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41.
Testing Hypotheses for the Success of Different Conservation Strategies   总被引:4,自引:0,他引:4  
Abstract:  Evaluations of the success of different conservation strategies are still in their infancy. We used four different measures of project outcomes—ecological, economic, attitudinal, and behavioral—to test hypotheses derived from the assumptions that underlie contemporary conservation solutions. Our hypotheses concerned the effects of natural resource utilization, market integration, decentralization, and community homogeneity on project success. We reviewed the conservation and development literature and used a specific protocol to extract and code the information in a sample of papers. Although our results are by no means conclusive and suffer from the paucity of high-quality data and independent monitoring (80% of the original sample of 124 projects provided inadequate information for use in this study), they show that permitted use of natural resources, market access, and greater community involvement in the conservation project are all important factors for a successful outcome. Without better monitoring schemes in place, it is still impossible to provide a systematic evaluation of how different strategies are best suited to different conservation challenges.  相似文献   
42.
The consideration of information on social values in conjunction with biological data is critical for achieving both socially acceptable and scientifically defensible conservation planning outcomes. However, the influence of social values on spatial conservation priorities has received limited attention and is poorly understood. We present an approach that incorporates quantitative data on social values for conservation and social preferences for development into spatial conservation planning. We undertook a public participation GIS survey to spatially represent social values and development preferences and used species distribution models for 7 threatened fauna species to represent biological values. These spatially explicit data were simultaneously included in the conservation planning software Zonation to examine how conservation priorities changed with the inclusion of social data. Integrating spatially explicit information about social values and development preferences with biological data produced prioritizations that differed spatially from the solution based on only biological data. However, the integrated solutions protected a similar proportion of the species’ distributions, indicating that Zonation effectively combined the biological and social data to produce socially feasible conservation solutions of approximately equivalent biological value. We were able to identify areas of the landscape where synergies and conflicts between different value sets are likely to occur. Identification of these synergies and conflicts will allow decision makers to target communication strategies to specific areas and ensure effective community engagement and positive conservation outcomes. Integración de Valores Biológicos y Sociales al Priorizar Sitios para la Conservación de la Biodiversidad  相似文献   
43.
The effects of fisheries on marine ecosystems, and their capacity to drive shifts in ecosystem states, have been widely documented. Less well appreciated is that some commercially valuable species respond positively to fishing‐induced ecosystem change and can become important fisheries resources in modified ecosystems. Thus, the ecological effects of one fishery can unintentionally increase the abundance and productivity of other fished species (i.e., cultivate). We reviewed examples of this effect in the peer‐reviewed literature. We found 2 underlying ecosystem drivers of the effect: trophic release of prey species when predators are overfished and habitat change. Key ecological, social, and economic conditions required for one fishery to unintentionally cultivate another include strong top–down control of prey by predators, the value of the new fishery, and the capacity of fishers to adapt to a new fishery. These unintended cultivation effects imply strong trade‐offs between short‐term fishery success and conservation efforts to restore ecosystems toward baseline conditions because goals for fisheries and conservation may be incompatible. Conflicts are likely to be exacerbated if fisheries baselines shift relative to conservation baselines and there is investment in the new fishery. However, in the long‐term, restoration toward ecosystem baselines may often benefit both fishery and conservation goals. Unintended cultivation can be identified and predicted using a combination of time‐series data, dietary studies, models of food webs, and socioeconomic data. Identifying unintended cultivation is necessary for management to set compatible goals for fisheries and conservation. Cultivo Accidental, Líneas de Base Cambiantes y el Conflicto entre los Objetivos para las Pesquerías y la Conservación  相似文献   
44.
Space-time data are ubiquitous in the environmental sciences. Often, as is the case with atmo- spheric and oceanographic processes, these data contain many different scales of spatial and temporal variability. Such data are often non-stationary in space and time and may involve many observation/prediction locations. These factors can limit the effectiveness of traditional space- time statistical models and methods. In this article, we propose the use of hierarchical space-time models to achieve more flexible models and methods for the analysis of environmental data distributed in space and time. The first stage of the hierarchical model specifies a measurement- error process for the observational data in terms of some 'state' process. The second stage allows for site-specific time series models for this state variable. This stage includes large-scale (e.g. seasonal) variability plus a space-time dynamic process for the anomalies'. Much of our interest is with this anomaly proc ess. In the third stage, the parameters of these time series models, which are distributed in space, are themselves given a joint distribution with spatial dependence (Markov random fields). The Bayesian formulation is completed in the last two stages by speci- fying priors on parameters. We implement the model in a Markov chain Monte Carlo framework and apply it to an atmospheric data set of monthly maximum temperature.  相似文献   
45.
The Complex Links between Governance and Biodiversity   总被引:1,自引:0,他引:1  
Abstract:  We argue that two problems weaken the claims of those who link corruption and the exploitation of natural resources. The first is conceptual and the second is methodological. Studies that use national-level indicators of corruption fail to note that corruption comes in many forms, at multiple levels, that may affect resource use quite differently: negatively, positively, or not at all. Without a clear causal model of the mechanism by which corruption affects resources, one should treat with caution any estimated relationship between corruption and the state of natural resources. Simple, atheoretical models linking corruption measures and natural resource use typically do not account for other important control variables pivotal to the relationship between humans and natural resources. By way of illustration of these two general concerns, we used statistical methods to demonstrate that the findings of a recent, well-known study that posits a link between corruption and decreases in forests and elephants are not robust to simple conceptual and methodological refinements. In particular, once we controlled for a few plausible anthropogenic and biophysical conditioning factors, estimated the effects in changes rather than levels so as not to confound cross-sectional and longitudinal variation, and incorporated additional observations from the same data sources, corruption levels no longer had any explanatory power.  相似文献   
46.
Gaps and Mismatches between Global Conservation Priorities and Spending   总被引:1,自引:0,他引:1  
Abstract:  Several international conservation organizations have recently produced global priority maps to guide conservation activities and spending in their own and other conservation organizations. Surprisingly, it is not possible to directly evaluate the relationship between priorities and spending within a given organization because none of the organizations with global priority models tracks how they spend their money relative to their priorities. We were able, however, to evaluate the spending patterns of five other large biodiversity conservation organizations without their own published global priority models and investigate the potential influence of priority models on this spending. On average, countries with priority areas received greater conservation investment; global prioritization systems, however, explained between only 2 and 32% of the US$1.5 billion spent in 2002, depending on whether the United States was removed from analyses and whether conservation spending was adjusted by the per capita gross domestic product within each country. We also found little overlap in the spending patterns of the five conservation organizations evaluated, suggesting that informal coordination or segregation of effort may be occurring. Our results also highlight a number of potential gaps and mismatches in how limited conservation funds are spent and provide the first audit of global conservation spending patterns. More explicit presentation of conservation priorities by organizations currently without priority models and better tracking of spending by those with published priorities are clearly needed to help make future conservation activities as efficient as possible.  相似文献   
47.
Postfire Management on Forested Public Lands of the Western United States   总被引:1,自引:0,他引:1  
Abstract:  Forest ecosystems in the western United States evolved over many millennia in response to disturbances such as wildfires. Land use and management practices have altered these ecosystems, however, including fire regimes in some areas. Forest ecosystems are especially vulnerable to postfire management practices because such practices may influence forest dynamics and aquatic systems for decades to centuries. Thus, there is an increasing need to evaluate the effect of postfire treatments from the perspective of ecosystem recovery. We examined, via the published literature and our collective experience, the ecological effects of some common postfire treatments. Based on this examination, promising postfire restoration measures include retention of large trees, rehabilitation of firelines and roads, and, in some cases, planting of native species. The following practices are generally inconsistent with efforts to restore ecosystem functions after fire: seeding exotic species, livestock grazing, placement of physical structures in and near stream channels, ground-based postfire logging, removal of large trees, and road construction. Practices that adversely affect soil integrity, persistence or recovery of native species, riparian functions, or water quality generally impede ecological recovery after fire. Although research provides a basis for evaluating the efficacy of postfire treatments, there is a continuing need to increase our understanding of the effects of such treatments within the context of societal and ecological goals for forested public lands of the western United States.  相似文献   
48.
Abstract: Ocean‐going vessels pose a threat to large whales worldwide and are responsible for the majority of reported deaths diagnosed among endangered North Atlantic right whales (Eubalaena glacialis). Various conservation policies have been implemented to reduce vessel‐strike mortality in this species. The International Maritime Organization adopted the Roseway Basin Area to be avoided on the Scotian Shelf as a voluntary conservation initiative to reduce the risk of lethal vessel strikes to right whales. We initiated the Vessel Avoidance & Conservation Area Transit Experiment to evaluate the efficacy of this initiative because the effectiveness of the avoidance scheme in reducing risk without the imposition of vessel‐speed restrictions depends entirely on vessel‐operator compliance. Using a network of automatic identification system receivers, we collected static, dynamic, and voyage‐related vessel data in near real time from the Roseway Basin region for 12 months before and 6 months after the implementation of the area to be avoided. Using pre‐ and post‐implementation vessel navigation and speed data, along with right whale sightings per unit effort data, all resolved at 3′N latitude by 3′W longitude, we estimated the post‐implementation change in risk of lethal vessel strikes. Estimates of vessel‐operator voluntary compliance ranged from 57% to 87% and stabilized at 71% within the first 5 months of implementation. Our estimates showed an 82% reduction in the risk of lethal vessel strikes to right whales due to vessel‐operator compliance. We conclude that the high level of compliance achieved with this voluntary conservation initiative occurred because the area to be avoided was adopted by the International Maritime Organization. Our results demonstrate that international shipping interests are able and willing to voluntarily alter course to protect endangered whales.  相似文献   
49.
Our goal was to determine whether it is more cost‐effective to control feral cat abundance with trap‐neuter‐release programs or trap and euthanize programs. Using STELLA 7, systems modeling software, we modeled changes over 30 years in abundance of cats in a feral colony in response to each management method and the costs and benefits associated with each method . We included costs associated with providing food, veterinary care, and microchips to the colony cats and the cost of euthanasia, wages, and trapping equipment in the model. Due to a lack of data on predation rates and disease transmission by feral cats the only benefits incorporated into the analyses were reduced predation on Wedge‐tailed Shearwaters (Puffinus pacificus). When no additional domestic cats were abandoned by owners and the trap and euthanize program removed 30,000 cats in the first year, the colony was extirpated in at least 75% of model simulations within the second year. It took 30 years for trap‐neuter‐release to extirpate the colony. When the cat population was supplemented with 10% of the initial population size per year, the colony returned to carrying capacity within 6 years and the trap and euthanize program had to be repeated, whereas trap‐neuter‐release never reduced the number of cats to near zero within the 30‐year time frame of the model. The abandonment of domestic cats reduced the cost effectiveness of both trap‐neuter‐release and trap and euthanize. Trap‐neuter‐release was approximately twice as expensive to implement as a trap and euthanize program. Results of sensitivity analyses suggested trap‐neuter‐release programs that employ volunteers are still less cost‐effective than trap and euthanize programs that employ paid professionals and that trap‐neuter‐release was only effective when the total number of colony cats in an area was below 1000. Reducing the rate of abandonment of domestic cats appears to be a more effective solution for reducing the abundance of feral cats. Costos y Beneficios de Captura‐Esterilización‐Liberación y Eutanasia para la Remoción de Gatos Urbanos en Oahu, Hawaii  相似文献   
50.
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