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1.
The expertise and knowledge of veterinary advisors on improving animal health management is key towards a better herd health status. However, veterinary advisors are not always aware of the goals and priorities of dairy farmers. To dairy farmers animal health is only one aspect of farm management and resources may be allocated to other more preferred areas. Veterinary advisors may experience this as non-compliant with their advice. To explore the preferences of European Union (EU) organic dairy farmers for improved animal health management relative to other farm management areas an adaptive conjoint analysis (ACA) was performed. A total of 215 farmers participated originating from organic dairy farms in France (n=70), Germany (n=60), Spain (n=28) and Sweden (n=57). The management areas udder health and claw health represented animal health management whereas barn, calf and pasture management represented potential conflicting management areas. Results indicate that EU organic dairy farmers differ in their preferences for improved animal health management within the farming system. In general, improved calf management was the most preferred area and improved claw health management was found to be least preferred, the remaining areas were of intermediate interest. Cluster analyses on claw health measures and udder health measures resulted in respectively seven and nine distinct preference profiles. The results indicate a high degree of variation in farmers’ preference, which cannot be explained by the typical herd characteristics. With the individual preferences revealed by ACA, a veterinary advisor can now find out whether his intended advice is directed at a favourable or unfavourable management area of the farmer. If the latter is the case the veterinarian should first create awareness of the problem to the farmer. Insights in individual farmers preferences will allow veterinary advisors to better understand why farmers were incompliant with their advice and improve their advice by showing, for example, the potential benefits of their advice.  相似文献   

2.
This study makes an explorative overview on two main research topics in economics of wildlife management: determination of population sizes and policy design. The results point out a large and comprehensive research on each of these issues, in particular on the estimation of values and costs of wildlife, where this information is necessary for the determination of population size. A drawback is that most of the value and cost studies do not relate their estimates to wildlife population size, which limits their usability for efficient policy design. Most valuation studies estimate the recreational value of hunting, which can range between 13 and 545 USD/hunting day (in 2013 prices), and two thirds of the included studies have been applied to wildlife in the USA. A majority of the studies on the costs of wildlife management calculate losses from carnivore predation on livestock and ungulate damage to crops, while a few consider dispersal of diseases and the cost of traffic collisions. Unlike valuation studies, several of the cost estimates apply to wildlife in developing and emerging economies. With respect to policy design the literature, which is mainly theoretical, suggests economic incentives for conflict resolution, where those suffering from wildlife damages are compensated for their losses. However, there are some issues which remain to be addressed by economists: relating costs and benefits to wildlife populations; estimating values and costs of wildlife in developing countries; evaluating wildlife policies in practice; addressing implications of uncertainty in population size, costs, and benefits for policy design; and estimating transaction costs for implementation and enforcement of wildlife policies.  相似文献   

3.
Lake Pátzcuaro, a97.5 km2 lake in central México, has animportant artisanal multi-species fishery thatis currently overexploited. Twelve fishes andone amphibian are important in the fishery,which is conducted largely from small woodenboats using seines, gill nets, and thetraditional butterfly net. Fishery yields fromthe lake peaked in 1988, but have declined tonear record lows since then. We propose amanagement plan to restore the fishery. Keycomponents of the plan include: 1) licensingand restricting the number of fishermen; 2)continuing a recent ban on seines andimplementing limits on the number and meshsizes of gill nets to allow fish to complete atleast one spawning before they are vulnerableto harvest; 3) establishing a closed season andareas closed to fishing to protect spawningfish; 4) increased education for fishermen inbasic skills, fishing technology, andalternative jobs; 5) continued monitoring andresearch to assess trends in the fishery and todevelop culture techniques to help restore fishpopulations; and 6) compliance and enforcementmechanisms to make the plan effective,including perhaps establishment of propertyrights for particular areas of the lake forspecific groups of fishermen and more generallyan equitable assignment of lake ecosystem usesbetween fishery and non-fishery users. Werecommend the plan be implemented in anadaptive fashion with provisions for adjustingregulations as conditions warrant. If at leastsome elements of this plan are not adopted thenthe Lake Pátzcuaro fishery is likely tocollapse.  相似文献   

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Management of ocean pollution must be based on the best available scientific information, with adequate consideration of economic, social, and political realities. Unfortunately, the best available scientific information about pollution effects on fisheries is often fragmentary, and often conjectural; therefore a primary concern of management should be a critical review and assessment of available factual information about effects of pollutants on fish and shellfish stocks. A major problem in any such review and assessment is the separation of pollutant effects from the effects of all the other environmental factors that influence survival and well-being of marine animals. Data from long-term monitoring of resource abundance, and from monitoring of all determinant environmental variables, will be required for analyses that lead to resolution of the problem. Information must also be acquired about fluxes of contaminants through resource-related ecosystems, and about contaminant effects on resource species as demonstrated in field and laboratory experiments. Other possible management activities include: (1) encouragement of continued efforts to document clearly the localized and general effects of pollution on living resources; (2) continued pressure to identify and use reliable biological indicators of environmental degradation (indicators of choice at present are: unusually high levels of genetic and other anomalies in the earliest life history stages; presence of pollution-associated disease signs, particularly fin erosion and ulcers, in fish; and biochemical/physiological changes); and (3) major efforts to reduce inputs of pollutants clearly demonstrated to be harmful to living resources, from point sources as well as ocean dumping. Such pollution management activities, based on continuous efforts in stock assessment, environmental assessment, and experimental studies, can help to insure that rational decisions will be made about uses and abuses of coastal/estuarine waters.  相似文献   

6.
Biodiversity is globally recognised as a cornerstone of healthy ecosystems, and biodiversity conservation is increasingly becoming one of the important aims of environmental management. Evaluating the trade-offs of alternative management strategies requires quantitative estimates of the costs and benefits of their outcomes, including the value of biodiversity lost or preserved. This paper takes a decision-analytic standpoint, and reviews and discusses the alternative aspects of biodiversity valuation by dividing them into three categories: socio-cultural, economic, and ecological indicator approaches. We discuss the interplay between these three perspectives and suggest integrating them into an ecosystem-based management (EBM) framework, which permits us to acknowledge ecological systems as a rich mixture of interactive elements along with their social and economic aspects. In this holistic framework, socio-cultural preferences can serve as a tool to identify the ecosystem services most relevant to society, whereas monetary valuation offers more globally comparative and understandable values. Biodiversity indicators provide clear quantitative measures and information about the role of biodiversity in the functioning and health of ecosystems. In the multi-objective EBM approach proposed in the paper, biodiversity indicators serve to define threshold values (i.e., the minimum level required to maintain a healthy environment). An appropriate set of decision-making criteria and the best method for conducting the decision analysis depend on the context and the management problem in question. Therefore, we propose a sequence of steps to follow when quantitatively evaluating environmental management against biodiversity.  相似文献   

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Background  

Collecting and managing information is a challenging task in a genome-wide profiling research project. Most databases and online computational tools require a direct human involvement. Information and computational results are presented in various multimedia formats (e.g., text, image, PDF, word files, etc.), many of which cannot be automatically processed by computers in biologically meaningful ways. In addition, the quality of computational results is far from perfect and requires nontrivial manual examination. The timely selection, integration and interpretation of heterogeneous biological information still heavily rely on the sensibility of biologists. Biologists often feel overwhelmed by the huge amount of and the great diversity of distributed heterogeneous biological information.  相似文献   

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Management recommendations that target urban invaders should consider environmental and socio-economic aspects peculiar to the urban landscape. Urbanization often leads to the fragmentation of the invaded landscape into subunits inaccessible to managers (restricted access) or for which detailed information is lacking. Using models to explore impact of these limitations on management success provides a useful approach to propose effective countermeasures. Here we deploy a spatially explicit age-structured model applied to a pond network to investigate how restricted access and lack of detailed information may affect management of three invasive anuran species across a peri-urban landscape. The target species, the guttural toad Sclerophrys gutturalis, the African clawed frog Xenopus laevis and the painted reed frog Hyperolius marmoratus, belong to different ecotypes (terrestrial, aquatic and arboreal, respectively) and have different life history traits. We show that restricted property access significantly constrains management success in two of the three species (the guttural toad and the painted reed frog), while lack of detailed information around the invaded landscape impedes successful management in only one species (the guttural toad). The species-dependent response we detected is due to contrasting demographic and spatial invasion dynamics linked to the different anuran ecotypes. Our work highlights the necessity to adopt a context-dependent approach when proposing management recommendations in urban environment.  相似文献   

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Background, aim, and scope  

The management of municipal solid waste and the associated environmental impacts are subject of growing attention in industrialized countries. European Union has recently strongly emphasized the role of LCA in its waste and resource strategies. The development of sustainable solid waste management systems applying a life cycle perspective requires readily understandable tools for modeling the life cycle impacts of waste management systems. The aim of the paper is to demonstrate the structure, functionalities, and LCA modeling capabilities of the PC-based life cycle-oriented waste management model EASEWASTE, developed at the Technical University of Denmark specifically to meet the needs of the waste system developer with the objective to evaluate the environmental performance of the various elements of existing or proposed solid waste management systems.  相似文献   

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Mathematical modelling may serve as a rational and powerful tool in the management of complex ecosystems. However, ecosystem models are drastic simplifications of the real world. As a rule they are based on a rather incomplete and scattered knowledge of the system in question. Furthermore, ecological systems and in particular marine systems are characterised by a high degree of complexity, spatial and functional heterogeneity, nonlinearity, complex behavioural features such as adptation and self-organisation, and a considerable stochastic element. Nevertheless, if management is to be based on predictions from mathematical models — and it has to be based on some kind of model in at least a broad sense — we need an estimate of prediction accuracy in terms of the management variables and constraints. One possible approach to model uncertainty is a probabilistic interpretation of model predictions, generated by use of Monte-Carlo techniques. Fuzzy data sets and ranges are used. The resulting model response allows the derivation of measures for model credibility. Probability distributions can be computed for certain system states under (un)certain input conditions, representing the effects of insufficient data and structural uncertainty on model-based predictions. Such analysis indicates that prediction uncertainty increases, not only with the uncertainty in the data, but also with increasing distance from the empirical conditions, and with time. Present ecoystem models can be a tool for qualitative discrimination between different management alternatives, rather than a credible means for detailed quantitative predictions of system response to a wide range of input conditions.  相似文献   

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Forest management modified the original structure of most European forests, and in the most extreme cases, genuinely natural and semi-natural forests were turned into plantations through clear felling and replanting, often using non-native species. We compared the bird community structure of native oak woods of northern Italy with that of their anthropogenic counter-parts: black locust and sweet chestnut woods. The three stand types were compared in terms of vegetation structure, bird species richness, diversity and abundance of foraging guilds. We analysed both the overwintering and the breeding community, to assess whether management had specific seasonal effects on bird diversity. Forestry-imposed disturbances affected bird diversity more consistently in winter than in breeding time: bird species richness and diversity were significantly greater in oak and chestnut stands, which were the preferred habitat for bark foragers and foliage gleaners. In the breeding period, bird diversity of black locust woodlands increased, and inter-stand differences were not significant. At this time of year, understorey gleaners were more abundant in black locust stands (where shrubs were denser). In winter, species richness, diversity and the abundance of several guilds were positively correlated with stand age, whereas in the breeding period canopy gleaners preferred younger woodlots. Despite the lack of inter-stand differences in breeding bird diversity, young-managed woods benefited generalist birds that need no particular conservation efforts. Conversely, priority species for forest conservation such as specialised bark foragers positively selected native and mature stands throughout the year. We suggest that detailed year-round studies on diversity and community composition could sharpen the precision with which it is possible to prescribe conservation measures in forested areas.  相似文献   

17.
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18.
How to account for habitat suitability in weed management programmes?   总被引:1,自引:0,他引:1  
Designing efficient management strategies for already established invasive alien species is challenging. Here, we ask whether environmental suitability, as predicted by species distribution models, is a useful basis of cost-effective spatial prioritization in large-scale surveillance and eradication programmes. We do so by means of spatially and temporarily explicit simulations of the spread of a case study species (Ambrosia artemisiifolia L.) in Austria and southern Germany under different management regimes. We ran these simulations on a contiguous grid of the study area with each grid cell (~35 km²) characterized by a habitat suitability value derived from the predictions of a species distribution model. The management regimes differed in terms of (a) a minimum habitat suitability rank p (suitability threshold) used to separate cells for surveillance from those which are not controlled; and (b) the strategy for selecting cells for annual campaigns from the pool defined by p. According to the results (i.e., number of cells infested in 2050 as well as infested on average per year) the most efficient way to base surveillance on suitability is to define the temporal sequence of management according to the grid cells’ suitability ranks. Management success declines sharply when the suitability threshold is set too high, but only moderately when it is set too low. We conclude that accounting for environmental suitability is important for large-scale management programmes of invasive alien species and that species distribution models are hence useful tools for designing such programmes.  相似文献   

19.

Purpose

In Portugal, the management of end-of-life vehicles (ELV) is set out in targets of the European Union policy for the year 2015, including 85 % recycling, 95 % recovery, and maximum of 5 % landfilling. These goals will be attained only through more efficient technologies for waste separation and recycling of shredder residues or higher rates of dismantling components. Focusing on this last alternative, a field experiment was carried out. There is potential for additional recycling/recovery of 10 %.

Methods

Three scenarios were proposed for the management of ELV wastes: (1) scenario 1 corresponds to the baseline and refers to the current management, i.e., the 10 % of ELV wastes are shredded whereby some ferrous and non-ferrous metals are recovered and the remaining fraction, called automotive shredder residues (ASR), is landfilled, (2) scenario 2 wherein the ASR fraction is incinerated with energy recovery, and (3) scenario 3 includes the additional dismantling of components for recycling and for energy recovery through solid recovered fuel, to be used as a fuel substitute in the cement industry. The environmental performance of these scenarios was quantified by using the life cycle assessment methodology. Five impact categories were assessed: abiotic resource depletion, climate change, photochemical oxidant creation, acidification, and eutrophication.

Results and discussion

Compared to the other scenarios, in scenario 1 no benefits for the impact categories of climate change and eutrophication were observed. Scenario 2 has environmental credits due to the recycling of ferrous and non-ferrous metals and benefits from energy recovery. However, this scenario has a significant impact on climate change due to emissions from thermal oxidation of polymeric materials present in the ASR fraction. A net environmental performance upgrading seems to be ensured by scenario 3, mainly due to replacing fossil fuel by solid recovered fuel.

Conclusions

The proposed additional dismantling of ELV (scenario 3) not only brings environmental benefits but also meets the European recovery and recycling targets. The associated increase of dismantling costs can be compensated by the additional recycling material revenues as well as social benefits by a rise in employment.  相似文献   

20.
Rainfall is a strong driver of quail populations on southwestern rangelands and can account for a large portion (~70–95%) of the variability in regional quail production and abundance. Landowners have attempted to moderate these boom-and-bust fluctuations via management; however, presently it is unknown whether management can increase or stabilize quail populations in semiarid environments or whether rainfall remains as influential at small spatial extents. Our objectives were to evaluate the efficacy of management at mitigating the effects of rainfall on northern bobwhite (Colinus virginianus) populations on semiarid rangelands and to quantify the influence of rainfall on bobwhite density at smaller spatial extents. We conducted a study to evaluate these objectives during 2014–2020 in the Rio Grande Plains (n = 11 sites; 1,100‒6,500 ha) and Rolling Plains (n = 4 sites; 1,900‒4,000 ha) of Texas, USA. We estimated bobwhite density during late autumn (Dec‒Jan) on all sites using helicopter surveys within a distance-sampling framework. We also obtained site-level seasonal rainfall (Apr‒Aug) and quantified management intensity via landowner surveys and a scoring rubric to categorize sites into 3 classes (low, medium, and high management intensity). Bobwhite populations during this study experienced a boom-bust cycle in both the Rio Grande Plains and Rolling Plains, with mean bobwhite density fluctuating considerably (0.57‒2.96 bobwhites/ha and 0.02‒2.88 bobwhites/ha, respectively). In the Rio Grande Plains, mean bobwhite density significantly increased from low to high management intensity in 2015 (1.12 ± 0.17 bobwhites/ha vs. 2.87 ± 0.39 bobwhites/ha, respectively), 2016 (1.06 ± 0.20 bobwhites/ha vs. 2.96 ± 0.36 bobwhites/ha, respectively), 2017 (0.73 ± 0.16 bobwhites/ha vs. 1.91 ± 0.32 bobwhites/ha, respectively), and 2019 (0.42 ± 0.14 bobwhites/ha vs. 1.01 ± 0.26 bobwhites/ha, respectively; P < 0.05). In addition, rainfall at the site level accounted for a low amount of the variation in bobwhite density (r2 = 0.09; P < 0.01). Similarly, in the Rolling Plains, mean bobwhite density significantly increased from low to high management intensity in 2015 (1.30 ± 0.27 bobwhites/ha vs. 2.20 ± 0.29 bobwhites/ha, respectively) and 2016 (1.26 ± 0.26 bobwhites/ha vs. 2.88 ± 0.34 bobwhites/ha, respectively; P < 0.05). Rainfall at the site level also accounted for a low amount of the variation in bobwhite density (r2 < 0.02; P = 0.82). Our findings suggest that management can increase bobwhite density beyond that of less-managed properties but does not completely eliminate inter-annual fluctuations in semiarid environments. In addition, rainfall appears to exert less of an influence on bobwhite density at a site level (e.g., 2,000 ha) than has been documented at a regional level (e.g., ≥8 million ha).  相似文献   

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