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891.
海洋浮游细菌的生态学研究   总被引:23,自引:2,他引:23  
海洋浮游细菌在海洋生态系统中的重要作用随着对其生物量和生产力的深入研究而得到了充分肯定。以浮游细菌为核心的微食物环研究的开展,也显示出微食物环在海洋生态系统动力学过程中有不可替代的作用,是主食物链的重要补充,特别是在贫营养的大洋生态系统中。在不同水 层和特殊环境中对海洋浮游细菌的研究结果表明其研究潜力巨大。就国内在这方面的研究现状和需进一步研究的内容进行了阐述。  相似文献   
892.
Studies of forests in Africa employ the term zone to denote a particular type of forested area. This limited usage speaks to a need for human geographers to pay more attention to elaborating and engaging with the concept of the zone. This article shows why human geography should pay the ‘zone’ more attention. Using Cameroon’s humid forest zone (HFZ) as a case study, the article focuses on how conceptual elaboration of the ‘zone’ can inform analyses of the food product trade in Cameroon. This trade is organized around various types of buyers and sellers (or buyam–sellam in pidgin), and offers a wide variety of wild products to Cameroon’s urban food consumers, including fruits and vegetables, game meat, condiments, medicinal plants, and fibers. Drawing on fieldwork surveys, interviews and focus groups in twenty-four markets of 203 buyam–sellams and 197 of their customers during the wet and dry seasons, this article analyzes narratives about Cameroon’s wild food zone. It ultimately shows what scholarly attention to the ‘zone’ offers in this case that other spatial concepts do not.  相似文献   
893.
1998~2007年中国农业用水分析   总被引:10,自引:0,他引:10       下载免费PDF全文
李保国  黄峰 《水科学进展》2010,21(4):575-583
中国农业用水在未来将面临巨大的挑战。根据国际农业用水研究和政策领域近10年出现的范式变迁的核心内容,建立了基于"绿水"、"蓝水"的中国农业用水的新综合分析框架。并利用广义农业水资源量和广义农业水土资源匹配的概念和评估方法,分析了全国1998~2007年10年间4种主要粮食作物(水稻、小麦、玉米和大豆)的农业用水、耗水以及水分生产力变化趋势和现状。结果表明:中国广义农业水资源量中57%来源于耕地有效降水的"绿水",43%来源于耕地灌溉"蓝水"。主要粮食作物水分生产力水平已经接近或达到世界较高水平。未来继续提升水分生产力的任务将会更加艰巨。因此,为保证中国粮食安全,建议国家设立"粮食安全水资源红线"。同时,根据广义农业水资源量的分析计算,主要粮食作物用水安全红线应该划定在大约7800亿m3左右。  相似文献   
894.
There is a general consensus that Small Island Developing States are among the most vulnerable to experience climate injustices. Vulnerability studies of climate change effects on communities have often focused on differences between communities given these climate injustices. However, there is a need to also focus on vulnerability within communities, referred to here as comparative vulnerabilities. Climate justice therefore becomes even more important with more focused attention given to the nuances within groups that fall within the vulnerable category. This article examines comparative vulnerabilities for the fishing community in Jamaica. A survey of 241 fishers from Old Harbour Bay, the largest fishing village in Jamaica, was conducted to examine the level of vulnerability of different fishers to climate change. A vulnerability index was constructed for the community and then comparative vulnerabilities were determined based on socio-demographic characteristics. Overall for the sample 46.9% of respondents would be considered as experiencing a comparatively high level of vulnerability to climate change. Climate change vulnerability was influenced by a number of socio-demographic variables with unique profiles emerging for groups that can be ranked as low, moderate, and high vulnerability. The paper therefore argues that within vulnerable populations there are comparative vulnerabilities based on economic factors and social capital, which must be taken into consideration for adaptation strategies to be implemented. Given these comparative vulnerabilities a more targeted approach to coping and adaptation strategies can then be taken. This will assist in building resilience of these communities that must now adjust to a new normal with climate change effects currently occurring.  相似文献   
895.
Energy poverty – or the condition of households that cannot adequately heat their homes – is produced at the confluence of multi-scalar processes, from regional labor market restructuring, to urban disinvestment, to geopolitical and geoeconomic struggles over extraction. Critical theorization of the concept is in its nascent phase and the notion itself has received relatively little attention in the United States. Our paper aims to address these lacunae by mobilizing an urban political ecology framework to consider a community-based campaign that targeted residential energy conservation funds in Buffalo, New York. We analyze how the community campaign drew upon the “network crisis” of the energy-poor home to frame critical justice demands that foregrounded energy poverty as the product of uneven socionatural development. Through spatial claims and scalar strategies, the campaign highlighted the contribution of neoliberal conservation programs to deepening patterns of uneven development, and demanded redress of disinvestment in urban housing stock through funding of weatherization for low-income households. We argue that contests over urban energy metabolism offer a fruitful area to explore the possibilities of transforming uneven development from below.  相似文献   
896.
Ryan Holifield 《Geoforum》2004,35(3):285-297
In response to the failings of the aggressive neoliberalism of the Reagan era, the Clinton administration sought new ways to promote and deepen the neoliberal project. One of its strategies was to develop “neocommunitarian” programs to support political empowerment and economic self-sufficiency in marginalized communities. Its environmental justice policy became an important vehicle for delivering these programs. This paper examines ways in which one regional office of the US Environmental Protection Agency translated the Clinton administration's environmental justice policy into practical guidelines for its managers. It investigates how these guidelines affected the work of personnel in the EPA's program to clean up hazardous waste sites. It asks how the Clinton administration's approach to environmental justice--emphasizing data analysis, managed public participation, and economic opportunity--helped both to deepen the neoliberal project and to transform the geography of risk and remediation. Although the EPA was unable to “normalize” the environmental justice community--to make it a standardized target for the Clinton administration's empowerment programs--its environmental justice policy both contributed to subtle changes in the distribution of hazardous waste risk and made the delivery of neocommunitarian programs an important part of the work of remedial personnel.  相似文献   
897.
Over the last decade, hundreds of climate change adaptation projects have been funded and implemented. Despite the importance of these first-generation adaptation projects for establishing funders and implementors’ “best practices,” very little is known about how early adaptation projects have endured, to what ends, and for whom. In this article, I propose a community-based methodology for ex-post assessment of climate change adaptation projects. This methodology contributes to recognitional justice by asking the individuals and collectives tasked with sustaining adaptation initiatives to define adaptation success and what criteria for success should be assessed. I apply this subjective assessment approach in 10 communities across Ecuador that participated in an internationally funded adaptation project that concluded in 2015. My analysis draws together participatory mapping, walking interviews with local leaders, participant observation, and surveys with former project participants. The results highlight that even adaptation projects that were deemed highly successful at their closure have uncertain futures. I find that the sustainability mechanisms that were envisioned by project implementors have not functioned, and communities are shouldering the burden of reviving failing adaptation interventions. These findings highlight that the current model of episodic funding for climate change adaptation projects and evaluation processes needs to be revisited to acknowledge the long-term challenges faced by communities. This analysis also calls attention to the importance of ex-post assessment for adaptation projects and the potential of subjective assessment approaches for building more ontological and epistemological pluralism in understandings of successful climate change adaptation.  相似文献   
898.
On the occasion of the thirtieth anniversary of the United Nations Framework Convention on Climate Change, this principal supra-national institution remains paramount to the project of planetary climate planning and governance. Reflections on this anniversary should serve to recall the contestations through which this foundational institution was formed, and the delegate dynamics that continue to be reproduced in its wake. The contentious debates and political dynamics that afflicted the Intergovernmental Negotiating Committee tasked with crafting the Framework Convention on Climate Change, as well as dissension in the periphery, remain as relevant today as they were three decades ago. Reprising these dynamics through detailed historical and archival analysis, this article excavates the negotiations of the 1992 Framework Convention on Climate Change by the Intergovernmental Negotiating Committee, which met in 5 sessions during 1991–1992. The aim is to identify key fault-lines and conflicts in the lead-up to the finalization of the 1992 Convention, in order to demonstrate whose epistemic and normative commitments came to be reflected in the final outcome and to show how the legacy of this process endures to date. I seek to render visible actors and proposals peripheralized in the formation of planetary climate governance to extrapolate normative boundaries and proffer heterodox lessons from the margins.  相似文献   
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