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151.
IntroductionMethane ( CH4) is a radiatively active trace gas ,contributing approximately 20 % to global warming(Bouwman, 1990) . An increasing concentration in theatmosphere, and ill-defined sink and source strengths haveled to a proliferation of the stud…  相似文献   
152.
南海南部海域浮游细菌群落特征及影响因素研究   总被引:4,自引:0,他引:4       下载免费PDF全文
采用高通量测序技术,对南海南部海域浮游细菌丰度、群落组成和群落多样性的分布特征及与环境因子的关系进行了研究.结果表明,该研究区域浮游细菌丰度为107~108个/L,近岸大于离岸,同一站位不同水层细菌分布差异明显.优势类群为变形菌门、蓝藻门和拟杆菌门,优势亚群为 γ-变形菌纲、α-变形菌纲、蓝藻菌纲和黄杆菌纲,研究区域内不同水体间物种组成存在较大差异,另外该海域还存在大量未被认知的细菌类群.该海域浮游细菌种类丰富,具有较高的多样性指数(H¢)(4.44~7.00),研究区域内表层水体H¢接近,分别为5.26、5.33和5.07,处于上升流的次表层水体中H¢为6.70明显高于其他水层.DOC和磷酸盐是影响该海域浮游细菌丰度的主要因素,同时磷酸盐也是影响其群落多样性的主要因素,表明该海域异养浮游细菌生长主要受P的限制.  相似文献   
153.
黑碳(black carbon,BC)的湿清除对其大气寿命和环境气候效应的评估至关重要。本研究使用黑碳仪(Aethalometer,AE-33)在南岭地区对BC开展了三次观测,结合指数衰减方程评估了传输过程中累计降雨量(accumulated precipitation along the trajectory,APT)对华南地区BC传输效率的影响。此外,将BC来源区分为生物质燃烧源(biomass burning,BB)和化石燃料燃烧源(fossil fuel burning,FF),探讨了不同排放源BC湿清除比例(wet scavenging ratio,WSR)的差异。结果表明:基于指数衰减方程结果和WSR的结果指出华南地区的BC受到湿清除的影响要明显大于日韩等偏远地区,可能反映了更高拟合的BC老化程度。APT在5—30 mm范围内的增加对BC的湿清除有显著的影响。不同来源BC的WSR存在显著差异:BCBB的WSR(44%—62%)高于BCFF(35...  相似文献   
154.
联合国将碳中和视为当今世界最为紧迫的任务,而农业是温室气体排放最多的产业之一,各国相继出台政策积极开展农业农村减排工作。韩国自2012年开始逐渐减少海洋粪污排泄量,并大力实行绿色种养循环农业,解决本国内畜禽粪污问题。韩国作为中国的重要海上邻国,不论是从研究借鉴角度抑或生态系统共享角度,了解其环境保护政策都是十分必要的。本文从韩国实施的主要政策、各地区农地养分收支现状、代表性运营模式案例、政策关注焦点等方面介绍韩国绿色种养循环农业的发展概况,结合中国绿色种养循环农业现状开展研究。提出三点政策建议:第一,进一步完善畜禽粪污资源化利用机具补贴辅助管理系统,提高系统在农户中的普及率;第二,提高全民环保意识的同时,政府的角色不应局限自上而下的引导型,应该积极促进种植户和养殖户间的自发组织,并大力提倡吸纳社会资本,集结社会各方力量;第三,促进绿色种养循环农业产品的商品化和品牌化,从而调动农户参与绿色种养循环农业的积极性。  相似文献   
155.
Adapting to climate variability: Pumpkins, people and policy   总被引:2,自引:0,他引:2  
Understanding of how best to support those most vulnerable to climate stress is imperative given expected changes in climate variability. This paper investigates local adaptation strategies to climate variability, focusing on agricultural decision‐making in a communal irrigation scheme in Vhembe District, Limpopo Province, South Africa. Research done through interviews, surveys and participatory methods demonstrates that adaptation strategies within a community are socially differentiated and present differing objectives and priorities. These results highlight the need for intervention and policy that support a heterogeneous response to a wide range of stresses. Evidence for climate change is clear and the need for adaptation is urgent. However, adaptation measures have to be sensitively integrated with ongoing development pathways to ensure they are sustainable and relevant to local priorities.  相似文献   
156.
江苏南部的下、中侏罗统,长期以来笼统称之为象山群。本文根据地层岩性特征和大量动植物化石的研究,结合与邻区地层之对比,将江苏南部下、中侏罗统进一步划分为下侏罗统南象山组及中侏罗统北象山组;前者为含煤地层,大致相当于原象山群下部(或下段为),后者为红色地层,大致相当于原象山群上部(或上段)。  相似文献   
157.
158.
Nationally Appropriate Mitigation Actions (NAMAs) were proposed as a policy framework that could provide middle ground for meeting both the development and mitigation objectives in developing countries. While South Africa engaged actively with the NAMA terminology in the United Nations Framework Convention on Climate Change negotiations, its engagement at the domestic level has been rather lacklustre. This presents an interesting paradox. The paper studies the interplay of international norms embodied in NAMAs with South Africa's domestic policy process. Disengagement and contestation around NAMAs in South Africa is played out at three stages: decision-making stage where the symptoms surrounding this contestation first emerge; policy formulation stage where NAMAs have to not only align with the National Development Plan but also compete with a predilection for domestically familiar terminology of flagships under the national climate policy; and finally the broader agenda-setting stage of policy process, where NAMAs have to prove useful in not only pursuing the developmental state agenda but also in tackling the underlying material factors that represent country's economic dependency on fossil fuels. NAMAs faced combined resistance from ideas and interests in various degrees at all these stages resulting in their disengagement.  相似文献   
159.
Can environmental provisions in preferential trade agreements (PTAs) foster an environmental race to the top? The ways in which different enforcement mechanisms in North–South PTAs affect the implementation of environmental standards in developing countries are examined. It is argued that environmental provisions in European Union (EU) and United States (US) PTAs will be effective in instigating policy change in partner countries, although the timing of the effect will vary significantly. Fines and sanctions in US PTAs incentivize partner countries to reform during the negotiation process. Reform in EU PTA partners is predicted to occur during agreement implementation as a result of the EU’s policy dialogue approach. Illustrative evidence is provided and the hypotheses are tested using statistical estimations of EU and US PTAs with environmental provisions on developing countries’ environmental policy reform.  相似文献   
160.
Academic understandings of environmental discourses are primarily based on global and national accounts, despite widespread acceptance of the local as an essential site of environmental action. Local water issues have been studied in a number of ways, including interviews and ethnographies that show the impacts of water scarcity, examine the role of mediating technologies, and provide diverse perspectives on governance. An overarching impression of key narratives and concerns at local scales, however, is lacking. In this paper, we examine water coverage in The Sowetan, a South African newspaper known for its distinctive voice, as a (albeit imperfect) proxy for local discourse. We identify key themes, location and scale, trigger events, actors, authors, and provide initial insights into the problem frames used in these texts. Our findings show distinct differences from the results of environmental media analyses at other scales, including strong individual citizen voices, emphasis on the politics of water, and rare use of language that accords with global environmental discourses; this also differs from results based on interviews and ethnographies at the local scale. Our findings raise important questions about the resonance of global discourse with local views and practices and how local discourses are produced, and suggest a need to more carefully examine the myriad ways of talking about justice and the environment at different scales and through different methodologies.  相似文献   
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