芦苇床中古细菌的群落多样性分析

为了描述剩余污泥稳定化芦苇床系统中有机质矿化、甲烷排放及相关微生物多样性之间的内在关系,采用PCR-DGGE技术分析了不同芦苇床、不同季节的稳定化污泥中古细菌群落结构及其多样性。序列分析发现,与DGGE条带序列亲缘关系最近的种属为未培养古细菌和未培养产甲烷古细菌。古细菌群落结构呈季节性变化,且同一季节不同芦苇床的群落结构存在一定差异。具有通气结构芦苇床的剩余污泥中产甲烷古细菌的丰度较低,同时甲烷排放量也较低,因此设置通气结构的芦苇床设计更合理。     

污泥干化芦苇床中芦苇内生菌群多样性研究

以污泥干化芦苇床中芦苇内生菌的多样性作为主要研究对象,结合16S rDNA高通量测序技术与PCR-DGGE技术,对污泥干化芦苇床和天然湿地中污泥菌群及芦苇内生菌群多样性进行了比较分析。结果表明,污泥干化芦苇床芦苇内生菌的细菌类群包含了20门、30纲、73目、152科、467属、1 167种细菌。其中变形菌门(65.6%)和拟杆菌门(25.5%)占绝对优势,γ-变形菌纲是丰度最高的纲,占总数的43.4%;排前20位的优势菌种相对百分比之和为46.5%,分属于所对应的18个属、12科、10目、6纲、3门。DGGE分析表明,污泥干化芦苇床中的污泥和芦苇内生菌优势菌群的种类与天然湿地相比差异显著;同时由于污泥的影响,芦苇内生菌群种类也发生了较为明显的变化。     

浅谈沈阳市地表水环境功能区达标存在的问题及应采取的措施

对沈阳市地表水水质现状及实现功能区达标存在的问题及原因进行了分析 ,并就如何实现地表水环境功能区达标的阶段目标提出了相应的对策     

Impacts of lands cover change on plant and bird species diversity in Hainan Island, China

--Hainan Island, located at the southern end of China, hasless than 0.4% of land area but contains 13% of plant and animalspecies in China. During the last four decades many primary forestshave been converted to shrub land, grassland, and tree planation(e.g., eucalyptus forest). As a result, area of primary tropicalforest has been reduced from 25.8% in the 1950s to 4% in the 1990s.To assess impacts of land conversion on plant and bird speciesdiversity, a series of samples in primary forest and four types ofconverted lands were took. The land conversion had tremendouslyreduced both plant and bird species diversity. Specifically, plantspecies richness per site was 83.7 in primary forest, 28.3 in shrubland, 12.5 in grassland, 14.4 in eucalyptus forest, and 21.4 inAcacia forest. Bird species richness showed a similar trend 22.0in primary forest, 14.5 in shrub land, 2.5 in grassland, 4.9 ineucalyptus forest, and 9.0 in Acacia forest. The Shannon speciesdiversity indices for plants in the five types of land cover were3.69, 1.99, 0.97, 1.47 and 2.07, respectively. Similarly, the Shannon indices for bird species diversity were the highest in primary forest, and lowest in grassland, and intermediate in shrubland and eucalyptus forest.     

北京地区蜉蝣目（Ephemeroptera）稚虫的分布及与水质关系的研究

报道了北京地区几条主要河流蜉蝣稚虫的种类分布，探讨了其群落结构特征及其与水体环境质量之间的关系，运用种类多样性指数和聚类分析方法对各水体质量状况进行分类评价，结果表明白河和拒马河质量为最好，其余依次为永定河、清水河上游、潮河和清水河。     

江西井冈山甜槠群落特征及物种多样性

井冈山自然保护区地处中亚热带的东部，以甜槠等为建群种的常绿阔叶林是井冈山的主要地带性植被。通过对甜槠群落进行分析研究，充分认识其群落学特征和物种多样性，为该植物群落多样性保护与持续利用提供科学依据。     

珠穆朗玛峰自然保护区的初步评价

对珠穆朗玛峰自然保护区的综合评价表明:珠峰自然保护区具有藏南高原和中喜马拉雅山地两大自然地理单元的地域特征,同时还含有代表上述地域特色的多种国家重点保护的珍稀、濒危动、植物种类,该保护区具很强的自然性,颇赋感染力;区内生态系统脆弱,急需进行保护;保护区地域辽阔,生物多样性强、具有很高的科研潜力。根据上述特征,珠峰自然保护区属综合型自然保护区(生态系统保护区),其级别应列为国家级。同时,珠峰自然保护区亦符合联合国教科文组织人与生物圈计划的生物圈保护区和联合国世界遗地的要求,所以可以申请加入生物圈保护区网和申请列为世界遗产地。     

Portfolio-Based Electricity Generation Planning: Policy Implications For Renewables And Energy Security

Renewable generating technologies offer an effective means for climate change mitigation. Policy makers, however, are wary because of the widespread perception that these technologies cost more than conventional alternatives so that increasing their deployment will raise overall electricity generating costs. Energy planning represents an investment-decision problem. Investors commonly evaluate such problems using portfolio theory to manage risk and maximize portfolio performance under a variety of unpredictable economic outcomes. Energy planners need to similarly abandon their reliance on traditional, “least-cost” stand-alone kWh generating cost measures and instead evaluate conventional and renewable energy sources on the basis of their portfolio cost – their cost contribution relative to their risk contribution to a mix of generating assets. Energy security generally focuses on the threat of abrupt supply disruptions. This paper suggests a more profound aspect: mitigating fossil price volatility. An extensive body of research indicates that fossil volatility significantly disrupts the economies of consuming nations, potentially exacting hundreds of billions of dollars from the US and EU economies alone. Energy security is reduced when countries hold inefficient portfolios that are needlessly exposed to fossil price risks. This paper describes essential portfolio-theory ideas and uses three case studies to illustrate how electricity-generating mixes can benefit from additional shares of wind, geothermal and other renewables. Compared to existing, fossil-dominated mixes, efficient portfolios reduce generating cost while including greater renewables shares in the mix thereby enhancing energy security. Though counter-intuitive, the idea that adding more costly renewables can actually reduce portfolio-generating cost is consistent with basic finance theory. An important implication is that in dynamic and uncertain environments, the relative value of generating technologies must be determined not by evaluating alternative resources, but by evaluating alternative resource portfolios.     

Variations of plant life form diversity along northeast China transect and its direct gradient analysis

Plant life form diversity and its direct gradientanalysis on a larger scale climate change gradient were tested,based on the data from Northeast China transect platform. Theresults showed that the species numbers, life form richness andlife form diversity were relative higher at the eastern forests andthe ecotone between typical vegetation, while those on the meadowgrasslands and typical steppes were lower. Although plant lifeforms can reflect the climate variations, life form diversity isnot consistent with the major global gradient along the NECT.     

杭州湾生态监控区浮游动物多样性研究

根据2004年5、8月2个航次杭州湾生态监控区浮游动物的监测资料,对浮游动物的种类组成和多样性进行了研究。结果表明,2个航次杭州湾生态监控区共监测到浮游动物49种,隶属于11大类,以桡足类为主,有21种;水母类5种;糠虾类4种;毛颚类3种;幼虫7种;磷虾类、樱虾类、端足类、十足类和多毛类各1种,其他类4种。生物量在8．3-400．0 mg／m3,栖息密度在22．5-285．0个／m3,平均栖息密度为116．25个／m3;5月大于8月。多样性指数在1．64-3．41,5、8月杭州湾浮游动物的多样性阈值平均为1．7、2．1,多样性水平Ⅲ级,显示杭州湾生态监控区浮游动物多样性较好。