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1.
介绍一种体外发射式植入刺激器的结构和电路原理。该机不但体积较小,耗电少,且可选择较强刺激电压,其植入部分的生物相容性较好,并初步观察了用此刺激器刺激骶神经以恢复截瘫狗排尿功能的情况。  相似文献   

2.
目的探索一种在无线遥测和刺激技术基础上的兔房颤模型的制作。方法新西兰兔皮下植入自主研发的植入式遥测刺激器,植入式遥测刺激器的制作是以TI公司(德州仪器)的MSP单片机和TI公司的RF无线收发芯片CC2250为核心开发设计。优化植入系统设计以满足新西兰兔房颤模型建立的探索实验;植入子植入新西兰兔腹部皮下,采集电极留置于左上肢和右上肢腋下皮下,两个刺激电极分别缝合于左心耳和左心房上,通过无线收发采集和刺激信号;实现利用Powerlab生理记录仪连续监测体表I导联心电信号,并通过专用计算机程序刺激软件,发放间歇(刺激2 s,暂停2 s)高频(频率20 Hz)阈上(强度2 mA,脉宽1 ms)刺激,若间歇期内出现房颤,则人为干预中止刺激,若转为窦性心律,则继续刺激。结果植入式遥测刺激器在体内可稳定工作(包括采集模拟心电信号和发放刺激)30 d,植入新西兰兔体内刺激3周后可诱导出房颤,持续时间〉48 h。结论用新西兰兔代替比格犬建立基于无线遥测和刺激基础上的房颤模型是完全可行的,同时也体现了动物福利优化和替代原则。  相似文献   

3.
《生物学通报》2008,43(2):46-46
深部脑刺激器是一种体内植入型治疗设备.它能连续不断地传送刺激脉冲到深部脑组织区域,这种作用称为深部脑刺激。神经外科医生通常会用深部脑刺激来治疗各种抗药性运动障碍疾病,如帕金森氏症、原发性震颤及肌张力异常等,但科学家们一直不清楚刺激作用改善疾病症状的机理。  相似文献   

4.
改进电子刺激器的使用方法电子刺激器或多用仪是动物生理学实验的常用仪器,然而使用时多使用刺激隔离器。有的利用变压器做隔离器,用变压器做隔离器,严重改变了电子刺激器的刺激强度和波形。一般刺激器或多用仪输出的是方波(也有锯齿波刺激器),而经隔离变压器输出后...  相似文献   

5.
本文介绍了目前世界各植入式神经刺激器厂家最新产品现状及植入式神经刺激器技术的发展趋势。  相似文献   

6.
刺激器是生理学及医学实验中广泛应用的一种电子仪器。近年来,随着针刺麻醉原理和临床研究的不断深入,广大科技工作者和医务人员研制了不少不同性能的刺激器,各有特点。为了适应慢性动物实验的需要,我们研制了一  相似文献   

7.
目前电刺激器在医院麻醉和理疗科室的应用已十分普遍。本文介绍的神经刺激器是用于麻醉时神经定位和神经肌肉功能监测。微处理器产生电脉冲,经过D/A(数/模)转化输出强度可调的脉冲电流,针对不同病人采用不同刺激频率,同时显示刺激电流的大小。刺激器有两种功能:自动循环进行刺激和手动选择刺激频率挡。  相似文献   

8.
任秋实 《生命科学》2009,(2):234-240
人工视觉假体是当今国际上对视网膜色素变性和老年性黄斑病变患者进行视觉修复的研究热点,该人工装置采集外界图像信息,并进行编码处理,通过微电流刺激器将刺激微电流信号加载到微电极阵列,对视觉神经系统进行作用,从而在视觉中枢产生光幻视,实现视觉功能修复。根据目前的国际研究现状,视觉假体可以对视觉通路的任意位置进行电刺激,以期产生视光感。按照植入位置的不同,视觉假体基本上可以分为视皮层假体、视网膜上假体、视网膜下假体和视神经假体。本文着重介绍了中国的C-Sight小组在视神经假体方面的工作进展和面临的挑战。  相似文献   

9.
慢性电极植入以及无线刺激技术被广泛应用于动物自由活动状态下的脑区功能研究。实现刺激器与脑内植入电极过渡连接的转接装置需固定在颅骨之上。鸟类特殊的骨质构造不利于转接装置的长期固定。以鸽子(Columba livia)为例设计制作了一种用于慢性运动诱导实验的9通道电极转接装置,长12.8 mm、宽9.5 mm、高5.5 mm,重0.42 g;根据鸽子颅骨特点在固定过程中对颅骨表面进行粗糙化处理增加固定时与牙科水泥的接触面积,并选取特定位点拧入螺钉进行固定,有效延长了转接装置的固定时间。经实验验证能够在鸽子头部稳定固定6个月以上,满足鸽子长期运动诱导研究的需求,未对动物正常活动产生影响。该装置及其固定方法亦可为其他小型动物的脑区功能研究提供借鉴。  相似文献   

10.
在美国大约有1300万人患有失禁症,他们不能控制膀胱的功能,排尿不能自制,常常令人窘迫,苦不堪言。据美国医疗保健政策研究机构报导,每年用于尿失禁的医疗费用高达110万美元。老年人的尿失禁是美国的托老所和敬老院获准入院最常见的理由和原因。 最近,美国Meditronic公司研制开发了一种植入式的神经刺激器,据称可以治疗这种疾病。这种刺激器使用电子信号超越控制促使失禁的脉冲,这种病症的特点是先突然感到马上  相似文献   

11.
林有润 《植物研究》2002,22(3):341-365
棕榈科原省藤亚科因其子房壁及外果皮被倒生、螺旋状排列的鳞片所覆盖,而区别于其他亚科,因而独立分出成一新科--省藤科。作者讨论了棕榈科的祖先种可能在石炭纪时,自原始裸子植物开以顿目在分化、衍生出苏铁目祖先种的进化干上,于白垩纪时分化出的一个分支。在棕榈科的祖先种出现不久后,在其进化的分支上,于白垩纪后期又分化出一旁支,成为棕榈科的姊妹科--省藤科的祖先种。从两祖先种分别再分化、衍生出现今分布地球上该二科的属与种。两科、尤其前者是被子植物、尤其是单子叶植物中最原始的类群之一。作者还提出棕榈科象牙椰亚科与贝叶棕亚科是该科最原始或较原始的两类群;槟榔亚科和腊材榈亚科是较进化的两类群;而水椰亚科祖先种可能源于象牙椰亚科的祖先种,但又演化为该科最进化与特化的类群。省藤科省藤亚科略比鳞果榈亚科原始。作者讨论了两科为泛热带分布的科,指出两科的"现代分布区"在南北两半球热带地区,少数种还延伸分布到两半球暖亚热带、甚至达中亚热带地区,分布区边缘最北达日本中部、中国长江流域及黄河下游的南部,美国加利佛尼亚州与佛罗里达州和地中海北部;最南达智利中部和新西兰南部;而"现代分布中心"在热带与暖亚热带的亚洲,中、南美洲,大洋洲及非洲的东、南、西部;但分布区的"密集中心"则在热带亚洲、热带中及南美洲、南太平洋群岛及非洲东南部。作者还介绍了近50年我国南方引种驯化成功的两科植物近400种(见*图谱),其中少数为耐寒的种类,有的种已引种到长江流域或更北的地区。引种的大部分种都有其重要的经济用途,包括:1. 食用,如淀粉和树液可制"西米"或制糖,酿酒、醋或作饮料;果或种子榨油,供食用或工业用;某些种的嫩芽作蔬菜,甚至种子代咖啡饮用;2. 药用,有消炎、止血、活血、驱虫、抗癌等用;3. 建筑、工艺与日用品,包括不少种的树干供建普通房子、桥梁、小船;少数种可提制工业用蜡;许多种的纤维制高级缆绳和编织品;还制工艺品与日用品等;4. 代表热带景观的园林工程、绿化及美化环境的观赏树和人行道树及建造园林景观生态类型的树种等。  相似文献   

12.
We review current knowledge of the most abundant sugars, sucrose, maltose, glucose and fructose, in the world's major crop plants. The sucrose‐accumulating crops, sugar beet and sugar cane, are included, but the main focus of the review is potato and the major cereal crops. The production of sucrose in photosynthesis and the inter‐relationships of sucrose, glucose, fructose and other metabolites in primary carbon metabolism are described, as well as the synthesis of starch, fructan and cell wall polysaccharides and the breakdown of starch to produce maltose. The importance of sugars as hormone‐like signalling molecules is discussed, including the role of another sugar, trehalose, and the trehalose biosynthetic pathway. The Maillard reaction, which occurs between reducing sugars and amino acids during thermal processing, is described because of its importance for colour and flavour in cooked foods. This reaction also leads to the formation of potentially harmful compounds, such as acrylamide, and is attracting increasing attention as food producers and regulators seek to reduce the levels of acrylamide in cooked food. Genetic and environmental factors affecting sugar concentrations are described.  相似文献   

13.
Microbes colonise all multicellular life, and the gut microbiome has been shown to influence a range of host physiological and behavioural phenotypes. One of the most intriguing and least understood of these influences lies in the domain of the microbiome's interactions with host social behaviour, with new evidence revealing that the gut microbiome makes important contributions to animal sociality. However, little is known about the biological processes through which the microbiome might influence host social behaviour. Here, we synthesise evidence of the gut microbiome's interactions with various aspects of host sociality, including sociability, social cognition, social stress, and autism. We discuss evidence of microbial associations with the most likely physiological mediators of animal social interaction. These include the structure and function of regions of the ‘social' brain (the amygdala, the prefrontal cortex, and the hippocampus) and the regulation of ‘social’ signalling molecules (glucocorticoids including corticosterone and cortisol, sex hormones including testosterone, oestrogens, and progestogens, neuropeptide hormones such as oxytocin and arginine vasopressin, and monoamine neurotransmitters such as serotonin and dopamine). We also discuss microbiome‐associated host genetic and epigenetic processes relevant to social behaviour. We then review research on microbial interactions with olfaction in insects and mammals, which contribute to social signalling and communication. Following these discussions, we examine evidence of microbial associations with emotion and social behaviour in humans, focussing on psychobiotic studies, microbe–depression correlations, early human development, autism, and issues of statistical power, replication, and causality. We analyse how the putative physiological mediators of the microbiome–sociality connection may be investigated, and discuss issues relating to the interpretation of results. We also suggest that other candidate molecules should be studied, insofar as they exert effects on social behaviour and are known to interact with the microbiome. Finally, we consider different models of the sequence of microbial effects on host physiological development, and how these may contribute to host social behaviour.  相似文献   

14.
云南干热河谷植被与环境研究进展   总被引:1,自引:0,他引:1  
特殊的地理位置和独特的地形地貌特征组合形成了典型的干热气候环境, 在云南省亚热带高原山地河谷下部发育了一类特有的植被类型, 即干热河谷植被。干热河谷植被具有非地带性和稀有性, 以及由土地利用变化为主的人为活动干扰导致的脆弱性。本文回顾了干热河谷植被的研究历史, 分别从干热河谷的植物群落学和植物区系学、干热河谷植被与土地的关系以及干热河谷植被保护与恢复三个方面进行了总结。植物群落与区系研究主要集中于群落分类、植被分类、群落特征、人为干扰影响、区系特征、性质和起源; 植被与土地关系研究侧重于土壤特性、土地利用/覆盖变化、土地退化及水土流失状况; 植被保护与恢复的热点在植被恢复目标、植被恢复功能区划、植被恢复引种及筛选及植被恢复效益评价研究。未来在这些区域应注重自然灾害及预防、水电工程建设对植被的影响及其响应等方面的研究, 深入开展大尺度植被时空格局的监测和动态服务功能分析。  相似文献   

15.
口唇部是主要的面部形态区域之一,具有重要的生理功能。嘴唇保护口腔免受外部物质的渗透,维持口腔内部的湿度和温度,帮助咀嚼,同时也是外科美容整形手术中的主要部位之一,且在法医物证研究中唇纹也具有重要的鉴别价值。目前关于口唇部形态的研究主要包括以下几个方面:口唇部形态变异的性别、年龄、族群差异;影响口唇部形态变异的因素,如遗传基因、饮食结构、牙齿及颌骨形态和呼吸方式等;口唇部形态研究在医学、个人身份识别及法医刑侦领域的相关应用等。国内口唇部形态研究相对较少,尤其缺乏较为系统的口唇部形态生长发育及变异研究。本文通过梳理和归纳国内外相关文献的研究数据和结论,对口唇部形态相关研究作简要概述,并对国内口唇部生长发育及形态变异研究作了简要回顾和展望。  相似文献   

16.
H. De Haan 《Hydrobiologia》1982,95(1):205-221
This paper attempts to generalize the major controlling factors and their impacts on the physico-chemical environment in Tjeukemeer in relation to the speciation of algal nutrients.Morphometry, man-made hydrology, climate, chemistry of drainage area and biology of the lake appear to control its physico-chemistry the most. Thus the shallow Tieukemeer is vulnerable to wind and therefore almost always completely mixed and often turbid owing to resuspended sediments. In normal summers the lake is oligohaline, hard, eutrophic and alkaline, and in winter it is hard, eutrophic, alkaline and humus-rich. The implications of these properties on the following physico-chemical components and their relevance for the speciation of algal nutrients are discussed: turbidity, colour, halinity, pH, alkalinity, salinity, conductivity, ionic composition, ionic balance and organic matter.Because of the relationships between the physico-chemical environment on the one hand and the speciation and bio-availability of nutrients on the other hand, special attention is given to the speciation of some major and minor elements as derived from ultra filtration experiments. In this context, the metal binding capacity of the organic matter (mainly fulvic acids) is also considered.  相似文献   

17.
Abstract

An introduction to the nomenclature and concept of “Romanowsky stains” is followed by a brief account of the dyes involved and especially the crucial role of azure B and of the impurity of most commercial dye lots. Technical features of standardized and traditional Romanowsky stains are outlined, e.g., number and ratio of the acidic and basic dyes used, solvent effects, staining times, and fixation effects. The peculiar advantages of Romanowsky staining are noted, namely, the polychromasia achieved in a technically simple manner with the potential for stain intensification of “the color purple.” Accounts are provided of a variety of physicochemically relevant topics, namely, acidic and basic dyeing, peculiarities of acidic and basic dye mixtures, consequences of differential staining rates of different cell and tissue components and of different dyes, the chemical significance of “the color purple,” the substrate selectivity for purple color formation and its intensification in situ due to a template effect, effects of resin embedding and prior fixation. Based on these physicochemical phenomena, mechanisms for the various Romanowsky staining applications are outlined including for blood, marrow and cytological smears; G-bands of chromosomes; microorganisms and other single-cell entities; and paraffin and resin tissue sections. The common factors involved in these specific mechanisms are pulled together to generate a “universal” generic mechanism for these stains. Certain generic problems of Romanowsky stains are discussed including the instability of solutions of acidic dye–basic dye mixtures, the inherent heterogeneity of polychrome methylene blue, and the resulting problems of standardization. Finally, a rational trouble-shooting scheme is appended.  相似文献   

18.
IPBES第一轮工作方案受到国际社会的广泛关注, 奠定了其作为第一个生物多样性领域政府间机制的重要地位。IPBES自成立以来相继发布了系列评估报告和决策者摘要, 引起了国际社会广泛关注, 因此, 其公平性、公正性、科学性和透明性始终为各界关注的焦点, 直接决定着IPBES评估报告的可信度和未来的发展。为有效提升工作效率, 提高其成果的科学性, IPBES通过定期开展内部和外部审查, 发现问题, 优化机构设置, 从而指导未来工作计划。本文以IPBES定期开展的审查以及现有工作机制为基础, 针对IPBES的工作效率和科学职能进行分析, 从根本上认识其地位和性质, 分析其机构设置的优势和存在的问题, 以及工作职能的发挥潜力, 针对存在的问题提出建议。并根据我国情况, 提出相关工作建议。总体来讲, IPBES在完善组织机构和规则程序, 推动产生新知识、财务资源有效管理等方面均取得了显著进展, 但在透明度、科学与政策衔接、学科和地域平衡, 以及政策支持方面存在一定不足, 在发挥成员国积极性和能力方面存在欠缺。为此, 建议IPBES未来能够更进一步发挥其特殊的政府间地位和作用, 促进科学职能的发挥, 特别是加强科学和政策的互动, 推动多利益攸关方参与, 形成稳定的财务制度并提升工作机制的透明度。同时, 建议加强对IPBES评估报告在国内的解读, 加大国内宣传力度, 并加强多学科的专家遴选, 弥补研究领域的国内空缺。  相似文献   

19.
中国昆虫染色体研究现状与展望   总被引:13,自引:1,他引:12  
简要叙述了中国昆虫染色体研究的现状,包括研究涉及的昆虫类群、核型分析结果、研究方法和手段、染色体有丝分裂、减数分裂、染色体形态变异、结构变异和数量变异等。我国学者对昆虫染色体研究从20世纪30年代开始,迄今已对蜉蝣目、蜚蠊目、直翅目、半翅目、同翅目、鞘翅目、鳞翅目、双翅目、蚤目和膜翅目等10目481种昆虫的核型进行了研究,主要集中在蝗虫、蝽类、蚜虫、蚕类、果蝇、摇蚊及实蝇等。在染色体行为方面的研究主要有:蚕类和果蝇等有丝分裂;蜚蠊类、蝗类、蝽类和蚕类的减数分裂及性别决定机制;部分昆虫的联会复合体分析。染色体结构变异的研究主要集中在果蝇和蚊类昆虫的唾腺染色体;果蝇的B染色体;蚕类和蚊类昆虫染色体的缺失、易位和倒位等变异;蚕蛾类的数量变异。研究结果多应用于昆虫系统分类和进化的探讨,揭示昆虫遗传与变异规律。通过与国外研究成果对比,提出昆虫染色体研究的必要性,并对我国未来昆虫染色体研究进行了展望。  相似文献   

20.
Mt. Wuyi, located at 27°37‛-27°54‛ N, 117°27‛-117°51‛ E, is the highest mountain in South-East China. Its main peak, Huanggangshan, is 2158 m above the sea level. In 1955, P. C. Chen organized the first expedition to Mt. Wuyi, and the authors investigated the different ravines and the forests of that area in 1976 and from 1979 to 1984 respectively. Up to now 355 species of the bryophytes have been found in Mt. Wuyi. I. The influence of the factors of geological history on the bryoflora of Mt. Wuyi Fujian Province, belonging to Cathaysian, one of three Chinese ancient lands, was a part of ocean until the end of the lower Tertiary. In the early Devonian, Fujian uplifted above the sea level, but it submerged in the sea later, and then uplifted above the sea level again in the upper Triassic. By the end of the lower Triassic the Himalayan movement influenced the paleogeography of China deeply, and the eastern and central mountains of Fujian uplifted again. In the Tertiary, Fujian was influenced by the hot maritime weather, so the tropical evergreen forests existed in southern Fujian at that time. The conclusion was made by Z. B. Zhao in 1983 after his long period of study on geological history of Fujian Province since the Yanshan movement. According to the morden geographical distribution of Chinese bryophytes, it seems that the above influence might be related to the bryophytes of Mt. Wuyi and also the southern part of Zhejian Province. By the end of the Tertiary the weather became cold in most parts of China. Since then the cold weather and hot weather alternated several times. One kind of the endemic elements of the bryoflora formed in the area from the south-eastern coast of China to the southeastern Xizang (Tibet), including Japan. They are not specialized at the family level or closely related to each other, but they have similar distribution and belong to different families. In the Quaternary, Mt. Wuyi gradually uplifted following the Himalayan movement. As the weather cooled down in the upper part of the mountain, deciduous broad-leaved and needleleaved trees increased there. Meanwhile, temperate genera and species of the bryophytes spread and invaded South China and entered Mr. Wuyi. Rhytidiadelphus and Hvlocomium probably began to grow in Mt. Wuyi at that time, and their distribution is quite different from their primary one. On the other hand, a part of tropical and subtropical bryophytes might enjoy the changed weather and environment in the Quaternary and existed in a few small localities of Mt. Wuyi, and the genera Haplomitrium, Endotrichella and Floribundaria are probably their representatives. From the point of view of geological history we are now living in the interglacial period and the present natural conditions will last continuously, so they will steadily influence the bryoflora of Mt. Wuyi in a long period of time. 2. Essential characteristics of the bryoflora in Mt. Wuyi Due to the geographical position and the other factors of Mt. Wuyi the bryoflora is represented by numerous tropical and subtropical elements (34.1%), but the East-Asiatic endemic ones (79.2%) are characteristic of the bryoflora in Mt. Wuyi (Tab. 1). The tropical and subtropical families of the bryophytes, found south of Changjiang (Yangtzi) River, are Haplomitriaceae (1 genus, 3 species), Porellaceae (2 genera, 8 species), Frullaniaceae (2 genera, 10 species), Lejeun eaceae (21 genera, 35 species), Trachypodaceae (3 genera, 4 species), Meteoriaceae (10 genera, 17 species), Neckeraceae (5 genera, 8 species) and Hookeriaceae (3 genera, 3 species). The above 8 families, including 46 genera and 85 species, represent about 1/4 genera (24.3%) and less than 1/4 species (23.9%) of the bryoflora of Mt. Wuyi. Most species of East-Asiatic elements show very close relationships with Japan, and are widely distributed from the low altitude of Mt. Wuyi to the summit of Mt. Huanggangshan. However, the Holarctic species (26.8%) are also important elements of the bryoflora in Mt. Wuyi, showing its transition nature, although it is located in the subtropics. Moreover, the in fluence of the Himalayas also exists in Mt. Wuyi, and the Himalayan elements cover 14.4% in the bryoflora of Mt. Wuyi. The similarity coefficients between the bryofloras of Central and South America, Africa and Oceania and that of Mt. Wuyi are from 5.0-9.2% respectively. The endemic species are not very many and cosmopolitan species are only 7 there. In 1958, P. C. Chen designated Mt. Wuyi as “the transition region of South and North China rich in East-Asiatic genera and species”. His very important conclusion is essentially in accordance with the fact of the bryoflora on Mt. Wuyi. Recently, some of the new records fur ther show the characteristics of the bryoflora in Wuyi. Two facts are worth being mentioned. One is that East-Asiatic genera are only five in Mt. Wuyi. However, there are 9 East-Asiatic genera in Mt. Huangshan more than in Mt. Wuyi; 4 East-Asiatic genera are recorded in Mt. Shennongjia. The other is that epiphyllous liverworts in Mt. Wuyi, consisting of 7 families, 21 genera and 36 species, are less than on Hainan Island and Xishuangbannan, located in the tro pics in China. 3. Comparison between the bryoflora of Mt. Wuyi and those of the neighbouring regions As China covers a very large area, bryofloristic elements are quite different in the diffe rent regions. In this section, we are concentrated on making a comparison between the bryof loras of Mt. Wuyi and the regions belonging to the Central China of the bryoflora named by P. C. Chen. Huaping Forest Region, Guangxi Zhuang Autonomous Region in South China, with both latitute and altitude very similar to Mt. Wuyi, is included in this comparison (Fig. 1). According to the rough estimation, the similarity coefficient of moss genera between Mt. Wuyi and Huaping is 56.3%, and those between the mountain and southern Zhejian and Mt. Huangshan, Anhui, are 62.7% and 51.6% respectively, while the similarity coefficient of the genera of the mossfloras between Mt. Shennongjia and Mt. Wuyi is 46.8%. Table 2 shows the statistics of mosses in Mt. Wuyi and the others, but the bryoflora of Huaping needs further study However, it is very interesting to note that Haplomitrium and Pleurozia of liverworts are both found in Mt. Wuyi and Huaping Forest Region, and the similarity coefficient between the mossfloras of Mt. Wuyi and Zhejian Province is also higher than those mentioned above. Tropical and subtropical elements reduce towards the north in China, and temperate ones increase. Huaping is located in the south, and, as expected, some tropical and subtropical genera such as Hookeriopsis and Symphyodon have been found there, but not in Mt. Wuyi; several temperate genera, such as Schwetschkeopsis and Fauriella, have been recorded in Mt. Huangshan, but not in Mt. Wuyi. For some unknown reasons, Octoblepharum and Neckeropsis are only found in southern Zhejiang, but not in Mt. Wuyi. Mt. Shennongjia, with its main peak over 1000 m higher than that of Mt. Wuyi, is located in its northwest, and more than ten temperate genera, such as, Ceratodon, Aulacomnium Myurella, Bryonoguchia and Abietinella have been found there. Generally, Mt. Wuyi belongs to the central subtropical region of China, and East-Asiatic endemic genera are the main elements of its bryoflora, but the bryoflora also consists of tropical and subtropical elements with some temperate ones. 4. East-Asiatic endemic genera in the bryoflora of Mt. Wuyi In the bryoflora of Mt. Wuyi, one of the main elements, East-Asiatic endemic genera, should not be neglected (Tab. 4). East-Asiatic endemic genera in Mt. Wuyi (five) are less than in Mt. Huangshan and Mt. West Tianmu, although the positions of the latter two are very close to Mt. Wuyi. East-Asiatic endemic genera of liverworts are Trichocolea and Macvicaria so far found in Mt. Wuyi, and the mosses are Myuriopsis, Meteoriella, Pseudospiridentopsis (Fig. 1). Myuriopsis is only distributed in Taiwan Province and Mt. Wuyi, and the other four are distributed in Mt. Huangshan or Mt. West Tianmu, and also in Taiwan, besides in Mt. Wuyi. About thirty EastAsiatic endemic genera have so far been known in China, which means that about one sixth of East- Asiatic endemic genera of the bryophytes occur in Mt. Wuyi. We may notice that nine and seven East-Asiatic endemic genera of the bryophytes have been recorded in Mt. Huangshan and Mt. West Tianmu respectively. In Mt. Shennongjia, Central China, there are four East Asiatic endemic genera, but only two have been found in the Huaping Forest Region, South China. In Mt. Dinghua, located south of Mt. Wuyi, on East-Asiatic endemic genus of the bryophytes has so far been found. East-Asiatic endemic genera of the bryophytes are mainly limited to China, Korea and Japan, including the East Himalayas, rarely occur in South Asia, Siberia of the Soviet Union. Therefore, these genera enjoy a warm and moist environment. In Mt. Wuyi, all the East-Asiatic endemic genera are monotypic ones with a disjunct distribution. Now in Taiwan Province five of six recorded East-Asiatic endemic genera are common to Mt. Wuyi. In Japan, about eleven, i.e. one third of, East Asiatic endemic genera so far found are common to China, which shows a long history of the phytogeographical relationships between Japan and China. East Asiatic endemic genera of the bryophytes might therefore exist on islands of Taiwan Province and Japan before they were separated from the mainland of Asia. However the fossil evidence is still lacking in the bryophytes, so we are not able to discuss about the distribution area and the distribution center of the East-Asiatic bryoflora in detail. The above estimation is more or less related to geological history, and we assume that the East-Asiatic endemic genera have existed at least since the end of the Tertiary. Starting from the Quaternary, the climatic change during glacial epoch has been possibly the most important factor affecting the bryoflora in Asia, and the upheaval of the Himalayas has stimulated the diversity and the specialization of the bryophy tes. Considering these factors, East-Asiatic endemic genera might be the “Tertiary fossil plants”. Another problem is difficult to explain, because Mts. Huangshan, West Tianmu and Shen nongjia were once influenced by glaciation directly, although Chinese geologists hold different views. However, no evidence of glaciation has been found in Mt. Wuyi. It is worth to study the close relationships between Mt. Wuyi, Mt. Huangshan and Mt. West Tianmu, where is the distri bution center of the East-Asiatic endemic genera. The above three mountain regions share half of the East-Asiatic endemic genera, and about 32% genera of the others are found in two of them (Fig. 2). Myuriopsis, one of the East Asiatic types, was only recorded in Taiwan Pro vince, Japan and Korea. Neodolichomitra, occuring in Taiwan Province, is endemic to China. More or less the differentiation has taken place in Mt. Huangshan, Mt. West Tianmu and Mt. Wuyi. The number of the East-Asiatic endemic genera is smaller in Mt. Wuyi, so it is possibly located on the border of the distributional center of the East-Asiatic endemic genera. Moreo ver, three of four East-Asiatic endemic genera in Mt. Shennongjia are also found in Mt. Huang shan and Mt. West Tianmu, but the other East-Asiatic genus in Mt. Wuyi is common to the mountain areas in SW China, the Qinglin Range of NW China, and the isolated mountain areas of NE China. Considering all the characteristics of the bryoflora of Mt. Shennongjia, we assume that Mt. Shennongjia may belong to another distribution center, including SW part of Sichuan Province, and the other neighbouring mountains.  相似文献   

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