FIRST RECORD OF FOSSIL CRICKETS (ORTHOPTERA:TRIGONIDIIDAE) FROM CHINA*

Abstract A new genus and a new species of fossil nemobiins, Liaonemobius tanae gen. et sp. nov., are described and illustrated. This is the first record of fossil cricket from China. All the specimens described here were collected from the Late Jurassic Yixian Formation of West Liaoning, China, and now are deposited in the National Geological Museum of China, Beijing.     

蟋蟀化石在我国的首次发现(直翅目:蛉蟋科)(英文)

本文描述针蟋化石1新属1新种：Liaonemobiustanaegen.etsp.nov.。这是蟋蟀化石在我国的首次发现。本文描述的所有标本均来自辽宁西部晚侏罗世义县组地层中,现保存在中国地质博物馆。     

红树植物分子生态与进化研究进展

红树林是热带与亚热带海洋森林和地球湿地生态系统的重要组成部分 ,是多种海洋动物及鸟类栖息繁衍的重要场所 ,在调节全球生态平衡及维持生物多样性方面起着十分重要的作用。有关红树林的生态生物学研究 ,特别是红树林及其生物多样性变化的监测研究 ,红树林的保护与管理已成为热带亚热带海洋及湿地生态学研究的重要内容。海南岛有长达 1 5 2 8ｋｍ的海岸线 ,红树林群落的分布十分广泛。孢粉学证据说明 ,海南岛滨海地区在第三纪时即有红树林出现[1 ] 。现海南岛红树林植物种类有 1 8科 2 6属 34种 ,占中国红树植物种数的 97.1 % [2 ] 。由于…     

Analysis of biodiversity across levels of biological organization: a problem of defining traits

Biodiversity is a term that comprises the appearance, structure and function of all levels of biological organization, including genes, species and ecosystems. The vast majority of measures of biodiversity (usually termed ‘diversity indices’) considers only number, proportion and distribution of species which belong to a specified group and exist in a defined area or ecosystem. Genetic diversity as a part of biodiversity within species (or populations) was either not regarded in this respect or was treated (by geneticists) as a separate entity of diversity quantified with separate measures. Little attention has been given to the integration of both types of diversity, within and among species, in a single measurement (termed ‘transspecific’ diversity). In order to attain this integration on a general basis, an operational trait concept is developed which allows the determination of variation in traits observable in members not only of the same species but also of different species. The concept rests on methods of investigation that can be adapted to a broader range of organisms without modification of their characteristics. Once a trait is specified on this basis, any meaningful measure of diversity can be applied to assess biodiversity across levels of biological organization. The utility of the concept is demonstrated by application to the results of an earlier study on associations between species and genetic diversity in a forest tree community. Attributes of isozymes which are visible in electrophoresis are used as a transspecific genetic trait.     

Spatial genetic structure in continuous and fragmented populations of Pinus pinaster Aiton

Habitat fragmentation, i.e., the reduction of populations into small isolated remnants, is expected to increase spatial genetic structure (SGS) in plant populations through nonrandom mating, lower population densities and potential aggregation of reproductive individuals. We investigated the effects of population size reduction and genetic isolation on SGS in maritime pine ( Pinus pinaster Aiton) using a combined experimental and simulation approach. Maritime pine is a wind-pollinated conifer which has a scattered distribution in the Iberian Peninsula as a result of forest fires and habitat fragmentation. Five highly polymorphic nuclear microsatellites were genotyped in a total of 394 individuals from two population pairs from the Iberian Peninsula, formed by one continuous and one fragmented population each. In agreement with predictions, SGS was significant and stronger in fragments ( Sp  = 0.020 and Sp  = 0.026) than in continuous populations, where significant SGS was detected for one population only ( Sp  = 0.010). Simulations suggested that under fat-tailed dispersal, small population size is a stronger determinant of SGS than genetic isolation, while under normal dispersal, genetic isolation has a stronger effect. SGS was always stronger in real populations than in simulations, except if unrealistically narrow dispersal and/or high variance of reproductive success were modelled (even when accounting for potential overestimation of SGS in real populations as a result of short-distance sampling). This suggests that factors such as nonrandom mating or selection not considered in the simulations were additionally operating on SGS in Iberian maritime pine populations.     

Mating system,pollen and propagule dispersal,and spatial genetic structure in a high-density population of the mangrove tree Kandelia candel

Mangrove tree species form ecologically and economically important forests along the tropical and subtropical coastlines of the world. Although low intrapopulation genetic diversity and high interpopulation genetic differentiation have been detected in most mangrove tree species, no direct investigation of pollen and propagule dispersal through paternity and/or parentage analysis and spatial genetic structure within populations has been conducted. We surveyed the mating system, pollen and propagule dispersal, and spatial genetic structure in a natural population of Kandelia candel, one of the typical viviparous mangrove tree species, using nuclear and chloroplast microsatellite markers. High diversity and outcrossing rates were observed. Paternity and parentage analysis and modelling estimations revealed the presence of an extremely short-distance component of pollen and propagule dispersal (pollen: 15.2 ± 14.9 m (SD) by paternity analysis and 34.4 m by modelling; propagule: 9.4 ± 13.8 m (SD) by parentage analysis, and 18.6 m by modelling). Genetic structure was significant at short distances, and a clumped distribution of chloroplast microsatellite genotypes was seen in K. candel adults. We conclude that the K. candel population was initiated by limited propagule founders from outside by long-distance dispersal followed by limited propagule dispersal from the founders, resulting in a half-sib family structure.     

Genetic structure at range edge: low diversity and high inbreeding in Southeast Asian mangrove (Avicennia marina) populations

Understanding the genetic composition and mating systems of edge populations provides important insights into the environmental and demographic factors shaping species' distribution ranges. We analysed samples of the mangrove Avicennia marina from Vietnam, northern Philippines and Australia, with microsatellite markers. We compared genetic diversity and structure in edge (Southeast Asia, and Southern Australia) and core (North and Eastern Australia) populations, and also compared our results with previously published data from core and southern edge populations. Comparisons highlighted significantly reduced gene diversity and higher genetic structure in both margins compared to core populations, which can be attributed to very low effective population size, pollinator scarcity and high environmental pressure at distribution margins. The estimated level of inbreeding was significantly higher in northeastern populations compared to core and southern populations. This suggests that despite the high genetic load usually associated with inbreeding, inbreeding or even selfing may be advantageous in margin habitats due to the possible advantages of reproductive assurance, or local adaptation. The very high level of genetic structure and inbreeding show that populations of A. marina are functioning as independent evolutionary units more than as components of a metapopulation system connected by gene flow. The combinations of those characteristics make these peripheral populations likely to develop local adaptations and therefore to be of particular interest for conservation strategies as well as for adaptation to possible future environmental changes.     

深圳湾福田红树林群落演替

对深圳湾福田凤塘河红树林演替过程中的群落结构、物种组成、多样性变化及演替趋势的研究结果表明:(1)演替各阶段群落均由秋茄(Kandelia candel)、木榄(Bruguiera gymnorrhiza)、桐花树(Aegiceras corniculatum)、白骨壤(Avicennia marina)及老鼠簕(Acanthus ilicifolius)5个种类组成。(2)演替早期(4 a)群落高度增长较快,之后继续保持较快增长,至17 a时趋于稳定,之后增长速度缓慢。(3)4 a和17 a的群落立木级均分布在Ⅱ级—Ⅳ级,56 a和73 a的群落立木均达到最高级Ⅴ级,该两群落立木在Ⅱ级—Ⅴ级均有分布。(4)随着演替的进展,除了73 a群落盖度较56 a群落稍有下降外,其它演替群落盖度逐渐增加;群落胸高断面积表现出与盖度一致的变化趋势;群落个体密度则逐渐下降;群落物种多样性和均匀度不断提高,群落优势度则逐渐下降;群落相似性系数的变化表明在演替过程中群落物种组成结构没有发生明显变化。(5)群落变化及演替为:秋茄+桐花树群落→秋茄群落→白骨壤+秋茄群落→白骨壤群落。     

Forest structure and biomass of mangroves in the Mgeni estuary,South Africa

Forest structure and biomass were determined in a mangrove stand dominated by Bruguiera gymnorrhiza (L.) Lam. Trees in 5 m² sample plots were harvested at ground level and then further cut into 1 m strata for separation into living wood, dead wood, leaves, reproductive material and pneumatophores. Mean above-ground living biomass was calculated at 94.49±7.83 t dry matter ha^–1, while dead wood contributed a mean mass of 7.63±0.89 t dry matter ha^–1. Excavations of roots yielded a below-ground biomass of 9.67 t dry matter ha^–1 which represented only 9.8% of the above-ground value. There was a mean density of 4700 living stems ha^–1 with plant heights ranging from 0.57 m to 5.80 m. Mean LAI was 4.95±0.80. As a basis for estimating standing biomass, regression lines were fitted to biomass values from individual trees of B. gymnorrhiza and Avicennia marina (Forssk.) Vierh. of various sizes. A comparison of these relationships with methods used by previous workers for estimating biomass suggests that most other methods cannot be applied without modification for local stands of mangroves.     

漳江口红树林沉积物可培养真菌多样性

红树林真菌由于其独特的生态特征、多样性特点和丰富的新型生物活性代谢产物而引起了广泛的关注。本文以漳江口红树林保护区4个采样点的沉积物为研究对象,采用8种筛选培养基（RBM、PDA、CDA、Martin、YM、SDA、ISP2和R2A）分离可培养真菌,根据ITS序列分析对其进行物种鉴定,并利用多样性指数分析评价不同采样点真菌群落的差异。结果共分离到274株真菌,隶属于2门12纲23目39科52属,其中优势属为枝顶孢属（Acremonium）（20.8%）和青霉属（Penicillium）（11.3%）,其次是枝孢属（Cladosporium）（7.3%）和帚枝霉属（Sarocladium）（7.3%）。8种筛选培养基中,分离出真菌种属类型最丰富的培养基是RBM,其次是PDA。根据Shannon-Wiener多样性指数（H′）、Simpson优势度指数（D）、Magalef丰富度指数（R）和Pielou均匀度指数（J）的分析结果,在属的水平上,距海洋的位置越近,真菌的群落多样性越高,真菌分布越均匀。     

八门湾红树林土壤小单孢菌的分离及其多样性

采用平板稀释法从海南八门湾红树林潮间带、木果榄和海莲红树根际土壤样品中分离和筛选小单孢菌科放线菌,对其分离方法进行了评价和比较,并通过16S rRNA基因测序探索了八门湾红树林小单孢菌科放线菌的多样性。采用4种预处理方法和5种分离培养基,经过排除重复菌株后共得到115株放线菌。16S rRNA基因测序结果显示,这些放线菌分布在5个科、9个属。其中小单孢菌科的菌株约占全部菌株的90%(105株),主要分布于3个属:Micromonospora(85%),Jishengella(9.5%)和Verrucosispora(5.5%),与其亲缘关系最近的菌株的相似性分布于98.5%~100%之间。     

厦门凤林红树林湿地大型底栖动物群落

为摸清厦门集美凤林红树林湿地的大型底栖动物群落结构及其多样性现状,2002年1、4、7和10月在厦门集美凤林红树林区进行大型底栖动物调查,4个季度共获得大型底栖动物42种。生物量优势种是软体动物门的珠带拟蟹守螺(Cerithideacingulata)和节肢动物门的弧边招潮(Ucaarcuata)。密度优势种是软体动物门的短拟沼螺(Assimineabrevicula)和环节动物门的沼蚓(Limnodriloidessp.)。集美凤林红树林区大型底栖动物年平均密度和年平均生物量分别为1,990ind./m2和139.0g/m2。密度的季节变化是:1月>4月>10月>7月,生物量的季节变化是1月>10月>4月>7月。聚类分析和数量分布表明,优势种珠带拟蟹守螺、短拟沼螺、弧边招潮和沼蚓的季节变化各不相同。与2002年10月深圳湾福田红树林区大型底栖动物群落的物种多样性指数平均值(0.56)比较,厦门凤林红树林区的平均值较高(2.66)。文中分析了影响大型底栖动物多样性的环境因素。     

东寨港红树林土壤芽胞杆菌分离及其多样性分析

采用热处理法从海南省东寨港红树林海漆林区土壤中分离到276株芽胞杆菌,利用PCR-RFLP与序列分析技术对其16S rDNA遗传多样性进行了研究。16S rDNA PCR-RFLP酶切图谱的聚类分析表明,在100%的相似性水平上,分离的276株芽胞杆菌分属于15个遗传类群,表明存在较为丰富的遗传多样性。15种遗传类型的26株代表芽胞杆菌的16S rDNA序列分析可知,这些芽胞杆菌主要分布于Bacillus(69.2%)、Halobacillus(3.8%)、Virgibacillus(7.7%)、Gracilibacillus(3.8%)、Oceanobacillus(7.7%)和Lysinibacillus(7.7%)6个属,其中Bacillus为优势属。有3株芽胞杆菌的16S rDNA序列与数据库中相应模式菌株的最大相似性在98.O%~98.9%之间,可能为潜在的新分类单元。     

Hermit crabs, humans and Mozambique mangroves

There is a complex interrelationship between upper shore hermit crabs (such as Coenobita sp. and Clibanarius sp.), coastal human populations and mangrove forests in Mozambique. The abundance, activity, shell selection and behaviour of three species of hermit crab are related to the level of mangrove cover. With increased density of mangrove trees, the study species of hermit crab changed in abundance, tended to become diurnal, spent more time feeding and were clustered in larger groups when doing so, and selected longer spired shells. All five of the same variables are also linked to the proximity and activity of humans through both direct and indirect actions. Direct effects included a tendency to nocturnal activity with proximity to human activity; indirect effects included increased and more clumped food supplies, and shell middens from intertidal harvesting and deforestation. Mangroves are important to local human populations as well as to hermit crabs, for a wide variety of (similar) reasons. Mangroves provide storm shelter, fisheries and fishery nursery grounds for adjacent human settlements, but they also harbour mosquito populations and their removal provides valuable building materials and fuel. Hermit crabs may be useful (indirectly) to coastal human populations by being a source of food to certain commercial species, and by quickly consuming rotting/discarded food and faeces (thereby reducing disease and pests). They can also cause minor problems to coastal human populations because they use shells of (fisheries) target mollusc species and can be more abundant than the living molluscs, thereby slowing down effective hand collection through confusion over identification. The mixture of positive and negative attributes that the three groups impart to each other in the Quirimba Archipelago, northern Mozambique, is discussed.     

海南两种红树林植物内生真菌的多样性分析

以海南红树林植物红海榄和秋茄为对象,研究了两种植物的内生真菌的多样性。结果表明:红海榄和秋茄的枝、叶中分别分离到内生真菌30株和27株,内生真菌的优势属分别是茎点霉属和拟盘多毛孢属;同种植物的枝和叶中内生真菌的定殖率差异显著;红海榄和秋茄内生真菌的多样性指数分别为1.7890和1.7473,均匀度指数分别为0.5260和0.5302。两种红树林植物的内生真菌显示出丰富的多样性。     

雷州半岛红树林湿地鸟类多样性

从2000年5月-2003年11月,调查了雷州半岛红树林湿地鸟类.共记录鸟类133种,水鸟和迁徙鸟分别占总记录鸟类数量的81.7%和70.4%.分别有9种、2种、16种和12种鸟被列为中国红皮书保护种、IUCN保护种、CITES保护种和中国国家Ⅱ级保护种;还有63种被列为中日候鸟协定保护种、32种被列为中澳候鸟协定保护种.不同调查地点,鸟类的种类和数量相差较大,高桥鸟类最丰富,记录到83种鸟;五里鸟类种类最少,仅记录到40种鸟,各地鸟类种的相似性很低.环颈鸻(Charadrius alexandrinus)、白腰杓鹬(Numenius arquata)和红嘴鸥(Larus ridibundus)在雷州半岛的种群数量达到国际重要湿地的标准.雷州半岛鸟类种的丰度和多度季节变化明显,冬季种类多、数量丰富,夏季种类少、数量贫乏.冬季和夏季总的鸟类数量(P=0.043)和水鸟数量(P=0.001)差异明显.保护整个沿海红树林湿地是保护雷州半岛红树林湿地鸟类多样性的关键.