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11.
We examined the principal effects of different information network topologies for local adaptive management of natural resources.
We used computerized agents with adaptive decision algorithms with the following three fundamental constraints: (1) Complete
understanding of the processes maintaining the natural resource can never be achieved, (2) agents can only learn by experimentation
and information sharing, and (3) memory is limited. The agents were given the task to manage a system that had two states:
one that provided high utility returns (desired) and one that provided low returns (undesired). In addition, the threshold
between the states was close to the optimal return of the desired state. We found that networks of low to moderate link densities
significantly increased the resilience of the utility returns. Networks of high link densities contributed to highly synchronized
behavior among the agents, which caused occasional large-scale ecological crises between periods of stable and high utility
returns. A constructed network involving a small set of experimenting agents was capable of combining high utility returns
with high resilience, conforming to theories underlying the concept of adaptive comanagement. We conclude that (1) the ability
to manage for resilience (i.e., to stay clear of the threshold leading to the undesired state as well as the ability to re-enter
the desired state following a collapse) resides in the network structure and (2) in a coupled social–ecological system, the
systemwide state transition occurs not because the ecological system flips into the undesired state, but because managers
lose their capacity to reorganize back to the desired state.
An erratum to this article can be found at . 相似文献
12.
Theoretical arguments for using a term structure of social discount rates (SDR) that declines with the time horizon have influenced government guidelines in the US and Europe. The certainty equivalent discount rate that often underpins this guidance embodies uncertainty in the primitives of the SDR, such as growth. For distant time horizons the probability distributions of these primitives are ambiguous and the certainty equivalent itself is uncertain. Yet, if a limited set of characteristics of the unknown probability distributions can be agreed upon, ‘sharp’ upper and lower bounds can be defined for the certainty-equivalent SDR. Unfortunately, even with considerable agreement on these features, these bounds are widely spread for horizons beyond 75 years. So while estimates of the present value of intergenerational impacts, including the social cost of carbon, can be bounded in the presence of this ambiguity, they typically remain so imprecise as to provide little practical guidance. 相似文献
13.
CARLOS CARROLL JOHN A. VUCETICH MICHAEL P. NELSON DANIEL J. ROHLF MICHAEL K. PHILLIPS 《Conservation biology》2010,24(2):395-403
Abstract: The U.S. Endangered Species Act (ESA) defines an endangered species as one “at risk of extinction throughout all or a significant portion of its range.” The prevailing interpretation of this phrase, which focuses exclusively on the overall viability of listed species without regard to their geographic distribution, has led to development of listing and recovery criteria with fundamental conceptual, legal, and practical shortcomings. The ESA's concept of endangerment is broader than the biological concept of extinction risk in that the “esthetic, ecological, educational, historical, recreational, and scientific” values provided by species are not necessarily furthered by a species mere existence, but rather by a species presence across much of its former range. The concept of “significant portion of range” thus implies an additional geographic component to recovery that may enhance viability, but also offers independent benefits that Congress intended the act to achieve. Although the ESA differs from other major endangered‐species protection laws because it acknowledges the distinct contribution of geography to recovery, it resembles the “representation, resiliency, and redundancy” conservation‐planning framework commonly referenced in recovery plans. To address representation, listing and recovery standards should consider not only what proportion of its former range a species inhabits, but the types of habitats a species occupies and the ecological role it plays there. Recovery planning for formerly widely distributed species (e.g., the gray wolf [Canis lupus]) exemplifies how the geographic component implicit in the ESA's definition of endangerment should be considered in determining recovery goals through identification of ecologically significant types or niche variation within the extent of listed species, subspecies, or “distinct population segments.” By linking listing and recovery standards to niche and ecosystem concepts, the concept of ecologically significant type offers a scientific framework that promotes more coherent dialogue concerning the societal decisions surrounding recovery of endangered species. 相似文献
14.
Settlement decisions in blue tits: difference in the use of social information according to age and individual success 总被引:1,自引:0,他引:1
Dispersers are expected to assess breeding habitat quality before settlement. Although cues reflecting habitat quality are
well studied, social cues have not been as well evaluated. In this paper, we studied breeding habitat selection during 3 years
in a natural population of blue tits, Cyanistes caeruleus, breeding in nest-boxes. Our aim was to investigate if this species used conspecific density and/or reproductive success
of con- and heterospecifics (i.e., social cues) in settlement decisions. The patterns observed were consistent with the idea
that juveniles, when dispersing from their natal patches, did not react to any of the cues that we tested. In contrast, breeders
that dispersed seemed to respond to both conspecific mean patch reproductive success (PRS) and breeding density of the settlement
patch in the year of dispersal, their response differing according to their own reproductive success. Indeed, failed breeders
moved to areas with high PRS and low density relative to source patches, while successful breeders behaved the opposite. The
comparison between juveniles and adults might be modulated by the limited time available to juveniles to gather information
on PRS and density at the end of the dispersing year. Adults lacking these time constraints, however, seemed to rely on these
conspecific cues although limited by their own quality. Additionally, breeders were more likely to be immigrants in patches
with relatively low breeding success and density the previous year, suggesting that settlement is influenced by multiple cues,
which may reveal information on different aspects of habitat and be available at different moments. Collectively, our results
support the importance of social cues for blue tits’ settlement. 相似文献
15.
Mikael Hildén 《Journal of Cleaner Production》2011,19(16):1798-1811
All member states of the EU have had to develop climate strategies following the commitment to the UN Framework Convention on Climate Change and the Kyoto Protocol. The evolution of the strategies provides insights into the learning that takes place at the level of policy development and offers material for analysing how ex ante and ex post evaluations have contributed to this learning. In the analysis, Finland is used as a case demonstrating different levels and types of learning, from deeper reframing to political learning. The results show that the full potential of the evaluations has not been utilised, partly because they have been constrained by their mandate. Greater openness and transparency in the policy processes would create favourable conditions for independent evaluations that could provide additional input to the policy processes. This would support social and reflexive learning and allow for greater adaptability. 相似文献
16.
Kristie Byrum 《Environmental Communication: A Journal of Nature and Culture》2019,13(2):209-221
This study addresses the use of message carriers to convey corporate social responsibility information to promote eco-purchasing involvement. The work tests various media formats transmitted via social media. The effects of corporate vs. peer communication in a corporate social responsibility campaign in stimulating self-reported eco-purchasing involvement are indicated. The research varies communication dimensions of a fictional corporate social responsibility campaign sent through social media. Multiple media formats; new release; article; and advertisement were tested, as was the inclusion of social media persuasive sentiment. The analysis of source/format combinations and source/format/sentiment combinations found statistically significant differences for consumer-to-consumer communication in stimulating eco-purchasing involvement in certain circumstances. This research suggests an emerging role for the consumer communicator as a content co-creator and validates the effective use of articles and news releases instead of advertising on social media, yielding managerial and scholarly implications. 相似文献
17.
Biomass is one of the renewable energy sources on which policy makers are greatly dependent on since it is a flexible feedstock capable of conversion into electricity, transport liquid fuels and heat by chemical and biological processes on demand. Though numerous publications have examined the relationship of economic growth with renewable energy and other parameters, biomass energy has never been included in these studies. Then, this study examines the causal relationship within a multivariate panel cointegration/error correction framework which combines the cross-section and time series data while allowing for heterogeneity across different provinces. After employing panel data regression model ranging from 2003 through 2012 to examine the relationships of biofuels production with sustainable development in China, the paper concludes that the development of biofuel energy production integrated with the consideration of the improvement of income per capita, and the attraction of more capital investment, does make a significant contribution to economic growth. However, some negative side effects including the increase of greenhouse emissions and the decrease of marginal land still coexist with the economic development. Of course, the importance of these findings lies on their implications and their adoption on strategic policies. 相似文献
18.
The farmer as a landscape steward: Comparing local understandings of landscape stewardship,landscape values,and land management actions 总被引:1,自引:0,他引:1
Christopher M. Raymond Claudia Bieling Nora Fagerholm Berta Martin-Lopez Tobias Plieninger 《Ambio》2016,45(2):173-184
We develop a landscape stewardship classification which distinguishes between farmers’ understanding of landscape stewardship, their landscape values, and land management actions. Forty semi-structured interviews were conducted with small-holder (<5 acres), medium-holders (5–100 acres), and large-holders (>100 acres) in South-West Devon, UK. Thematic analysis revealed four types of stewardship understandings: (1) an environmental frame which emphasized the farmers’ role in conserving or restoring wildlife; (2) a primary production frame which emphasized the farmers’ role in taking care of primary production assets; (3) a holistic frame focusing on farmers’ role as a conservationist, primary producer, and manager of a range of landscape values, and; (4) an instrumental frame focusing on the financial benefits associated with compliance with agri-environmental schemes. We compare the landscape values and land management actions that emerged across stewardship types, and discuss the global implications of the landscape stewardship classification for the engagement of farmers in landscape management. 相似文献
19.
Rebecca Pearse 《环境政策》2016,25(6):1079-1101
Reporting on the origins and directions of social movement strategy on climate and energy issues in the last decade, the shifts in ‘climate movement’ practice are discussed using a neo-Polanyian account of the political economy of climate change combined with sociological analysis of the strategic decisions campaigners reported making. Since the mid-2000s, Australia’s climate movement has been engaged in three concurrent arenas of political contestation. The longest-standing arena of movement activity has been negotiations over climate policy. More recently, activists and communities are engaged in a struggle over the expansion of fossil fuels. A third contest has been waged over the present and future position of renewable energy technologies in Australia’s electricity market. In the wake of climate policy failure, energy campaigns have been deepened, and it seems that a broader energy justice agenda is being forged. New strategic dilemmas are visible in the field. 相似文献
20.
In the United States, few constituents know and understand climate policy, prioritize it as a political topic, or let their voting decisions depend on it. In these conditions, representatives would not be expected to pay heed to constituents’ climate concern in their voting decisions. Still, even after controlling for the presence of interest groups, campaign finance, and legislators’ party affiliation and ideology, there is a consistent link between public opinion and votes on cap-and-trade legislation in the House (and to a lesser degree in the Senate). The same is true when public opinion is simulated based on pre-vote district characteristics. Explanations for these findings are discussed. 相似文献