2011年胶州湾网采浮游植物群落结构及其环境影响因子

本文于2011年1-12月对胶州湾海域浮游植物进行了周年调查,获得了同步的温盐和营养盐数据,分析了浮游植物丰度、优势种类、多样性指数和季节变化特征及其与环境影响因子的关系。结果表明：共检出浮游植物108种（包括变种和变型）,其中硅藻门34属93种,甲藻门6属14种,金藻门1属1种。浮游植物主要由硅藻和甲藻两大类组成,其中硅藻占绝对优势,全年甲藻/硅藻比均小于0.08。优势种共有35种,夏、冬季优势种交替明显,全年几乎均出现的种类为圆筛藻（Coscinodiscus spp.）,旋链角毛藻（Chaetoceros curvisetus）和中肋骨条藻（Skeletonema costatum）。生态类型主要以广布种、广温近岸种、温带近岸种为主,也出现了少数暖水种和外洋种。浮游植物丰度分别在2月、4月和7月份达到峰值,其中4月全年最高,为591×10⁶cell/m³,2月是次高峰,数量为468×10⁶cell/m³,7月为172×10⁶cell/m³,秋季浮游植物丰度相对较低。本研究结果与胶州湾浮游植物典型双峰型变化不同。浮游植物群落多样性指数平均为2.4,秋、冬季节较高,春、夏季节偏低,水平分布上呈现湾外 > 湾口 > 湾内的趋势,均匀度平均值为0.26,分布趋势与多样性指数基本相同。由此可见,湾外浮游植物群落结构较湾口和湾内更为稳定,温度、硅酸盐、亚硝酸盐、硝酸盐、铵盐和磷酸盐对浮游植物丰度和群落结构存在明显影响。     

南黄海夏初网采浮游植物分布与长期变化

本文根据2012和2013年夏初南黄海网采浮游植物调查数据,与1959、2002及2003年的调查资料作比较,研究了南黄海海域浮游植物的分布和长期变化规律。结果表明,浮游植物生物量的年际变化波动较大,1959年全国海洋综合调查时期的浮游植物生物量显著低于2012—2013年的生物量。2013年浮游植物平均丰度和碳含量最高,分别为(18.73±46.68)×104cell/m3和(1110.71±2107.82)μg C/m3。近岸海域的浮游植物对南黄海浮游植物总生物量有主要贡献。1959年,硅藻在群落中的丰度比例大于93%,而2012—2013年,这一比例下降为50%—60%。相应地,硅藻碳含量比例由70%—85%下降为18%—28%,且甲藻占优势的区域扩大。硅藻碳含量比例在群落中明显下降一方面是因为硅藻碳密度相对较低,另一方面是因为甲藻丰度的增大。相对于1959年,近年来硅藻中的角毛藻属(Chaetoceros)和伪菱形藻属(Pseudonitzschia),以及甲藻中的角藻属(Ceratium)和夜光藻属(Noctiluca)成为新的优势种属。与环境因子的相关性分析表明,影响南黄海夏初浮游植物群落分布的关键环境因子为温度、盐度、硅酸盐和溶解性无机氮。     

北黄海獐子岛邻近海域大型底栖动物群落结构和季节变化

本文以2009年8月-2010年6月在北黄海獐子岛海域4个季度航次调查的大型底栖动物资料为基础,分析了该海域大型底栖动物群落的结构和季节变化。结果表明,4个航次共采集了211种底栖动物,调查海域主要优势种为薄索足蛤(Thyasira tokunagai)、斑角吻沙蚕(Goniada maculata)、紫蛇尾(Ophiopholis mirabilis)、博氏双眼钩虾(Ampelisca bocki)和短角双眼钩虾(Ampelisca brevicornis),各季节的优势种组成有明显变化;运用聚类分析和MDS研究了其群落结构,将该区域大型底栖动物分为3个群落,即,群落I--位于调查区北部的美原双眼钩虾(Ampelisca miharaensis)-短角双眼钩虾(Ampelisca brevicornis)-斑角吻沙蚕群落,群落II--位于獐子岛邻近的紫蛇尾(Ophiopholis mirabilis)-日本倍棘蛇尾群落(Amphioplus japonicus),群落III--位于南部区域的薄索足蛤-浅水萨氏真蛇尾(Ophiura sarsii vadicola)群落,各群落有一定的季节变化;运用ABC曲线分析了4个季节群落受扰动情况,表明该海域环境良好,受扰动较小,夏季受扰动略大于其它季节。     

船舶的微生物腐蚀与防护技术*

海洋环境中的微生物腐蚀已被公认为是海洋工程金属构筑物的腐蚀破坏的重要形式。航行在海洋中的船舶不仅受到海水腐蚀的影响,各个部件还会受到微生物腐蚀的影响。严重的微生物腐蚀会导致管路阻塞、部件失效和腐蚀穿孔,不仅影响船舶设备正常运行,也严重威胁船舶安全。本文系统分析了船舶微生物腐蚀发生的位点和危害、不同位点的腐蚀微生物群落结构特征、船舶材料的微生物腐蚀以及不同防护技术的适用范围,并在此基础上提出对船舶微生物腐蚀研究工作的建议。     

Reed litter Si content affects microbial community structure and the lipid composition of an invertebrate shredder during aquatic decomposition

The decomposition of plant litter is an important mechanism in regard to energy and nutrient dynamics of ecosystems. Silicon concentration of plant tissue can affect these processes by changing litter quality, i.e. nutrient stoichiometry and cellulose and phenols content. To determine which group of microbial decomposers benefits from high Si content in plants and how this impacts on animal decomposers, a batch experiment was conducted with reed leaf litter (Phragmites australis) differing in Si content in the presence/absence of invertebrate shredders (Gammarus pulex). Lipid concentration of G. pulex, in reed litter and fine particulate matter (FPOM) were examined. High Si concentration in reed resulted in a decline of gram positive bacteria in the heterotrophic biofilm and of gram negative bacteria in FPOM. The lipid composition in the next trophic level, the decomposer G. pulex, changed too, indicating a diet shift in favor of bacteria and algae with increasing litter Si concentration. Thus, basal decomposers were affected by the Si availability in plant resources, and these effects likely persist along the food chain, as FPOM is a dominant food supply for other groups, e.g. collectors. This impact of Si content on plant substrate quality for decomposer food webs may have global relevance, due to related modifications in carbon and nutrient cycling during litter decomposition.     

Mind mapping as an interactive tool for engaging complex geographical issues

Students and communities engaging with complex geographical issues require tools to assist them structure and contextualise data. This paper examines the use of mind mapping as a tool in geographical education. Case studies are presented from a sample of undergraduate and cross-cultural educational settings demonstrating the use of mind mapping in communication, analysis and problem solving. In critiquing this educational tool, we conclude that mind mapping is particularly effective with communities whose cultures are strong on visual communication but weaker on written communication and in cross-cultural situations where use of written English would disadvantage learners.     

甘肃沙葱的地理分布与群落结构特征

甘肃沙葱主要分布于河西走廊北部荒漠区及白银、兰州市的西北部部分县(区)的黄土低山丘陵区,分布区总面积约125 715.9km²。有气候和土壤因素形成的两种生态类型,且沙葱荒漠的物种组成成分相对简单,共有76种,分属14科45属;群落类型可划分为5类14个群丛组合,表现出以超旱生小灌木层片、强旱生小半灌木层片及沙旱生草层片为主的旱生结构特征。此外,甘肃沙葱种群及群落表现出均匀度低、优势度高、分布范围广、群落结构单一、适应性极强、具有地域性等特征。     

Phylogenetic analysis of bacterial community in deep-sea sediment from the western Pacific “warm pool”

A depth profile of bacterial community structure in one deep-sea sediment core of the western Pacific ＂warm pool＂ （WP） was investigated and compared with that in a sediment sample from the eastern Pacific （EP） by phylogenetic analysis of 16S rDNA fragments. Five bacterial 16S rDNA clone libraries were constructed, and 133 clones with different restriction fragment length polymorphism （RFLP） patterns were sequenced. A phylogenetic analysis of these sequences revealed that the bacterial diversity in a sample from the WP was more abundant than that in the EP sample. The bacterial population in the sediment core of WP was composed of eight major lineages of the domain bacteria. Among them the γ-Proteobacteria was the predominant and most diverse group in each section of WP sediment core, followed by the α-Proteobacteria. The genus Colwellia belonging to γ-Proteobacteria was predominant in this sample. The shift of bacterial communities among different sections of the WP sediment core was δ-, ε-Proteobacteria, and Cytopahga-Flexibacteria-Bacteroides （CFB） group. The ratios between them in the bacterial communities all showed inversely proportional to the depth of sediment. The sequences related to sulphate reducing bacteria （SRB） were detected in every section. The bacterial community structure in this sediment core might be related to the environmental characteristics of the surface seawater of the western Pacific WP.     

青海湖鸟岛沙地植物群落物种多样性研究

根据野外样地调查资料,采用丰富度指数、物种多样性指数和均匀度指数对青海湖鸟岛沙地植物群落的多样性进行了研究,并用相关分析研究了多样性指数间的关系,结果表明:①鸟岛7个主要沙地群落间的植物多样性差异很大,分布于固定沙丘上的赖草、甘青铁线莲等群落均具有较高的丰富度指数、多样性指数,而西伯利亚蓼、藏虫实等分布在流动沙丘上的群落则最小,但均匀度指数最高。②从流动沙丘到固定沙丘阶段的变化过程中,丰富度指数、Shannon Wiener指数和Simpson指数的变化趋势基本一致,而均匀度指数则呈相反趋势,半固定沙丘是这一变化的重要转折点。③物种在各沙地类型中出现频率的多样性指数差异很大,特有种多样性指数在固定沙丘中最高,占主导地位,而在流动沙丘阶段,普通种的物种多样性指数最高。④植物生活型上各沙丘类型上的物种多样性指数均以多年生草本为最高,其次为一年生草本,而且从流动沙丘至固定沙丘阶段呈递增变化。⑤丰富度指数与多样性指数、均匀度指数之间存在极显著的相关性。     

旅游景区市场化运作对目的地社区的影响评析——"凤凰模式"的个案研究

以湖南凤凰县8大景区为个案,通过旅游地社区政府部门、投资商和社区居民三大利益主体以及旅游者的实地调查和访谈,对景区市场化运作给旅游地社区所带来的经济、社会、文化和环境影响进行了实证分析,结果表明旅游景区市场化运作的绩效显著但矛盾并存,文中就如何完善旅游景区市场化运作模式,规避经营管理风险和负面影响等方面作了进一步的理论思考.