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1.
中国淡水双壳类特有种的地理分布   总被引:9,自引:0,他引:9       下载免费PDF全文
通过查阅有关文献整理得出,中国淡水双壳类特有种计有58种,隶属于双壳纲(Bivalvia)2科17属,其中主要是蚌科(Unionidae)的种类(16属57种)。我国淡水双壳类特有种的组成和区系成分,以东洋界华中区的种类占绝对优势,仅有少数种类渗透到古北界;特有种在我国16个省有分布,但主要集中分布于江西、湖南、安徽、浙江、江苏五省。双壳类特有种的形成和保存可能与我国古地理环境及其生活的水域环境有关。  相似文献   

2.
中国东北部种子植物种的地理成分分析   总被引:15,自引:2,他引:15  
通过对中国东北部2555种种子植物种的分布进行对比研究,划分之为27个地理成分和34个地理成分亚型,统计分析表明,本地区的种子植物除少数的世界分布种之外,温带、寒带和热带的种数分别点88.5、6.8和4.7%,说明植物区系基本上属温带性质,本地区种子植物中的特有植物共有117种,分属于6个地理成分和4个地理成分亚型之中,其丰富度的国内是较为偏低的。  相似文献   

3.
中国森林种子植物区系的特征   总被引:8,自引:1,他引:8  
本文主要根据中国种子植物区系研究的最新资料,简要介绍中国现代森林种子植物区系的多样性、地理成分、区系性质及地区差异等特征,供森林研究和中国生物多样性研究参考。  相似文献   

4.
武汉东湖南部湖汊的鼓藻类   总被引:6,自引:0,他引:6  
从1963年9月到1964年12月,作者在武汉东湖南部的湖汊定点采得48号藻类标本,其鼓藻类十分丰富,经鉴定共有20个属,164个种,75个变种和13个变型。其中有2个新种、7个新变种和2个新变型,12个种、25个变种和5个变型是中国的新记录;在四季中出现频率较高的优势种类有11个种和1个变种。在不同季节共6次所采得的鼓藻种类的统计结果得出,在夏季(6月、8月)的种类最多,秋季和冬季(9月、10月、12月)次之,春季(4月)最少。在东湖252个鼓藻类的分类单位中,热带、亚热带类群共有45个,其中的19个是南亚和东南亚地区特有或普遍分布的类群,13个是以广西为模式产地的类群,从而反映武汉地区鼓藻类区系具有亚热带类型的特点,并与南亚和东南亚的鼓藻类区系关系密切。  相似文献   

5.
熊安东  赵志礼  嘎务 《广西植物》2015,35(4):468-470
中国-喜马拉雅植物亚区不仅是乌头属植物地理分布的频度中心、多样性中心,原始类群的保存中心、分化中心,而且是特有类群的分布中心。作为该亚区特有物种之一的江孜乌头(Aconitum ludlowii Exell),是Arthur Wallis Exell于1926年根据采自我国西藏江孜的标本发表的新种。其繁殖器官特征及地理分布特点均与原始文献记载(狭域种)不尽一致。为此,对其做分类学修订。该研究应用经典植物分类学方法,进行野外考察、标本采集与鉴定,查阅中国科学院植物研究所植物标本馆(PE)的相关标本并进行形态学观察比较。结果表明:该物种不同标本心皮从无毛、近无毛至被毛,呈现一连续过渡情况。因此,考虑将心皮被毛一类不作为新分类群处理,只在以上研究基础上,做如下修订:心皮5,无毛或上部被毛,西藏拉萨、山南地区、那曲地区及日喀则地区均有分布。该研究结果可为国产乌头属植物的整理以及江孜乌头遗传多样性分析和物种保护提供基础资料。  相似文献   

6.
中国槲寄生属植物及其寄主的地理分布   总被引:4,自引:0,他引:4       下载免费PDF全文
对槲寄生属植物在世界的分布状况和在中国的分布特点进行了讨论。通过对其寄主植物进行统计并分析其分布区类型的特点,结合该属目前的核型分析结果和现存类群的分布特点,论证了槲寄生属植物属古南大陆起源,并对其起源时间和迁移路线作了推测。  相似文献   

7.
内蒙古地区的C4植物及其生态地理特性的研究   总被引:8,自引:0,他引:8  
根据实测的280余种植物的稳定性碳同位素值(δ13C)和内蒙古地区植被资料以及国内外已发表的C4植物名录,从分类学和生态学角度划分并整理出内蒙古地区的野生C4植物。共有C4植物125种,隶属于12科57属。C4植物所在的科、属、种分别占内蒙古全区维管植物科、属、种的9%、8.4%和5.4%。分析了该地区C4植物的分类群、生活型、水分生态型与区系地理成分等特性,并对其与环境间的关系作了探讨。C4植物分布的科、属均极其集中,82.4%集中于禾本科、藜科和莎草科,与它们固有的遗传特性有关。生活型以一年生草本植物居多,可能起源于草本的某些科属。水分生态型总体偏旱,与C4植物的起源相一致,为喜热、耐旱的类群  相似文献   

8.
广东省国家级珍稀濒危保护植物及其分布   总被引:6,自引:0,他引:6  
广东省境内目前有第一批国家重点保护的珍稀濒危植物共59种,其中蕨类植物1种、裸子植物10种、被子植物48种;确定为濒危的9种、渐危的34种、稀有的16种;被列为一、二、三级重点保护的分别有1种、22种和36种。根据它们在广东境内的分布范围,可将它们划分为广布种、间断分布种和偶见种三种分布类型。珍稀濒危植物在广东各地的分布明显不均匀,以粤北、粤西种类最多,部分市县种类达20多种,而粤东则最少。已建立的以森林生态系统为主的自然保护区是珍稀濒危植物逃脱灭绝境地的天然避难所。  相似文献   

9.
Astragalus is a species-rich genus occurring in the western arid habitats in China and its diversification and infrageneric relationships in this region remain unclear. In the present study, based on molecular data, we aim to (i) test whether Phyllolobium (previously treated as a subgenus Pogonophace in Astragalus ) should be warranted; and (ii) date the origin of Phyllolobium and probable diversification of Astragalus sensu stricto (s.s.). We sequenced five species from Phyllolobium first and collected all related sequences from the genus, Astragalus s.s and their close relatives ( Oxytropis and Caragana etc.). Our phylogenetic analyses suggested that all species of Phyllolobium comprise a monophyletic sister-group to genera of the subtribe Coluteinae. Molecular dating suggested that Phyllolobium and Astragalus s.s. originated around 8 and 10 million years ago. These two estimates are highly consistent with the intense uplifts of the Qinghai-Tibetan Plateau inferred from geological evidence. In addition, one section of Pogonophace (Sect. Robusti) was estimated to originate 2.5 million years ago and this section with a tendency for dry habitats seems to be evidence of Asian intensified aridity resulting from the intense uplift of the Qinghai-Tibetan Plateau.  相似文献   

10.
The Espinhaço Range, a mountain chain located in the Brazilian states of Minas Gerais and Bahia, contains one of the richest floras in Brazil, with a high frequency of endemic species. Since 2005 it is designated as UNESCO biosphere reserve and is situated at the joint border of two global hotspots for biodiversity conservation. Endemic species with congruent occurrence patterns were identified in order to establish areas of higher endemism within the Espinhaço Range. Taxonomic reviews were analyzed in order to identify endemic taxa and a dataset was elaborated containing 1765 records from 178 endemic species of vascular plants, representing 17 families and including the geographic coordinates for each record. Two maps were produced showing species richness and collection effort in 15′ quadrats. The congruent occurrences were identified and a third map was provided, delimiting 10 candidate areas of endemism for a “parsimony analysis of endemicity” (PAE). One most parsimonious cladogram is then retrieved, evidencing three major clades corresponding to the northern, central and southern portions of the Espinhaço, in addition to four subclades included into the central clade. We finally identified six major areas of endemism. Furthermore, there is a strong correlation between species richness and collector effort, revealing which areas are in need of further field inventories.  相似文献   

11.
    
Cremanthodium weixiense (Asteraceae, Senecioneae), a new species from northwestern Yunnan, China, is described and illustrated. The new species is referred to C. ser. Calcicola based on its palmately veined leaves, discoid capitula and leaflike, herbaceous phyllaries. However, it is unique in this series in having dissected leaves. It is somewhat similar to C. pinnatisectum in C. ser. Campanulata in the dissected leaves and the discoid capitula, but differs by the suborbicular (versus subreniform) basal leaves with deeply cordate (versus subtruncate) bases and very narrow (versus obviously divergent) sinuses, the presence (versus absence) of a conspicuously sheathed petiolar base of stem leaves, the broadly cylindrical (versus campanulate) involucres and the leaflike, herbaceous (versus petaloid, membranous) phyllaries.  相似文献   

12.
Occurrence of some Glomales in Finland   总被引:4,自引:1,他引:4  
M. Vestberg 《Mycorrhiza》1995,5(5):329-336
By using trap plants, 17 species of arbuscular mycorrhizal fungi (AMF) belonging to the order Glomales were identified in 266 soil samples collected in the period 1987–1989. Of the identified isolates, 87.1% belonged to the genus Glomus Tulasne & Tulasne, 8.5% to Acaulospora Gerdemann & Trappe, 4.1% to Scutellospora Walker & Sanders and 0.3% to Entrophospora. Of the individual species identified, Glomus hoi Berch & Trappe was the most frequently identified, followed by G. fistulosum Skou & Jakobsen and G. mosseae (Nicol. & Gerd.) Gerdemann & Trappe. Only small differences in AMF trapping ability were observed between the four trap plants used, Trifolium pratense L., Zea mays L., Allium cepa L. var. cepa and Fragaria x ananassa Duch. T. pratense was chosen for further study because it had the highest AMF sporulation index in trap cultures and it also performed better than the other plants when grown in soils with different physical and chemical properties. The proportion of soil samples where AMF were identified decreased from close to 100% in the southern and central parts of Finland to about 50% in northern Finland.  相似文献   

13.
混沟原始森林地区有野生种子植物529种,隶属于321属、97科,其中裸子植物3科、3属、5种,被子植物94科、318属、524种;其中双子叶植物87科、284属、470种,单子叶植物7科、34属、54种。此外,该地区分布有14种国家重点保护野生植物和26种山西省重点保护野生植物,是山西省珍稀濒危植物分布最集中的区域。种子植物区系成分在属的水平上以温带分布占绝对优势,热带分布略现突出,显示了该区系的特征是亚热带向暖温带过渡;在种的水平上以中国特有分布最多,温带分布和东亚分布略占优势,而热带分布显得十分逊色,这一方面显示该区系在中国植物区系形成与发展过程中的分布中心地位,同时反映了该区系的温带性质及其与东亚植物区系的密切联系。混沟地区地质历史悠久,自然生态条件优越,生态系统稳定,因此,既保留了较多的单型属和寡种属以及古老的孑遗植物,而且,许多亚热带区系成分也构成了该区系的重要成分。混沟地区有17类野生资源植物,大多数种类的植物具有多种利用价值,但是由于种种原因,没有得到有效的开发和利用。因此,应该有选择、有重点、有计划,系统化、规模化、产业化地研究开发。  相似文献   

14.
    
Translocations are a tool to restore populations of threatened plant species that are being widely used. However, these techniques are not without risks and require rigorous protocols to carry them out and for their subsequent monitoring. In translocation projects, hybridization with other species is one of the most important risks and may threaten the survival of the species we want to protect. Here we present the case of Helosciadium bermejoi (L. Llorens) Popper and M.F. Watson, a Critically Endangered plant from the island of Menorca (Western Mediterranean). It occurs only in one locality and has been introduced to three new locations during recent years according to its Recovery Plan (2008). Recently, intermediate forms between the endangered species and a native congener, Helosciadium nodiflorum (L.) Koch, have been detected. The aims of this study were (i) to elucidate whether these plants originated through a hybridization event and (ii) to provide information about the current conservation status of the species. Exhaustive monitoring of all subpopulations (number of patches and area of occupancy) was performed from September 2015 to June 2016, and the rDNA ITS region and cpDNA rps16-trnK intergenic spacer region were sequenced for several samples of the putative hybrid and its putative parental species. Overall, the entire population of H. bermejoi greatly increased from 2010 (last census with available data) to 2015 in terms of both number of patches and area of occupancy: from 110 to 277 patches and from 299.2 to 791.3 dm2. Molecular analysis confirmed the hybrid origin of Helosciadium × clandestinum Rita, Capó and Cursach and that both H. bermejoi and H. nodiflorum (L.) Koch can act as donors of pollen or ovules. We discuss the advantages and disadvantages of translocations, as well as the great importance of monitoring them for at least the next ten years, both to know if the actions have been successful and to prevent or mitigate risks. We also present this case as an example for the importance of fast decision and coordination between environmental managers.  相似文献   

15.
    
《Mycoscience》2014,55(3):196-212
The Longibrachiatum Clade of the genus Trichoderma in Japan was examined, among which two new species and three new records are herewith reported. The new species, T. tsugarense and T. kunigamense were isolated from a bed log (cultivation of Lentinula edodes) and volcanic ash soil, respectively. These species are distinguished from closely related species by growth and morphological characteristics and in phylogenetic analysis. Additional species new to Japan were T. ghanense, T. parareesei and T. sinense. The significance of their distribution is discussed. Most species of the Longibrachiatum Clade are tropical rather than temperate in distribution. Their in vitro optimum growth tends to be >35 °C but the optimum temperature for some Japanese species was lower. Some species are endophytes of temperate plant species, some of which are endemic in Japan.  相似文献   

16.
河南鸡公山木本植物区系的研究   总被引:6,自引:0,他引:6  
鸡公山国家级自然保护区是我国北亚热带森林生态系统自然保护区之一,地处亚热带与暖温带的过渡地带,是华中、华东和华北三大植物区系的交汇区之一,木本植物种类比较丰富。据初步统计,该区有木本植物71科、181属、543种,其中裸子植物5科、5属、7种。该区木本植物区系具有下列基本特点:1)区系成分比较丰富;2)古老和孑遗成分繁多;3)区系成分过渡性明显。该区木本植物可分为14种地理成分(分布区类型),其中热带属占35.0%,温带和亚热带分布的属占65.0%。  相似文献   

17.
南岳衡山蕨类植物区系研究   总被引:1,自引:0,他引:1  
南岳衡山蕨类植物共计235种(含种下等级),隶属于36科75属。区系分析表明:该地蕨类植物具有较强的热带性质,同时也显示出该区蕨类植物区系向温带渗透和过渡的性质,科、属的分布区类型均以热带、亚热带分布型为主,而种以温带分布型为主。热带、亚热带分布型在该区有18科38属69种,分别占科、属、种数的50.00%、50.67%和29.36%;其中泛热带分布型有14科21属5种,分别占科、属、种数的38.89%、28.00%和2.13%;温带性分布型有3科18属158种,分别占科、属、种数的8.33%、24.00%和67.23%。表明泛热带分布型是该区科、属最重要的分布类型;在种的区系上,温带性成分占明显优势,反映了该区热带成分与温带成分的交汇与兼容。该区虽没有自己的特有属,但具1种特有种,而且中国特有种丰富,共计46种,占总种数的19.57%。该区系与周邻联系广泛,地理成分以华东成分为主。在区系关系上,该区与武夷山、庐山的关系密切,而与万佛山的关系较为疏远。  相似文献   

18.
青冈亚属植物的地理分布   总被引:5,自引:0,他引:5  
对壳斗科青冈亚属(Quercus subg.Cyclobalanopsis)植物分布区内各地区的分布作了分析和统计。通过分析,认为中国南部、西南部和中南半岛北部,即印度支那植物地区,是青冈亚属植物地理分布的分布区中心。基于其形态、现代分布和地史资料,马来西亚地区分布有许多性状较原始的类群,是青冈亚属原始类的保存中心。青冈亚属植物中有许多地区 特有种,它们的分布区很狭窄,集中分布在加里曼丹、台湾、海南和云南东部部,其产生的原因主要是地理隔离,如海峡、高山等,以及气候和地史的复杂性。青冈亚属植物还存在许多替代现象,如青冈(Q.schottkyana)、赤皮青冈(Q.gilva)和黄毛青冈(Q.delavayi)`、云山青冈(Q.sessifolia)和窄叶青冈(Q.augustinii)为中国-日本分布式和中国-喜马拉雅分布式之间替代。  相似文献   

19.
番荔枝科的地理分布   总被引:4,自引:0,他引:4       下载免费PDF全文
番荔枝科的地理分布陈伟球(中国科学院华南植物研究所,广州510650)关键词番荔枝科;地理分布THEGEOGRAPHICALDISTRIBUTIONOFTHEANNONACEAE¥ChenWeichiu(SouthChinaInstituteofBo...  相似文献   

20.
论世界芨芨草属(禾本科)的地理分布   总被引:12,自引:0,他引:12  
本文详细讨论了世界芨芨草属的地理分布等问题。1.全世界芨芨草属共有23种1变种,分为5个组。本文对它们进行了系统介绍。2.属的地理分布,最北为北纬62°(羽茅、毛颖芨芨草),最南为北纬26°(林阴芨芨草)。就海拔而论,分布最低的海拔记录为120m(雀麦芨芨草),分布最高的海拔记录为4600m(干生芨芨草和藏芨芨草)。3.本文讨论了芨芨草属5个组(芨芨草组,钝基草组,直芒草组,新芨芨草组,拟芨芨草组)的系统位置,和每个组包括的种类及5个组的分布格局。4.根据塔赫他间世界植物区系区划,统计了每个区的种数,明显看出伊朗—土兰区种类(18/24)是第一位,东亚区(14/24)居第二位。中国有17种,横断山脉地区、华北地区和唐古特地区种数最丰富(10种和9种)。5.研究结果表明:(A)从种的分布格局分析可见,横断山脉地区北部、唐古特地区东部和华北地区西部的交汇地是芨芨草属分布中心。(B)根据芨芨草属形态特征演化趋势分析和地史学资料推测横断山脉地区北部是芨芨草属的起源地。(C)有三条路线向外散布:a)从横断山脉地区向西沿喜马拉雅山脉,经克什米尔地区抵达地中海和中欧;b)从横断山脉向西北经祁连山、天山、塔里木盆地西侧山地,抵吉尔吉斯斯坦伊塞克湖; c)由横断山脉向东北经甘肃、宁夏、陕西、山西、河北和东北,抵达西伯利亚,东达堪察加半岛,西至鄂毕河上游,并经白令海峡陆桥分布到美国内华达山脉和落基山山脉。(D)该属植物集中分布于北半球半湿润、半干旱和干旱地区,以及极端干旱的荒漠区山地。植物的形成、发展和生态适应与气候相联系,并经过长期的适应和进化,塑造了一系列中生、旱中生的形态-生态特征和生活型。  相似文献   

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