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501.
When reserve networks are established over time, there is a risk that sites will be developed in areas planned for future reservation, reducing the effectiveness of reserves. We developed a dynamic reserve design model that maximizes the expected number of species conserved, taking account of the risk of future habitat loss and fragmentation. The model makes use of the union-find algorithm, which is an efficient method for maintaining a list of connected regions in a graph as nodes and edges are inserted. A simple extension of the algorithm allows us to efficiently determine, for each species, when a sequence of site selections results in a reserve in which the species can persist. The extension also allows us to determine when a sequence of deforestation events results in the species becoming non-viable. The dynamic reserve design model is much more effective than commonly used heuristics, particularly when multiple connected sites are required for species persistence. The model also is able to solve much larger problems with greater effectiveness than the only previous dynamic reserve design model that considered site connectivity relationships. The union-find algorithm has much scope for addressing ecological management problems in which dynamic connectivity needs to be considered. 相似文献
502.
Wendy Y. Chen 《国际发展与全球生态学杂志》2013,20(1):44-53
To optimise the use and management of Hong Kong's country parks, ecotourism has recently been promoted by the government and echoed by the leisure sector. Visitors' valuation of ecotourism development hitherto remains scant and could add a new dimension to the knowledge and management base. This study estimated the potential value of ecotourism development using the contingent valuation method (CVM). A total of 613 visitors in three country parks were interviewed. The results showed that the bid amounts and the motives to experience and learn more about nature were significant predictors of willingness-to-pay (WTP). The mean and median WTP were, respectively, HK$101.1 and HK$85.0 annually, varying slightly between parks. The differences were associated with the special ecological and accessibility characteristics of individual parks. The results could justify financial support from the government for ecotourism development and associated nature conservation endeavours and promote the incorporation of natural resource valuation in formulation of public policies in Hong Kong and other developing regions. 相似文献
503.
为有效监测生活必需品的应急储备情况,改善储备工作中的不足,确保储备质量,提升保障能力。在分析国内外生活必需品应急储备工作的基础上,对监测准备、数据采集加工、监测分析、储备评估等关键环节展开研究。提出了融合多种手段的全方位监测数据采集与集成技术,基于数据挖掘和知识发现的多维分析与预测预警技术,以及结合责任、风险、反馈与保障能力的综合评估技术,形成了全面、动态、智能的生活必需品应急储备渠道监测体系,并运用系统工程的思想和方法,借助物联网和地理信息系统等技术,构建了生活必需品应急储备一体化渠道监测平台。研究成果有利于提前发现问题,减少风险,优化储备计划,节省储备成本,提高储备质量与保障能力,具有非常重要的现实意义。 相似文献
504.
Carlos Carroll Reed F. Noss Lindsay M. Dreiss Healy Hamilton Bruce A. Stein 《Conservation biology》2023,37(5):e14075
Comprehensive biodiversity assessments play an essential role in strengthening global and national conservation strategies. The recently announced first U.S. National Nature Assessment (NNA) provides an unparalleled opportunity to comprehensively review status and trends of biodiversity at all levels. This broad context can help in the coordination of actions to conserve individual species and ecosystems. The scientific assessments that informed the Kunming–Montreal Global Biodiversity Framework adopted at the 2022 Convention on Biological Diversity (CBD) conference of parties provide models for synthesizing information on trends at multiple levels of biodiversity, including decline in abundance and distribution of species, loss of populations and genetic diversity, and degradation and loss of ecosystems and their services. The assessments then relate these trends to data on drivers of biodiversity loss and pathways to their mitigation. The U.S. NNA can augment such global analyses and avoid the pitfalls encountered by previous U.S. efforts by ensuring policy-relevant design, data accessibility, and inclusivity in process and product and by incorporating spatial data relevant to national and subnational audiences. Although the United States is not formally a CBD party, an effective NNA should take full advantage of the global context by including indicators adopted at the 2022 meeting and incorporating an independent review mechanism that supports periodic stocktaking and ratcheting up of ambition in response to identified shortfalls in stemming biodiversity loss. The challenges to design of an effective U.S. assessment are relevant globally as nations develop assessments and reporting to support the new global biodiversity framework's targets. By considering and incorporating the diverse ways in which society values and benefits from nature, such assessments can help bridge the gap between research and conservation practice and communicate the extent of the biodiversity crisis to the public, fostering broad-based support for transformative change in humanity's relationship to the natural world. 相似文献
505.
陈桂洲 《中国特种设备安全》2021,(1):42-44,61
当儿童跟随大人乘坐电梯时,经常发生在电梯门区儿童受伤安全事故.本文介绍了儿童的好奇和探险行为、有限的认知能力以及有限的运动神经控制能力等天性行为,并通过对一些典型电梯事故案例中的儿童天性行为的分析,提出儿童的天性行为是导致这些电梯安全事故的根本原因,并指出儿童在乘坐针对成年人设计的电梯产品时存在的安全隐患,给电梯的设计... 相似文献
506.
云南纳板河自然保护区周边社区参与生态旅游的模式研究 总被引:1,自引:0,他引:1
当前,国内许多自然保护区都把生态旅游作为发展规划的重点,通过社区参与生态旅游,不仅使村民直接从中获得经济效益,生活水平得到提高,更重要的是形成了"政府、企业和当地社区村民的利益共同体",使自然保护区的生态环境保护形成"自愿机制",有效地促进了保护区生态旅游资源的保护和开发效用最大化。针对社区参与生态旅游的现状,研究借鉴国内外社区参与生态旅游模式的经验,以纳板河自然保护区为研究对象进行了有益的探索。 相似文献
507.
对品种繁多的应急物资进行分类是科学储备应急物资的前提和基础。以应急物资的自然属性和社会属性以及突发事件的应急需求为基础,从应急物资的有效使用期限、用途、生产周期、价格、市场流通量、社会集中拥有量、突发事件的预计需求量和需求层次8个方面建立应急物资的分类指标体系;采用模糊聚类的方法对应急物资进行分类,并用经验正交函数方法确定应急物资的最佳分类数量;最后探讨了每一类应急物资的储备模式,为应急物资的科学储备提供借鉴。 相似文献
508.
Kontoleon Andreas 《中国人口.资源与环境(英文版)》2009,7(2):59-66
Due to historic reasons, there are several human settlements in nature reserves and national parks, which may constitute a threat to biodiversity. Establishment of nature reserves may however generate constraints for development of local communities residing in these reserves. The village ecosystem of Zhuanjinglou Village in Wolong Nature Reserve includes population, farming and livestock (domestic and alpine) and forest ecosystem. An emergy analysis of agro-ecosystem (including the farming and livestock ecosystem) and energy consumption in Zhuanjinglou Village indicates that livestock ecosystem plays an important role in village ecosystem, which may be the source of great pressure on the state of the local environment. The increasing ratio of electricity in energy consumption may play a positive role for environmental conservation. Despite some successful experiences, there are some remaining issues that need to be addressed in the ecological rehabilitation of the village ecosystem. 相似文献
509.
人类社会可持续发展的资本视角 总被引:1,自引:0,他引:1
由于当代人与后代人共同占有整个地球,因此从理论上讲,解决代际公平问题成为可持续发展理论研究的首要问题。从经济学角度讲。整个资本世界可以分为人力资本、人造资本、环境资本、社会资本等四个组成部分,分析表明,不同类型资本之间的替代与互补关系,对维持可持续发展至关重要。尤其,应该大力培育人力资本与环境友好的社会资本。 相似文献
510.
煤炭应急供应的储备机制研究 总被引:2,自引:0,他引:2
借鉴关于石油储备的研究,界定煤炭应急储备的含义,分析煤炭储备的功能。根据我国煤炭供应的特点,探讨煤炭应急储备模式,提出我国煤炭应急储备的基本构想,指出我国煤炭应急储备应以地方储备、企业储备、现货储备为主,应急储备和日常储备相结合。从煤炭消费量、自给率、运输条件、经济实力4个方面分析影响储备规模的因素,测算各省区的储备规模。结合煤炭应急储备的基本构想和煤炭应急储备计划、轮换、动用的要求,提出煤炭储备管理的二级储备体系和三级管理体系,以及政府监督、市场运作、企业主导的储备运行模式。该研究成果对我国煤炭应急储备体系的建设具有很好的借鉴和参考意义。 相似文献