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211.
Evaluating stream restoration projects 总被引:2,自引:3,他引:2
River and stream restoration projects are increasingly numerous but rarely subjected to systematic postproject evaluation.
Without conducting such evaluation and widely disseminating the results, lessons will not be learned from successes and failures,
and the field of river restoration cannot advance. Postproject evaluation must be incorporated into the initial design of
each project, with the choice of evaluation technique based directly upon the specific project goals against which performance
will be evaluated. We emphasize measurement of geomorphic characteristics, as these constitute the physical framework supporting
riparian and aquatic ecosystems. Techniques for evaluating other components are briefly discussed, especially as they relate
to geomorphic variables. Where possible, geomorphic, hydrologic, and ecological variables should be measured along the same
transects. In general, postproject monitoring should continue for at least a decade, with surveys conducted after each flood
above a predetermined threshold. Project design should be preceded by a historical study documenting former channel conditions
to provide insights into the processes suggest earlier, potentially stable channel configurations as possible design models. 相似文献
212.
Several innovative directions for landscape policy development and implementation have emerged over recent years. These include: (i) an expansion of scope to include all landscape aspects and landscape types, (ii) an increased emphasis on public participation, (iii) a focus on designing measures appropriate for different contexts and scales, and (iv) encouraging support for capacity-building. In this paper, we evaluate the extent to which these policy directions are reflected in the practice of academic landscape research. We evaluate all research papers published in three leading landscape journals over six years, as well as published research papers relating directly to the European Landscape Convention. The latter, which was adopted in 2000, establishes a framework for landscape protection, planning and management in Europe and is to date the only international legal instrument of its kind. Results indicate that whilst policy innovations do not appear to be a major stimulus for academic research, studies nevertheless address a range of landscape aspects, types and scales (albeit with a slight bias towards bio-physical landscape aspects). However, geographical representativeness of research is weak and dominated by the United States and northern/western Europe, and research capacity likewise appears to be unevenly distributed. Landscape research is also limited in the extent to which it involves stakeholders or develops innovative methods for doing so, notwithstanding that this remains a key challenge for policy-makers. Results point to the potential for landscape research to address areas (topical and geographical) which have received little attention to date, as well as suggesting mutual benefits of stronger links between policy and academia. 相似文献
213.
Yaser Abunnasr Elisabeth M. Hamin Elizabeth Brabec 《Journal of Environmental Planning and Management》2015,58(1):135-155
There is a pressing need for municipalities and regions to create urban form suited to current as well as future climates, but adaptation planning uptake has been slow. This is particularly unfortunate because patterns of urban form interact with climate change in ways that can reduce, or intensify, the impact of overall global change. Uncertainty regarding the timing and magnitude of climate change is a significant barrier to implementing adaptation planning. Focusing on implementation of adaptation and phasing of policy reduces this barrier. It removes time as a decision marker, instead arguing for an initial comprehensive plan to prevent maladaptive policy choices, implemented incrementally after testing the micro-climate outcomes of previous interventions. Policies begin with no-regrets decisions that reduce the long-term need for more intensive adaptive actions and generate immediate policy benefits, while gradually enabling transformative infrastructure and design responses to increased climate impacts. Global and local indicators assume a larger role in the process, to evaluate when tipping points are in sight. We use case studies from two exemplary municipal plans to demonstrate this method's usefulness. While framed for urban planning, the approach is applicable to natural resource managers and others who must plan with uncertainty. 相似文献
214.
Elisabeth Wendelen 《Safety Science》1996,23(2-3)
For a number of years now, enterprises have become increasingly interested in training in the area of health and safety at work. Even though trade unionists and managers see different advantages in such training, they share the same willingness to reduce occupational injuries. Even if demand for training is sometimes limited on purpose (all that is expected of it is to pass on recipes enabling work to be continued without getting hurt), training in safety and health is a privileged point of contact between researchers and trade unionists. But the contact between these two groups of actors in the process of changing working conditions does not happen without raising a number of questions: that of reciprocal mental images of each other, for instance, something which will condition the ways in which their knowledge meets; or the issue of the target groups of training: all the workers or just the delegates representing the workers in cooperation bodies? Other fundamental questions relate to the context in which training takes place: what type of training should take pride of place? What is the role of the expert in this approach? And how should the expert's knowledge be linked in with that of the workers? 相似文献
215.
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217.
Elisabeth Simelton Evan D.G. Fraser Mette Termansen Piers M. Forster Andrew J. Dougill 《Environmental Science & Policy》2009,12(4):438-452
Why is it that sometimes small droughts trigger serious crop losses while in other cases even large droughts do not have such a major effect? In this paper, we identify socio-economic indicators associated with sensitivity and resilience to drought for each of China's main grain crops (rice, wheat and corn). Provincial harvest and rainfall data (1961–2001) are used to calculate an annual “crop-drought vulnerability index”. We separate “sensitive cases” (where significant harvest losses occurred in years with only minor droughts) and “resilient cases” (where harvest losses were minimal despite there being a major drought) and explore the socio-economic characteristics of these different situations. Results show that sensitive cases were particularly common in economically poor landlocked provinces and in wealthy coastal areas that have a limited land base. In such “sensitive cases”, the size of the rural population and the quantity of agricultural inputs were negatively correlated with drought vulnerability, while for resilient cases, vulnerability was negatively correlated with the abundance of land. This leads us to propose a series of drought-vulnerability typologies based on the extent to which land, labour, capital, agricultural technology, and infrastructure buffer or exacerbate the effect of a drought event. 相似文献
218.
Rachel A. Page Tanja Schnelle Elisabeth K. V. Kalko Thomas Bunge Ximena E. Bernal 《Die Naturwissenschaften》2012,99(6):505-509
Predators are often confronted with a broad diversity of potential prey. They rely on cues associated with prey quality and palatability to optimize their hunting success and to avoid consuming toxic prey. Here, we investigate a predator’s ability to assess prey cues during capture, handling, and consumption when confronted with conflicting information about prey quality. We used advertisement calls of a preferred prey item (the túngara frog) to attract fringe-lipped bats, Trachops cirrhosus, then offered palatable, poisonous, and chemically manipulated anurans as prey. Advertisement calls elicited an attack response, but as bats approached, they used additional sensory cues in a sequential manner to update their information about prey size and palatability. While both palatable and poisonous small anurans were readily captured, large poisonous toads were approached but not contacted suggesting the use of echolocation for assessment of prey size at close range. Once prey was captured, bats used chemical cues to make final, post-capture decisions about whether to consume the prey. Bats dropped small, poisonous toads as well as palatable frogs coated in toad toxins either immediately or shortly after capture. Our study suggests that echolocation and chemical cues obtained at close range supplement information obtained from acoustic cues at long range. Updating information about prey quality minimizes the occurrence of costly errors and may be advantageous in tracking temporal and spatial fluctuations of prey and exploiting novel food sources. These findings emphasize the sequential, complex nature of prey assessment that may allow exploratory and flexible hunting behaviors. 相似文献
219.
220.
Bo B. Bet Maartje C. Snoep Elisabeth van Leeuwen Ingeborg H. Linskens Monique C. Haak Lieke Rozendaal Ingmar Knobbe Joost van Schuppen Carlijn E. L. Hoekstra David R. Koolbergen Sally-Ann Clur Eva Pajkrt 《黑龙江环境通报》2023,43(5):629-638