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741.
742.
大连新港"7.16"输油管道爆炸溢油事故发生后,为探究石油污染与细菌群落结构变化之间的关系及在石油生物降解过程中起重要作用的细菌菌群,本研究对大连湾表层沉积物中石油烃含量和细菌宏基因组16SrDNA V3区进行分析。结果表明:溢油初期2010年8月DLW01站位表层沉积物石油烃含量高达1 492mg/kg,符合第三类沉积物质量标准,随着时间推移,2011年4月、2011年7月、2011年12月航次各站位沉积物中石油烃含量基本呈下降趋势,且均符合第一类沉积物质量标准;16S rDNA PCR-DGGE方法分析表明,石油烃含量高的区域优势细菌种类少,反之则较丰富;海洋环境中同一地点的细菌群落能保持一定稳定性;大连湾石油污染沉积物中变形菌门γ-变形菌纲和拟杆菌门一直保持较高的优势度,是在石油生物降解过程中起重要作用的细菌菌群,而厚壁菌门只在石油烃含量低的区域出现;此外,出现的对污染物敏感的嗜冷杆菌可作为石油污染指示生物进行深入研究。 相似文献
743.
Lidita Khandeparker Priya M. D'Costa Arga C. Anil Subhash S. Sawant 《Marine Ecology》2014,35(2):233-248
Interactions between microfouling components influence the biofilm community and the cascading events, thus playing an important role in the biofouling process. Bacteria and diatoms are among the dominant forms reported in biofilms. Experiments were carried out with natural marine biofilms from a tropical monsoon‐influenced environment to evaluate the interactions between bacteria and diatoms through application of antibiotics (streptomycin and chloramphenicol). Overall, chloramphenicol inhibited diatom communities, whereas streptomycin did not. These antibiotic‐mediated changes in the fouling diatom community were consistent across the seasons. However, the rates at which the fouling communities changed depended on the initial species composition. It was also observed that elevated nutrient concentrations overrode the inhibitory effect of chloramphenicol. Maximum Vibrio enhancement was observed in the enriched conditions during the pre‐monsoon and unenriched conditions during the monsoon (with naturally elevated background nutrient concentrations), highlighting the relevance of nutrient concentrations for Vibrio spp. This has interesting implications for antibiotic‐mediated interactions between fouling diatom and bacterial communities under differing nutrient regimes. Although this study indicates the relevance of ‘cross‐talk’ at the microfouling level, understanding the effects of additional microbial products (e.g. bacteriocins and peptidoglycan) on these community‐level interactions will represent a step forward. 相似文献
744.
Vivek N. Mathur Stavros Afionis Jouni Paavola Andrew J. Dougill Lindsay C. Stringer 《Climate Policy》2014,14(1):42-62
The literature on equity and justice in climate change mitigation has largely focused on North–South relations and equity between states. However, some initiatives (e.g. the Clean Development Mechanism (CDM), the Reducing Emissions from Deforestation and Forest Degradation programme (REDD), and voluntary carbon markets (VCMs)) are already establishing multi-level governance structures that involve communities from developing countries in global mitigation efforts. This poses new equity and justice dilemmas: how the burdens and benefits of mitigation are shared across various levels and how host communities are positioned in multi-level governance structures. A review of the existing literature is used to distill a framework for distinguishing between four axes of climate justice from the perspective of communities. Empirical evidence from African and Asian carbon market projects is used to assess the distributive and procedural justice implications for host communities. The evidence suggests that host communities often benefit little from carbon market projects and find it difficult to protect their interests. Capacity building, attention to local power relations, supervision of business practices, promotion of projects with primarily development aims and an active involvement of non-state actors as bridges between local communities and the national/international levels could potentially contribute towards addressing some of the key justice concerns.Policy relevance International negotiations on the institutional frameworks that are envisaged to govern carbon markets are proceeding at a rather slow pace. As a consequence, host countries and private-sector actors are making their own arrangements to safeguard the interests of local communities. While several standards have emerged to guide carbon market activity on the ground, distributive as well as procedural justice concerns nevertheless remain salient. Four empirical case studies across Asia and Africa show that within the multi-scale and multi-actor carbon market governance, local-level actors often lack sufficient agency to advance their claims and protect their interests. This evidence suggests that ameliorating policy reforms are needed to enhance the positioning of local communities. Doing so is important to ensure future acceptability of carbon market activity in potential host communities as well as for ensuring their broader legitimacy. 相似文献
745.
One of the fundamental questions in community ecology is whether communities are random or formed by deterministic mechanisms. Although many efforts have been made to verify non-randomness in community structure, little is known with regard to co-occurrence patterns in above-ground and below-ground communities. In this paper, we used a null model to test non-randomness in the structure of the above-ground and below-ground mite communities in farmland of the Sanjiang Plain, Northeast China. Then, we used four tests for non-randomness to recognize species pairs that would be demonstrated as significantly aggregated or segregated co-occurrences of the above-ground and below-ground mite communities. The pattern of the above-ground mite commu- nity was significantly non-random in October, suggesting species segregation and hence interspecific competition. Additionally, species co-occurrence patterns did not differ from randomness in the above-ground mite community in August or in below-ground mite com- munities in August and October. Only one significant species pair was detected in the above-ground mite community in August, while no significant species pairs were recognized in the above-ground mite community in October or in the below-ground mite communities in August and October. The results indicate that non-randomness and significant species pairs may not be the general rule in the above-ground and below-ground mite communities in farmland of the Sanjiang Plain at the fine scale. 相似文献
746.
Metazoan/microbial biostalactites from present‐day submarine caves in the Mediterranean Sea
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Rossana Sanfilippo Antonietta Rosso Adriano Guido Adelaide Mastandrea Franco Russo Robert Riding Emma Taddei Ruggiero 《Marine Ecology》2015,36(4):1277-1293
Biostalactites formed by metazoan–microbialite associations from three submerged marine caves in the Plemmirio Peninsula (south of Syracuse, Ionian Sea) are randomly distributed and show different sizes and morphologies, as well as variations in surface roughness/smoothness. The biostalactites consist of crusts a few centimeters thick of small serpulids and other metazoans, associated with fine‐grained carbonate; the larger ones often include a nucleus of serpulid tubes (Protula). The metazoans include mainly serpuloideans, sponges, bryozoans and foraminifers but microbial carbonates are also significant components. The composition of both the living communities and thanatocoenoses on the outer surfaces, as well as the composition and fabric of the internal framework, were analysed and used to reconstruct the history of the caves. All of the identified sessile faunas mainly consist of cryptic and sciaphilic dwellers that reflect cave conditions and their variations through time. The distribution pattern, composition and abundance of the present‐day dwellers largely depend on the degree of roughness of the biostalactite surfaces and their positions within the caves. It has been suggested that the Protula specimens in the nuclei represent pioneer populations that formed aggregates during the early cave colonization phase, in response to relatively high food supply from seawater inflow and intruding continental waters. By contrast, the outer metazoan–microbialite carbonates reflect more confined conditions in the caves caused by Holocene sea‐level rises. Hypotheses are proposed for biostalactite growth, taking into account information about the growth rates of some constituents, and evidence of dissolution effects. Similarities and differences between these biostalactites and other Holocene deposits previously described from submarine caves in the Mediterranean Sea and in tropical reefs are discussed. 相似文献
747.
Agricultural expansion remains the most important proximate cause of tropical deforestation, while interactions between socio-economic, technological and institutional factors represent the fundamental drivers. Projected population increases could further raise the pressure on the remaining forests, unless agricultural intensification allows raising agricultural output without expanding agricultural areas. The purpose of this article is to understand the role of institutional factors in governing the intensification process towards the goal of preserving forests from agricultural pressures, with a focus on Indigenous Peoples’ and local communities’ rights to forests (as embedded in the various tenure regimes). In this paper we adopt an international dimension and analyse the process of agricultural expansion across eleven Latin American countries over the period 1990–2010 to assess whether, in a context of agricultural intensification, different land tenure regimes impact differently on the realization of land-sparing or Jevons paradox. The results, based on a number of multivariate statistical models that controls for socio-economic factors, strongly suggest that the formal recognition of Indigenous Peoples and local communities’ forest rights has played an important role in promoting land sparing or attenuating Jevons paradox. 相似文献
748.
目前,我国的土地整治已进入生态化土地整治阶段。作为一种多类型、多尺度的综合生态治理系统,生态化土地整治可以从区域和工程尺度开展村域空间布局和工程设计,营造村域生态空间、生产空间和生活空间。村域生态空间营造可以通过村域绿色基础设施构建,形成绿色网络空间;村域生产空间(主要是农业生产空间)营造主要是通过生态化农田整理工程布局和单体工程设计,提升生态服务价值;村落生活空间营造可以通过村落空间格局塑造、街巷空间组织,庭院空间布局和公共空间建设等多个层次,形成营造适宜的居住空间。 相似文献
749.
Junxi Qian 《Singapore journal of tropical geography》2023,44(1):28-36
This commentary serves as a tribute to the late Pow, a remarkable scholar in urban geography and urban studies, summarizing his contributions to urban China studies. It aims to showcase the way in which Pow's work manoeuvred adroitly with an implicit comparative gesture—building a bridge between situated Chinese cases and wider theoretical debates in urban studies in order to enrich both domains. The essay then summarizes Pow's work in the field of urban China studies by focusing on two most emblematic topics that he delved into in great depth, i.e., gated communities and eco-city developments. The final section develops a brief quantitative analysis of the impact that Pow's work has generated. Using the software packages CiteSpace and HistCite, I unpack how his publications are cited and used by scholars, journals, and different areas of research. 相似文献
750.
村庄分类作为乡村地区制定差异化发展政策的科学手段,是认识和明晰区域乡村振兴路径的重要抓手。论文基于乡村地域系统演化规律,综合考虑地方主观发展意愿,构建了一套基于“政策-潜力-意愿”整合视角的村庄分类框架,按照“政策影响?发展潜力+在地发展意愿”的逻辑思路逐级识别村庄类型,并以西峰区100个行政村作为案例区进行实证分析。结果表明:(1)通过梳理现有政策文件,识别出54个村庄的类型,这部分村庄特征相对显著;其余部分村庄通过“发展潜力-在地发展意愿”耦合分析,确定其发展类型;(2)村庄发展潜力与在地发展意愿不完全耦合,其中“高潜力-低意愿”及“低潜力-高意愿”各占39.13%和6.52%;(3)西峰区村庄最终分为就地城镇化类、集聚提升类、城郊融合类、特色保护类、整治改善类及搬迁撤并类等六种类型,论文据此提出相应的乡村振兴途径及措施建议。 相似文献