely over a longer time period. The last level of freedom space represents exceptional flood zones. We propose the freedom space concept to be implemented in current river management legislation because it promotes a sustainable way to manage river systems, and it increases their resilience to climate and land use changes in comparison with traditional river management approaches which are based on frequent and spatially restricted interventions. 相似文献
293.
294.
Lisa A. Taylor David L. Clark Kevin J. McGraw 《Behavioral ecology and sociobiology》2011,65(5):1133-1146
In many animals, conspicuous coloration functions as a quality signal. Indicator models predict that such colors should be
variable and condition dependent. In Habronattus pyrrithrix jumping spiders, females are inconspicuously colored, while males display brilliant red faces, green legs, and white pedipalps
during courtship. We tested the predictions of the indicator model in a field study and found that male body condition was
positively correlated with the size, hue, and red chroma of a male’s facial patch and negatively correlated with the brightness
of his green legs. These traits were more condition dependent than non-display colors. We then tested a dietary mechanism
for condition dependence using two experiments. To understand how juvenile diet affects the development of coloration, we
reared juvenile spiders on high- and low-quality diets and measured coloration at maturity. To understand how adult diet affects
the maintenance of coloration, we fed wild-caught adults with high- or low-quality diets and compared their coloration after
45 days. In the first experiment, males fed high-quality diet had redder faces, suggesting that condition dependence is mediated
by juvenile diet. In the second experiment, red coloration did not differ between treatments, suggesting that adult diet is
not important for maintaining the color after it is produced at maturity. Diet had no effect on green coloration in either
experiment. Our results show different degrees of condition dependence for male display colors. Because red is dependent on
juvenile diet, it may signal health or foraging ability. We discuss evidence that green coloration is age dependent and alternatives
to indicator models for colorful displays in jumping spiders. 相似文献
295.
M. Service A. E. Durrant J. A. Mills J. E. Taylor D. Faughey 《Journal of Coastal Conservation》1996,2(2):159-168
Studies were conducted on nutrient cycling in two coastal embayments; Strangford Lough and Belfast Lough, in order to classify
these coastal waters in compliance with the European Union Urban Waste Water Treatment and Nitrates Directives. Analysis of
the data suggests that Strangford Lough is nitrogen-limited throughout much of the growing season with chlorophyll-a levels
comparable to the open Irish Sea. In contrast, much of Belfast Lough is never nitrogen-limited and, with chlorophyll-a levels
at times exceeding 50 μg/l, is exhibiting symptoms of eutrophication. 相似文献
296.
Desire to Bargain and Negotiation Success: Lessons About the Need to Negotiate from Six Hydropower Disputes 总被引:1,自引:0,他引:1
/ We investigated the notion that successful negotiations require that all parties to the dispute must have a desire to bargain. This desire is most likely to be present when the dispute exhibits ripeness and each party believes a bargained solution is the most cost-effective way to resolve differences. Structured interviews of participants in six Federal Energy Regulatory Commission hydropower licensing consultations were conducted to determine the level of need to negotiate for each party. The findings indicate that a need to negotiate is a necessary, but not sufficient, condition for success. Several factors were associated with a need to negotiate: a weak BATNA (best alternative to a negotiated agreement); a salient issue; participants' sense of efficacy; a sense of inevitability; professional roles encouraging negotiation; and disputes about facts as opposed to disputes about values. Participants' need to negotiate fluctuated throughout the process and intensified when questions were ripe: i.e., critical issues were debated or the regulatory process required action.KEY WORDS: Alternative dispute resolution; Federal licenses; Federal Energy Regulatory Commission; Instream flow; Environmental planning 相似文献
297.
Incorporating fragmentation and non‐native species into distribution models to inform fluvial fish conservation 下载免费PDF全文
Fluvial fishes face increased imperilment from anthropogenic activities, but the specific factors contributing most to range declines are often poorly understood. For example, the range of the fluvial‐specialist shoal bass (Micropterus cataractae) continues to decrease, yet how perceived threats have contributed to range loss is largely unknown. We used species distribution models to determine which factors contributed most to shoal bass range loss. We estimated a potential distribution based on natural abiotic factors and a series of currently occupied distributions that incorporated variables characterizing land cover, non‐native species, and river fragmentation intensity (no fragmentation, dams only, and dams and large impoundments). We allowed interspecific relationships between non‐native congeners and shoal bass to vary across fragmentation intensities. Results from the potential distribution model estimated shoal bass presence throughout much of their native basin, whereas models of currently occupied distribution showed that range loss increased as fragmentation intensified. Response curves from models of currently occupied distribution indicated a potential interaction between fragmentation intensity and the relationship between shoal bass and non‐native congeners, wherein non‐natives may be favored at the highest fragmentation intensity. Response curves also suggested that >100 km of interconnected, free‐flowing stream fragments were necessary to support shoal bass presence. Model evaluation, including an independent validation, suggested that models had favorable predictive and discriminative abilities. Similar approaches that use readily available, diverse, geospatial data sets may deliver insights into the biology and conservation needs of other fluvial species facing similar threats. 相似文献
298.
H. Von Blottnitz D. Boiadjiev T. Taylor S. Arnold 《Journal of Environmental Planning and Management》2006,49(3):413-433
This paper estimates the environmental impacts and damage costs (‘external costs’) of synthetic nitrogen fertilizer and discusses options for reducing these impacts, including their consequences for farmers and for producers of fertilizer. The damage costs of the fertilizer life cycle that could be estimated are large, about 0.3 [euro]/kgN (compared to the current market price of about 0.5 [euro]/kgN); much of that is due to global warming by N2O and CO2 emissions during fertilizer production and N2O emissions from fertilized fields. Policy options for internalizing these costs are discussed, and the consequences of reduced fertilizer input on crop yield are explored. If the damage costs were internalized by a pollution tax or tradable permits that are auctioned by the government, the economic consequences would be heavy, with a large revenue loss for farmers. However, if it is internalized by tradable permits that are given out free, the revenue loss for farmers is small. The loss for fertilizer producers increases linearly with the amount of external cost that is internalized, by contrast to the loss for farmers which increases quadratically but is very small for a damage cost of 0.3 [euro]/kgN. Expressed as a change in the fertilizer-dependent part of the farmers' revenue (crop yield × crop price – fertilizer used× fertilizer price), the decrease is less than 0.5% for most crops; the losses are larger only for crops with low [euro]/ha revenue. Averaged over wheat, barley, potatoes, sugar beet and rapeseed, the loss to farmers is about 0.1% in the UK and 0.4% in Sweden. The revenue loss for fertilizer producers is larger, about 8% in the UK and 14% in Sweden. 相似文献
299.
For a variety of reasons, acceptance of traditional postmortem examination following foetal or neonatal death has declined significantly in recent years in the UK. Here, we review the case for the development of less invasive autopsy using combined investigations including imaging techniques, in particular, magnetic resonance imaging and computerised tomography. Copyright © 2010 John Wiley & Sons, Ltd. 相似文献
300.
Stewart Lockie Geoffrey Lawrence Allan Dale Bruce Taylor 《Journal of Environmental Planning and Management》2002,45(6):813-826
The complexity of relationships between social change and natural resource management has generated interest in the identification of indicators that might provide more streamlined means for monitoring and planning. In the case of Australia's National Land and Water Resources Audit, interest has focused on the capacity of resource managers to implement more sustainable resource-use practices. This paper reports on an attempt to develop indicators of 'capacity for change' that are statistically reliable and both meaningful and useful to resource managers at a variety of scales. It will be argued, however, that social, spatial and temporal variability in change processes means that no discrete list of social indicators can achieve this task. At the same time that rigorous testing is needed to challenge common-sense assumptions about who is capable of change and where to target capacity-building programmes, data collection and interpretation must be embedded in processes of ongoing negotiation and adaptation among all those involved in, or affected by, resource management. 相似文献