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1.
Humanity depends on the marine environment for a range of vital ecosystem services, at global (e.g. climate regulation), regional (e.g. commercial fisheries) and local scales (e.g. coastal defence and recreation). At the same time, marine ecosystems have been exploited for centuries, and many systems today are under stress from multiple sources. Recent studies have shown how both climate change and fishing have caused long-term changes in the marine environment. However, there is still poor understanding of how these changes influence change in coastal ecosystem services. In this paper, an integrated modelling approach is used to assess how the final delivery of marine ecosystem services to coastal communities is influenced by the direct and indirect effects of changes in ecosystem processes brought about by climate and human impacts, using fisheries of the North Sea region as a case study. Partial least squares path analysis is used to explore the relationships between drivers of change, marine ecosystem processes and services (landings). A simple conceptual model with four variables—climate, fishing effort, ecosystem process and ecosystem services—is applied to the English North Sea using historic ecological, climatic and fisheries time series spanning 1924–2010 to identify the multiple pathways that might exist. As expected, direct and indirect links between fishing effort, ecosystem processes and service provision were significant. However, links between climate and ecosystem processes were weak. This paper highlights how path analysis can be used for analysing long-term temporal links between ecosystem processes and services following a simplified pathway.  相似文献   

2.
Offshore wind power generation represents a chance to supply energy in a more sustainable way; however, the ecological risks associated with the construction and operation of offshore wind farms are still largely unknown. This paper uses the concept of ecological risk for analysing ecological changes during construction of offshore wind farms. “Ecological risk” is defined as the potentially reduced ability of providing ecosystem services. The ERSEM ecosystem model allows assessing ecological risk based on a number of selected variables (integrity indicators) and under the assumption that increased suspended matter concentration during construction of wind farms affects ecosystem functioning. We conclude that ecological risk is adequate to describe the effects of wind farm constructions, although the computation procedure still needs to be refined and the choice of indicators further optimised. In this context, the choice of indicators available in modelling as well as in monitoring time-series may offer the way forward.  相似文献   

3.
Governments in the Lower Mekong Basin (LMB) face decisions that involve trade-offs between the economic benefits from hydropower generation and potentially irreversible negative impacts on the ecosystems that provide livelihoods and food security to the rural poor. As a means of comparing these trade-offs, a sensitivity analysis of the benefit-cost analysis of certain Basin Development Plan (BDP) scenarios was undertaken. By changing some key assumptions in the BDP about discount rates, the value of lost capture fisheries, future aquaculture production in the LMB, and the value of lost ecosystem services from wetlands to reflect the full range of uncertainty, at the extremes, there could be a reversal of the Net Present Value (NPV) estimates of the scenarios from a positive $33 billion to negative $274 billion. This report recommends when dealing with large-scale, complex projects: a more comprehensive, integrated human and natural systems framework and adaptive management approach to LMB planning and development that deals with the entire watershed; a more comprehensive analysis and treatment of risk and uncertainty; a more thorough assessment of the value of direct and indirect ecosystem services; a broader set of scenarios that embody alternative models of development, broader stakeholder participation; and better treatment of the effects of infrastructure construction on local cultures and the poor.  相似文献   

4.

Explorations of future land use change are important to understand potential conflicts between competing land uses, trade-offs associated with particular land change trajectories, and the effectiveness of policies to steer land systems into desirable states. Most model-based explorations and scenario studies focused on conversions in broad land use classes, but disregarded changes in land management or focused on individual sectors only. Using the European Union (EU) as a case study, we developed an approach to identifying typical combinations of land cover and management changes by combining the results of multimodel simulations in the agriculture and forest sectors for four scenarios from 2000 to 2040. We visualized land change trajectories by mapping regional hotspots of change. Land change trajectories differed in extent and spatial pattern across the EU and among scenarios, indicating trajectory-specific option spaces for alternative land system outcomes. In spite of the large variation in the area of change, similar hotspots of land change were observed among the scenarios. All scenarios indicate a stronger polarization of land use in Europe, with a loss of multifunctional landscapes. We analyzed locations subject to change by comparing location characteristics associated with certain land change trajectories. Results indicate differences in the location conditions of different land change trajectories, with diverging impacts on ecosystem service provisioning. Policy and planning for future land use needs to account for the spatial variation of land change trajectories to achieve both overarching and location-specific targets.

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5.
An examination of ecological risk assessment and management practices   总被引:5,自引:0,他引:5  
Ecological risk assessment has grown and evolved since the 1980s, as have new challenges (e.g. global climate change, loss of habitat and biodiversity and the effects of multiple anthropogenic chemicals on ecological systems) that need to be factored into the risk assessment processes. There is also an on-going shift from evaluating adverse health impacts on particular, often small scale, environments to undertaking more complex ecological assessments of whole populations and communities across ecologically meaningful landscapes. These trends are generating an increased demand for much more complex ecological assessments, making it increasingly clear that to achieve its potential as a management tool, methods must be developed to apply ecological risk assessment to larger and more complex scales. This paper reviews the development of the ecological risk assessment paradigm in the United States, identifies ways it is being applied and adapted in other countries, explores future research needs and practice improvements, and examines current issues that need to be considered in taking forward the scientific development of ecological risk assessment as a useful environmental management tool.  相似文献   

6.
The recently developed concepts of aggregate risk and cumulative risk rectify two limitations associated with the classical risk assessment paradigm established in the early 1980s. Aggregate exposure denotes the amount of one pollutant available at the biological exchange boundaries from multiple routes of exposure. Cumulative risk assessment is defined as an assessment of risk from the accumulation of a common toxic effect from all routes of exposure to multiple chemicals sharing a common mechanism of toxicity. Thus, cumulative risk constitutes an improvement over the classical risk paradigm, which treats exposures from multiple routes as independent events associated with each specific route. Risk assessors formulate complex models and identify many realistic scenarios of exposure that enable them to estimate risks from exposures to multiple pollutants and multiple routes. The increase in complexity of the risk assessment process is likely to increase risk uncertainty. Despite evidence that scenario and model uncertainty contribute to the overall uncertainty of cumulative risk estimates, present uncertainty analysis of risk estimates accounts only for parameter uncertainty and excludes model and scenario uncertainties. This paper provides a synopsis of the risk assessment evolution and associated uncertainty analysis methods. This evolution leads to the concept of the scenario-model-parameter (SW) cumulative risk uncertainty analysis method. The SMP uncertainty analysis is a multiple step procedure that assesses uncertainty associated with the use of judiciously selected scenarios and models of exposure and risk. Ultimately, the SMP uncertainty analysis method compares risk uncertainty estimates determined using all three sources of uncertainty with conventional risk uncertainty estimates obtained using only the parameter source. An example of applying the SMP uncertainty analysis to cumulative risk estimates from exposures to two pesticides indicates that inclusion of scenario and model sources.  相似文献   

7.
Commercial feedlots for beef cattle finishing are potential sources of a range of trace chemicals which have human health or environmental significance. To ensure adequate protection of human and environmental health from exposure to these chemicals, the application of effective manure and effluent management practices is warranted. The Australian meat and livestock industry has adopted a proactive approach to the identification of best management practices. Accordingly, this review was undertaken to identify key chemical species that may require consideration in the development of guidelines for feedlot manure and effluent management practices in Australia. Important classes of trace chemicals identified include steroidal hormones, antibiotics, ectoparasiticides, mycotoxins, heavy metals and dioxins. These are described in terms of their likely sources, expected concentrations and public health or environmental significance based on international data and research. Androgenic hormones such as testosterone and trenbolone are significantly active in feedlot wastes, but they are poorly understood in terms of fate and environmental implications. The careful management of residues of antibiotics including virginiamycin, tylosin and oxytetracycline appears prudent in terms of minimising the risk of potential public health impacts from resistant strains of bacteria. Good management of ectoparasiticides including synthetic pyrethroids, macrocyclic lactones, fluazuron, and amitraz is important for the prevention of potential ecological implications, particularly towards dung beetles. Very few of these individual chemical contaminants have been thoroughly investigated in terms of concentrations, effects and attenuation in Australian feedlot wastes.  相似文献   

8.
Agricultural water management needs to evolve in view of increased water scarcity, especially when farming and natural protected areas are closely linked. In the study site of Doñana (southern Spain), water is shared by rice producers and a world heritage biodiversity ecosystem. Our aim is to contribute to defining adaptation strategies that may build resilience to increasing water scarcity and minimize water conflicts among agricultural and natural systems. The analytical framework links a participatory process with quantitative methods to prioritize the adaptation options. Bottom-up proposed adaptation measures are evaluated by a multi-criteria analysis (MCA) that includes both socioeconomic criteria and criteria of the ecosystem services affected by the adaptation options. Criteria weights are estimated by three different methods—analytic hierarchy process, Likert scale and equal weights—that are then compared. Finally, scores from an MCA are input into an optimization model used to determine the optimal land-use distribution in order to maximize utility and land-use diversification according to different scenarios of funds and water availability. While our results show a spectrum of perceptions of priorities among stakeholders, there is one overriding theme that is to define a way to restore part of the rice fields to natural wetlands. These results hold true under the current climate scenario and even more so under an increased water scarcity scenario.  相似文献   

9.
石油农业导致生态系统退化与环境受损.人们在寻找新的农业途径时,将目光转向传统农业,开始对传统农耕模式的价值进行挖掘.稻鱼共生是最为典型的中国传统生态农业模式之一,因其历史悠久、景观独特和效益显著而被联合国粮农组织列为首批全球重要农业文化遗产保护试点之一.在数千年的农耕文化演变过程中,同宗的青田县和从江县的传统农业系统,由于受到不同的自然、经济和文化的影响,分别形成了以养鱼为主和以种稻为主的稻鱼共生系统.本文采用市场价值法、造林成本法、替代价格法、大气污染治理成本法和水库工程费用法等,分别对青田县和从江县传统农业区生态系统服务功能的经济进行评估.结果表明,以养鱼为主的青田县直接经济价值比以种稻为主的从江县平均每公顷高近1.70万元,但其闻接价值却比后者低,从江县稻鱼共生系统的气体调节和养分保持价值分别是青田县的1.35和1.59倍.最后,本文提出了提高农民收入的途径,以更好地保护这一具有全球重要意义的农业文化遗产.  相似文献   

10.
This article reviews the state of the science regarding the health effects of polybrominated dibenzo-p-dioxins (PBDDs) and dibenzofurans (PBDFs). While thousands of articles have been published on the health effects of 2,3,7,8-tetrachlorodibenzo-p-dioxin and related polychlorinated dibenzodioxins (PCDDs) and dibenzofurans (PCDFs), little is know about the brominated and mixed chloro/bromo homologs. Available literature suggests that brominated compounds have similar toxicity profiles to their chlorinated homologs. However, further research investigating health effects will only be useful if exposure scenarios truly exist. Current exposure data is extremely limited, posing a major data gap in assessing potential risk of these chemicals. The rapid increase in the use of brominated flame retardants has raised the level of environmental concern regarding PBDDs/PBDFs as it is likely that human, as well as wildlife, exposure to brominated dioxins and furans will increase with their use.  相似文献   

11.
Azole fungicides are widely used to treat fungal infection in human. After application, these chemicals may reach to the receiving environment via direct or indirect discharge of wastewaters, thus posing potential risks to non-target organisms. We aimed to review the occurrence, fate and toxicological effects of some representative household azole fungicides in the environment. Azole fungicides were widely detected in surface water and sediment of the aquatic environment due to their incomplete removal in wastewater treatment plants. These chemicals are found resistant to microbial degradation, but can undergo photolysis under UV irradiation. Due to different physiochemical properties, azole fungicides showed different environmental behaviors. The residues of azole fungicides could cause toxic effects on aquatic organisms such as algae and fish. The reported effects include regulation changes in expression of cytochrome P450-related genes and alteration in CYP450-regulated steroidogenesis causing endocrine disruption in fish. Further studies are essential to investigate the removal of azole fungicides by advanced treatment technologies, environmental fate such as natural photolysis, and toxic pathways in aquatic organisms.  相似文献   

12.
Invasive species alter the functioning of natural ecosystems, creating “novel ecosystems” comprising species occurring in combinations with no analogs within a given biome. This poses major challenges for managers who cannot rely exclusively on previous experiences. Multiple factors that drive invasion and which interact in complex ways demand innovative management approaches. We show the utility of scenario planning in considering options for management in a region with substantial problems with invasive alien plants: South Africa’s Cape Floristic Region. The approach allows us to identify the driving forces that shape the status and trajectories of major woody invasive plants and to identify sensible strategies by considering a set of scenarios based on the main uncertainties that encapsulate the linkages between the various components of the management of biological invasions. Attitudes of landowners and management capacity are shown to be the crucial uncertainties influencing the spread of major invasive species; axes based on these factors define our scenarios. Mapping current management projects onto scenario axes highlighted key differences among areas. These insights can assist in directing particular management units toward more desirable futures. Our study highlights the need to link social, political and legal constraints with ecological processes to assure the effectiveness of management operations in controlling biological invasions.  相似文献   

13.
Wetland productivity in the Prairie Pothole Region (PPR) of North America is closely linked to climate. A warmer and drier climate, as predicted, will negatively affect the productivity of PPR wetlands and the services they provide. The effect of climate change on wetland productivity, however, will not only depend on natural processes (e.g., evapotranspiration), but also on human responses. Agricultural land use, the predominant use in the PPR, is unlikely to remain static as climate change affects crop yields and prices. Land use in uplands surrounding wetlands will further affect wetland water budgets and hence wetland productivity. The net impact of climate change on wetland productivity will therefore depend on both the direct effects of climate change on wetlands and the indirect effects on upland land use. We examine the effect of climate change and land-use response on semipermanent wetland productivity by combining an economic model of agricultural land-use change with an ecological model of wetland dynamics. Our results suggest that the climate change scenarios evaluated are likely to have profound effects on land use in the North and South Dakota PPR, with wheat displacing other crops and pasture. The combined pressure of land-use and climate change significantly reduces wetland productivity. In a climate scenario with a +4 °C increase in temperature, our model predicts that almost the entire region may lack the wetland productivity necessary to support wetland-dependent species.  相似文献   

14.
The regulation of the emissions of 'traditional' primary air pollutants (fluorides, sulfur dioxide) has changed the pattern of exposure of ecological systems, with greatly reduced exposure close to sources, but with a smaller effect in some remote areas. Measurements show that recovery is occurring at some sites, in fresh water chemistry (reduced acidity) and in sensitive biota (sustainable fish populations). However, the pattern of change in exposure has not always been simply related to emission reductions. An understanding of responses to recent changes will improve our predictions of the response to future emission changes, both locally and globally. As exposure to 'traditional' pollutants is reduced, the potential for other pollutants to have effects becomes more evident. In the aqueous phase, we need to understand the role of soluble and suspended organics, but this also means explicit recognition of the possibility of phase exchange, and the role of photolytic reactions on plant, soil, and water surfaces. Do highly reactive free radicals in the atmosphere, formed by the action of sunlight on volatile organic compounds, have direct effects on plants? Organic compounds and heavy metals may be bioactive as gases and particles, but for many potentially toxic compounds, the experimental evidence for biotic response is very limited. To evaluate the potential effects of pollutants, we need to understand the pathways by which airborne pollutants enter and react within ecosystems. For vegetation, we have to consider bidirectional fluxes, and distinguish among uptake through stomata, through leaf surfaces, or through roots. There are several challenges for the future. (1) Can we devise experiments that permit exposure of vegetation to gases, particles, and/or aqueous pollutants at 'realistic' concentrations? (2) Can we include the potential interactions with photolytically derived free radicals, and the dynamics of exchange? (3) How do we allow for responses to pollutant mixtures, or the simultaneous exposure to pollutants in gas, particle, and aqueous phases? The recognition of the importance of the dynamic exchange of pollutants between phases will be the key to the development of effective experimental approaches to evaluating cause-effect relationships between pollutant mixtures and ecosystem responses.  相似文献   

15.
通过仿真模拟中国土地利用系统状况,探寻实现土地利用系统健康发展的情景模式,为中国在2035年基本实现社会主义现代化,及进一步实现可持续发展目标提供参考路径。研究采用系统动力学模型构建土地利用系统,共模拟得到18种情景方案。通过设定经济发展、粮食安全和生态安全目标对情景方案进行筛选,保留了6种情景。采用"压力-状态-响应"(PSR)模型构建土地利用系统健康评价体系,对6种情景进行评价。研究结果表明:第2种情景土地利用系统的健康水平最优且符合国情需要。最优政策情景具体表现为经济保持中速发展,到2035年GDP增长率稳落在4%,总量达到约200万亿;人口中速增长,2035年人口稳定在约14.85亿;土地整治力度大幅提升,土地整治投资金升至每年600~1 000亿元。  相似文献   

16.
ABSTRACT

Urban planning has become a widely concern for minimizing the negative effects of urban expansion on terrestrial ecosystems. We developed an interdisciplinary modeling framework to evaluate the effectiveness and shortcomings of urban expansion management strategies. A three-step method was applied to Yinchuan Plain in the northwestern of China, including (1) analyzing the relationship between landscape pattern and ecosystem service values through mathematical statistics; (2) predicting landscape pattern and ecosystem services change under different scenarios based on cellular automaton model (SLEUTH-3r model); and (3) designing and validating optimized scenario through integrating historical analysis experiments and future multi-comparison suggestions. Results have suggested that landscape composition and configuration can significantly affect regional ecosystem service values, especially the connectivity and shape of landscape. Compact urban growth policy and medium environment protection policy are the appropriate setting for urban expansion plan. Optimization validation of the combined designed scenario implied the reliability of this method. Our results highlighted the significance of integrating application of landscape pattern analysis, ecosystem service value evaluation, model simulation and multi-scenario prediction in urban planning.  相似文献   

17.
Research aimed at understanding the response of plants to ozone has been conducted for over four decades but little of it has addressed intact natural systems. Even so, there is sufficient scientific information at this time to support air quality standards that will protect natural terrestrial ecosystems from ozone. What is unknown is the risk associated with continued exposure of natural systems, including both above- and below-ground components, in combination with other stresses including changing temperature and precipitation, elevated carbon dioxide, pests and pathogens, invasive species, and other activities that may fragment the landscape. Research to support an assessment of the ecological risk associated with ozone as it exists, in a milieu of stresses, must include endpoints beyond those addressed in the past, primarily productivity and species composition. To estimate the risk to society of ozone impacts on natural systems, endpoints such as the integrity of soil food webs, the quantity and quality of water supplied from terrestrial ecosystems, wildlife and recreational values, and the transfer and fate of carbon, nutrients, and water within the systems must be quantified. Not only will this research provide the basis for a sound estimate of risk, but also it will improve our understanding of fundamental ecosystem processes.  相似文献   

18.
基于计算机模型的湿地公园规划具有低成本、高效率、多情景等优点,可以为规划研究提供初步方案的评优和选择。将CLUE-S模型运用到湿地公园规划中,结合生态保护情景和旅游开发情景的设定,对新济洲湿地公园进行2020年景观格局模拟预测,最后从湿地鸟类穿越的最小累积阻力模型角度,对两种情景进行了比较分析,得出如下结论:(1)对CLUE-S模型在研究区的适用性进行验证,经过计算,模拟的精度检验指数Kappa值为0.763,表明CLUE-S模型用来做新济洲湿地公园景观格局变化的预测模型具有良好的可靠性;(2)土壤有机质含量是推动新济洲湿地公园景观变化的最重要驱动因子,其影响力度远远高于其他因子;(3)通过建立MCR模型可以发现,两种情景都具有各自的优缺点,对于生态保护情景需要注意的是拓宽湿地鸟类穿越廊道,减少最小累积阻力路线生态缓冲区内的人为干扰。而对于旅游开发情景来说,构建整体的生态串联性则显得尤为重要,需要在中部大阻力区域为湿地鸟类穿越开辟一条良好的保护通道。  相似文献   

19.
Contributions of direct and indirect (via precursors) pathways of human exposure to perfluorooctane sulfonic acid (PFOS) isomers and perfluoroalkyl carboxylic acids (PFCAs) are estimated using a Scenario-Based Risk Assessment (SceBRA) modelling approach. Monitoring data published since 2008 (including samples from 2007) are used. The estimated daily exposures (resulting from both direct and precursor intake) for the general adult population are highest for PFOS and perfluorooctanoic acid (PFOA), followed by perfluorohexanoic acid (PFHxA) and perfluorodecanoic acid (PFDA), while lower daily exposures are estimated for perfluorobutanoic acid (PFBA) and perfluorododecanoic acid (PFDoDA). The precursor contributions to the individual perfluoroalkyl acid (PFAA) daily exposures are estimated to be 11–33% for PFOS, 0.1–2.5% for PFBA, 3.7–34% for PFHxA, 13–64% for PFOA, 5.2–66% for PFDA, and 0.7–25% for PFDoDA (ranges represent estimated precursor contributions in a low- and high-exposure scenario). For PFOS, direct intake via diet is the major exposure pathway regardless of exposure scenario. For PFCAs, the dominant exposure pathway is dependent on perfluoroalkyl chain length and exposure scenario. Modelled PFOS and PFOA concentrations in human serum using the estimated intakes from an intermediate-exposure scenario are in agreement with measured concentrations in different populations. The isomer pattern of PFOS resulting from total intakes (direct and via precursors) is estimated to be enriched with linear PFOS (84%) relative to technical PFOS (70% linear). This finding appears to be contradictory to the observed enrichment of branched PFOS isomers in recent human serum monitoring studies and suggests that either external exposure is not fully understood (e.g. there are unknown precursors, missing or poorly quantified exposure pathways) and/or that there is an incomplete understanding of the isomer-specific human pharmacokinetic processes of PFOS, its precursors and intermediates.  相似文献   

20.
基于InVEST模型的鄱阳湖湿地生物多样性情景分析   总被引:6,自引:0,他引:6  
生态系统服务与功能的评估越来越多地被应用到自然资源管理政策制定中。通过参与式评估框架(FoPIA)方法建立鄱阳湖湿地到2020年的不同土地利用情景,以此作为参数应用到生态系统服务与功能的评估权衡模型(InVEST),以鄱阳湖湿地指示性生物(越冬候鸟)的栖息地为研究对象,定量和空间化评估典型村落未来土地利用情景下候鸟栖息地质量和空间分布特征。结果表明:在生态保育情景下,受生态退耕等因素的影响,栖息地规模增加,人类胁迫活动减少,鄱阳湖湿地典型村落候鸟栖息地的平均质量提高到0.89,比现状水平提高27.0%;在经济发展情景下,人类活动范围的扩张使得候鸟栖息地受到的胁迫增强,栖息地的平均质量下降为0.57,比现状水平低14.0%;在自然增长情景下,候鸟栖息地平均质量为0.66,比现状水平增加了1.5%。  相似文献   

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