Significant population genetic structuring of the holoplanktic scyphozoan Pelagia noctiluca in the Atlantic Ocean     

《African Journal of Marine Science》2013,35(3):425-430

Pelagia noctiluca is thought to have a global distribution, yet our understanding of genetic connectivity across the range of this problem animal is poor. Here, we investigate the genetic structure of populations off southern Africa using mitochondrial COI and nuclear ITS1 and ITS2 genes, and compare the results to recent work conducted in the North-East Atlantic. Analyses showed significant differentiation between the southern and northern Atlantic population groups (COI Φ _st = 0.72, ITS2 Φ _st = 0.23, p < 0.001), which suggests historical rather than contemporary gene flow. Southern African samples showed high haplotypic (h = 1) and low nucleotide (π = 0.008) diversity, similar to those from Europe. Phylogenetic analyses suggest South African samples to have diverged earlier than those from the northern Atlantic.  相似文献   

藏北高原高寒草地围栏禁牧和生长季降水对物种丰富度和多样性的影响(英文)   总被引：2，自引：2，他引：0  

武建双  张宪洲  沈振西  石培礼  余成群  宋明华  李晓佳 《资源与生态学报(英文版)》2012,(3):236-242

2009和2010年夏天沿藏北高原高寒草地样带调查了高寒草地生态系统(高寒草甸、高寒草原和荒漠草原)在围栏禁牧和自由放牧管理下的物种丰富度和多样性(Shannon-Wiener指数,Simpson优势度指数和Pielou均匀度指数)。研究结果显示:自2006年起藏北高原围栏禁牧在植被类型和区域尺度上没有显著改变物种丰富度和多样性。物种丰富度和多样性主要受生长季降水驱动,超过87%的变异可由生长季降水来解释。物种丰富度和多样性在自由放牧和围栏禁牧2类样地对生长季降水的响应方式一致。物种丰富度随降水呈指数型增长关系,多样性指数则呈现正线性关系。研究结果预示藏北高原地区生长季降水的变化对于物种丰富度和多样性管理至关重要,在未来高寒草地保护研究中应予以重视。  相似文献   

贵州省喀斯特山区植被恢复的物种选择现状分析   总被引：1，自引：0，他引：1  

田秀玲  吕娜  朱飞鸽  倪健 《亚热带资源与环境学报》2012,7(2)

喀斯特山区生态系统的恢复和重建,已经成为决定西南地区环境、经济和社会能否持续发展的关键问题,其中植被的生态恢复无疑是极为基础和重要的环节之一,物种选择又是重中之重．通过互联网搜索、文献阅读和野外实地考察,针对喀斯特分布极广且石漠化最为严重的贵州省,本研究调查和分析了喀斯特山区植被生态恢复过程中所选择的物种分布现状,对其恢复效果进行了初步评价,希望能对西南喀斯特山区的生态恢复,尤其是对即将全面铺开的石漠化综合治理提供参考和建议．结果表明：在贵州省78个岩溶县（市、区）的328个地点,共调查收集到用于植被恢复的物种87种,其中生态林物种26种（主要是松、杉、柏、香椿、杨树和车桑子等）,经济林物种47种,包括26种药用植物（太子参、天麻等）和其他21种经济林物种（茶、油茶、梨、桃、李、板栗等）,另外有牧草14种（白花三叶草、黑麦草、紫花苜蓿等）．这些物种聚集或零散种植在不同的喀斯特石漠化综合治理大区：A区（黔西高原山地）、B区（黔中丘原山地）、C区（黔东低山丘陵）和D区（无石漠化）．就恢复效果而言,油茶、茶、中药材、花卉栽培及草地畜牧业均显示出了规模化、产业化发展的良好势头,板栗、核桃、花椒、桃、梨等经济林物种也在其生长适宜地取得了良好的生态和经济效益．然而,植被生态恢复中所营造的人工林,均存在树种单一、物种配置简单、经营粗放等问题,林分的整体功能和生态、经济效益较低,亟待进行改造;不同喀斯特石漠化综合治理区域也需要采取不同的物种配置措施．  相似文献   

Isotopic composition of salt efflorescence from the sandstone castellated rocks of the Bohemian Cretaceous Basin (Czech Republic)   总被引：1，自引：0，他引：1  

Jana Schweigstillová  Richard P?ikryl  Miroslava Novotná 《Environmental Geology》2009,58(1):217-225

The origin of sulphates in sulphate-rich efflorescences on quartz sandstones with a clay matrix, exposed in rural areas of the Czech Republic is interpreted, based upon an isotopic study of S and O. Sulphates such as gypsum and/or alums exhibit δ³⁴S ranging from +1.3 to +6.1‰ and δ¹⁸O from +5.3 to +8.8‰. The low variability of S and O isotopes indicates a common source of the sulphur and a similar mode of sulphate formation. Atmospheric sulphates with a similar isotopic signature occur in the area, due to the combustion of sulphurous coal in power plants, located a few tens of kilometres from the sampling points. The sulphates crystallize from supersaturated pore waters that represent atmospheric precipitation, rich in sulphates, having percolated through the porous sandstone system. The previously proposed model of efflorescence growth (that it is due to the oxidation of pyrite) can be excluded, due to both the rare occurrence of pyrite and also to its different isotopic signature (δ³⁴S about −22‰). Although gypsum prevails in the central and eastern part of the studied area, the north and north-west of the Bohemian Cretaceous Basin (the most polluted region) exhibits a significant presence of alums (NH₄ ⁺ or K⁺−NH₄ ⁺-rich). Formation of alums can be explained by the partial dissolution of clay minerals or feldspars present in the sandstone matrix. Release of alumina from these phases is facilitated by the low pH of the precipitation (pH 4–4.5) and also locally by organic acids, traces of which were found in the studied efflorescences by the use of infrared spectroscopy.  相似文献   

东天山喀尔里克山北坡-淖毛湖植物群落物种多样性研究   总被引：2，自引：0，他引：2  

张海燕  钱亦兵  段士民  王忠臣  黄彩霞 《冰川冻土》2009,31(5):976-985

以东天山喀尔里克山北坡-淖毛湖为研究区,探讨了该区山地-荒漠生态系统的植物种类组成、植被类型及群落物种多样性特征.结果表明:该区共有高等植物33科93属133种,植物生活型组成以草本植物居多.群落物种多样性测度指数的主成分分析结果显示,物种丰富度指数(R)、Pielou均匀度指数(Jsi)、Shannon-Wiener多样性指数(H)和Simpson优势度指数(C)能很好地描述群落结构和组成特征.其中,多样性指数、均匀度指数和丰富度指数的变化趋势基本一致,优势度指数则和前三者呈负消长的关系.随着海拔升高,群落物种多样性指数、丰富度指数和均匀度指数变化均呈现单峰分布格局,即植物群落的物种多样性在山前荒漠生态系统和高海拔山地生态系统中较低,而在中海拔地区达到最大.  相似文献   

2011年全球发现的新矿物种     

蔡剑辉 《岩石矿物学杂志》2024,43(1):131-198

在系统梳理2011年度全球发现并经国际矿物学协会(IMA)新矿物与矿物分类命名专业委员会(CNMNC)批准的122个新矿物种资料的基础上,从矿物名称、晶体化学式、晶系和空间群、晶胞参数、主要粉晶数据、物理性质、光学性质、产地与产状、与其他矿物种的关系、矿物名称来源、化学反应和光谱学特征等方面归纳总结了这些新矿物的重要矿物学特征。并按照中国新矿物及矿物命名专业委员会颁布的《矿物种汉名审订条例》,对122个新矿物种的中文名称进行了审订。通过适时公布国际新矿物工作的新进展和新成果,并逐步完善和规范矿物种中文译名体系,为我国新矿物的发现和研究提供有科学价值的参考和借鉴,不断推动矿物种中文译名规范化与标准化的进程。  相似文献   

Discovery of the first hydraenid beetle in amber,with description of a new genus and species (Coleoptera: Staphylinoidea: Hydraenidae)     

《Cretaceous Research》2017

  相似文献   

New Prionoglarididae from Burmese amber (Psocodea: Trogiomorpha: Prionoglaridetae)     

《Cretaceous Research》2017

One new genus with three new species of the family Prionoglarididae, Palaeosiamoglaris leinhardi Azar, Huang et Nel gen. et sp. nov.; P. burmica Azar, Huang et Nel sp. nov. and P. inexpectata Azar, Huang et Nel sp. nov. are characterised, illustrated and described from Cretaceous Burmese amber. Palaeosiamoglaris gen. nov. share several characters with the recent genus Siamoglaris Lienhard, 2004, endemic to the Oriental (Sino-Indian) Region. A new tribe Siamoglaridini Azar, Huang et Nel trib. nov. is established to accommodate the group Siamoglaris + Palaeosiamoglaris; the other Prionoglaridinae being attributed to Prionoglaridini. This discovery implicates a palaeobiogeographic repartition for this particular tribe (Siamoglarini) that is still the same currently. Most diagnostic features show a nearly stasis state, supporting the notion that these characters appeared at least by the early Cenomanian. A checklist of all prionoglaridids is given.  相似文献   

Reflection on the first five years of South Africa’s Acoustic Tracking Array Platform (ATAP): status,challenges and opportunities     

PD Cowley  RH Bennett  A-R Childs  TS Murray 《African Journal of Marine Science》2017,39(4):363-372

The Acoustic Tracking Array Platform (ATAP) is a marine science programme that monitors the movements and migrations of inshore marine animals along the South African coastline. Acoustically tagged animals are monitored by an expanded network of approximately 100 automated data-logging acoustic receivers moored at strategic node sites, from Cape Point in the west to the South Africa–Mozambique border in the east. During five years since its inception, in 2011, the ATAP has achieved outstanding progress in terms of the numbers of animals and the variety of species tagged. To date, the ATAP has yielded over 2.6 million detections from more than 700 acoustically tagged animals, representing 27 different species from 20 families, including the African penguin Spheniscus demersus, fishery-at-risk species (e.g. dusky kob Argyrosomus japonicus) and iconic elasmobranchs (e.g. white shark Carcharodon carcharias). Following a period of considerable equipment loss in 2014, refinement of the receiver network was required and the deeper receivers at each site were decommissioned without influencing the integrity of the nationwide array. The platform, managed by the South African Institute for Aquatic Biodiversity, ultimately represents a low-cost method of collecting long-term data that currently benefits approximately 25 researchers from 14 organisations. Case studies are presented to expose the opportunities provided by the ATAP, which will undoubtedly yield new discoveries and provide a greater understanding of the movement patterns and migrations of a wide variety of inshore marine and estuary-associated species.  相似文献   

海洋石油降解菌深海弯曲菌的种类多样性及地理分布特征分析          下载免费PDF全文

刘仁菊  董纯明  李登峰  邵宗泽 《应用海洋学学报》2017,36(4):565-574

深海弯曲菌(Thalassolituus)是一类海洋专属的石油降解菌.为认识其多样性与地理分布、获取石油降解菌资源,本研究对西太平洋和厦门近海的表层海水分别通过石油烃富集和直接涂布石油烃平板,对获取的菌株进行了分离鉴定.在此基础上,对Gen Bank数据库中该属的可培养和未培养菌株信息,进行了系统进化与物种多样性分析.结果表明,从西太富集菌群分离得到的32个菌株中,主要优势菌为假单孢菌(Pseudomonas)和海杆菌(Marinobacter);其次是食烷菌(Alcanivorax)和弧菌(Vibrio).深海弯曲菌仅有2株,但它们代表1个潜在的新种,它们与模式菌株T.marinus IMCC1826T的同源性仅为96.9%和97.0%.从厦门表层海水中分离到1株深海弯曲菌,与模式菌株T.marinus IMCC1826T的相似度为99.66%.基于本研究分离菌株及Gen Bank可培养及未培养菌株的16S rRNA基因序列开展的系统发育分析表明,该属存在3个明显的进化分支,即2个模式种T.oleivorans与T.marinus分别代表的2个分支和1个独立分支;此外,不同分支呈现明显的地理分布特征,即来自同一纬度范围的菌株或序列多聚类于同一分支中.我们推测,深海弯曲菌在进化过程中,可能因适应不同纬度海域的温度等环境因子,逐步进化出3个不同环境适应性的分支.本研究加深了对深海弯曲菌在不同温度海洋环境中种类多样性分布特征的认识,为海洋石油污染生物修复提供了新资源.  相似文献