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1.
2012年秋季渤海和北黄海浮游植物群落   总被引:2,自引:0,他引:2  
应用Utermhl方法对2012年秋季渤海和北黄海浮游植物的物种组成、细胞丰度和群落结构特征等进行了分析,并应用典范对应分析(CCA)对调查海域浮游植物和环境因子进行了相关性分析.本次调查共鉴定出浮游植物3门38属94种,其中硅藻门29属62种,甲藻门8属31种,金藻门1属1种,物种生态习性以温带种和广布种为主.调查海域浮游植物细胞丰度介于0.30×103~10.48×103 L-1,平均值为2.79×103 L-1,硅藻主要优势物种为具槽帕拉藻(Paralia sulcata)和圆筛藻(Coscinodiscus sp.);甲藻主要优势种为梭状角藻(Ceratium fusus)和三角角藻(Ceratium tripos).浮游植物群落Shannon-Wiener多样性指数介于0.32~2.95,平均值为1.49;Pielou均匀度指数介于0.16~0.89,平均值为0.55.CCA分析结果显示,调查海域优势种主要受磷酸盐限制.与历史资料比较发现,该海域浮游植物群落由早期的硅藻占绝对优势向硅藻甲藻联合占优转变.  相似文献   

2.
为研究金沙江典型河段浮游藻类的群落结构特征及主要影响因素, 于2014年秋季(10 月)在石鼓至宜宾江段布设6 个断面进行浮游藻类群落监测。通过显微镜观察, 共鉴定出浮游藻类6门30属52种, 其中硅藻的物种数、细胞密度和生物量分别占65.38%, 74.07%和80.65%, 是优势门类。浮游藻类总细胞密度和生物量都呈现坝上逐渐降低、坝下逐渐升高的规律, 石鼓最高, 向家坝最低。多样性分析表明, 攀枝花的浮游藻类群落多样性最高, 溪洛渡和向家坝均较低。浮游藻类与环境因子的RDA分析表明, 总氮是影响浮游藻类群落结构的主要环境因子。优势属现存量与环境因子的相关性分析结果表明, 包括尖针杆藻Synedra acus 和曲壳藻Achnanthes sp.在内的6种硅藻与水位正相关, 与水温负相关, 是适合在低温下生活的藻类, 小环藻Cyclotella sp.则适合在温度较高的环境中生长。网状空星藻 Coelastrum reticulatum、栅藻Scenedesmussp.、尖尾蓝隐藻Chroomonas acuta 和小环藻Cyclotella sp.的现存量与总氮显著正相关, 能够指示水体中的氮浓度; 近缘桥弯藻Cymbella affinis 和谷皮菱形藻Nitzschia palea的现存量与总磷呈显著正相关, 能够指示水体中的磷浓度。  相似文献   

3.
2011年秋季北黄海浮游植物群落   总被引:4,自引:0,他引:4  
2011年11月21—25日在北黄海海域对32个站位进行了生物采样,应用Utermohl方法对调查海域的浮游植物群落进行了研究.经115个样品的分析,共发现浮游植物3门31属64种.调查区浮游植物群落主要由硅藻和甲藻组成,还有少量的金藻,物种以暖温性和广布性物种为主,主要优势种为:具槽帕拉藻、虹彩圆筛藻、三角角藻、斯氏几内亚藻、梭形角藻和旋链角毛藻等.本次调查浮游植物细胞丰度平均值为4.2×10^3个/L;硅藻占浮游植物细胞丰度的比例最大,平均值为3.6x10^3个/L;其次为甲藻,平均值为O.95×10^3个/L.调查海域浮游植物细胞丰度分布不均匀,辽宁南岸海域最高,山东近岸海域其次,北黄海中部海域最低.细胞丰度在水体中的垂直分布趋势为先降低后升高,其中底层的细胞丰度主要由具槽帕拉藻和虹彩圆筛藻贡献.从断面分布上看,细胞丰度高值多集中在受陆源输入影响明显的近岸海域.调查区浮游植物群落多样性指数和均匀度指数均在北黄海北部海域较高,在近岸海域较低.与历史资料的对比发现,近30年来北黄海浮游植物群落结构比较稳定.  相似文献   

4.
2006年夏季渤海湾赤潮重点监控区的网采浮游植物群落   总被引:4,自引:0,他引:4  
研究了2006年夏季渤海湾赤潮重点监控区6个测站大面积调查的网采浮游植物物种及其群落特征,共发现浮游植物5门32属60种,物种主要以硅藻为主,但甲藻在群落中的比重也很明显,在个别站位上成为优势类群.优势物种主要为格氏圆筛藻(C.granii Gough)、星脐圆筛藻(C.asteromphalus)、琼氏圆筛藻(C.jonesianus)和中华盒形藻(Biddulphia sinensis).细胞丰度的站住分布主要由浮游硅藻的分布所决定,其高值区分布在4号站住.  相似文献   

5.
2015年7月、10月和2016年1月、4月通过对青山湖浮游藻类群落结构及水体污染状况进行调查,鉴定出浮游植物有7门73属112种,其中绿藻门最多,共计33属56种,占总种数的50%.浮游植物细胞密度为3.40×108~7.26×108cells·L-1,以蓝藻为主;浮游植物平均生物量为8.105 mg·L-1,以硅藻和绿藻为主;细胞密度优势种为假鱼腥藻、细小平裂藻、美丽星杆藻、二尾栅藻、极小单针藻,生物量优势种包括颗粒直链藻极狭变种、新星形冠盘藻、栅藻、卵囊藻.利用Shannon-Wiener多样性指数、Pielou均匀度指数、Margalef指数及丰富度指数(S)与水体的理化性质相结合对水质作出了评价,结果显示青山湖水质处于中度污染状态.  相似文献   

6.
泉州湾虾池浮游植物种类多样性研究   总被引:2,自引:0,他引:2  
2003年11月~2004年5月对福建泉州湾东海虾池进行定点采样,并分析其浮游植物的种类多样性和种群动态.结果表明,泉州湾虾池共有浮游植物42属166种,硅藻为优势种群,共35属154种;甲藻3属6种.新月筒柱藻Cylindrotheca closterium、微小小环藻Cyclotella caspia、狭窄双眉藻Amphora angusta、菱形藻属Nitzschia为主要优势种,它们在浮游植物群落总细胞数中的百分比平均高达34.8%.通过对水温、营养盐、浮游植物种群密度及群落的多样性指数和均匀度的分析,发现虾池高强度的排污排废所引起的富营养化已很大程度影响了浮游植物的群落结构和时空分布,使生物多样性和均匀度下降,少数优势种类大量繁殖.硅藻和甲藻赤潮的发生机会增多.  相似文献   

7.
泉州湾虾池浮游植物种类多样性研究   总被引:4,自引:0,他引:4  
2003年11月~2004年5月对福建泉州湾东海虾池进行定点采样,并分析其浮游植物的种类多样性和种群动态.结果表明,泉州湾虾池共有浮游植物42属166种,硅藻为优势种群,共35属154种;甲藻3属6种.新月筒柱藻Cylindrotheca closterium、微小小环藻Cyclotella caspia、狭窄双眉藻Amphora angusta、菱形藻属Nitzschia为主要优势种,它们在浮游植物群落总细胞数中的百分比平均高达34.8%.通过对水温、营养盐、浮游植物种群密度及群落的多样性指数和均匀度的分析,发现虾池高强度的排污排废所引起的富营养化已很大程度影响了浮游植物的群落结构和时空分布,使生物多样性和均匀度下降,少数优势种类大量繁殖.硅藻和甲藻赤潮的发生机会增多.  相似文献   

8.
为了研究秦皇岛贝类养殖区滤食性贝类饵料来源和摄食选择性特点,于2019年5月对该海域的海水和4种贝类(紫贻贝、海湾扇贝、长牡蛎、栉孔扇贝)进行采样调查。利用显微镜检法和光合色素液相色谱法(HPLC)对海水和贝类胃容物中的浮游植物种群结构进行比较研究。结果显示,水体中浮游植物主要由硅藻、甲藻、隐藻组成,硅藻在丰度上占有绝对优势。光合色素HPLC检出水体中特征色素主要为硅藻、青绿藻和甲藻,而贝类胃容物中主要为甲藻和硅藻,少量青绿藻检出。四种贝类摄食选择性相似且不受水体中优势藻种的影响,主要以甲藻、硅藻中不占优势的藻种为食,对部分占优势藻种表现出避食性(中肋骨条藻和角毛藻),微微型浮游植物(青绿藻)对4种贝类的饵料贡献率较低。  相似文献   

9.
为探究四丰水库封冻前后浮游植物种类组成和优势种生态位物种与生态位变化关系.采用抽样检验、优势度指数和Levins指数法对四丰水库浮游植物进行调查分析.结果表明:四丰水库封冻前后浮游植物中硅藻门最多,其次是绿藻门,再次是隐藻门;优势种有5个,分别是甲藻门的真蓝裸甲藻(Gymnodinium eucyaneum),金藻门的胞鞭藻,绿藻门的四尾珊藻(Scenedes-mus quadricauda),隐藻门的卵形隐藻(Cryptomons ovata),硅藻门的变异直链藻(Melosira vari-ans)和梅尼小环藻(Cyclotella meneghiniana);浮游植物的生态位随封冻前后水体环境发生变化不明显.  相似文献   

10.
【目的】研究浙江南麂列岛海洋自然保护区浮游植物群落结构特征及其与环境的关系,为评价该海域生态环境质量的现状及其变化趋势提供科学依据。【方法】以2013年11月和2014年5月对该保护区28个站位的调查数据为基础,分析浮游植物的种类组成,以及细胞丰度、优势度指数、多样性指数、综合富营养化指数等。【结果】南麂列岛多数水体处于富营养状态。春季调查共发现浮游植物2门24种(属),秋季调查共发现浮游植物2门22种(属);物种组成以广温性近岸种为主,主要优势种为甲藻和硅藻。春季调查中夜光藻(Noctilucas cintillans)、圆筛藻属(Coscinodiscus sp.)和海链藻属(Thalassiosirasp.)成为优势类群;秋季调查中具槽帕拉藻(Paralia sulcata)成为优势类群。【结论】南麂列岛浮游植物群落在近二十年来物种数及丰度均发生了一定程度的变化:物种数大幅减少,春秋季平均丰度上升。  相似文献   

11.
Language markedness is a common phenomenon in languages, and is reflected from hearing, vision and sense, i.e. the variation in the three aspects such as phonology, morphology and semantics. This paper focuses on the interpretation of markedness in language use following the three perspectives, i.e. pragmatic interpretation, psychological interpretation and cognitive interpretation, with an aim to define the function of markedness.  相似文献   

12.
何延凌 《科技信息》2008,(4):258-258
Language is a means of verbal communication. People use language to communicate with each other. In the society, no two speakers are exactly alike in the way of speaking. Some differences are due to age, gender, statue and personality. Above all, gender is one of the obvious reasons. The writer of this paper tries to describe the features of women's language from these perspectives: pronunciation, intonation, diction, subjects, grammar and discourse. From the discussion of the features of women's language, more attention should be paid to language use in social context. What's more, the linguistic phenomena in a speaking community can be understood more thoroughly.  相似文献   

13.
王慧 《科技信息》2008,(10):240-240
Wuthering Heights, Emily Bronte's only novel, was published in December of 1847 under the pseudonym Ellis Bell. The book did not gain immediate success, but it is now thought one of the finest novels in the English language. Catherine is the key character of this masterpiece, because everybody and everything center on her though she had a short life. We can understand this masterpiece better if we know Catherine well.  相似文献   

14.
The Williston Basin is a significant petroleum province, containing oil production zones that include the Middle Cambrian to Lower Ordovician, Upper Ordovician, Middle Devonian, Upper Devonian and Mississippian and within the Jurassic and Cretaceous. The oils of the Williston Basin exhibit a wide range of geochemical characteristics defined as "oil families", although the geochemical signature of the Cambrian Deadwood Formation and Lower Ordovician Winnipeg reservoired oils does not match any "oil family". Despite their close stratigraphic proximity, it is evident that the oils of the Lower Palaeozoic within the Williston Basin are distinct. This suggests the presence of a new "oil family" within the Williston Basin. Diagnostic geochemical signatures occur in the gasoline range chromatograms, within saturate fraction gas chromatograms and biomarker fingerprints. However, some of the established criteria and cross-plots that are currently used to segregate oils into distinct genetic families within the basin do not always meet with success, particularly when applied to the Lower Palaeozoic oils of the Deadwood and Winnipeg Formation.  相似文献   

15.
There are numerous geometric objects stored in the spatial databases. An importance function in a spatial database is that users can browse the geometric objects as a map efficiently. Thus the spatial database should display the geometric objects users concern about swiftly onto the display window. This process includes two operations:retrieve data from database and then draw them onto screen. Accordingly, to improve the efficiency, we should try to reduce time of both retrieving object and displaying them. The former can be achieved with the aid of spatial index such as R-tree, the latter require to simplify the objects. Simplification means that objects are shown with sufficient but not with unnecessary detail which depend on the scale of browse. So the major problem is how to retrieve data at different detail level efficiently. This paper introduces the implementation of a multi-scale index in the spatial database SISP (Spatial Information Shared Platform) which is generalized from R-tree. The difference between the generalization and the R-tree lies on two facets: One is that every node and geometric object in the generalization is assigned with a importance value which denote the importance of them, and every vertex in the objects are assigned with a importance value,too. The importance value can be use to decide which data should be retrieve from disk in a query. The other difference is that geometric objects in the generalization are divided into one or more sub-blocks, and vertexes are total ordered by their importance value. With the help of the generalized R-tree, one can easily retrieve data at different detail levels.Some experiments are performed on real-life data to evaluate the performance of solutions that separately use normal spatial index and multi-scale spatial index. The results show that the solution using multi-scale index in SISP is satisfying.  相似文献   

16.
The discovery of the prolific Ordovician Red River reservoirs in 1995 in southeastern Saskatchewan was the catalyst for extensive exploration activity which resulted in the discovery of more than 15 new Red River pools. The best yields of Red River production to date have been from dolomite reservoirs. Understanding the processes of dolomitization is, therefore, crucial for the prediction of the connectivity, spatial distribution and heterogeneity of dolomite reservoirs.The Red River reservoirs in the Midale area consist of 3~4 thin dolomitized zones, with a total thickness of about 20 m, which occur at the top of the Yeoman Formation. Two types of replacement dolomite were recognized in the Red River reservoir: dolomitized burrow infills and dolomitized host matrix. The spatial distribution of dolomite suggests that burrowing organisms played an important role in facilitating the fluid flow in the backfilled sediments. This resulted in penecontemporaneous dolomitization of burrow infills by normal seawater. The dolomite in the host matrix is interpreted as having occurred at shallow burial by evaporitic seawater during precipitation of Lake Almar anhydrite that immediately overlies the Yeoman Formation. However, the low δ18O values of dolomited burrow infills (-5.9‰~ -7.8‰, PDB) and matrix dolomites (-6.6‰~ -8.1‰, avg. -7.4‰ PDB) compared to the estimated values for the late Ordovician marine dolomite could be attributed to modification and alteration of dolomite at higher temperatures during deeper burial, which could also be responsible for its 87Sr/86Sr ratios (0.7084~0.7088) that are higher than suggested for the late Ordovician seawaters (0.7078~0.7080). The trace amounts of saddle dolomite cement in the Red River carbonates are probably related to "cannibalization" of earlier replacement dolomite during the chemical compaction.  相似文献   

17.
理论推导与室内实验相结合,建立了低渗透非均质砂岩油藏启动压力梯度确定方法。首先借助油藏流场与电场相似的原理,推导了非均质砂岩油藏启动压力梯度计算公式。其次基于稳定流实验方法,建立了非均质砂岩油藏启动压力梯度测试方法。结果表明:低渗透非均质砂岩油藏的启动压力梯度确定遵循两个等效原则。平面非均质油藏的启动压力梯度等于各级渗透率段的启动压力梯度关于长度的加权平均;纵向非均质油藏的启动压力梯度等于各渗透率层的启动压力梯度关于渗透率与渗流面积乘积的加权平均。研究成果可用于有效指导低渗透非均质砂岩油藏的合理井距确定,促进该类油藏的高效开发。  相似文献   

18.
As an American modern novelist who were famous in the literary world, Hemingway was not a person who always followed the trend but a sharp observer. At the same time, he was a tragedy maestro, he paid great attention on existence, fate and end-result. The dramatis personae's tragedy of his works was an extreme limit by all means tragedy on the meaning of fearless challenge that failed. The beauty of tragedy was not produced on the destruction of life, but now this kind of value was in the impact activity. They performed for the reader about the tragedy on challenging for the limit and the death.  相似文献   

19.
In the 19th century the society was controlled by men, and women were just appendants of them, they had not any rights and freedom. But Jane was an exception, she showed some characteristics of early feminist. Jane showed her characteristics of feminism in three aspects: rebellion, equality, and independence. These characteristics were helpful to her success, and feminism is the only way out for women of that time.  相似文献   

20.
1 Rise of studies on climate change's effects on biodiversity
Until the 1980s, climate change and biodiversity were studied as two independent disciplines for more than a century. In 1992, the Ecological Society of America's annual report named climate change, biodiversity, and the sustainable ecological system as the three major global environmental issues of the twenty-first century [1].  相似文献   

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