A biodiversity evaluation framework for restoration of aquatic macrophyte communities in shallow lakes driven by hydrological process management     

Shuhan Li  Tao Sun  Wei Yang  Baoshan Cui  Xinan Yin 《水文研究》2021,35(1):e13983

Macrophyte community diversity and composition respond to ecosystem conservation and local environmental factors. In this study, we developed a multidimensional diversity framework for macrophyte communities, including the taxonomic and functional alpha and beta diversity. We used the framework to explore the relationships among water level regimes and these diversity parameters in a case study of China's Baiyangdian Lake. Analysis of indicators of hydrologic alteration divided the water level from 1959 to 2019 into four regimes (dry, <6.42 m; low, 6.42–7.23 m; medium, 7.23–8.19 m; high, >8.19 m). Alpha and beta diversity were significantly higher in the medium regime than in the low and high regimes. Redundancy analysis indicated that the maximum water depth significantly affected taxonomic alpha diversity, and total nitrogen (TN) and chemical oxygen demand (COD) concentration significantly affected functional alpha diversity, respectively. Mantel tests showed that TN, Secchi depth (SD), and water depth in the high water level regime significantly increased the total beta diversity and turnover components. TN was the main factor that increased total taxonomic beta diversity. Water level regime mainly influenced interspecific relationships by changing the TN and COD concentration. The water level should be maintained between the medium and high water level regimes to promote restoration of the macrophyte community and improve ecosystem stability. The biodiversity evaluation framework would provide a deeper insight into the hydrological process management for restoration of aquatic macrophyte communities in shallow lakes.  相似文献   

GROWTH OF NEW ECONOMIC SECTORS IN SECOND-TIER EXTENDED CITIES IN THE CHANGJIANG RIVER DELTA——Case of Suzhou, Wuxi, Changzhou     

《中国地理科学(英文版)》2004,14(4):296-303

1INTRODUCTIONUrbanrelationshipaswellasurbansystemhas beenthemostimportantandlastingdirectioninthestudyofur-bangeographysinceCHRISTALLER(1933)putfor-wardthecentralplacetheory.Alongwiththepaceofglobalizationinthe1980s,somepioneer researchessen-sitivelyexpoundedaworldcitysystem,includingworldcity,internationalcity,nationalcity,regionalcityandlocalcity(FRIEDMAN,1986).Lotsofresearchesfo-cusedonthedevelopingmechanismofthebigcitiesandurbansystemnetwork(GU,2000;ZHOU,1997;CUI,1992;HUeta…  相似文献   

A taxonomical and ecological survey of rotiffer communities in Krottensee (Austria)     

Zhu Ge-yan 《中国海洋湖沼学报》1996,14(4):308-315

The composition and distribution of benthic, periphytic and planktonic rotifers in different habitats in Krottensee were investigated. Sixty-five rotifer taxa were identified, their relative abundance estimated. Classification of the data set by cluster analysis allowed the recognition of distinct habitat groups confined to acid bog ponds, macrophytes, sediments and open water. Five groups of rotifer taxa were identified on the basis of their habitat preferences and the occurrence of the taxa. Highest diversities were found on macrophytes and in acid bog ponds.  相似文献   

The spatial implications of the functional proximity deriving from air passenger flows between European metropolitan urban regions     

Malcolm C. Burns  Josep Roca Cladera  Montserrat Moix Bergadà 《GeoJournal》2008,71(1):37-52

Until recently the traditional spatial configuration of the European geography was based upon the core-periphery model. The ‘pentagon’, broadly defined as lying between London, Paris, Milan, Munich and Hamburg, was seen as the core area characterised by having the highest concentration of economic development in the European Union (EU), with the remainder of the European territory viewed as peripheral, albeit to varying degrees. In a number of cases such peripheral areas equated with clear regional disparities. The elaboration of the European Spatial Development Perspective (ESDP) (CEC, European spatial development perspective, towards balanced and sustainable development in the territory of the European Union, 1999) challenged this core-periphery model. European spatial planning policies, aimed at encouraging social and economic, and with ever increasing importance, territorial cohesion, seek amongst other aspects to encourage the development of a balanced and polycentric urban system. This paper adopts a network analysis approach to the analysis of air passenger flows between some 28 principal European metropolitan urban regions. The evaluation of these flows contributes to an enhanced comprehension of the spatial dynamics of the European metropolitan territory which goes beyond that deriving from the more standard analyses of the individual components of the urban system. Several indicators are used, deriving from gravitational modelling techniques, to analyse the complexity of the air passenger flows. A multidimensional scaling (MDS) technique is introduced in order to interpret and visualise the resulting spatial configuration and positioning of the different metropolitan centres within the conceptual European ‘space of air passenger flows’, thereby contrasting with the more traditional map-based geographical image of Europe, based upon Cartesian coordinates.

Malcolm C. BurnsEmail:

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湛江港外海水富营养化水平与浮游植物多样性   总被引：3，自引：0，他引：3  

彭昆仑  贾后磊 《海洋通报》2007,26(2):113-116

利用2001年12月在湛江港外海现场调查的资料,分析研究了湛江港外海水营养化水平及其与浮游植物多样性的关系。结果表明:湛江港外海水营养状态指数由北向南、由湾口向湾外递减;浮游植物多样性指数和均匀度则是由北向南增加,东南部水质较好,东北部水质较差;将营养盐含量及营养状态水平与浮游植物多样性指数和均匀度利用最小二乘法进行相关性,相关性不显著,另外,调查期间氮磷比例均失去平衡,这可能是影响该海域浮游植物量与营养盐水平之间关系的原因。  相似文献   

Functional responses for zooplankton feeding on multiple resources: a review of assumptions and biological dynamics     

Wendy Gentleman  Andrew Leising  Bruce Frost  Suzanne Strom  James Murray 《Deep Sea Research Part II: Topical Studies in Oceanography》2003,50(22-26):2847

Modelers often need to quantify the rates at which zooplankton consume a variety of species, size classes and trophic types. Implicit in the equations used to describe the multiple resource functional response (i.e. how nutritional intake varies with resource densities) are assumptions that are not often stated, let alone tested. This is problematic because models are sensitive to the details of these formulations. Here, we enable modelers to make more informed decisions by providing them with a new framework for considering zooplankton feeding on multiple resources. We define a new classification of multiple resource responses that is based on preference, selection and switching, and we develop a set of mathematical diagnostics that elucidate model assumptions. We use these tools to evaluate the assumptions and biological dynamics inherent in published multiple resource responses. These models are shown to simulate different resource preferences, implied single resource responses, changes in intake with changing resource densities, nutritional benefits of generalism, and nutritional costs of selection. Certain formulations are further shown to exhibit anomalous dynamics such as negative switching and sub-optimal feeding. Such varied responses can have vastly different ecological consequences for both zooplankton and their resources; inappropriate choices may incorrectly quantify biologically-mediated fluxes and predict spurious dynamics. We discuss how our classes and diagnostics can help constrain parameters, interpret behaviors, and identify limitations to a formulation's applicability for both regional (e.g. High-Nitrate-Low-Chlorophyll regions comprising large areas of the Pacific) and large-scale applications (e.g. global biogeochemical or climate change models). Strategies for assessing uncertainty and for using the mathematics to guide future experimental investigations are also discussed.  相似文献   

Trends in biomass, density and diversity of North Sea macrofauna   总被引：6，自引：2，他引：6  

Heip  C.; Basford  D.; Craeymeersch  J. A.; Dewarumez  J. M.; Dorjes  J.; de Wilde  P.; Duineveld  G.; Eleftheriou  A.; Herman  P. M. J.; Niermann  U.; Kingston  P.; Kunitzer  A.; Rachor  E.; Rumohr  H.; Soetaert  K.; Soltwedel  T. 《ICES Journal of Marine Science》1992,49(1):13-22

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Microbial Diversity in Nankai Trough Sediments at a Depth of 3,843 m   总被引：6，自引：0，他引：6  

Lina Li  Jean Guenzennec  Peter Nichols  Pierre Henry  Miki Yanagibayashi  Chiaki Kato 《Journal of Oceanography》1999,55(5):635-642

Dense populations of bivalves, primarily Calyptogena sp., were observed at cold seeps of the Nankai Trough. Bacterial input to the sediment was estimated through determination of phospholipid ester-linked fatty acid (PLFA) and DNA profiles. Results indicated a bacterial biomass of 10⁹ cells (g dry wt)^-1 while individual fatty acid profiles revealed a predominance of monounsaturated fatty acids, mainly 18:1 isomers. The presence of these fatty acids can be interpreted to reflect a response to low temperature and a predominance of psychrophilic bacteria. DNA fragments encoding bacterial ribosomal RNA small-subunit sequences (16S rDNA) were amplified by the polymerase chain reaction method using DNA extracted directly from the sediment samples. From the sequencing results, at least 19 kinds of bacterial 16S rDNAs related to mostly the Proteobacteria and a few gram-positive bacteria were identified. These results suggest that the bacterial community in the Nankai Trough sediments consists of mainly bacteria belonging to the Proteobacteria , , and subdivisions. Bacteria belonging to the and subdivisions, which are known to include epibiont and sulfate reducing bacteria, respectively, were mostly detected in the sediment obtained from inside the area of the Calyptogena community, and the -Proteobacteria may function to supply reduced sulfur to bacterial endosymbionts of Calyptogena.  相似文献   

绒螯蟹种质资源研究进展   总被引：1，自引：1，他引：1  

张秀梅  柳广东  高天翔 《中国海洋大学学报(自然科学版)》2002,32(4):533-542

本文综述了近年来有关绒螯蟹属在形态学、遗传学和育种学方面的研究进展 ,着重介绍了同工酶、RAPD和 mt DNA技术在绒螯蟹群体遗传学中的应用 ,提出遗传学分类标准的建立是绒螯蟹属分子分类的关键所在。  相似文献   

花尾胡椒鲷养殖群体遗传多样性的等位酶研究   总被引：5，自引：1，他引：5  

丁少雄  王军  苏永全  全成干  张纹  郭丰  马梁 《台湾海峡》2001,20(2):224-227,T002

应用聚丙烯酰胺凝胶电泳（PAGE）技术对取自厦门火烧屿海水网箱的花尾胡椒鲷人工鱼养殖群体的遗传多样性进行等位酶分析。结果表明：所检测的16种同工酶的24个基因座位中，在XDH和GCDH基因座位上发现多态性，其平均多态位点比例为8．33％，基因座位有效等位基因的平均数Ne为1.083，平均杂合度的观测值Ho为0．00556，预期值He为0．00537,Hardy-Weinberg遗传偏离指数（D)为0．035。与其他鱼类相比较说明了其遗传多样性处于较低水平，文中对此进行了探讨并提出相应的种质资源管理保护措施。  相似文献