Meiobenthic communities of seagrass beds (Zostera capricorni) and unvegetated sediments along the coast of New South Wales,Australia     

Gustavo Fonseca  Pat Hutchings  Fabiane Gallucci 《Estuarine, Coastal and Shelf Science》2011

Seagrass beds have higher biomass, abundance, diversity and productivity of benthic organisms than unvegetated sediments. However, to date most studies have analysed only the macrofaunal component and ignored the abundant meiofauna present in seagrass meadows. This study was designed to test if meiobenthic communities, especially the free-living nematodes, differed between seagrass beds and unvegetated sediments. Sediment samples from beds of the eelgrass Zostera capricorni and nearby unvegetated sediments were collected in three estuaries along the coast of New South Wales, Australia. Results showed that sediments below the seagrass were finer, with a higher content of organic material and were less oxygenated than sediments without seagrass. Univariate measures of the fauna (i.e. abundance, diversity and taxa richness of total meiofauna and nematode assemblages) did not differ between vegetated and unvegetated sediments. However multivariate analysis of meiofaunal higher taxa showed significant differences between the two habitats, largely due to the presence and absence of certain taxa. Amphipods, tanaidacea, ostracods, hydrozoans and isopods occurred mainly in unvegetated sediments, while kinorhyncs, polychaetes, gastrotrichs and turbellarians were more abundant in vegetated sediments. Regarding the nematode assemblages, 32.4% of the species were restricted to Z. capricorni and 25% only occurred in unvegetated sediments, this suggests that each habitat is characterized by a particular suite of species. Epistrate feeding nematodes were more abundant in seagrass beds, and it is suggested that they graze on the microphytobenthos which accumulates underneath the seagrass. Most of the genera that characterized these estuarine unvegetated sediments are also commonly found on exposed sandy beaches. This may be explained by the fact that Australian estuaries have very little input of freshwater and experience marine conditions for most of the year. This study demonstrates that the seagrass and unvegetated sediments have discrete meiofaunal communities, with little overlap in species composition.  相似文献   

2007年夏季南海北部浮游植物的物种组成及丰度分布   总被引：8，自引：0，他引：8  

柯志新  黄良民  谭烨辉  尹健强 《热带海洋学报》2011,30(1)

2007年8月10-29日对南海北部41个站位进行了浮游植物群落结构的调查.调查结果表明,共发现浮游植物5门80属216种(包括变种、变形、未定种),调查期间南海浮游植物以硅藻为主,占所有物种数的64.81%,占总浮游植物细胞丰度的89.11%:甲藻次之,占所有物种数的30.56%,占总浮游植物细胞丰度的10.62%;蓝藻门的红海束毛藻Trichodesmium erythraeum在许多站位也占有相当的比例.绿藻和一些淡水的蓝藻只在珠江口附近的站位才被检出.主要优势种为海链藻Thalassiosira sp.、菱形海线藻Thalassionema nitzschioides、中肋骨条藻Skeletonema costatum、微小原甲藻Prorocentrum minimum和裸甲藻Gymnodinium sp..从平面分布来看,南海北部在珠江口外围和台湾浅滩海域存在2个浮游植物丰度高值区.表层和次表层浮游植物的平面分布格局差异很大,表层浮游植物的丰度平均为25.21×10<'3>个·L<'-1>,高值区在珠江口附近海域;次表层浮游植物丰度平均为9×10<'3>个·L<'-1>,高值区在台湾浅滩海域.调查区域的浅水站位(<200m)的浮游植物丰度远高于深水站位(>200m).从垂直分布来看,浮游植物的细胞丰度基本上自上而下随水深的增加而逐渐降低,最大丰度在10m水层.深水站位与浅水站位的浮游植物垂直分布结构有很大的差异.硅藻类在浅水站位中基本随深度的增加而减少,但在10m处出现最大值;而在深水站位则存在次表层(75m)最大值的现象.甲藻类在浅水站位中随深度增加显著减少,而在深水站位的75m以上其分布比较均匀.越靠近外海,浮游植物中硅藻所占的比例越小,硅甲藻比率大的海区一般具有高的生产力和较高的浮游植物丰度.调查海区表层和次表层的浮游植物Shannon-Wiener指数的平均分别为2.8和3.0,生物多样性高的区域分别位于珠江口、粤东近海和海南的东部近海,浅水站位的浮游植物多样性指数远高于深水站位.  相似文献   

新疆阿克达拉水库浮游植物群落生态特征     

吴惠仙  王琼  蔡桢  朱新英  李周永  薛俊增 《干旱区地理》2011,34(3):505-510

为了解其水生生物生态现状,于2008年7月(平水期)、10月(枯水期)和次年5月(丰水期)对阿克达拉水库内浮游植物群落生态特征进行了研究.共采集到浮游植物8门101种,其中硅藻40种、绿藻38种、蓝藻7种、裸藻6种、黄藻4种、金藻3种、隐藻2种和甲藻1种,绿藻与硅藻在种类组成上具有显著优势.不同时期浮游植物种类组成呈现...  相似文献   

华南地区稻鸭共作系统节肢动物群落多样性的研究     

秦钟  赵本良  章家恩  骆世明 《资源与生态学报(英文版)》2011,2(2):151-157

在稻鸭共作系统中,鸭子在田间的觅食活动对稻田系统中节肢动物群落可能产生的影响已引起了较多关注。本研究通过设置稻鸭共作（RD）、常规稻作（CC）和对照（cK）3-ff处理的小区试验来研究稻鸭共作对稻田节肢动物群落的影响。结果表明,稻鸭共作和常规稻作处理区中节肢动物群落的个体数比空白区均有不同程度的减少;稻鸭共作处理区节肢动物群落的个体数、Simpson指数（D）和Shannon指数（H’）均高于常规稻作区;在晚稻生长的分蘖期和孕穗期,稻鸭共作处理区节肢动物群落的个体数、丰富度指数（R）、D、和H’均高于常规稻作区。稻鸭共作有利于维持稻田系统中节肢动物群落的多样性。与施用化学农药和肥料所引起的节肢动物群落丰富度和多样性降低相比,稻鸭共作对稻田节肢动物群落的多样性影响相对较低。  相似文献   

Integrated management of marine biodiversity in Europe: Perspectives from ICZM and the evolving EU Maritime Policy framework     

Betty Queffelec  Valerie Cummins  Denis Bailly 《Marine Policy》2009,33(6):871

Biological diversity, or biodiversity, is high on the international agenda for nature conservation. Marine and coastal ecosystems account for an important share of the biological diversity on Earth. As a consequence many international conventions, European legislation and national laws refer to marine biodiversity. The protection of marine biodiversity is a complex legal issue as it requires consideration of geographic (between land and sea), political (between conservation and exploitation), and economic (between fisheries, tourism, intellectual property and many other sectors) factors. Like Matryoshka dolls, marine biodiversity is a heterogeneous notion difficult to address as one discrete area in the development of policy agendas or juridical frameworks. In the past decade, the EU has been very active in Promoting Integrated Coastal Zone Management and in developing a framework for an Integrated Maritime Policy. This article reviews the status of marine biodiversity in the policy and legal initiatives of the European Union, a challenging issue to both the objectives of conservation and to the concept of integration.  相似文献   

桂西南喀斯特瀑布水生苔藓植物生物多样性与生态沉积类型研究   总被引：5，自引：1，他引：4  

张朝晖  陈家宽 《沉积学报》2007,25(4):603-611

作者于2005年11月赴桂西南野外考察了14个喀斯特瀑布,共采集245份水生苔藓植物标本和沉积样品。经室内分析研究,该地苔藓植物具有下列生物多样性特征:(1) 苔藓(Bryophytes) 种类多样性由11科19 属36 种 (含变种亚种) 组成, 其中含广西新记录25 种;藓类(Mosses)含8科15属30种,苔类(Liverworts)3科4属6种。(2)生活型多样性含高丛集型(38.89%)、矮丛集型(19.44%)、交织型(27.78%)和平埔型( 13.89%) 4种类型。(3)地理成分多样性含世界分布 ( 13.89%), 北温带分布( 36.11%),热带亚洲分布s( 16.67%),东亚分布 (19.44.11%) 和中国特有(13.89% )等5种成分。(4)苔藓生殖系统多样性由3种类型组成, 其中雌雄异株(Dioecious) 占总数的83.33%, 雌雄同株异苞(Autoecious) 占总数的2.78%, 雌雄同株同苞(Synoecious)的种类仅占总数的13.89%。根据桂西南喀斯特瀑布沉积的环境和生物组成特征, 可把生态沉积类型划分为:溪流瀑华, 河流瀑华, 石灰华坝和洞穴钙华4种沉积类型及12种生物沉积亚类型。  相似文献   

Disturbance impacts of land use change on biodiversity conservation priority areas across China:1990-2010     

ZHAO Guosong  LIU Jiyuan  KUANG Wenhui  OUYANG Zhiyun  XIE Zhenglei 《地理学报(英文版)》2015,25(5)

  相似文献   

Mapping of forest tree distribution and estimation of forest biodiversity using Sentinel-2 imagery in the University Research Forest Taxiarchis in Chalkidiki,Greece     

Maria Kampouri  Polychronis Kolokoussis  Demetre Argialas  Vassilia Karathanassi 《国际地球制图》2013,28(12):1273-1285

Abstract

The aim of this study is to investigate the potential of Sentinel-2 imagery for the identification and determination of forest patches of particular interest, with respect to ecosystem integrity and biodiversity and to produce a relevant biodiversity map, based on Simpson’s diversity index in Taxiarchis university research forest, Chalkidiki, North Greece. The research is based on OBIA being developed on to bi-temporal summer and winter Sentinel-2 imagery. Fuzzy rules, which are based on topographic factors, such as terrain elevation and slope for the distribution of each tree species, derived from expert knowledge and field observations, were used to improve the accuracy of tree species classification. Finally, Simpson’s diversity index for forest tree species, was calculated and mapped, constituting a relative indicator for biodiversity for forest ecosystem organisms (fungi, insects, birds, reptiles, mammals) and carrying implications for the identification of patches prone to disturbance or that should be prioritized for conservation.  相似文献   

广西涠洲岛柳珊瑚共附生真菌多样性及其抑菌活性*     

陆春菊  陆玫霖  刘昕明  刘永宏  高程海  徐新亚 《热带海洋学报》2021,40(5):45-52

文章使用4种分离培养基, 从10个广西涠洲岛柳珊瑚样本中分离可培养真菌, 通过菌落形态观察和内转录间隔区序列系统发育分析, 得到涠洲岛柳珊瑚共附生真菌多样性信息, 并采用96孔板法测定了真菌发酵液乙酸乙酯提取物的抑菌活性和抗生物被膜形成活性。试验结果表明, 从涠洲岛柳珊瑚样本中分离得到191株共附生真菌, 鉴定为26个种。这些真菌均属于子囊菌门, 分布于6个属: 曲霉属(Aspergillus)、青霉属(Penicillium)、链格孢属(Alternaria)、枝孢菌属(Cladosporium)、黑孢霉属(Nigrospora)和Parengyodontium属。曲霉属(Aspergillus)为优势种属, 占总菌株种类的69.23%; 次优属为枝孢菌属(Cladosporium)。抑菌活性筛选发现有11种真菌至少对一种指示菌有抑制活性, 占菌种总数的42.31%; 有7种真菌对表皮葡萄球菌生物被膜形成具有抑制活性, 半数有效浓度(EC₅₀)范围为40.3~155μg·mL^-1, 菌株Penicillium cinnamopurpureum GXIMD00518、Aspergillus carneus GXIMD00519具有抗耐甲氧西林金黄色葡萄球菌生物被膜形成活性, EC₅₀分别为105.4μg·mL^-1和117.4μg·mL^-1。  相似文献   

Colonisers of the dark: biostalactite‐associated metazoans from “lu Lampiùne” submarine cave (Apulia,Mediterranean Sea)     

Antonietta Rosso  Rossana Sanfilippo  Adriano Guido  Vasilis Gerovasileiou  Emma Taddei Ruggiero  Genuario Belmonte 《Marine Ecology》2021,42(1):e12634

Metazoan/microbial bioconstructions, or biostalactites (BSTs), discovered in submarine caves of Apulia c. 20 years ago—and later found in several shallow‐water Mediterranean caves—are receiving increasing attention in the last years. Examination of a single BST from the “lu Lampiùne” cave (Apulia), at the limit between the Adriatic and the Ionian seas, has been addressed for the first time in this paper. The BST started growing at c. 6,000 years ago with a rapid accretion of large‐sized serpulids (Protula), slowing down since about 3,000–4,000 years ago with a shift in main bioconstructors, probably caused by environmental changes. The present‐day community on the outer BST surface is dominated by skeletonised epibionts, mostly small‐sized serpulids, bryozoans and foraminifers, which contribute carbonate to the BST growth, by encrusting sponges, and by a few endobionts, including boring bivalves and insinuating sponges. New data remarkably increase biodiversity known for the “lu Lampiùne” cave and the cave habitat in the region. Thirty‐five taxa (16 bryozoans, 10 serpulids, 3 brachiopods, 2 foraminifers, 2 sponges, 1 bivalve and 1 cirriped) are recorded for the first time from Apulian marine caves, highlighting the need for further research in the area. In addition, the BST‐associated community seems to differ from those of individual BSTs from other Mediterranean caves, revealing the individuality of these communities.  相似文献