317 resultados para Coastal South China


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Aega sheni sp. nov. from Chinese and Australian waters, is described and figured. This species is characterized by the plate-like expansion of antennule peduncle articles 1 and 2, very large eyes (nearly making contact), numerous robust setae on the inferior margins of the ischium of pereopods 2 and 3, large distal lobe on the propodus of pereopods 1-3, shape and setation of the uropods, and the rounded pleotelson posterior margin. Aega sheni has been recorded at depths of 300-435 metres.

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A new species of spider crab, Doclea unidentata, is described from the South China Sea. Allied to D. brachyrhynchos Bleeker, 1856, and D. macracanthus Bleeker, 1856, it can easily be distinguished by its very short, unidentate rostrum. The identity of Doclea canalifera Stimpson, 1857, is resolved with the selection of a neotype, and it is here regarded as a senior subjective synonym of D. japonica Ortmann, 1893. The taxonomy of this species as well as the allied D. ovis (Fabricius, 1787) is also discussed.

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The jinjiang oyster Crassostrea rivularis [Gould, 1861. Descriptions of Shells collected in the North Pacific Exploring Expedition under Captains Ringgold and Rodgers. Proc. Boston Soc. Nat. Hist. 8 (April) 33-40] is one of the most important and best-known oysters in China. Based on the color of its flesh, two forms of C rivularis are recognized and referred to as the "white meat" and 11 red meat" oysters. The classification of white and red forms of this species has been a subject of confusion and debate in China. To clarify the taxonomic status of the two forms of C. rivularis, we collected and analyzed oysters from five locations along China's coast using both morphological characters and DNA sequences from mitochondrial 16S rRNA and cytochrome oxidase 1, and the nuclear 28S rRNA genes. Oysters were classified as white or red forms according to their morphological characteristics and then subjected to DNA sequencing. Both morphological and DNA sequence data suggest that the red and white oysters are two separate species. Phylogenetic analysis of DNA sequences obtained in this study and existing sequences of reference species show that the red oyster is the same species as C. ariakensis Wakiya [1929. Japanese food oysters. Jpn. J. Zool. 2, 359-367.], albeit the red oysters from north and south China are genetically distinctive. The white oyster is the same species as a newly described species from Hong Kong, C. hongkongensis Lam and Morton [2003. Mitochondrial DNA and identification of a new species of Crassostrea (Bivalvia: Ostreidae) cultured for centuries in the Pearl River Delta, Hong Kong, China. Aqua. 228, 1-13]. Although the name C. rivularis has seniority over C. ariakensis and C. hongkongensis, the original description of Ostrea rivularis by Gould [1861] does not fit shell characteristics of either the red or the white oysters. We propose that the name of C. rivularis Gould [1861] should be suspended, the red oyster should take the name C. ariakensis, and the white oyster should take the name C. hongkongensis. (C) 2004 Elsevier B.V. All rights reserved.

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Phosphorus is an important biological and ecological element that to a certain degree constrains ecological environment and nutrient (including carbon) cycling. Marine sedimentary phosphorites are the principal phosphorus supply of the mankind. In the eastern to southern margins of the Yangtze Craton, South China, there are two phosphogenetic events at the Doushantuo stage of the Late Sinian and the Meishucun stage of the Early Cambrian respectively, corresponding two explosion events of life across the Precambrian\Cambrian boundary. Phosphorus ores from the Sinian and Cambrian phosphate in South China can be classified roughly into two categories, namely, grained and non-grained phosphorites. Grained phosphorites, hosted in dolostone type of phosphogenetic sequences and with larger industrial values, occur mainly in margins of the Upper Yangtze Platform, formed in shallow-water environments with high hydraulic energy and influenced by frequent sea-level change. Non-grained phosphorites, hosted principally in black-shale type of phosphogenetic sequences and with smaller industrial values, are distributed mainly in the Jiangnan region where deeper-water sub-basins with low hydraulic energy were prevailing at the time of phosphogenesis. Secular change ofδ~(13)C, δ~(18) O, ~(86)Sr/~(87)Sr values of carbonates from Sinian and Cambrian sequences were determined. A negative abnormal ofδ~(13)C, δ~(18)O values and positive abnormal of 86Sr/87Sr values from the fossiliferous section of the Lowest Cambrian Meishucun Formation implies life depopulation and following explosion of life across the PrecambriamCambrian boundary. Based on a lot of observations, this paper put forward a six-stage genetic model describing the whole formational process of industrial phosphorites: 1) Phosphorus was transported from continental weathering products and stored in the ocean; 2) dissolved phosphates in the seawater were enriched in specific deep seawater layer; 3) coastal upwelling currents took this phosphorus-rich seawater to a specific coastal area where phosphorus was captured by oceanic microbes; 4) clastic sediments in this upwelling area were enriched in phosphorus because of abundant phosphorus-rich organic matters and because of phosphorus absorption on grain surfaces; 5) during early diagenesis, the phosphorus enriched in the clastic sediments was released into interstitial water by decomposition and desorption, and then transported to the oxidation-reduction interface where authigenic phosphates were deposited and enriched; 6) such authigenic phosphate-rich layers were scoured, broken up, and winnowed in shallow-water environments resulting in phosphate enrichment. The Sinian-Cambrian phosphorites in South China are in many aspects comparable with coastal-upwelling phosphorites of younger geological ages, especially with phosphorites from modern coastal upwelling areas. That implies the similarities between the Sinian-Cambrian ocean and the modern ocean. Although Sinian-Cambrian oceanic life was much simpler than modern one, but similar oceanic planktons prevail, because oceanic planktons (particularly phytoplanktons) are crucial for phosphate enrichment related to coastal upwelling. It implies also a similar seawater-layering pattern between the Sinian-Cambrian ocean and the modern ocean. The two global phosphate-forming events and corresponding life-explosion events at the Sinian and Cambrian time probably resulted from dissolved-phosphate accumulation in seawater over a critical concentration during the Earth's evolution. Such an oceanic system with seawater phosphorus supersaturation is evidently unstable, and trends to return to normal state through phosphate deposition. Accordingly, this paper put forward a new conception of "normal state <=> phosphorus-supersaturation state" cycling of oceanic system. Such "normal state <=> phosphorus-supersaturation state" cycling was not only important for the three well-known global phosphate-forming events, also related to the critical moments of life evolution on the Earth. It might be of special significance. The favorable paleo-oceanic orientation in regard to coastal-upwelling phosphorite formation suggests a different orientation of the Yangtze Craton between the Sinian time and the present time (with a 135° clockwise difference), and a 25° anti-clockwise rotation of the Yangtze Craton from late Sinian to early Cambrian. During the Sinian-Cambrian time, the Yangtze Craton might be separated from the Cathaysia Block, but might be still associated with the North China Craton.

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A continuous long (224m) and high-resolution core TY2 was recovered from paleo-maar-lake Tianyang, tropical South China. Based on the diatom records of the upper 130-m core, this paper focuses on exploring climate change and the lake evolution history in tropical South China during the past 240ka. The most typical and unique characteristics of the diatom assemblages is that, Aulacoseira granulata was dominant or absolutely dominant species (80-90%) during most parts of the 130-m core, while Cyclotella stelligera var. tenuis and Fragilaria construens var. venter were subdominant species in only limited parts of the lower and upper core, respectively. Time scale is always the biggest problem for the study of TY2 core, so although diatom is seldom used for establishing time scale, here we attempt this by correlating the diatom-reconstructed temperature sequence with the time scale of ODP core 806B from Equatorial Western Pacific. Verified by the few most reliable ages from TY2 core and the parallel core TYl, a rather reasonable and reliable time scale was established. 01S 7/6 falls at the depth of 100m (ca. 194kaBP), OIS 6/5 at 75m (ca. 132kaBP), OIS 5/4 at 46m (ca. 75kaBP), OIS 4-3 at 35m (ca. 60kaBP). Qualitative and quantitative environmental reconstructions are made on the basis of diatom assemblage ecotype and EDDI dataset. Correlation of diatom-reconstructed temperature and moisture changes of Core TY2 with pollen-reconstructed temperature and rainfall sequence of Core TYl proves that the results are quite consistent in most periods. Thus the reconstruction results from diatom are quite reliable, and probably have a much higher resolution than pollen results. Combined with lithological and magnetic susceptibility variations, the diatom analysis reveals that, the general climate in tropical South China during the past 240ka was warm and wet. On the time scale of glacial-interglacial, warm and wet, cool and dry are not always synchronous. It was relatively warm-wet during the penultimate interglacial, cool-dry during the penultimate glacial, warm-dry during the last interglacial, and cooler-drier during the last glacial. In contrast, on the time scale of subglacial-subinterglacial scales, warm and dry, cool and wet corresponds very obviously, showing very clear 21-23 ka precession cycle. Analysis also shows that, the water of Tianyang paleo-maar-lake was generally warm, turbulent, turbid, meso-trophic, slightly alkaline, low conductivity and fresh during the past 240 kaBP, with small variations in some parts. Tianyang paleolake experienced shallow to semi-deep lake in OIS7d, open shallow lake in OIS7c-OIS5b, shallow coastal lake in OIS5a-OIS4c, swamp in OIS4b, and then completely dried up in OIS3c. The lake evolution was mainly controlled by temperature and precipitation changes in tropical China. While temperature and precipitation changes were probably controlled by the migrations of monsoon rainband and the evaporation rate, which was in turn controlled by the evolution of East Asian monsoon. Therefore, when the summer monsoon was strongest the climate was warm-dry, when stronger the climate was warm-wet; when the winter monsoon was strongest the climate was cool-dry, stronger cool-wet. This mechanism caused the warm-dry sub interglacial and cool-wet subglacial climate in the tropical South China.

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The induced flow fields by internal solitary waves and its actions on cylindrical piles in density stratified ocean with a basic density profile and a basic velocity profile are investigated. Some results, such as the time evolution of flow fields and hydrodynamic forces on the piles are yielded both by theoretical analysis and numerical calculation for general and specific cases. Several kinds of ambient sea conditions of the South China Sea are specified for numerical simulation. Moreover, the effects of relative density difference, depth ratio and wave steepness on maximal total force and total torque are analyzed.

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针对南海北部海域特点建立了模拟该区域小尺度沙波运移过程的准三维力学模型.以多波束海底地貌扫描数据和水文资料为基础,预测了研究区域沙波的运移,其结果在沙脊脊沟处与实际观测一致,而在脊背上与实际观测值存在差异.分析表明,本文所提出的物理模型可以用于预测南海海域以推移质泥沙运动为主的小尺度沙波运移规律.这一结果对该区域海底管线等工程设计是很有意义的.

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本文详细研究在我国华南泥盆系地层中发现的一种新的原真蕨植物—原蕨属(新属)propterophyton gen. nov.并详细探讨原真蕨植物的分类问题。 原真蕨植物在早期陆地维管植物系统发育中占有十分重要的地位。它是处于原始的裸蕨植物和进步的真蕨植物之间的一种过渡类型,兼具这两类植物的主要特征。 原始蕨植物的研究已有几十年的历史。但往往由于化石材料的奇缺和破碎,限制人们对它的正确认识,因而研究工作的进展一直十分缓慢。近二十多年来,一方面随着原裸子植物的确认和原裸子植物纲(progymospermopsida)的建立,一些所谓的原真蕨植物经研究后被转移到这个新钢里。另一方面,特别是近十年来,世界各国尤其是欧美的古植物学家对新发现的不少珍贵的原真蕨植物化石进行了深入研究,而使人们对这类灭绝植物的认识得以深化,并就它的分类问题,古植物学家不断提出新的见解。 在我国首次发现的原蕨属的标本十分丰富,保存完整。经过深入细致的研究,使我们对这种植物的外部形态和内部结构有了较全面的认识。并由此涉及到对整个原真蕨植物的认识得以进一步的完善,从而提出一个有关原真蕨植物的新概念。在此研究的基础上,综合国际植物学界人士近二十多年来对原真蕨植物研究的资料,本文拟把原真蕨植物归入原真蕨亚纲(primofilices)置于真蕨纲(Filicopsida)之下,与真蕨亚纲(Filices)并列。 大部分原蕨属的标本采自湖北省汉阳县米粮山采石场。化石层位于上泥盆统珞珈山群的下部,距该群底界与下伏中志留统地层之间的假整合面大约有9米。该层为—巨大的粘土岩透镜体,夹在厚至巨厚层的石英砂岩中。依据分散孢子组合的资料,这种植物的地质时代不会晚于晚泥盆世早期,即弗拉斯期(Frasnian)。另有一部分标本则采自湖南市长沙县跳马涧。其时代大约是中泥盆世晚期,即吉维特期(Givetian)。 原蕨属的化石主要保存为炭化的压型标本,部分黄铁矿化。这些标本经过精心修整,采用多种技术处理,并运用扫描电子显微镜观察,显示出了这种植物主要的外部形态和内部组织的特性。 泥盆原蕨(proptrophyton devonicum sp. Nov.)由根状茎、蕨叶和不定根三部分组成。根状茎横生地下,以细而少分枝的不定根固着于土壤中。蕨叶中仅有一枚直接由根状茎顶部生出,余为侧生,以螺旋排列为主。蕨叶由三次羽状分枝的枝系组成,单轴,不具叶片。成对的羽片在叶轴两侧互生。小羽片也以同样的方式成对互生在羽轴两侧。从而形成一种立体生长的四列式蕨叶。小羽片多为六次等二岐式分枝,没有蹼化。生殖小羽片顶部生出成对孢子囊。估计每枚小羽片上可以生长六十四个孢子囊。幼小的孢子囊圆至纺锤形,下垂。成熟的孢子囊弯眉形,直立。两个孢子囊在小羽片顶部排列成山羊角状。四个孢子囊成两对着生,形成一束。孢子囊沿囊壁内面纵裂,不具环带。孢子同型,具三裂缝。蕨叶具轴有两侧对称的维管结构:两个椭圆柱状的维管束在一侧相连,形成一个v字型结构。在维管束的另一侧具有原生木质部腔(lacuna)。后生木质部管胞放射状相连,具有梯形,椭圆形至圆形的具缘纹孔。成对的小羽片迹由两个维管束不相连的一侧交互产生。皮层分为具薄壁组织的外层和具后角组织的内层。表皮上的气孔器很小,散生,气孔与轴行,无副卫细胞。 泥盆原蕨的蕨叶由不具叶片的枝系组成,立体方式生长。小羽片等二岐式分枝。根状茎顶部直接生长一枚蕨叶。孢子囊定生,纵向开裂。这些属于裸蕨植物的原始性状,明显地不同于真蕨植物。但根、茎、叶的初步分化、蕨叶的单轴生长和羽片在叶轴两侧排列以及与之相对应的蕨叶轴内两侧对称的维管结构,表明泥盆原蕨已部分发展到真蕨植物的水平。由此可见,原蕨属即具有裸蕨植物的原始性状,又具有真蕨植物的进步性状,属于一种典型的原真蕨植物。 综合原蕨属及其它原真蕨植物如指蕨属(pseudosporochnus),羽裂蕨属(Rhacophyton)和十字蕨属(Stauropteris)的特征,归纳出原真蕨植物的孢子体具有以下主要性状:(1)植物体由茎、蕨叶和不定根组成。(2)茎直立或匍伏生长,具放射状对称的内部结构。(3)不定根自茎生出,有的也从叶柄或叶轴生出。(4)蕨叶由完整的羽状分枝的枝系组成。由此形成的蕨叶与枝系在形态上的差异不甚明显。(5)蕨叶单轴式生长,一次多次羽状,呈背腹状或至少叶轴具备背腹性。(6)羽片和小羽片成对的或单个的侧生在轴两侧,形成立体或平面生长的蕨叶。(7)小羽片等二岐式分枝,不具叶片。(8)叶轴和羽轴具两侧对称的,中始式的维管结构。(9)孢子囊远端位着生,无环带,具简单的开裂机制。(10)孢子多为同形,稀有大小两种。简言之,原真蕨植物是一类蕨叶由羽状枝系组成,不具叶片和孢子囊不具环带的原始的真蕨植物。 这种原真蕨植物的新概念为原真蕨植物的分类和蕨叶的起源提供新的解释。 裸蕨植物与原真蕨植物的主要区别,在于后者已经出现根、茎、叶的初步分化,在系统发育中达到一个新的演化水平。但是,原真蕨植物的蕨叶仅由枝系组成,还没有形成叶片,孢子囊叶不具环带,这些特征在系统发育中又低于真蕨植物所达到的一般水平。因此,有无蕨叶叶片和孢子囊有无环带作为区分原真蕨植物和真蕨植物的主要标志。原真蕨植物应以蕨叶未形成叶片和孢子囊不具环带为特征。而真蕨植物则至少应以有叶片的蕨叶或孢子囊具环带为特征。 原真蕨植物,原裸子植物和原始楔叶植物都起源于裸蕨植物,是共同生活在泥盆,演化水平彼此接近的三大分类群。它们之间的区别主要在于叶器官和生殖器官的不同。这里又涉及到蕨叶起源的问题。 历史人们认为蕨叶(复合叶)起源于一个等二岐式分枝的侧枝。但根据已发现的化石资料,特别是原蕨属所表现的性状,蕨叶可能直接起源于具有完整的至少一次羽状分枝枝系的植物。枝系的扁化和蹼化则发生在以后的演化过程中,逐步形成具叶片的枝状复合蕨叶。而仅仅由一个等二岐式分枝的侧枝起源的叶则应归属于简单的枝状叶。本文所讨论的原裸蕨子植物和原始楔叶植物的叶,就是在茎上螺旋排列或轮生的单叶。在蕨叶中,只有小羽片才是由等二岐式分枝的侧枝起源,排列在羽轴两侧。因此,在系统发育中,原裸子植物和原始楔叶植物的茎及其着生的单叶与原真蕨植物的复合蕨叶是同源的。而单叶则与小羽片同源。 根据上述对原真蕨植物的概念和蕨叶及单叶起源的观点,结合化石植物形态学和解剖学两方面的性状,特别是以生殖器官的性状作为分类的依据,纵观几十年来原真蕨植物的分类,大致经历了三个时期。 第一个阶段于本世纪六十年代以前。这个时期的原真蕨植物的分类,受材料限制,研究的程度不够深入,基本上仅以解剖性状作为分类的主要依据。这一时期归属原真蕨植物的“蕨状植物”包括原始蕨类(protopterids),枝木类(cladoxylaeans)和合生蕨类(coenopterids)这实际上是一个庞杂的类群,包括了后来分出的原裸子植物,原始楔叶植物以及真蕨植物。 第三个阶段从六十年代至七十年代末。由于美国 C. B. Beck博士的重大发现和深入研究的结果,不仅确立了原裸子植物是一类处于裸蕨植物和裸子植物之间的过渡类型,而且为古植物学的研究提供了很好的范例。即化石植物的正确分类也必须依据形态学和解剖学两方面的证据。生活在中泥盆世至晚泥盆世的原裸子植物既有原始维管植物自由孢子生殖的特征,又具有裸子植物木材的组织特征,即次生木质部的管胞具有典型的松柏类的圆形具缘纹孔。一些所谓的“蕨状植物”经过细致地研究被证实应属于原裸子植物,从而被转移到原裸子植物纲内。 六十年代中期,比利时古植物学家 S. Leclercq 和西德古植物学家H. J. Schweitzer 发现芦形木(Cala-mophyton)的维管结构为枝木形。因而将原来归属于原始楔叶植物叉叶目(Hyeniales)的芦形木和叉叶(Hyenia)转移到枝木目中,作为蕨状植物看待。对此,国际古植物学界尚有不同的看法。主要是由于这两种植物的生殖器官业已分化为原始的孢子囊梗,而且单叶的排列也由螺旋着生演化到假轮生的水平。 在此期间,合生蕨植物的自然分类的问题日趋被人重视。 第三个阶段开始于本世纪八十年代。这个时期有关原真蕨植物分类的核心问题。是如何确定芦形木等属的正确的分类位置和如何对合生蕨植物进行更接近于自然的分类。 枝木目(Cladoxylales)目1 9 2 7年建立以来,主要包含了一些生活在早石炭世的植物。这些植物的轴具有多维管束的组织结构。而植物体的整体形态不详。归入此目的有具枝木型维管结构的中泥盆植物指蕨,帚枝木(Cladoxylon scoparium )和芦形木都显示出相似的掌状分枝的外形.但是指蕨的叶为羽状蕨叶,小羽片两侧排列,孢子囊纺锤形,成对顶生,纵向开裂。而帚枝木和芦形术的叶为螺旋排列在茎上的单叶。芦形木的孢子囊已形成了雏形孢囊梗。帚枝木的生殖器官最初被认为是扇状深裂叶具边缘着生的孢子囊。但是1 9 8 0年Scheitger 和Giestn重新研究后,发现它的生殖结构类似芦形木,为原始的孢子囊梗。帚枝木,芦形木和叉叶的单叶与原其蕨植物的蕨叶不仅形态上截然不问,而且在排列上已趋向于轮生。与此同时,孢子囊梗已初步形成。这些性状表明这些植物与楔叶植物有密切的亲缘关系。本文不仅赞同J.E.Skog 及L. P. Banks (1973年)和W.N. Stevart (1983年)将芦形木和叉叶仍归回原始楔叶植物叉叶目,而且将蒂枝木也归入同—个目内。另外,指蕨属根据蕨叶和孢子囊的性状应属于原真蕨植物。到此为止,枝木目(狭义的)只包括具有多维管束的硅化轴的器官属,其分类位置不明。 合生蕨目(Coenopteridales)历来被认为是原真蕨植物的主要代表。过去对这类植物的认识主要建立在解剖材料上,特别是依据叶轴维管结构的形态。在某种程度上,这个目也是一个庞杂的类群。随着合生蕨的生殖结构的不断发现,人们对这类植物的分类,逐渐转移到以孢子囊的性状作为主要的分类依据。本文赞同根据孢子囊的结构,特别是依据环带的形态结构,把该目中的五个科Botryoptoridaceae, Anacboropteridaceae, Sermaytaceae, Tedeleacoae 和 Psallxochlaenacoae转移到真蕨亚纲的真蕨目(Filicales )内。另外本文还对比了该目中的孪生蕨科(Zygopteridaceae )的几个属的囊群,孢子囊及环带的性状与莲座目(Marattiales )中莲座科的一个化石属和一个现代属(Angiopteris )的生殖器官的性状。根据它们之间的相似程度,建议将孪生蕨科移至莲座目。Iridopterids曾被认为是合生蕨植物。根据新的研究资料, lridopterids 与原始楔叶植物的关系比与其它植物的关系更为密切。合生蕨植物中的羽裂蕨属和十字蕨属因蕨叶不具叶片和孢子囊不具环带,似应归入原真蕨亚纲,置于各目的目下。至此为止,合生蕨植物分别归属不同类群而使该目趋于解体。 原真蕨亚纲包括四个目(指蕨目Pseudosporochnales,原蕨目Propterophytales,羽裂蕨目Rhacophytales,十字蕨目Stauropteridales)六个属( Pseudosporochrmus, Propterophyton, Rhacophyton,Protocaphalopteris, Chlidanophyton, Stauropteris) 代表两条演化路线。指蕨目独自代表一条路线。蕨叶为两度空间生长的二列式蕨叶,即单个羽片侧生在叶轴上,与现代蕨叶相似。但与现代真蕨植物之间的演化关系不详。原厥目,羽裂蕨目和十字蕨目代表另一条路线。蕨叶为立体的四列式蕨叶,即成对的羽片侧生在叶轴上。在后一条演化路线中,原蕨目处于较原始的水平。原蕨属可能直接起源于一种与裸蕨植物Pertica 相近似的祖先。羽裂蕨目较为进化。而十字蕨目则达到极为特化,即蕨叶高度简化,出现异形孢子的水平。真蕨亚纲的祖先植物可能自后一条路线中产生。

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九万山位于广西省的北部,横贯融水、环江和罗城等县,东经108°27'-59',北纬25°10'-25°25'地处我国两大植物区系(泛北极植物区和古热带植物区)的交汇区域,属于亚热带常绿阔叶林地区。最高海拔1693m,最低处仅170m。 经对所获得的约1500号藓类植物标本的鉴定,得知本地区的藓类植物共有35科,101属,189种。其区系成分以东亚成分为主(39.33%),其次为热带,亚热带成分(38.20%),温带成分仅占18.54%。 选取九万山周围5个地区与其比较,在属和种的相似性方面与福建西北部的武夷山具较密切的关系。 东亚成分的种类中,中国-日本成分的数目明显高于中国—喜马拉雅成分,并有四个东亚特有的藓类植物属。它们的分布范围更具偏南的特点。 九万山的典型热带分布的属和种系组成它区系的重要因素之一,一般来说,这些属的分布范遍及新旧热带地区,而其热带种类则相应贫乏,它们多局限在热带亚洲,通过定量和定性讨论,作者认为:从苔藓植物角度分析九万山呈现由热带向亚热带过渡的特性,其分界线可能位于它的南侧。

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为了重建东亚季风区域2.5MaB.P.前后植被和气候变化的历史,更好地了解低纬度地区植被变化及其对全球变化的响应,本研究选择了南海南部ODP1143站深海沉积物中的孢粉样品进行研究。通过高分辨率(7ka)的孢粉样品的分析研究,建立起3.0~2.0MaB.P.时段南海深海沉积孢粉组合序列,系统建立了这一时段植被演替序列。在此基础上,重点研究了2.5MaB.P.前后气候变化在南海周边地区植被演替中的响应,为探索和揭示东亚古季风及古环境演变提供了孢粉学依据。 ODP 1143站位于南沙海区,北纬9º22´,东经113º17´,深海柱状样采于水深2772m的大陆坡。本研究以生物地层学和氧同位素年代学为依据建立了年龄框架,对1143站135~95m(3.0~2.6 Ma B. P.)深海沉积中的孢粉样品进行了分析,建立了3.0~2.0MaB.P.时段南海深海沉积孢粉组合序列。孢粉样品处理方法主要是用盐酸去掉钙质和氢氟酸浸泡溶解硅质后,再用筛子将样品在超声波发生器中震荡过滤。孢粉的鉴定和统计在光学透视显微镜下完成。研究结果表明: 1、孢粉谱的主要特征是沉积率变化显著。与3.0~2.6 Ma B. P. 相比,2.6~2.0 Ma B. P.各类型花粉及孢子沉积率均有显著提高。该结果表明2.6 Ma B. P.南海海平面有显著下降,可与北半球冰盖形成、东亚季风增强相对应。 2、2.6 Ma B. P.以来,各类型孢粉沉积率变化与深海氧同位素分期相对应,代表了多次冰期-间冰期旋回。该结果表明南海海平面曾有多次上升和下降。 3、频谱分析结果表明,3.0~2.0 Ma B. P.存在0.1 Ma(偏心率)和46.9ka(斜率)的周期。

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海表面温度(Sea Surface Temperature, SST)是海洋生态环境变化的重要因子,也是海洋观测研究的最重要的因子之一。海表温度场表征了海洋热力、动力过程和海洋与大气相互作用的综合结果,是反映海气热量、动力和水汽交换的重要参量,也是气候变化及海洋营养盐浓度和初级生产力的重要影响因子。台风过后通常会在上层海洋引起冷迹,即台风路径附近的海表温度降低。海表温度的变化是台风与海洋之间能量交换的关键,对于台风的产生,演化和强度变化有非常重要的作用。因此,研究上层海洋对台风的响应,特别是海表温度对台风的响应过程有非常重要的科学意义。本研究主要利用微波SST逐日数据资料统计研究了海表面温度对南海台风的响应过程,并分析了中尺度涡(特别是气旋性涡)对台风所引起的降温幅度和降温位置的影响作用。在此研究基础上初步尝试提出了一种新的量化台风降温效应的方法。 首先,本研究以1998-2009年总共12年内经过中国南海的92个台风为研究对象,利用逐日连续的微波TMI及TMI-AMSER海表温度数据资料分析了92个台风所引起的最大降温幅度以及冷迹位置的分布特征。统计结果表明有64个(69.6%)台风引起了海表温度明显的降低(降温≥2oC),而对最大降温出现的位置进行分析发现:有超过半数(56个)的台风引起的最大降温位于台风路径的附近或路径右侧,同时还有8个(8.7%)台风引起的最大降温明显位于路径的左侧。文中选取了冷迹相对于台风路径出现在不同位置(左、右、附近)的4个台风为例来说明台风引起的降温特征。通过量化降温中心到台风路径的距离发现台风所引起的最大降温出现的位置主要集中分布在路径左右两侧100km范围内。另外,通过对比台风来之前的海平面高度距平发现先于台风之前处在于上层海洋环境的冷涡,特别是强冷涡,在台风引起的海表面降温幅度和位置分布中可能起着重要的作用,其中冷涡的位置与台风所引起的最大降温中心出现的位置有很好的相关性。 其次,本研究提出一个新的描述降温效应的指数。台风所经过的海域往往会出现海表温度的降低,而海表温度的变化对海洋生态系统有很重要的影响。台风的降温效应因台风、背景温度场和台风前的海洋环境条件而异。目前,海表温度对台风的响应效应主要是通过三个物理量来描述,降温幅度、冷迹范围、冷迹持续时间。但是还没有一个综合的量来对台风的降温效应进行定量的描述。本研究利用遥感微波SST数据尝试初步

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海洋中的微生物多样性是十分丰富的。南海北部区域表层水的微生物群落结构及物种多样性情况仍不十分清楚。本研究,采用构建基因克隆文库的方法,对该区域内表层水中的微生物多样性及分布特点进行研究。获得了8000多个细菌16S rDNA基因、真核微生物ITS 区基因及光合微型生物 psbA 基因单克隆。本研究结果表明:在南海北部区域表层水中存在两种不同微生物类群,即近海岸带海洋微生物类群和开阔海域海洋微生物类群。 16S rDNA基因克隆文库中,确定了507个OTUs。93.7% 的16S rDNA 序列定义在同一种水平上,1.4 %的16S rDNA序列定义在同一属的水平上,2.7%的16S rDNA序列定义在同一纲的水平上,1.2%的16S rDNA序列定义在同一门的水平上。值得一提的是有0.7%的南海表层水样品的16S rDNA 序列,属于目前数据库中的未知序列。系统育树分析表明这类序列可归属于4个不同的分枝群。与Venter’s Sorcerer II 海洋科考(马尾岛海域)的结果不同,南海北部区域表层水中,并没有发现SAR11分支细菌、丝状杆菌(Fibrobacter)和Rheinheimera细菌序列,但南海北部区域却发现了马尾岛海域未检测到的物种,如酸杆菌门、恐球菌-栖热菌门、厚壁菌门,硝化螺旋菌门,浮霉菌门以及疣微菌类细菌。除疣微菌外,其他5种细菌都是海洋环境样品中较为常见的细菌。变形菌门、蓝细菌及厚壁菌门细菌序列是南海北部表层样品16S rDNA基因克隆文库中的主要类群。 真核生物如浮游植物和海洋真菌是海洋表面生物质的主要组成部分之一。现有的研究多集中在环境样品的原核微生物的群落结构研究上,很少关注海洋微型真核生物的多样性及群落结构分布。本研究通过构建ITS基因克隆文库的方法,得到了3044条ITS序列,最终定义了1288个OTUs。其中,329个OTUs序列定义在同一种水平上,310个OTUs序列定义在同一属或纲的水平上,123个OTUs序列定义在同一门的水平上。值得注意的是有339个OTUs的序列,属于目前数据库中的未知序列。系统发育树分析表明它们分别归属于4个不同的分枝群。这表明以往对海洋真核微型生物的多样性仍知之甚少。盘菌亚门、体腔动物门和担子菌纲是南海北部表层样品ITS基因克隆文库中的主要类群。此外,在南海北部区域还发现了少数归属于绿藻、链形植物、定鞭金藻类、放射虫类、Stramenopiles、Typhlocoela、壶菌类、多孢囊霉目、子囊菌门、地位未定的物种、 酵母、领鞭毛虫门、不可培养的后生动物和海绵动物的ITS序列。 海洋初级生产力主要是依靠光合微型浮游生物进行光合作用完成的。利用新设计的psbA通用引物,对南海北部33个表层水样滤膜进行基因克隆文库建库分析,最终获得了南海北部区域表层水微生物多样性及其分布特点研究3062条部分psbA基因序列,并将其划分为957个 OTUs。其中蓝细菌和未培养的病毒序列在psbA基因库中的数量最多。本研究还发现了南海北部区域存在11个独立分支的新型psbA类群。研究证实psbA基因可以作为一种研究海洋光合微型浮游生物群落结构的指示基因。 克隆文库相似性分析发现,在所有的16S rDNA克隆文库中没有任意两个站点的克隆文库相似性超过50%。虽然N401和N420站点的16S rDNA克隆文库相似性最大,但它们在地理位置上并不接近。一些地理位置接近的站点,其16S rDNA克隆文库之间相似性比较接近。比如,海南岛区域的克隆文库之间就比较相似,且在同一分支。大多数地理环境相似的站点的16S rDNA克隆文库都聚在同一大分支上。例如,来自于珠江口区域站点的克隆文库之间的相似性比较接近,而且分布在一个大分支中;开阔海洋区域的16S rDNA克隆文库,也大多聚类在同一分支中。但也有例外的情况:比如 N107 和N400 站点的16S rDNA克隆文库,就聚类到一起,分析发现这两个文库中所处的环境都是甲烷产生区,其中都含有相似的与甲烷代谢相关的菌群。不过从整体来看,整个南海北部的细菌群落,大致分为两大类:中国大陆近海岸微生物群落和开阔海域微生物群落。33个ITS克隆文库的相似性分析发现:相似性在10%以下的类群,可以分成两大分支,而且该分类,比细菌群落的分布情况更接近南海北部的地理环境特征。对psbA基因克隆文库的相似性分析也验证了在南海北部区域表层水中存在两种不同微生物生态系统。 此外,本研究针对分子生态专业软件DOTUR程序在处理大量克隆文库数据时所遇到的

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Archaeological, anatomical, linguistic, and genetic data have suggested that there is an old and significant boundary between the populations of north and south China. We use three human genetic marker systems and one human-carried virus to examine the north/south distinction. We find no support for a major north/south division in these markers; rather, the marker patterns suggest simple isolation by distance.

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1. The stripe-backed weasel Mustela strigidorsa is one of the rarest and least-known mustelids in the world. Its phylogenetic relationships with other Mustela species remain controversial, though several unique morphological features distinguish it from congeners. 2. It probably lives mainly in evergreen forests in hills and mountains, but has also been recorded from plains forest, dense scrub, secondary forest, grassland and farmland. Known sites range in altitude from 90 m to 2500 m. Data are insufficient to distinguish between habitat and altitudes which support populations, and those where only dispersing animals may occur. 3. It has been confirmed from many localities in north-east India, north and central Myanmar, south China, north Thailand, north and central Laos, and north and central Vietnam. Given the limited survey effort, the number of recent records shows that the species is not as rare as hitherto believed. Neither specific nor urgent conservation needs are apparent.

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Akrokolioplax, new genus, is erected for the reception of Epalzeorhynchos bicornis Wu, 1977. It shares with the remaining species of Epalzeorhynchos what have usually been called "rostral lateral lobes" on the snout, which are non-homologous structures used to distinguish the two genera from all other Labeoninae genera. Akrokolioplax and Epalzeorhynchos differ in the position and structure of these lobes, and also in the morphology of the oromandibular structures. A detailed redescription is also provided for the type species of this monotypic genus, A. bicornis. It is presently known from the upper Salween River (=Nu Jiang in Chinese) basin in Yunnan (South China), Myanmar and Thailand.