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1.
国际海洋生物普查计划   总被引:1,自引:0,他引:1  
孙松  孙晓霞 《地球科学进展》2007,22(10):1081-1086
国际海洋生物普查计划(Census of Marine Life,CoML)是一个在全球尺度上评估和解释海洋生物分布、丰度和多样性的国际计划。重点介绍了国际海洋生物普查计划的背景、发展策略、研究项目、采用的新技术与方法以及我国CoML的筹备和发展,旨在提供海洋生物多样性最新研究动态,为相关领域的研究与决策提供参考。   相似文献   

2.
深海热液环境中的铁氧化菌及其矿化   总被引:1,自引:0,他引:1  
深海热液系统极端的物理化学条件蕴育了完全不依赖于太阳光的独特生态系统,化能自养型微生物是支撑这些生态系繁荣的初级生产者.铁氧化菌是海底热液环境中常见的化能自养微生物之一,能够从低价态铁氧化成高价态铁的化学反应中获取代谢能量.它们对海底金属元素的地球化学循环过程、金属矿床的形成和堆积以及丰富热液生态系统功能等有重要的影响.介绍了深海热液环境中存在的铁氧化菌,以及它们的分类、氧化机理和与之伴生的生物矿化现象.  相似文献   

3.
真核微生物是深海中数量占优势、多样性高且功能重要的微型生物类群。开展深海真核微生物多样性的研究,将为理解深海生态系统结构以及微型生物多样性及其地理分布提供科学依据。迄今,深海真核微生物多样性的研究明显滞后于原核微生物,对于其形态多样性的认识仍局限于有孔虫等无需培养且通过壳体可直接鉴定的少数类群。分子生物学技术的广泛应用,极大地拓展了对深海真核微生物群落结构和多样性的认识,发现了深海中存在的大量未知的新阶元,揭示了较之形态多样性更高的分子多样性。在综述国内外研究进展的基础上,针对真核微生物多样性的研究策略、存在的问题及未来研究应关注的问题提出了建议。  相似文献   

4.
海洋无脊椎动物和细菌间的化能合成共生作用的发现,改变了人们对深海热液口初级生产力主要来源的认知.近年的研究表明,营化能合成共生的动物隶属于纤毛门、软体动物门、环节动物门和节肢动物门;其中无脊椎动物作为宿主在与共生菌的长期共生过程中,伴随着部分器官和功能的退化或消失,逐渐形成和演化出了与此相适应的形态结构,并产生了一些特殊的行为;在深海热液口发现的所有化能合成共生菌都属于革兰氏阴性菌,它们的宿主大致可以分为2个群体;通过16 SrRNA基因编码分析,不同代谢类型的共生菌在系统发育中通常处于不同分支,形态也有所差异;共生菌独特的传播方式和进化模式也使其更加适应共生生活;由无脊椎动物和化能合成细菌构成的共生体系与环境相互作用,影响了深海热液口生态系统的演化.对共生菌蛋白质及代谢组学的研究,以及对宿主生理和代谢机制的研究将成为未来热液口化能合成共生作用研究的新热点.  相似文献   

5.
宋艾  杨久成  丁文娜  刘佳 《冰川冻土》2021,43(3):786-797
近年来,随着DNA测序技术的发展,青藏高原及周边地区的生物地理学研究取得重大成果,从生物演化方面着手探讨了青藏高原隆升历史及其气候效应。综合近年来地质学、古生物学与生物地理学研究进展,我们发现高原及周边地区高寒生物类群的起源和分化时间以及多样性演化过程表明早在渐新世青藏高原部分地区就已经存在高寒生态系统,晚中新世以来青藏高原不同组成部分的地貌与气候格局发生重大改变,高寒生物的祖先类群不断迁入正在生长的高原或在高原上就地演化出适应高寒生境的新物种。晚上新世高寒区物种分化速率快速升高,多样性增加,可能是高原巨大山系和水系以及冰川作用造成地理隔离的结果。同时,生物地理学研究发现青藏高原及周边地区的高寒区与北半球高纬度地区存在密切联系,在第四纪冰期期间并未形成覆盖整个青藏高原的大冰盖,高原面上仍存在很多生物避难所。地质学、古生物学与生物地理学等进行的多学科交叉研究对全方位理解青藏高原隆升历史及其气候效应具有重要意义。  相似文献   

6.
生物多样性是指生命有机体及其借以存在的生态复合体的多样性.生物多样性包括遗传多样性、物种多样性和生态系统的多样性三层含义.遗传多样性,即指所有遗传信息的总和;物种多样性,即生命机体变化的多样化;生态系统的多样性,即栖息地、生物群落和生物圈内生物过程的多样化.相应的生物多样性保护也在环环相扣的多个生物空间等级层次上进行,即景观和生态系统总和体层次、群落层次、物种层次、基因层次[1].  相似文献   

7.
原位观测技术在生物海洋学过程研究中的应用,从海洋生物多样性、海洋生物的生理生态响应和宏观的生态过程及其变动机制等方向的研究中得到迅速的发展,极大提高了对海洋生物学、生态学以及不同时空尺度生物地球化学过程的认识.包括原位光学检测技术、水下显微摄像与自动化鉴定技术、水下流式细胞技术、分子生物传感器等新型原位观测技术,拓宽了各类型观测平台的研究对象范围.重点阐述生物海洋学原位观测技术的发展现状、应用实例及其在立体海洋观测系统中的应用前景.  相似文献   

8.
李延梅  张志强  巩杰 《地球科学进展》2005,20(11):1262-1268
“生物可持续性”(bioSUSTAINABILITY)科学计划是生物多样性计划(DIVERSITAS)3个核心科学计划之一,是一个有关生物多样性的国际计划。bioSUSTAINABILITY有3个密切相关的研究焦点:①评价目前生物多样性保护和持续利用所采取的措施的有效性;②导致生物多样性丧失的社会、政治和经济驱动因子分析;③生物多样性保护与持续利用的社会选择和决策取向研究。介绍了bioSUSTAINABILITY的主要内容及其实施战略,并分析了它对保护和可持续利用生物多样性的重要作用。  相似文献   

9.
深海热液喷口生物群落研究进展   总被引:1,自引:0,他引:1  
近年来深海热液喷口生物群落的研究取得了大量的成果。通过调查发现,除温度外,环境化学参数、地理位置、喷口类型、热液活动周期、生物可利用率等因素都对深海热液喷口生物群落分布产生影响。随着实验室热液微生物的分离、培养成功,一些新的属种及其特殊的生理特征被发现。分子生物学技术的发展,使得对于深海热液生物基因测序、基因功能的研究和表达,功能基因对微生物生理功能的调控作用,动物与微生物之间的共生关系,生物对极端环境的适应机制等问题的研究都能够进行。对于目前不能进行实验室分离培养的微生物,通过基因组分析,也能够了解其群落结构。不同的深海热液喷口,其病毒的类型、分布、丰度以及病毒对热液生态系统的影响是不同的。通过这些研究,科学家探讨了热液喷口环境中生物群落的能量合成与代谢途径的相关理论,并提出了生命有可能起源于热液喷口环境的假说。  相似文献   

10.
海底生物扰动作用及其对沉积过程和记录的影响   总被引:8,自引:1,他引:7  
海底生物扰动作用主要由底栖生物的摄食、掘穴和栖所建造等活动造成,它可以充分改变沉积物的物理、化学特性,扭曲或模糊地层学信号,影响早期成岩过程和沉积记录以及沉积物的稳定性。海底生物扰动作用的研究,对于全面、精确地掌握海洋中各种物质的生物地球化学循环过程,正确回溯古气候、古海洋和古生态记录,合理调节和控制海底生态系统的多样性具有十分重要的意义。简要回顾了海洋生物扰动作用的研究进展,并着重对海洋沉积物中生物扰动作用的观测和定量研究方法、主要影响因素及其对沉积过程和记录的影响进行了评述。  相似文献   

11.
Seamounts support unique biological communities and might act as important nodes of species dispersal and evolution in deep ocean ecosystems. Seamounts have been one of the few characteristic ecosystems that remain underexplored in the abyssal world. However, our knowledge of seamount animals remains very limited due to the difficulty in access to technology, resulting in controversial explanation on their fauna, biodiversity, and biogeography. There have been several hypotheses on seamount biota, including the Endemicity Hypothesis, the Source Sink Hypothesis, the Insular Isolation Hypothesis, and the Oasis Hypothesis. We summarize the pros and cons of seamount fauna and biodiversity, and put forward proposals for future investigation on seamount ecosystem.  相似文献   

12.
A common management technique for preserving and maintaining biodiversity is the establishment of large refuges and preserves. Although extensive sanctuaries can provide crucial protection for many organisms and ecosystems, they cannot fulfill all the needs of regional conservation. An alternative to a few large refuges is to create many different habitats across the landscape that enhance and improve local and regional biodiversity and provide immediate benefits to nearby communities in the form of ecosystem services. Furthermore, these can all be initiated and achieved by individuals or communities. Some key landscape enhancements can be undertaken on a local level: the creation or expansion of small wooded areas, windbreaks, or hedgerows; the construction of small wetlands; and the release of some lands from heavy pressure for the reestablishment of natural ecological processes, namely, the natural accumulation of woody and other organic materials. Newly created ecosystems can be inoculated at the outset with soil biota such as seed banks, microbes, fungi, and organic material that can accelerate ecological functioning and balance. In addition to increasing much local and regional biodiversity, locally enhanced areas can provide fuel, plant and animal food and medicinal products, and agroforestry products directly to the nearby community. These small ecological oases can serve as nesting and overwintering sites for numerous pollinators that are hugely beneficial to agricultural production. Moreover, several ecosystem enhancements may contribute positively to local and regional hydrologic cycles and prevent prolonged droughts. Enhancements to local landscapes can take on many forms. We believe that any changes that increase structural complexity in natural systems almost certainly lead to increases in local biological complexity. In addition, wider landscape level considerations, such as corridors and connectivity of populations, can be integrated on a broader scale to improve regional biodiversity and ecosystem services. Small landscape enhancements undoubtedly cannot provide for all conservation needs, but they can greatly increase widespread biodiversity, restore local ecosystem services, and can be used to complement the relatively few larger parks.  相似文献   

13.
陆地生态系统与气候相互作用的研究进展   总被引:43,自引:4,他引:43  
陆地生态系统与气候系统通过地面与大气之间能量平衡、水汽交换和生物地球化学循环相互作用,影响大气中温室气体浓度和气溶胶,继而影响气候变化。较系统分析总结了当代国际上陆地生态系统与气候相互作用的最新研究进展。首先介绍了陆地生态系统与气候相互作用的机制与过程,总结了陆地生态系统与气候相互作用研究的三个发展阶段,以及当代相互作用的过程模拟研究中三类主要的全球生态系统模型,即生物物理模型、生物地理模型和生物地球化学模型。并介绍了气候对生态系统变化的响应,即两种主要的反馈机制。最后,对未来的研究方向和重点作了分析。  相似文献   

14.
Mixing of hydrothermal fluids and seawater at the ocean floor, combined with slow reaction kinetics for oxidation/reduction reactions, provides a source of metabolic energy for chemolithotrophic microorganisms which are the primary biomass producers for an extensive submarine ecosystem that is essentially independent of photosynthesis. Thermodynamic models are used to explore geochemical constraints on the amount of metabolic energy potentially available from chemosynthetic reactions involving S, C, Fe, and Mn compounds during mixing of hydrothermal fluids with seawater. For the vent fluid used in the calculations (EPR 21 degrees N OBS), the model indicates that mixing environments are favorable for oxidation of H2S, CH4, Fe2+ and Mn2+ only below approximately 38 degrees C, with methanogenesis and reduction of sulfate or S degrees favored at higher temperatures, suggesting that environments dominated by mixing provide habitats for mesophilic (but not thermophilic) aerobes and thermophilic (but not mesophilic) anaerobes. A maximum of approximately 760 cal per kilogram vent fluid is available from sulfide oxidation while between 8 and 35 cal/kg vent fluid is available from methanotrophy, methanogenesis, oxidation of Fe or Mn, or sulfate reduction. The total potential for chemosynthetic primary production at deep-sea hydrothermal vents globally is estimated to be about 10(13) g biomass per year, which represents approximately 0.02% of the global primary production by photosynthesis in the oceans. Thermophilic methanogens and sulfate- and S degree-reducers are likely to be the predominant organisms in the walls of vent chimneys and in the diffuse mixing zones beneath warm vents, where biological processes may contribute to the high methane concentrations of vent fluids and heavy 34S/32S ratios of vent sulfide minerals. The metabolic processes taking place in these systems may be analogs of the first living systems to evolve on the Earth.  相似文献   

15.
深海洋底热泉生态系和冷泉生物研究综述   总被引:9,自引:0,他引:9  
现代海洋学、微生物学和生物学的研究表明,在深海火山活动和板块消减带所形成的地质背景下分别可能有海底热泉和冷泉的存在。在这种海底热泉和冷泉区的特殊环境中能够能海底热泉生态系的冷泉生物。它们能够依靠体内共生化学厌氧合成细菌产生营养,因而可能存在于完全缺氧的还原环境。海底热泉和冷泉生物学研究是对传统的生物学和地质学的挑战,人们还可能通过古代海底热泉和冷泉生态系的识别和分析,对涉及生命发生、生物演化、生物  相似文献   

16.
Spheres of discharge of springs   总被引:3,自引:0,他引:3  
Although springs have been recognized as important, rare, and globally threatened ecosystems, there is as yet no consistent and comprehensive classification system or common lexicon for springs. In this paper, 12 spheres of discharge of springs are defined, sketched, displayed with photographs, and described relative to their hydrogeology of occurrence, and the microhabitats and ecosystems they support. A few of the spheres of discharge have been previously recognized and used by hydrogeologists for over 80 years, but others have only recently been defined geomorphologically. A comparison of these spheres of discharge to classification systems for wetlands, groundwater dependent ecosystems, karst hydrogeology, running waters, and other systems is provided. With a common lexicon for springs, hydrogeologists can provide more consistent guidance for springs ecosystem conservation, management, and restoration. As additional comprehensive inventories of the physical, biological, and cultural characteristics are conducted and analyzed, it will eventually be possible to associate spheres of discharge with discrete vegetation and aquatic invertebrate assemblages, and better understand the habitat requirements of rare or unique springs species. Given the elevated productivity and biodiversity of springs, and their highly threatened status, identification of geomorphic similarities among spring types is essential for conservation of these important ecosystems.  相似文献   

17.
The geologic production of abiotic organic compounds has been the subject of increasing scientific attention due to their use in the global carbon flux balance, by chemosynthetic biological communities, and for energy resources. Extensive analysis of methane(CH4) and other organics in diverse geologic settings, combined with thermodynamic modelings and laboratory simulations, have yielded insights into the distribution of specific abiotic organic molecules on Earth and the favorable c...  相似文献   

18.
While the steady state is often seen as the final result of development in nature, a more realistic concept may be that nature pulses regularly to make a pulsing steady stata—a new paradigm gaining acceptance in ecology and many other fields. In this paper we compare tidal salt marshes, tidal freshwater marshes, and seasonally flooded fresh-water wetlands as examples of pulsed ecosystems. Despite marked differences in species composition, biodiversity, and community structure, these wetland types are functionally similar because of the common denominator of water flow pulses. Often a period of high production alternates with a period of rapid consumption in these fluctuating water-level systems, a biotic pulsing to which many life histories, such as that of the wood stork, are adapted. Pulsing of medium frequency and amplitude often provides an energy subsidy for the community thus enhancing its productivity. The energy of large-scale pulses such as storms are usually dissipated in natural ecosystems with little harm to the biotic network; however, when seawalls, dikes, or stabilized sand dunes are constructed to confront these strong pulses, the whole ecosystem (and associated human structures) may be severly damaged when the barriers fail because too much of the storm energy is concentrated on them. The relationship between biologically mediated internal pulsing, such as plant-herbivore or predator-prey cycles, and physical external pulsing is discussed not only in wetlands but in other ecosystem types as well. An intriguing hypothesis is that ecosystem performance and species survival are enhanced when external and internal pulses are coupled. We suggest that if pulsing is general, then what is sustainable in ecosystems, is a repeating oscillation that is often poised on the edge of chaos.  相似文献   

19.
全球生态系统的状况与趋势   总被引:3,自引:0,他引:3  
简要介绍了千年生态系统评估(MA)项目状况与趋势工作组的报告《生态系统与人类福祉:现状与趋势》中的第3部分,即“对提供生态系统服务的各类系统的评估”。评估结果表明,在20世纪的后50年,全球生态系统的变化幅度和速度皆超过了人类历史上有记录的任何一个相等时间段的情况,目前人类活动实际上已经显著地改变了地球上的所有生态系统。这些变化主要表现在:① 大约1/4的地球陆地表层已经转变为垦殖系统,而且在1950年之后的30年中,转变为农田的土地面积比1700—1850年这150年间转变的总和还要多;②全球大多数的重要流域,由于水资源利用造成的栖息地丧失与破碎化,以及由于养分、沉积物、盐分及有毒物质造成的污染,已经显著地破坏了河流、湖泊和盐水沼泽等湿地生态系统的功能与生物多样性;③ 旱区系统存在着水资源匮乏、过度垦殖、过度放牧和过度砍伐树木等问题,生态状况尤其令人担忧;④ 栖息地的丧失与破碎化、过度开发、污染以及气候变化,已经对海滨系统造成了严重的生态威胁;⑤ 不可持续的农业开发模式,已经严重地破坏了热带森林生态系统的结构与功能。  相似文献   

20.
冷泉流体沉积碳酸盐岩的地质地球化学特征   总被引:39,自引:3,他引:36  
冷泉流体是指来自海底沉积界面之下的低温流体以喷涌和渗漏方式注入盆地, 并产生系列的物理和化学及生物作用, 这种作用及产物称为冷泉?它是继洋中脊以盆下源中高温流体的热泉被发现和研究之后的又一个新的盆地流体沉积领域?日前研究较多的是以水? 碳氢化合物 (天然气和石油) ? 硫化氢? 细粒沉积物为主要成分, 温度与海水相近的流体, 广泛发育于活动和被动大陆边缘斜坡海底?冷泉流体沉积体系发育高密度的化学自养生物群, 以碳酸盐岩和天然气水合物为主, 有少量的硫化物和硫酸盐等?冷泉碳酸盐岩的产状有丘? 结核? 硬底? 烟囱? 胶结物和小脉等, 以化学自养生物碎屑和多期次的自生碳酸盐胶结物组成的生物丘最为常见, 它在物质来源? 形成环境? 形成作用等方面与传统来源于海水碳的碳酸盐岩建隆不同, 用术语 C h e r m o h e r m 表示, 以区别于传统海水碳酸盐岩建隆术语b i o h e r m s ? l i t h o h e r m s ? p s e u d o b i o h e r m s 和 b i o s t r o m e s ?地层中石化的化学自养生物丘常是含有大量底栖生物化石的碳酸盐岩建隆产于深水相沉积地层中, 在沉积环境和相分析上出现纵向和横向的不连续, 甚至出现反常现象?矿物以镁方解石? 白云石和文石为主, 与传统的碳酸盐岩相似, 在地球化学组成上最大的区别是冷泉流体沉积碳酸盐岩的碳来源于冷泉体系中的细菌生物成因碳, 具有特别负的碳同位素值?冷泉在海底主要沿构造带和高渗透地层呈线性群, 或围绕泥火山或盐底劈顶部呈圆形或不规则状冷泉群分布,或以海底地形低凹处和峡谷转向处呈孤立冷泉形式产出?冷泉流体以沉积建造流体为主?上覆快速堆积? 成岩压实和胶结作用? 构造挤压和变形作用? 深部的后生作用和成岩作用? 海底沉积物中的天然气水合物分解作用是建造流体向上运移进入海底成为冷泉的驱动力?冷泉碳酸盐岩的沉积作用主要有胶结作用? 充填作用和生物化学沉积作用?冷泉流体中的碳主要是以甲烷为主的碳氢化合物形式存在, 经微生物作用转变为 C O2 ,最终形成冷泉碳酸盐岩?  相似文献   

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