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51.
    

Economic development has increased pressures on natural resources during the last decades. The concept of planetary boundaries has been developed to propose limits on human activities based on earth processes and ecological thresholds. However, this concept was not developed to downscale planetary boundaries to sub-global level. The absence of boundaries at sub-global levels constrains the use of the concept in environmental governance and natural resource management, because decisions are typically taken at these levels. Decisions at the national level are currently supported, among others, by statistical frameworks in particular the System of National Accounts. However, statistical frameworks were not developed to compile environmental information, hindering environmental decision making. Our study examines if and how ecosystem accounting can be used in combination with the concept of planetary boundaries in guiding human activities at the level of a river basin. We assess the applicability of both frameworks for natural resource management in the Orinoco river basin, based on adaptive management components. Our analysis indicates that differences in the purpose of analysis, information provided, and methods constrain the potential integration of both frameworks. Nevertheless, the way both frameworks conceptualize the social system and the interactions between social and ecological systems can facilitate translating planetary boundaries into indicators considered in ecosystem accounting. The information recorded in national ecosystem accounts can support establishing ecological thresholds and, more fundamentally, to relate ecological thresholds to human impacts on ecosystem condition. Capitalizing on these synergies requires further exchange of experiences between the communities working on ecosystem accounting and planetary boundaries.

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52.
生态移民的空间位移引致了迁入区多因素的相互作用及长期演化,成为多学科深入探究的重要问题之一。以闽宁镇生态移民社区为例,采用主成分分析法和地理探测器分析法,对生态移民社区生活空间融合的影响因素和机理进行了研究,结果发现:(1)生态移民社区生活空间融合与重构受多种因素影响,生活基础设施、经济收入增长、移民社区环境、邻里关系、政府政策、民族生活六个主成分对生态移民社区生活空间融合的影响可以起到解释作用。(2)影响生态移民社区生活空间的因子解释力由强到弱依次排序为:X1生活基础设施>X2经济收入增长>X3邻里关系>X4政府政策>X5民族生活>X6移民社区环境;交互探测结果表明社区各要素因子交互后因子解释力呈双线性增强,即任意两个因子交互作用对于生态移民社区生活空间融合的影响强度都大于单个因子的独自作用强度。(3)各影响因素之间的互动影响,共同促进生态移民社区固有的生活方式、文化习惯、社会交往关系的演化,进而形成了生活空间的融合与重构。  相似文献   
53.
54.
    
Journal of Material Cycles and Waste Management - Leakage modeling can be crucial for environmental management and control of waste landfills. However, defining boundary conditions for these models...  相似文献   
55.
Increased reliance on the Internet for critical infrastructure and the global nature of supply chains provides an opportunity for adversaries to leverage dependencies and gain access to vital infrastructure. Traditional approaches to assessing risk in the cyber domain, including estimation of impacts, fall short due to uncertainty in how interconnected systems react to cyber attack. This paper describes a method to represent the pathways of disruption propagation, evaluate the macroeconomic impact of cyber threats and aid in selecting among various cybersecurity policies. Based on state of the art agent-based modeling, multicriteria decision analysis, and macroeconomic modeling tools, this framework provides dynamic macroeconomic, demographic and fiscal insights regarding shocks caused by cyber attacks to the regional economy over time. The interlinkage of these models will provide a robust and adaptive system that allows policy makers to evaluate complex issues such as cybersecurity threats and their impacts on the geopolitical, social, environmental, and macroeconomic landscape.  相似文献   
56.
环境会计发展的理念与实践是以实现经济、社会、环境的可持续发展为前提,通过实施环境会计制度,可以使企业准确掌握经营活动的资源消耗、环境负荷,促进其提供环境友好产品及服务,推进经济朝着低碳、绿色、可持续模式发展。日本经过十几年的发展,目前已形成较为完善的环境会计体系。本文通过介绍和分析日本环境会计体系产生的背景、发展变化与作用,探讨我国环境会计体系构筑问题。  相似文献   
57.
The present study deals with sediment dynamics affecting sediment-associated metal distributions in an embayment system experiencing pollution from coastal industries. Sedimentary metal content may originate from diagenetic processes of foundation rock on the bottom, allochthonous minerals from natural sources, and metals from industrial effluents along the coast. The study presents experimental estimations of quantities of metals entering the bay in industrial wastewater, measurements of metal content in particulate material captured in sediment traps, and metals distribution in surface sediments. Quantitative estimations of metals entering the system in industrial effluent showed the relation Pb Zn > Cu > Cr Ni > Cd. That of metals associated with particulate material from traps was Zn > Cr Cu > Pb > Ni > Cd and the abundance of metals in sediments was Zn > Cr > Cu > Pb > Ni > Cd. Finally, rates of bottom sediment accumulation are estimated in relation to the time of residence of water in the bay. The experimental data on sedimentation and sediment abundance were consistent with field observations on distribution and accumulation at sites of major sedimentation in this bay.  相似文献   
58.
Populations of reintroduced California condors (Gymnogyps californianus) develop complex social structures and dynamics to maintain stable group cohesion, and birds that do not successfully integrate into group hierarchies have highly impaired survivability. Consequently, improved understanding of condor socioecology is needed to inform conservation management strategies. We report on the dominance structure of free-ranging condors and identify the causes and consequences of rank in condor populations by matching social status with the behavioral and physical correlates of individual birds. We characterized the hierarchical social structure of wild condor populations as mildly linear, despotic, and dynamic. Condor social groups were not egalitarian and dominance hierarchies regulated competitive access to food resources. Absence of kin-based social groups also indicated that condor social structure is individualistic. Agonistic interactions among condors were strongly unidirectional, but the overall linearity and steepness of their hierarchies was low. Although one aggressive male maintained the highest dominance rank across the 3-year observation period, there was considerable fluidity in social status among condors within middle and lower rank orders. Older condors were more dominant than younger birds and younger males supplanted older females over time to achieve higher status. Dominance rank did not predict the amount of time that a bird spent feeding at a carcass or the frequency that a bird was interrupted while feeding. Thus, younger, less dominant birds are able to obtain sufficient nutrition in wild social populations.  相似文献   
59.
Taxonomical composition and abundance of the planktonic ciliate assemblage in a Lake Tezozomoc, a hypertrophic pond located into an urban park in Mexico City, was investigated along the rainy season (May to October). The aims of the study were to know the main trophic roles and ecological significance of ciliates in a highly productive environment. A low number of taxa (27) and a wide abundance fluctuation (104-387 cil ml(-1)) were found. The most abundant species (up to 162 cil ml(-1)) was Halteria grandinella, an oligotrich ciliate that graze on bacteria and picoplankton, but also several big body sized species that feed on pico and nanoplankton were abundant. Sudden temporal changes in species dominance occurred. Ciliate biomass was very high and fluctuated widely (1.6-88 10(6) microm(3) ml(-1)) being dominated by the >50 microm size fraction that mainly included the pico and nanoplankton feeders. Ciliates are a very important component in the plankton of hypertrophic lakes and their main control factor seems to be the grazing by big-body size Daphnia species.  相似文献   
60.
This work shows how ambient radon concentrations measured at Cabauw station in central Netherlands are influenced by transport from different regions under typical transport conditions occurring during April and November, 2007 by means of atmospheric Lagrangian particle dispersion modelling in a receptor-oriented approach. Four specific regions have been isolated to assess their contribution to the modelled radon ambient concentrations at Cabauw, and two different radon flux assumptions. Westerly flows coming from the ocean are poor in radon and do not increase radon air concentrations unless there is some fetch over the British Isles. Continental transport, mainly from eastern and southern Europe, significantly increases radon background concentrations, reaching increments of 3 Bq m?3. A constant 0.66 atoms cm?2 s?1 radon flux over land and zero over water bodies is a good approximation for the source term in order to study regional contributions and modulation of the radon background.  相似文献   
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