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1.
浙江岱山岛潮间带大型底栖动物的群落结构   总被引:4,自引:0,他引:4  
分析了浙江岱山岛潮间带大型底栖动物的种类组成、数量分布和生物多样性等群落结构特征.该海域潮间带调查采获的大型底栖动物标本26种,其中软体动物16种,节肢动物6种,脊索动物2种,腔肠动物与环节动物各1种.潮问带大型底栖动物总平均生物量为279.22g/m2,总平均栖息密度为493 ind/m2.在各类群底栖动物中,平均生物量及密度都以软体动物居首位.岱山岛潮间带大型底栖动物的多样性指数、丰富度指数和均匀度指数的分布范围分别在1.176~2.115、0.833~1.897和0.565~0.801,平均值分别为1.490±0.429、1.223±0.465和0.654±0.104.岱山潮间带大型底栖动物ABC曲线分析表明底栖动物群落中度的污染或者干扰.  相似文献   

2.
广东闸坡潮间带大型底栖动物的群落特征   总被引:1,自引:0,他引:1  
分析了广东省闸坡潮间带生物的种类组成、数量分布和生物多样性等特点。结果表明,该海域潮间带调查采获的潮间带生物标本共55科80种,以软体动物和甲壳类出现的种类最多,两者占了总种类数的85%,其中部分属经济价值较高的种类。潮间带生物总平均生物量为7 420.92 g/m2,总平均栖息密度为3 929.93 ind/m2。全年各类群生物中,平均生物量及栖息密度都以软体动物居首位。其Shannon-Weaner多样性指数(H)属中等水平,分布范围在1.657~4.226,平均为2.848;均匀度(J′)为0.390~0.721,平均为0.612;种类丰度(D)为2.062~4.234,平均为2.964。  相似文献   

3.
浙江沿岸人工鱼礁拟投海域大型底栖生物生态比较研究   总被引:5,自引:0,他引:5  
根据2003年7~9月在浙江沿岸休闲生态型人工鱼礁拟投海域开展的本底调查所获的大型底栖生物等资料,对各人工鱼礁拟投海域大型底栖生物的种类组成、数量分布和群落结构特征进行了详细的比较研究.调查共鉴定176种大型底栖生物,主要为沿岸广温广布种,其中多毛类、软体动物和甲壳动物占总种数的90%以上,构成了浙江沿岸人工鱼礁拟投海域底栖生物的主要类群.各拟投海域底栖生物的生物量和栖息密度分布不均匀,最高生物量和栖息密度分别为57.23 g/m2和872.5个/m2,最低仅0.23 g/m2和35个/m2.大部分拟投海域底栖生物的多样性指数和均匀度都较高,表明其群落结构比较稳定.  相似文献   

4.
根据2006年3月同安湾12个调查站位所采集的大型底栖生物样品,对同安湾底栖生物组成和群落结构进行叙述和讨论.结果表明:同安湾大型底栖生物共有163种,其中多毛类、软体动物和甲壳动物为三大主要类群.海区大型底栖生物平均丰度为845 ind./m2,平均生物量是13.81 g/m2,鳄鱼屿附近海域丰度和生物量相对较低.根据Cluster聚类和MDS标序的结果,同安湾大型底栖生物可划分成3个群落,群落Ⅰ的多样性水平最高.同时,使用复合k-优势度曲线法对各个群落结构受扰动的程度进行分析,结果显示3个群落均出现一定扰动.  相似文献   

5.
为了掌握浙江玉环披山省级海洋特别保护区岩礁潮间带贝类资源状况,于2015年11月、2016年2月、5月、8月,共4次对该区岩礁潮间带的5个断面进行了定量与定性采样调查,并对贝类的种类、数量、区系组成、优势种和物种多样性进行了分析。共鉴定出披山岩礁潮间带贝类33种,隶属于3纲9目17科。根据温度适应性质分,属于4个类群:广温广布性种18种,占54.6%;温带种1种,占3.0%;亚热带种13种,占39.4%;热带种1种,占3.0%。此次调查贝类总平均生物量为413.84 g/m~2,总平均栖息密度为266.71个/m~2。条纹隔贻贝是4个季度的绝对优势种。贝类物种Margalef丰富度指数D为1.75,Shannon-Wiener多样性指数H'为1.56,Pielou均匀度指数J'为0.67。研究表明,玉环披山潮间带贝类多样性指数属正常范围,显示未过度开发。  相似文献   

6.
在浙江玉环披山省级海洋特别保护区布设5个岩相潮间带断面,于2015年11月至2016年8月,分季度对潮间带大型底栖藻类进行了采样调查。结果表明:该保护区岩相潮间带共有大型底栖藻类43种,其中,红藻16种、褐藻5种、绿藻5种、蓝藻1种。春夏秋冬四季的大型底栖藻类的平均生物量为167.97 g·m-2,其中春季最高(337.49 g·m-2),夏季最低(99.76 g·m-2)。根据其适温性分析,该调查区域的大型底栖藻类以暖温带种类为主,占总种类数的63%;其次是亚热带种。鼠尾藻是四季唯一共有优势种。大型底栖海藻类四季物种丰富度指数(D)总平均值为0.50,均匀度指数(J′)为0.32,多样性指数(H′)为0.43,三者数值按季节从大到小排序均为春冬秋夏。  相似文献   

7.
本文报导了六横岛潮间带底栖生物的种类、组成、数量分布及其与环境因子的关系。经鉴定,六横岛泥沙滩潮间带共有底栖生物27种,其中软体动物占40.8%,多毛类和甲壳类各占29.6%。泥沙滩底栖生物密度(除沙滩节肢动物外)均以高潮区→低潮区逐渐降低,不同潮区生物量均无明显的变化规律,但不同生境潮间带决定着不同底栖生物种类组成,泥滩以多毛类占优势,沙滩则以软体动物占优势.  相似文献   

8.
【目的】研究渤海海域底栖生物群落状况,探明2011年发生的蓬莱19-3平台溢油事故对该海域底栖生物群落结构的长期影响。【方法】根据2014年夏季对渤海海域32个站位底栖生物的采样调查资料,并与历史数据进行比较,分析渤海海域底栖生物的群落结构、物种组成和底质状况。【结果】渤海海域32个站位共鉴定出大型底栖生物191种,其中多毛类环节动物83种,甲壳动物40种,软体动物42种,棘皮动物15种,其它类群动物11种。优势种为凸壳肌蛤(Musculus senhousei)。调查海域大型底栖生物平均丰度为676.88ind/m2,变化范围为15~11 555ind/m2,低于溢油前水平;平均生物量为30.77g/m2,变化范围为0.09~141.55g/m2,高于溢油前水平。生物量的主要贡献者为棘皮动物,丰度的主要贡献者为软体动物,底栖生物群落结构的小型化有减缓趋势。Shannon-Wiener物种多样性指数、Margalef物种丰富度指数和Pielou物种均匀度指数平均值分别为3.11±1.20,2.89±1.40和0.82±0.22。ABC曲线显示渤海海域正处于中度扰动状态,溢油区各站位ABC曲线均显示底质状况较好,但个别站位生物量起点较低且曲线整体偏左,说明有向中度干扰发展的趋势。【结论】溢油事故3年后,受溢油影响的底栖生物群落已得到不同程度的恢复。  相似文献   

9.
乌贼的生殖习性,是把卵产附于枝状或棒状附着物上。在自然海区可供附卵的底栖生物有珊瑚、海柏、大型海藻等。但是,在传统的乌贼产卵场,这些底栖附着物数量大量减少,如东极区附近岛屿一带,经潜水调查,柳珊瑚每平方米只有0.5株,大陈因暖海性特征较强,柳珊瑚相应多些,马道头、屏风山最密处每平方米可达70~80株,但分布不均匀,如上屿、中屿和下屿就很少见到。大型藻类东极区较多,而大陈较少,且大型藻类分布在水下  相似文献   

10.
山东半岛东部海域诸岛潮间带底栖海藻的研究   总被引:4,自引:1,他引:3  
报道山东半岛东部海域主要以威海市北面和南面8个岛屿春、秋两季潮间带底栖海藻群落组成、生物量、季节变化及主要环境因子。在两季度月得到海藻88种,秋季比春季种数多,北面4岛种类略多于南面4岛,群落构成都以红藻类为主。各岛平均生物量秋季高于春季,北面4岛高于南面4岛。就各岛生物量而言,北断面高于南断面。  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.
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   

13.
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   

14.
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   

15.
AcomputergeneratorforrandomlylayeredstructuresYUJia shun1,2,HEZhen hua2(1.TheInstituteofGeologicalandNuclearSciences,NewZealand;2.StateKeyLaboratoryofOilandGasReservoirGeologyandExploitation,ChengduUniversityofTechnology,China)Abstract:Analgorithmisintrod…  相似文献   

16.
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   

17.
正The periodicity of the elements and the non-reactivity of the inner-shell electrons are two related principles of chemistry,rooted in the atomic shell structure.Within compounds,Group I elements,for example,invariably assume the+1 oxidation state,and their chemical properties differ completely from those of the p-block elements.These general rules govern our understanding of chemical structures and reactions.Using first principles calcula-  相似文献   

18.
We have developed an adiabatic connection to formulate the ground-state exchange-correlation energy in terms of pairing matrix linear fluctuations.This formulation of the exchange-correlation energy opens a new channel for density functional approximations based on the many-body perturbation theory.We illustrate the potential of such approaches with an approximation based on the particle-particle Random Phase Approximation(pp-RPA).This re-  相似文献   

19.
正The electronic and nuclear(structural/vibrational)response of 1D-3D nanoscale systems to electric fields gives rise to a host of optical,mechanical,spectral,etc.properties that are of high theoretical and applied interest.Due to the computational difficulty of treating such large systems it is convenient to model them as infinite and periodic(at least,in first approximation).The fundamental theoretical/computational problem in doing so is that  相似文献   

20.
For molecular systems,the quantum-mechanical treatment of their responses to static electromagnetic fields usually employs a scalar-potential treatment of the electric field and a vector-potential treatment of the magnetic field.Although the potential for each field separately is associated with the choice of an(unphysical)origin,the precise choice of the origin for the electrostatic field has little consequences for the results.This is different for the  相似文献   

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