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1.
Partnerships and co-operative environmental management are increasing worldwide as is the call for scientific input in the public process of ecosystem management. In Hawaii, private landowners, non-governmental organizations, and state and federal agencies have formed watershed partnerships to conserve and better manage upland forested watersheds. In this paper, findings of an international workshop convened in Hawaii to explore the strengths of approaches used to assess stakeholder values of environmental resources and foster consensus in the public process of ecosystem management are presented. Authors draw upon field experience in projects throughout Hawaii, Southeast Asia, Africa and the US mainland to derive a set of lessons learned that can be applied to Hawaiian and other watershed partnerships in an effort to promote consensus and sustainable ecosystem management. Interdisciplinary science-based models can serve as effective tools to identify areas of potential consensus in the process of ecosystem management. Effective integration of scientific input in co-operative ecosystem management depends on the role of science, the stakeholders and decision-makers involved, and the common language utilized to compare tradeoffs. Trust is essential to consensus building and the integration of scientific input must be transparent and inclusive of public feedback. Consideration of all relevant stakeholders and the actual benefits and costs of management activities to each stakeholder is essential. Perceptions and intuitive responses of people can be as influential as analytical processes in decision-making and must be addressed. Deliberative, dynamic and iterative decision-making processes all influence the level of stakeholder achievement of consensus. In Hawaii, application of lessons learned can promote more informed and democratic decision processes, quality scientific analysis that is relevant, and legitimacy and public acceptance of ecosystem management.  相似文献   
2.
We present a numerical model based on the hydro-morphodynamical coupling to study coastal sandbar migration. In order to improve both nonlinear and dispersive wave processes in relatively shallow water, we developed a finite element model based on the Legendre polynomials and on the Extended Boussinesq model. This model reproduces the propagation of wave trains with a high degree of accuracy on a greater range of depths than the standard Boussinesq models. We also implemented the Total Variation Diminishing schemes to improve the quality of the computed hydrodynamic fields, especially in areas where sharp flow gradients occurred. The coupled morpho-hydrodynamical model is then used to simulate the migration of real sandbars observed at Rousty beach (Mediterranean French coast). For verification the model results are compared with field measurements obtained from a small-scale field campaign carried out over two years at Rousty beach, and the results of this comparison are thoroughly discussed and analyzed.  相似文献   
3.
The study presented here describes a method for defining set-back lines along eroding coasts. The method (a mathematical model) combines the long-term shoreline retreat trend with short-term shoreline erosion (during storms). Simulations are carried out for 2030 and compared with the beach width to determine whether the shoreline is likely to shift onshore. The mathematical model is applied to the Frontignan and Carnon beaches (south of France). Both sites possess hard engineering coastal structures and downdrift erosion on the natural beaches. The set-back lines indicate that beaches with groynes are generally wide enough to resist shoreline retreat, while the downdrift “natural” beaches are not. We discuss the possible utilisation of set-back line estimations.  相似文献   
4.
Experimental trawl surveys were performed in the Gulf of Lions. A multicompartmental approach was used to study the spatial distribution of demersal assemblages and to estimate their associations with two other components of the ecosystem: the benthic macrofauna and substratum type. At the Gulf scale, we found that these components explained 38 and 19% of the total variability of the spatial organization of groundfishes, respectively. Our results showed that groundfish and benthic macrofauna species were primarily distributed along a coast–open sea gradient and secondarily along a longitudinal axis. The longitudinal variability of the spatial organisation of species was maximal in the shelf area, whereas the upper-slope and coastal areas were characterized by strong homogeneity. Although no partitioning could be made based on their spatial distribution, the coastal groundfish assemblages were split into two groups. In the first group, groundfishes were strongly associated with both benthic macrofauna and type of substratum; in the second group, they were strongly independent of these two components. Furthermore, in the Gulf of Lions, the presence of productive zones associated with the Rhône river plume or with shelf-break upwelling seemed to attract some groundfishes. This study illustrates how useful such a multicompartmental approach can be for both fisheries management and community ecology.  相似文献   
5.
Environmental Geochemistry and Health - Metal(loid) contamination of soil, resulting from the mining activities, is a major issue worldwide, due to its negative effects on the environment and...  相似文献   
6.
ABSTRACT: This paper brings together spatially and temporally explicit mechanistic models of hydrodynamic, water quality, and ecological processes with an economic model to examine water management alternatives for California's Sacramento River and Delta ecosystem, a large‐scale watershed. Overallocated water supplies in most years, combined with increasing demand for water for environmental purposes, have created a politically charged atmosphere and a need for quantitative assessment of the implications of policy alternatives. By developing and analyzing a common set of policy scenarios, this integrated framework allows us to consider tradeoffs between agricultural economic factors, water quality, and population dynamics for two at‐risk fish species. We analyze two rather extreme types of policy options; one involves structural modifications to change the flow of water within the watershed but no change in water diversions, while the other reallocates water from agricultural users to fish and wildlife. Results suggest that substantial environmental improvements could be made at a relatively modest cost to farmers (1 to 4 percent reductions in revenues) but that those costs could be significant locally. In addition to tradeoffs between farmers and environmental interests, results suggest that policy makers may need to balance competing environmental objectives.  相似文献   
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Environmental Chemistry Letters -  相似文献   
9.
Theory predicts that individuals at the periphery of a group should be at higher risk than their more central conspecifics since they would be the first to be encountered by an approaching terrestrial predator. As a result, it is expected that peripheral individuals display higher vigilance levels. However, the role of conspecifics in this “edge effect” may have been previously overlooked, and taking into account the possible role of within-group competition is needed. Vigilance behavior in relation to within-group spatial position was studied in impalas (Aepyceros melampus) feeding on standardized patches. We also controlled for food distribution in order to accurately define a “central” as opposed to a “peripheral” position. Our data clearly supported an edge effect, with peripheral individuals spending more time vigilant than their central conspecifics. Data on social interactions suggest that it was easier for a foraging individual to defend its feeding patch with its head lowered, and that more interactions occurred at the center of the group. Together, these results indicate that central foragers may reduce their vigilance rates in response to increased competition. Disentangling how the effects of competition and predation risk contribute to the edge effect requires further investigations.  相似文献   
10.
The objective of this study was to model the trade-offs between ecological and productive performance of a grassland agroecosystem. We developed a dynamic model linking grass dynamics controlled by livestock grazing to stochastic population dynamics of two wader bird species with high conservation value. Bird dynamics were driven by both direct and indirect effects of grazing. Viable control framework was used to predict grazing strategies ensuring production and conservation and to generate the whole trade-off curve between ecological and productive performance. Bird population size was used as an indicator of ecological performance and the total number of grazing days defined productive performance. Model results show that conciliating ecological and productive performance implies a temporal shift in grazing sequences. The best ecological performance was obtained at intermediate levels of productive performance. Without grazing or with too low a grazing intensity, it was not possible to maintain any of the bird populations due to the indirect effects of grazing on habitat quality. However, too high a level of grazing implied fast population decline for both populations due to direct negative effects of grazing on nest survival. Field data on current grazing regimes and grass height showed a low proportion of suitable fields in our case study area. This result indicates an antagonism between direct and indirect effects of grazing on wader birds, implying the need of very specific management of grassland. Our results illustrate the fact that European grasslands are anthropic habitats which are highly dependent on human activity. In such habitats, trade-off curves are not expected to be strictly decreasing or increasing.  相似文献   
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