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271.
Water is a scarce resource in many parts of the developed world. Two solutions are possible to address water scarcity: conservation of existing resources, or the further production of water from new sources e.g. through recycling of wastewater or desalination of seawater. However, the main hurdle to implementation of many of these solutions is often viewed as a lack of public willingness to adopt these alternative water behaviours. Research in this area is therefore crucial. Yet, and possibly due to the interdisciplinary nature of such research, there is currently no comprehensive overview of what has been done before. This study fills this gap by (1) choosing a general consumer behaviour perspective as a starting point, (2) developing a conceptual model of research required in the area of water-related public acceptance studies, (3) identifying eight key water-related behaviours which require future research attention, and (4) reviewing which areas of the conceptual model have been investigated in the past by conducting an extensive literature review of water-related social science research.The review established that the majority of work which has been conducted is located at the cross-roads of personal characteristics and behavioural intentions. Significant gaps exist in relation to researching the adoption of a wide range of demand-side water behaviours. This indicates a dominance of supply-side solutions in social-research exploration. The review identifies a number of research needs including: the exploration of actual adoption of water-related behaviours (rather than behavioural intentions); and to widen the scope of water behaviour enquiry to include more demand-side solutions. Given the increasing scarcity of water in many areas of the world, addressing these identified gaps will be of significant importance. Thus our model informs the social-research agenda for water policy. 相似文献
272.
Exploring alternative states in ecological systems with a qualitative analysis of community feedback
Martin P. Marzloff Jeffrey M. Dambacher Stewart D. Frusher 《Ecological modelling》2011,222(15):2651-2662
Demonstrating and predicting the existence of alternative states in natural communities remains a challenge for ecologists and is essential for resource managers. Positive feedback is often presented as central in maintaining alternative ecosystem states, but no formal approach relates this part of theory to real world applications. Through qualitative modelling of community response to long-term perturbations, we define generic mechanistic links between positive feedback and the occurrence of alternative states. Positive feedback diminishes a system's overall resistance to change, and can create and maintain correlations in the relative abundance of variables that coincide with alternative states.Through specific models of the dynamics of Tasmanian rocky-reef communities, which are affected by climate and fishing and persist within alternative states, we demonstrate the ability of our theoretical framework to predict alternative states in ecosystems and inform management intervention. A qualitative knowledge of community structure permits a thorough analysis of system feedback and an assessment of the potential for an ecosystem to exhibit alternative states. We illustrate the usefulness of the approach to inform management priorities, and to focus monitoring and field research on the key drivers of ecosystem dynamics. 相似文献
273.
A Combined Park Management Framework Based on Regulatory and Behavioral Strategies: Use of Visitors' Knowledge to Assess Effectiveness 总被引:1,自引:0,他引:1
KOSTANTINOS PAPAGEORGIOU 《Environmental management》2001,28(1):61-73
In light of the increasing mandate for greater efficiency in conservation of natural reserves such as national parks, the
present study suggests educational approaches as a tool to achieve conservation purposes. Currently, the management of human–wildlife
interactions is dominated by regulatory strategies, but considerable potential exists for environmental education to enhance
knowledge in the short run and to prompt attitude change in the long run. A framework for conservation based on both traditional
regulatory- and behavior-oriented strategies was proposed whereby the level of knowledge that park visitors have acquired
comprises an obvious outcome and establishes a basis upon which the effectiveness of regulatory- and behavior-based regimes
could be assessed. The perceptions regarding park-related issues of two distinct visitor groups (locals and nonlocals) are
summarized from a survey undertaken in Vikos-Aoos national park. The findings suggest a superficial knowledge for certain
concepts but little profound understanding of the content of such concepts, indicating that knowledge-raising efforts should
go a long way towards establishing a positive attitude for the resource. Visitors' poor knowledge of the park's operation
regulation contest the efficiency of the presently dominant regulatory management regime. While geographical distances did
not appear to significantly differentiate knowledge between the two groups, wilderness experience (as certified by visits
to other parks) was proved to be an impetus for generating substantial learner interest in critical park issues among nonlocal
visitors. School education and media were found to be significant knowledge providers. 相似文献
274.
Light duty vehicles, i.e. passenger cars and light trucks, account for approximately half of global transportation energy demand and, thus, a major share of carbon dioxide and other emissions from the transport sector. Energy consumption in the transport sector is expected to grow in the future, especially in developing countries. Cars with alternative powertrains to internal combustion engines (notably battery, hybrid and fuel-cell powertrains), in combination with potentially low carbon electricity or alternative fuels (notably hydrogen and methanol), can reduce energy demand by at least 50%, and carbon dioxide and regulated emissions much further. This article presents a comparative technical and economic assessment of promising future fuel/vehicle combinations. There are several promising technologies but no obvious winners. However, the electric drivetrain is a common denominator in the alternative powertrains and continued cost reductions are important for widespread deployment in future vehicles. Development paths from current fossil fuel based systems to future carbon-neutral supply systems appear to be flexible and a gradual phasing-in of new powertrains and carbon-neutral fluid fuels or electricity is technically possible. Technology development drivers and vehicle manufacturers are found mainly in industrialised countries, but developing countries represent a growing market and may have an increasingly important role in shaping the future. 相似文献
275.
Corjan Brink Carolien Kroeze Zbigniew Klimont 《Atmospheric environment (Oxford, England : 1994)》2001,35(36):2618
Agriculture is an important source of NH3, which contributes to acidification and eutrophication, as well as emissions of the greenhouse gases CH4 and N2O. Because of their common sources, emission reduction measures for one of these gases may affect emissions of others. These interrelations are often ignored in policy making. This study presents an analysis of the effects of measures to reduce NH3 emissions on emissions of N2O and CH4 from agriculture in Europe. The analysis combines information from the NH3 module of the Regional Air pollution INformation and Simulation (RAINS) model for Europe with the IPCC method for national greenhouse gas inventories. The IPCC method for estimating agricultural emissions of N2O and CH4 is adjusted in order to use it in combination with the RAINS database for the European agricultural sector. As an example, we applied the adjusted method to the agricultural sector in the Netherlands and found that application of several NH3 abatement options may result in a substantial increase in N2O emissions while the effect on CH4 emissions is relatively small. In Part 2 of this paper we focus on the resulting emissions for all European countries for 1990 and 2010. 相似文献
276.
MARCELO TABARELLI ANTONIO V. AGUIAR LUCIANA C. GIRÃO CARLOS A. PERES ARIADNA V. LOPES 《Conservation biology》2010,24(6):1654-1663
Abstract: Despite many studies on fragmentation of tropical forests, the extent to which plant and animal communities are altered in small, isolated forest fragments remains obscure if not controversial. We examined the hypothesis that fragmentation alters the relative abundance of tree species with different vegetative and reproductive traits. In a fragmented landscape (670 km2) of the Atlantic Forest of northeastern Brazil, we categorized 4056 trees of 182 species by leafing pattern, reproductive phenology, and morphology of seeds and fruit. We calculated relative abundance of traits in 50 1‐ha plots in three types of forest configurations: forest edges, small forest fragments (3.4–83.6 ha), and interior of the largest forest fragment (3500 ha, old growth). Although evergreen species were the most abundant across all configurations, forest edges and small fragments had more deciduous and semideciduous species than interior forest. Edges lacked supra‐annual flowering and fruiting species and had more species and stems with drupes and small seeds than small forest fragments and forest interior areas. In an ordination of species similarity and life‐history traits, the three types of configurations formed clearly segregated clusters. Furthermore, the differences in the taxonomic and functional (i.e., trait‐based) composition of tree assemblages we documented were driven primarily by the higher abundance of pioneer species in the forest edge and small forest fragments. Our work provides strong evidence that long‐term transitions in phenology and seed and fruit morphology of tree functional groups are occurring in fragmented tropical forests. Our results also suggest that edge‐induced shifts in tree assemblages of tropical forests can be larger than previously documented. 相似文献
277.
Drylands (41 and 35% of global land and population, respectively) have the lowest biological productivity of any ecosystem,
contain populations with the highest growth rates on earth, and share a significant fraction of global poverty for which desertification
is implicated. A global assessment of the available information indicates that the inherent low productivity of drylands,
when combined with other adverse factors, can generate poverty. It additionally indicates that while the drylands may exist
in a locally stable and sustainable state, this is readily destabilized by non-linear, threshold-crossing transitions to an
alternative steady-state leading to desertification, poverty and conflicts. The “desertification paradigm” (human and climatological
pressures driving overexploitation of land resources, leading to desertification, poverty and reduced security) is challenged
by its “counter-paradigm” (adversity elicits innovation, leading to ingenuous solutions for avoiding desertification). But
the latter does not account for the inevitability of continued and increasing pressure on the finite dryland resources, expected
to be further exacerbated by a globally increasing need for agricultural land. A companion paper points out that this situation
can be avoided by reducing dependence on land productivity, through adoption of “alternative livelihoods.” These livelihoods,
while economically advantageous, reduce pressure on land resources. 相似文献
278.
Limit values (LVs) are legal concentration limits for constituents, residues and contaminants in consumer products or for
emissions from production processes into environmental compartments. They are a traditional regulatory aid to manage chemicals
in human environments. To make them proactive, LVs should become enforced by means of a transparent and informed decision
process whose starting point is the Basic Rule of Environmental Hygiene, BREH:Avoid useless exposure as far as possible, minimize useful exposure in a reasonable manner, and prevent that exposure which
is dangerous. The BREH calls upon minimizing exposure not only according toon site risk potentials and acceptance, but also tooff site avoidability and acceptability. 相似文献
279.
Abstract: Current conservation mitigation plans often fail to ensure full in-kind habitat replacement for endangered species, which suggests the need for improved methods for calculating mitigation credits. A simple, yet biologically meaningful method for calculating mitigation credits would be to let the number of mitigation credits assigned to a parcel of land scale with the reproductive value of the individuals occupying that parcel. This can be accomplished by dividing the population into 2 or more subdivisions with different reproductive values, calculating the densities of these subdivisions as a function of one or more habitat parameters, and then forming a weighted sum of these densities such that each density distribution is weighted by the reproductive value of its respective subdivision of the population. This weighted sum is the density distribution of reproductive value, and by integrating it over a particular parcel, one can determine the mitigation value of that parcel. We carried out this procedure for a population of California tiger salamanders ( Ambystoma californiense ), with distance from breeding site as our habitat parameter and the 3 visually identifiable age classes (adults, juveniles, and metamorphs) as our population subdivisions. This led to a density distribution of reproductive value that decreased exponentially with increasing distance from a breeding site. Mitigation strategies derived from this function will be more likely to ensure the persistence of California tiger salamander populations than current approaches, which assign all land within 1.6 km of a breeding site the same mitigation value. Use of the density distribution of reproductive value as a basis for mitigation plans is a procedure that can be applied to all endangered species, and it should improve the quality of mitigation decisions. 相似文献
280.
This paper introduces a functional-structural plant model based on artificial life concepts and L-systems. This model takes into account realistic physiological rules, the architecture of the plants and their demography. An original benefit of this approach is that it allows the simulation of plant evolution at both functional and life-history levels implementing mutations to the L-systems and a set of genetic parameter values. The conducted experiments focus on the evolutionary emergence of different life history strategies in an environment with heterogeneous resource availability and disturbance frequency. It is found that, depending on the encountered conditions, the plants develop three major strategies classified as competitors, stress-tolerators and ruderals according to Grime's CSR theory. Most of the evolved characteristics comply with theoretical biology or field observations on natural plants. Besides these results, our modelling framework is highly flexible and many refinements can be readily implemented depending on the issues one intends to address. Moreover, the model can readily be used to address many questions at the interface between evolutionary ecology, plant functional and community ecologies and ecosystem ecology. 相似文献