574 research outputs found
Towards a Structural View of Resilience
The result of resilience is persistence: the maintenance
of certain characteristic behavioral properties in the face
of stress, strain and surprise. But the origins of this resilient
behavior lie in the structure of the systems which
concern us. Our need as policy analysts may only be one of
comparative measures: Which system is more resilient? But
as active designers -- as engineers, managers, or responsible
policy advisors -- we need to be able to say what mechanisms
or relationships make a system resilient, and what actions we
can take to make it more or less so.
This need for a causal view of resilience led us to a
search for persistence-promoting (or "resilient") mechanisms
and relationships in a variety of natural and man-made systems
A Case Study of Forest Ecosystem Pest Management
The boreal forests of North America have, for centuries, experienced periodic outbreaks of a defoliating insect called the Spruce Budworm. In anyone outbreak cycle a major proportion of the mature softwood forest in effected areas can die, with major consequences to the economy and employment of regions like New Brunswick, which are highly dependent on the forest industry. An extensive insecticide spraying programme initiated in New Brunswick in 1951 has succeeded in minimizing tree mortality, but at the price of maintaining incipient outbreak conditions over an area considerably more extensive than in the past. The present management approach is, therefore, particularly sensitive to unexpected shifts in economic, social and regulatory constraints, and to unanticipated behavior of the forest ecosystem.
Most major environmental problems in the world today are characterized by similar basic ingredients: high variability in space and time, large scale, and a troubled management history. Because of their enormous complexity there has been little concerted effort to apply systems analysis techniques to the coordinated development of effective descriptions of, and prescriptions for, such problems. The Budworm-forest system seemed to present an admirable focus for a case study with two objectives. The first, of course, was to attempt to develop sets of alternate policies appropriate for the specific problem. But the more significant purpose was to see just how far we could stretch the state of the art capabilities in ecology, modeling, optimization, policy design and evaluation to apply them to complex ecosystem management problems.
Three principal issues in any resource environmental problem challenge existing techniques. The resources that provide the food, fibre and recreational opportunities for society are integral parts of ecosystems characterized by complex interrelationships of many species among each other and with the land, water and climate in which they live. The interactions of these systems are highly non-linear and have a significant spatial component. Events in anyone point in space, just as at any moment of time, can affect events at other points in space and time. The resulting high order of dimensionality becomes all the more significant as these ecological systems couple with complex social and economic ones.
The second prime challenge is that we have only partial knowledge of the variables and relationships governing the systems. A large body of theoretical and experimental analysis and data has led to an identification of the general form and kind of functional relations existing between organisms. nut only occasionally is there a rich body of data specific to anyone situation. To develop an analysis which implicitly or explicitly presumes sufficient knowledge is therefore to guarantee management policies that become more the source of the problem than the source of the solution. In a particularly challenging way present ecological management situations require concepts and techniques which cope creatively with the uncertainties and unknowns that in fact pervade most of our major social, economic and environmental problems.
The third and final challenge reflects the previous two: How can we design policies that achieve specific social objectives and yet are still "robust"? Policies which, once set in play, produce intelligently linked ecological, social and economic systems that can absorb the unexpected events and unknowns that will inevitably appear. These "unexpecteds" might be the one in a thousand year drought that perversely occurs this year; the appearance or disappearance of key species, the emergence of new economic and regulatory constrains or the shift of societal objectives. We must learn to design in a way which shifts our emphasis away from minimizing the probability of failure, towards minimizing the cost of those failures which will inevitably occur
Lessons for Ecological Policy Design: A Case Study of Ecosystem Management
This paper explores the prospects for combining elements of the ecological and policy sciences to form a substantive and effective science of ecological policy design. This exploration is made through a case study whose specific focus is the management problem posed by competition between man and an insect (the spruce budworm, Choristoneura fumiferana) for utilization of coniferous forests in the Canadian Province of New Brunswick
Recommended from our members
U-Mo Foil/Cladding Interactions in Friction Stir Welded Monolithic RERTR Fuel Plates
Interaction between U-Mo fuel and Al has proven to dramatically impact the overall irradiation performance of RERTR dispersion fuels. It is of interest to better understand how similar interactions may affect the performance of monolithic fuel plates, where a uranium alloy fuel is sandwiched between aluminum alloy cladding. The monolithic fuel plate removes the fuel matrix entirely, which reduces the total surface area of the fuel that is available to react with the aluminum and moves the interface between the fuel and cladding to a colder region of the fuel plate. One of the major fabrication techniques for producing monolithic fuel plates is friction stir welding. This paper will discuss the interactions that can occur between the U-Mo foil and 6061 Al cladding when applying this fabrication technique. It has been determined that the time at high temperatures should be limited as much as is possible during fabrication or any post-fabrication treatment to reduce as much as possible the interactions between the foil and cladding. Without careful control of the fabrication process, significant interaction between the U-Mo foil and Al alloy cladding can result. The reaction layers produced from such interactions can exhibit notably different morphologies vis-Ã -vis those typically observed for dispersion fuels
Project Status Report: Ecology and Environment Project
We present here the extended outline and copies of the illustrations used in the Status Report of the IIASA Ecology and Environment Project, presented at Schloss Laxenburg on 21 June 1974.
Section 1., "General Review", is covered in the outline. Section 2., "A Case Study of Ecosystem Management", is the subject of a major monograph now in preparation. Section 3., on Selected Conceptual Developments, is in part documented in IIASA Research Reports RR-73-3 and RR-74-3
Epistemic and social scripts in computer-supported collaborative learning
Collaborative learning in computer-supported learning environments typically means that learners work on tasks together, discussing their individual perspectives via text-based media or videoconferencing, and consequently acquire knowledge. Collaborative learning, however, is often sub-optimal with respect to how learners work on the concepts that are supposed to be learned and how learners interact with each other. One possibility to improve collaborative learning environments is to conceptualize epistemic scripts, which specify how learners work on a given task, and social scripts, which structure how learners interact with each other. In this contribution, two studies will be reported that investigated the effects of epistemic and social scripts in a text-based computer-supported learning environment and in a videoconferencing learning environment in order to foster the individual acquisition of knowledge. In each study the factors ‘epistemic script’ and ‘social script’ have been independently varied in a 2×2-factorial design. 182 university students of Educational Science participated in these two studies. Results of both studies show that social scripts can be substantially beneficial with respect to the individual acquisition of knowledge, whereas epistemic scripts apparently do not to lead to the expected effects
User-informed marketing versus standard description to drive demand for evidence-based therapy: A randomized controlled trial.
Direct-to-consumer (DTC) marketing represents a vital strategy to disseminate evidence-based therapies (EBTs). This 3-phase research program, informed by the marketing mix, developed and evaluated user-informed DTC materials for parents concerned about adolescent substance use (SU). Phases 1 and 2 consisted of qualitative interviews (n = 29 parents) and a quantitative survey (n = 411), respectively, to elicit parents’ preferred terms and strategies to disseminate EBT. Building upon prior phases, the current study (Phase 3) developed a user-informed infographic (128 words, 7th-grade level) focused on SU therapy. Parents were randomly assigned to view the user-informed infographic (n = 75) or a standard EBT description (n = 77) from the American Psychological Association (529 words, 12th-grade level). Logistic regressions examined the effect of marketing condition on parent-reported behavioral intentions and actual requests for EBT information, controlling for correlates of parent preferences in Phase 2 (parent education level; adolescent internalizing, externalizing, legal, and SU problems). Counter to hypotheses, condition did not have a main effect on either outcome. However, there was a significant interaction between condition and adolescent SU problems: among parents whose adolescents had SU problems, the user-informed infographic predicted 3.7 times higher odds of requesting EBT information than the standard description. Additionally, parents whose adolescents had legal problems were more likely to request EBT information than parents whose adolescents did not. The infographic was 4 times shorter and written at 5 grade levels lower, thereby providing a highly disseminable alternative. Findings highlight the value of specificity in DTC marketing, while advancing methods to create tailored marketing materials and communicate knowledge about psychological science
- …