太湖底泥中微囊藻环境适应性的实验研究     

吴生才  陈伟民 《海洋湖沼通报》2004,(4):41-45

研究太湖冬季底泥和经过处理后的底泥中活体微囊藻 (Microcystisspp .)细胞的数量 ,并将分离出来的微囊藻经过低温 (3～ 4℃ )、高温 (>38℃ )、干燥、无光等处理 ,探讨了太湖微囊藻对不良环境的适应 ,为研究太湖藻类季节性变化规律和微囊藻水华的爆发机理。结果表明 ,微囊藻能在低温、高温、干燥、低光或无光的环境中长时间生存 ,条件适宜时又能快速增殖。这些特性使得微囊藻不仅具备良好的环境适应性和耐受性 ,而且具备良好的传播和增殖能力。讨论了微囊藻对不良环境的适应与其在水华中的优势地位的相关性。  相似文献   

Distributions of Calanus spp. and other mesozooplankton in the Labrador Sea in relation to hydrography in spring and summer (1995-2000)     

E.J.H Head  L.R HarrisI Yashayaev 《Progress in Oceanography》2003,59(1):1-30

We collected mesozooplankton samples in the upper 100 m in spring or early summer each year between 1995 and 2000 along a section from Hamilton Bank (Labrador) to Cape Desolation (Greenland), and along additional sections in spring 1997 and early summer 1995. The North Atlantic waters of the central basin were characterised by the presence of the copepods Calanus finmarchicus, Euchaeta norvegica and Scolecithrocella minor and euphausiids. Calanus glacialis, Calanus hyperboreus and Pseudocalanus spp. were associated with the Arctic waters over the shelves. Amongst the other enumerated groups larvaceans were concentrated over the shelves and around the margins. Amphipods, pteropods and the copepods Oithona spp. and Oncaea spp. showed no definable relationships with water masses or bathymetry, while the diel migrant ostracods and chaetognaths were confined to deep water. Metrida longa, also a strong diel migrant, and Microcalanus spp., a mainly deep water species and possible diel migrant, were both sometimes quite abundant on the shelves as well as in the central basin, consistent with their likely Arctic origins.Analysis of community structure along the section across the Labrador Sea indicated that stations could be grouped into five different zones corresponding to: the Labrador Shelf; the Labrador Slope; the western and central Labrador Sea; the eastern Labrador Sea and Greenland Slope; and, the Greenland Shelf. The boundaries between zones varied spatially between years, but community composition was relatively consistent within a given zone and a given season (spring versus early summer). The relationship between community composition and water masses was not entirely straightforward. For example, Labrador Shelf water was generally confined to the shelf, but in spring 2000 when it also dominated the adjacent slope zone, the community in the Labrador Slope zone was similar to those found in other years. Conversely, in spring 1997, when Arctic organisms were unusually abundant in the Labrador Slope zone, there was no increased contribution of shelf water. In addition, North Atlantic organisms were often found on the shelves when no slope or central basin water was present.Although other organisms were sometimes very abundant, the mesozooplankton preserved dry weight biomass was dominated everywhere by the three species of Calanus, which together always accounted for ≥70%. One species, C. finmarchicus, comprised >60% of the total mesozooplankton biomass and >80% of the abundance of large copepods in spring and summer throughout the central Labrador Sea. In western and central regions of the central basin average C. finmarchicus biomass was ca 4 g dry weight m⁻² and average abundance, ca 17?000 m⁻² over both seasons. Highest levels (ca 7 g dry weight m⁻², >100?000 m⁻²) occurred in the northern Labrador Sea in spring and in eastern and southwest regions in early summer. C. hyperboreus contributed ca 20% of the total mesozooplankton biomass in the central basin in spring and <5% in early summer, while C. glacialis accounted for <1%. Over the shelves, C. hyperboreus contributed a maximum of 54% and 3.6 g dry weight m⁻², and C. glacialis, a maximum of 29% and 1 g dry weight m⁻², to the total mesozooplankton biomass.  相似文献   

三种织纹螺性畸变的发展过程与雄性结构效应     

施华宏  黄长江  于秀娟  朱四喜  张瑜斌 《海洋科学》2004,28(9):36-41

从2000年3月到2002年10月对中国沿海海产腹足类性畸变的大范围调查过程中．在广东省汕头港、湛江港和厦门港分别采集到西格织纹螺(Nassarius siquijorensis)、胆形织纹螺(Nassarius thersites)和节织纹螺(Nassarius hepaticus)等3个种，解剖观察发现3种织纹螺的雌性个体都发生了性畸变现象。根据织纹螺性畸变的发展过程，对目前的性畸变发展划分体系作了新的修改和补充。通过对比性畸变个体与正常雄性个体的特征．探讨了雄性个体结构特征在性畸变过程中的效应。  相似文献   

柽柳灌丛热量收支特性与蒸散研究   总被引：5，自引：1，他引：5  

张小由  龚家栋  周茂先  司建华 《高原气象》2004,23(2):228-232

Bowen能量平衡法是广泛用于测定各种低矮植物蒸散的常用方法。本文将改进的波文比—能量观测系统用于测定灌木柽柳群落的测定，通过6～9月对感热通量、潜热通量、土壤热通量等的测定，计算出额济纳地区柽柳灌丛(6～9月)的蒸散量为335．31mm；在8月潜热通量占能量支出量的62．85％，感热通量占32．85％，土壤热通量占4．44％。在日变化中，潜热在上午大于感热，下午感热交换大于潜热。  相似文献   

应用热脉冲技术对胡杨和柽柳树干液流的研究   总被引：38，自引：2，他引：36  

张小由  龚家栋  周茂先  司建华 《冰川冻土》2003,25(5):585-590

应用热脉冲技术对干旱区胡杨(Populus euphrtaicr)和柽柳(Tamaris spp.)树干液流速度进行了研究.结果表明:在正常生长状态下,胡杨树干单位面积液流通量为0 34L·cm^-2·d^-1,柽柳为0 15L·cm^-2·d^-1.树液流速的日变化表现出多峰形特征,在午后有短暂液流急速减小的现象,而晚上植物为了补充体内水分亏缺,保持一定的树液流量.随着胸径的增大,茎流速率和茎流量也随之增大.在生长季节胸径21cm和15cm的胡杨日平均耗水量23.3L和19.25L;基径5cm和4cm的柽柳日平均耗水量0.62L和0.37L.在生长季节(5～10月)胡杨总蒸腾量为3419.4L,柽柳仅为63.9L.  相似文献   

Sensitive skates or resilient rays? Spatial and temporal shifts in ray species composition in the central and north-western North Sea between 1930 and the present day   总被引：8，自引：5，他引：3  

Walker  P. A.; Hislop  J. R. G. 《ICES Journal of Marine Science》1998,55(3):392-402

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太湖浮游植物和各形态无机氮的时空分布特征   总被引：6，自引：1，他引：5  

冯露露  李正魁  周涛 《湖泊科学》2012,24(5):739-745

为研究太湖浮游植物和各形态无机氮的时空分布特征及其相互关系,于2010年3月至2011年2月在太湖全湖范围内选取9个采样点进行每月采样分析,结果表明:太湖无机氮主要以硝态氮和铵氮形式存在,前者占76%,后者占22%;太湖北部靠近西北沿岸的湖区以及竺山湾的铵氮和亚硝态氮浓度通常要明显高于其他点位.太湖各采样点TIN(总溶解性无机氮)的季节变化趋势很相似,都表现为春季最高,夏秋季降低,冬季又有所升高;夏季北部湖区TIN降幅明显大于南部,使得前者TIN/TSP(总溶解性磷)远小于后者.春季太湖南部的微囊藻复苏量大于北部,但夏秋季微囊藻的暴发主要发生在太湖北部,此时微囊藻大暴发的点位(如梅梁湾)通常都伴随着很低的硝态氮浓度和TIN/TSP,使得这些点位比其他地方更容易发生N限制;Chl.a/浮游植物的比值与浮游植物总数呈极显著负相关,而与TIN/TSP的比值呈极显著正相关,这说明当藻类大量暴发而TIN/TSP下降时,浮游植物单个细胞内的平均Chl.a含量会有所下降,这种现象的原因有待进一步研究;绿藻、硅藻、裸藻和隐藻在时空分布上有一定相似性,而这四种藻与微囊藻则有较大差异.  相似文献   

太湖微囊藻的生长动力学     

陈伟民  陈宇炜  高锡云 《湖泊科学》1998,10(S1):347-356

Following the development of local industries, agriculture and the increase of living standard of people, Lake Taihu is in the meso-eutrophication stage. The main eutrophication part in this lake is the Meiling Bay. The dominant phytoplankton species are Microcystis, Anabena, Melosira, Cyclotella and Cryptomonas. In summer, Microcystis spp. occupys 85% of algae biomass and form the water bloom. This causes the trouble for the people lived around the lake, especially for the drinking water of Wuxi City.The Microcystis intrinsic rate was high, the Max. growth rate 1.27. Besides Microcystis own characteristics, its growth depended on irradiation, temperature and nutrients, especially the phosphorus. This paper also discussed the possibility of biomanipulation for restoration of lake ecology and the control strategy of lake eutrophication.  相似文献   

太湖群体微囊藻对同形溞(Daphnia similis)生长和繁殖影响的模拟     

戴曦  陈非洲 《湖泊科学》2012,24(1):149-155

富营养湖泊中蓝藻水华对枝角类种群和群落结构有显著的影响,但自然条件下群体微囊藻对大型枝角类溞属不同种类的影响仍存在争议.本研究通过两次为期各10 d的模拟实验,利用过滤后的太湖原水模拟群体微囊藻(20～100μm和100 ～200 μm)添加对大型枝角类同形溞(Daphnia similis)种群特征的影响,结果显示两次实验的同形溞均大量存活,不同浓度和颗粒大小的群体微囊藻对其生长和繁殖的影响不同,添加群体微囊藻的同形溞的生长和繁殖显著大于未添加微囊藻的.说明在自然条件下藻毒素对同形溞种群并没有明显的抑制作用,同形溞能够与微囊藻水华共存,其种群特征与微囊藻群体大小组成和生物量有关.  相似文献   

Hydrocarbon-Degrading Bacteria and Paraffin from Polluted Seashores 9 Years after the Nakhodka Oil Spill in the Sea of Japan     

Kazue TAZAKI Hiroaki WATANABE Siti Khodijah CHAERUN Koichi SHIRAKI Ryuji ASADA 《《地质学报》英文版》2006,80(3):432-440

Pollution of petroleum hydrocarbons, in particular oil spills, has attracted much attention in the past and recent decades. Oil spills influence natural microbial community, and physical and chemical properties of the affected sites. The biodegradation of hydrocarbons by microorganisms is one of the primary ways by which oil spill is eliminated from contaminated sites. One such spill was that of the Russian tanker the Nakhodka that spilled heavy oil into the Sea of Japan on January 2, 1997. The impact of the Nakhodka oil spill resulted in a viscous sticky fluid fouling the shores and affected natural ecosystems. This paper describes the weathering of hydrocarbon-degrading bacteria （genus Pseudomonas） and crystallized organic compounds from the Nakhodka oil spill-polluted seashores after nine years. The Nakhodka oil has hardened and formed crust of crystalline paraffin wax as shown by XRD analysis （0.422, 0.377, and 0.250 nm d-spacing） in association with graphite and calcite after 9 years of bioremediation. Anaerobic reverse side of the oil crust contained numerous coccus typed bacteria associated with halite. The finding of hydrocarbon-degrading bacteria and paraffin wax in the oil crust may have a significant effect on the weathering processes of the Nakhodka oil spill during the 9- year bioremediation.  相似文献