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1.
本文根据吴征镒教授对中国种于植物属分布区类型研究结果.研制出定量化研究区域性种子植物区系的电子计算机程序.应用本程序可完成某区系的分布区类型统计分析.科属组成分析和与其它地区以共有属关系构建的相似性系数的计算.同时可大量节省研究人员的劳动强度和时间,对提高研究水平有一定的效果。  相似文献   

2.
本文根据吴征镒教授对中国种子植物属分市区类型研究结果,研制出定量化研究区域性种子植物区系的电子计算机程序,应用本程序可完成某区系的分布区类型统计分析,科属组成分析和与其它地区以共有属关系构建的相似性系数的谁知盘中计算,同时可大量节省研究人员的劳动强度和时间,对提高研究水平有一定的效果。  相似文献   

3.
巴岳山-西温泉风景名胜区种子植物区系特征分析   总被引:1,自引:1,他引:0  
在对重庆市巴岳山-西温泉风景名胜区种子植物详细调查、标本采集及鉴定的基础上,对其科、属的分布区类型进行统计分析,其种子植物区系特征如下:(1)区系成分丰富,有136科,573属,1043种;包括11种科的分布区类型和15种属的分布区类型。(2)优势科、属明显。(3)种子植物区系起源古老,单型科、单型属及原始多心皮古老类群较多。(4)科属分布区类型以热带分布为主,温带分布类型也占相当比例;同时,有许多分布区亚型及间断分布类型,呈现出明显的区系过渡性质。(5)珍稀濒危及重点保护植物、中国特有分布类型丰富,有较高的保护价值。  相似文献   

4.
统计分析了杭州西湖风景区野生种子植物区系,该区共有野生种子植物143科,572属,1111种(含种下分类群)。科的分布区类型以泛热带占优势,达48.9%,热带成分的科远多于温带成分的科(64∶28);从属的分布区类型看,温带成分的属多于热带成分的属(268∶220);种的分布区类型中,温带成分的种数远比热带成分的种数多(502∶234);说明该区亚热带北部区系特征显著。另一方面,本区以单种属和寡种属为主,种的分布区类型中,东亚分布(33.7%)与中国特有分布(32.2%)相当,东亚分布中绝大部分属于中国-日本共有。以中国区系分区标准,将中国特有分布种划分成9个分布亚型,其中以华东-华中-华南分布最多(46.0%)。结果表明该区种子植物丰富、地理成分多样,具有明显的华东东部植物区系特征。  相似文献   

5.
马边大风顶国家级自然保护区种子植物区系研究   总被引:2,自引:0,他引:2  
马边大风顶国家级自然保护区位于四川省马边县境内。在野外考察及查阅文献的基础上,对保护区内种子植物区系进行了研究。结果显示:保护区内有种子植物120科,446属,1240种,其中裸子植物5科,11属,27种;被子植物115科,435属,1213种。保护区区系成分较复杂,古老区系成分和滇藏高原成分较多。种子植物科的分布区类型有11个,具有较强的热带性质,泛热带(热带广布,Pantropic)型34科,占总科数的40.96%,属的分布区类型有15个,以温带区系成分为主,共264属,占总数属的64.71%。相似性系数计算结果显示,其与美姑大风顶自然保护区种子植物区系亲缘关系十分密切,区系组成相当一致,应该属于同一古老区系演化而成。  相似文献   

6.
中国种子植物区系统计分析   总被引:371,自引:8,他引:371  
中国种子植物初步统计有337科,3200属,26276~27268种,其中裸子植物有10科,36属,191~195种,单子叶植物有57科,679属,4493~4661种。本文对我国种子植物分别就科、属、种分布区类型,大小顺序排列,特有性等方面进行区系统计分析,并在种级水平上对各区系地区或具体区系进行对比,为中国种子植物区系深入研究提供基本素材  相似文献   

7.
华中地区藤本种子植物区系的研究   总被引:10,自引:0,他引:10  
以湖南和湖北两省为代表对华中地区藤本种子植物的区系进行了研究。本区共有藤本种子植物62科175属838种,其中土著种类有60科159属784种。在科、属、种的水平上对藤本种子植物区系特性进行了较深入的统计和分析,并对本区藤本种子植物与邻近地区的关系、本区内的藤本种子植物的地带性分异进行了探讨。统计表明,本区藤本种子植物种数占该区种子植物总种数的11%,且61.7%的种类主要集中在30种以上的大科中;热带分布型明显多于温带分布型;泛热带、热带亚洲、东亚(中国)特有和东亚—北美间断分布科属比较集中,其中许多属为古老成分;本区藤本种子植物特有成分丰富,计有东亚特有科1科、中国特有属6属、中国特有种507种(其中华中地区特有种35种)。通过研究认为:本区藤本种子植物具有种类丰富、分布类型多样、特有成分较多、区系较古老的特点;与本区的全部种子植物区系相比,藤本种子植物区系的热带性更强,具有明显的热带亲缘性,并与喜马拉雅及中国西南有较强的地理渊源。  相似文献   

8.
滇东南热带雨林种子植物区系的初步研究   总被引:7,自引:3,他引:7  
李耀利  朱华  王洪 《广西植物》2002,22(4):320-326
通过对滇东南地区热带雨林植被的初步调查 ,统计滇东南热带雨林种子植物区系有种子植物 119科 ,378属 ,6 73种 (包括变种和亚种 )。种子植物分布区类型组成是主产热带和亚热带的科占 82 .35% ;热带分布属占非世界属数的 93.87% ;典型热带分布种占总种数的 75.93%。热带分布属中以亚洲热带分布属最多 ,占非世界属数的 4 0 .2 7% ;典型热带分布种中以热带亚洲分布及其变型越南 (印度支那 )至云南 (华南 )分布占比例最高 ,分别为 71.4 7%和 16 .34 %。分布区类型分析表明滇东南热带雨林种子植物区系具有热带亚洲区系的特点 ,属于古热带植物区中的马来亚森林植物亚区之中的北部湾区系。进一步分析表明此区系具热带北缘的性质。分布区类型的组成也表明此区系古特有种丰富。  相似文献   

9.
在实地考察和标本采集鉴定的基础上,对云南省元江自然保护区种子植物的组成、分布区类型和区系特征等进行了分析.结果表明:保护区有种子植物166科835属2 080种,其中,裸子植物3科4属8种;被子植物166科835属2 072种;种子植物区系表现出热带向亚热带过渡,具有明显的热带性质;种子植物区系为东亚植物区系,隶属于中国一喜马拉雅植物亚区,起源上受热带亚洲植物区系影响很大;特有类型丰富,有东亚特有科3科,中国特有属5属,中国特有种647种.  相似文献   

10.
岷江上游流域种子植物区系研究   总被引:11,自引:0,他引:11  
岷江上游流域在地理位置上位于青藏高原、四川盆地两个自然地理区域的过渡地带;其在植被分区上属于泛北极植物区中国—喜马拉雅森林植物亚区横断山脉地区的一部分。区内共有种子植物169科,726属,2162种。其中大科、大属在区系组成中起着非常重要的作用。该区种子植物区系包含有15种分布区类型及其14个变型,其中泛热带分布、北温带分布、旧世界温带分布、东亚分布等成分占有重要地位。其种子植物区系的主要特征为:地理过渡特征明显,区系成分新老并存;区系地理成分复杂,以北温带成分为主;沿海拔梯度植物区系地理成分差异显著。在该区未来的生态建设中,应充分利用其植物区系的基本特征,保护现有物种,并充分利用当地具有特殊抗性的珍贵物种资源和遗传资源。  相似文献   

11.
Similarities in the temperate floras of eastern Asia and North America have been appreciated for more than 200 yr, but the generality of the floristic relationships among eastern Asia (EAS), eastern North America (ENA), and western North America (WNA), postulated by Asa Gray about 150 yr ago, has not been tested until now. In this article, floristic relationships based on genera shared among EAS, ENA, and WNA were examined at different spatial scales for different phylogenetic groups using complete floras. Floristic similarity between EAS and ENA is higher than that between EAS and WNA, and the floras of ENA and WNA are more closely related to each other than are the floras of EAS and ENA. Compared with ENA and WNA, the number of genera common to EAS and ENA is significantly higher in basal angiosperms and significantly lower in asterids. Floristic similarities tend to decrease from more basal to more modern lineages between EAS and ENA and between EAS and WNA but not between ENA and WNA. Similarly, from more basal to more modern divisions, the fraction of shared genera decreases between EAS and ENA and between EAS and WNA, whereas the floristic similarity between ENA and WNA tends to increase. Furthermore, floristic similarity between EAS and ENA increases with latitude. The causes of the observed patterns of floristic similarity between EAS, ENA, and WNA are discussed.  相似文献   

12.
1. Based upon the analyses in the floristic elements of the three genera (Suaeda, Salsola and Zygophyllum) in different regions we can see that the genesis of our desert floras in these regions is very much diversified. The flora of Songaria is similar to that of the Middle Asia, while the Hosi Corridor seems to be a transitional area very close to Alashan and also related to the Tarim Basin in floristic elements. Thus, we may classify the desert floras into three parts: the flora of Songaria, of Alashan including the Hosi Corridor and of the Tarim Basin including the Tsaidam Basin. The ages and approaches in their formation are different. 2. There are plenty species but no or rare endemics in Songaria. In spring there are a number of ephemeral plants. The variation of aspect is evident. The vegetation cover is abundant. The floristic elements are developed from the flora of Middle Asia and it was formed in Quaternary period. 3. The floristic elements of the Tarim Basin are poor, but there are not few endemics and the distribution of the endemics is much limited. They are of the characteristics of relic species. Therefore it was formed in the Tertiary period and developed in Quaternary period. The elements are related to the Mediterranean flora. 4. There are a large number of endemics and many endemic monotypie genera in Alashan. They represent the flora formed in Tertiary period. Although it is of a special style, it relates both to the Middle-Asian and the Mediterranean flora. 5. The historic causes for the formation of the different floras lie chiefly on: (1) The rise of the Tibetan plateau and mountains strongly changed the climatic and edaphic conditions and in the long course of evolution some species survived or even developed, while the others deteriorated or even died out from the flora. (2) Because the circumstances of transgression or regression of the Tethys were different in these regions. (3) The mountain-making movement, the transgression and regression and the fluence of glaciation, all the mutation of these associated factors modified the climatic zonation and then the plant species changes followed, new species formed and migration of floristie elements occurred. (4) Songaria is the nearest region to the then Sibirian glacier, so the frozen injury to the flora might be the greatest. (5) In the Glacial period the descension of snow line in Songaria was greater than that of the Tarim Basin, so the frozen injurymight be greater.  相似文献   

13.
云南热带植物区系地理成分复杂,生物多样性极其丰富。为了解不同地区和生境热带植物区系的物种组成差异,本文选取云南南部和东南部3个有代表性的热带植物区系——西双版纳龙脑香林植物区系(DFX)、西双版纳石灰岩山植物区系(LFX)和文山古林箐石灰岩山植物区系(LFG)为研究对象,比较不同植物区系的科属数量结构、科内多样性、科属分布区类型及植物区系相似性。研究结果显示:(1)3个热带植物区系均具有较高的物种多样性,但种类组成、科属数量结构及科内多样性差异较大;(2)热带分布的科、属在3个热带植物区系中均占绝对优势;(3)3个热带植物区系的共有物种极少,而专有物种(即在3个植物区系之间相对专有)相对较多,植物区系之间的种级相似性极低。云南不同地区和生境热带植物区系强烈的热带亲缘、物种组成的多样性和复杂性以及较低的植物区系相似性,揭示了地理和生境差异会影响各地热带植物区系的演化与发展。  相似文献   

14.
Aim  To quantify the occurrence of processes of homogenization or differentiation in the vascular flora of six oceanic islands.
Location  Six islands in the south-eastern Pacific drawn from the Desventuradas Archipelago, Easter Island and the Juan Fernández Archipelago.
Methods  Using published floristic studies, we determined the floristic composition of each island at two different stages: (1) pre-European colonization and (2) current flora. We compared changes in the number of shared plants and the floristic similarity among islands for each stage.
Results  The number of plant species doubled from 263 in pre-European flora to 531 species currently. Only three native species became extinct, four natives were translocated among the islands and 271 plant species were introduced from outside. The frequency of plant species shared by two or more islands is higher in the post-European floras than prior to European contact, and the level of floristic similarity between islands increased slightly.
Main conclusions  Considering the low naturalization rate of alien plants, the small number of extinctions and the meagre increase in floristic similarity, these islands are undergoing a slow process of floristic homogenization.  相似文献   

15.
关于地区间植物区系亲缘关系研究方法问题讨论   总被引:5,自引:0,他引:5  
属的分布区类型组成(谱)中各类型所占百分比的类似性不能实质性反映各地区间植物区系的亲缘,因为亲缘关系疏远的不同分类群(属)可以有同样的分布区类型。植物属的分布区类型组成的类似性只反映了不同地区植物区系各地理成分的比例关系的类似性,并非直接的亲缘关系。地区植物区系之间的亲缘关系应是指它们的分类群的类似性,即血缘或共同起源关系,通常是由它们共有的植物科、属、种相似性系数,特别是其共特有分类群相似系数来反映的。  相似文献   

16.
湖北大洪山种子植物区系的研究   总被引:8,自引:3,他引:5  
报道大洪山有种子植物1052种,隶属516属147科,在分析主要科的地理分布和全部属的分布区类型的基础上,认为温带属占主导地位,还讨论了该地区与我国其它10个不同纬度山区植物区系的关系,并通过植物区系的属相似性系数的对比分析,讨论了该区系与华东,华中和华北植物区系的关系,得到大洪山属于华东植物区系的结论。  相似文献   

17.
A biogeographical study on tropical flora of southern China   总被引:1,自引:0,他引:1       下载免费PDF全文
Hua Zhu 《Ecology and evolution》2017,7(23):10398-10408
The tropical climate in China exists in southeastern Xizang (Tibet), southwestern to southeastern Yunnan, southwestern Guangxi, southern Guangdon, southern Taiwan, and Hainan, and these southern Chinese areas contain tropical floras. I checked and synonymized native seed plants from these tropical areas in China and recognized 12,844 species of seed plants included in 2,181 genera and 227 families. In the tropical flora of southern China, the families are mainly distributed in tropical areas and extend into temperate zones and contribute to the majority of the taxa present. The genera with tropical distributions also make up the most of the total flora. In terms of geographical elements, the genera with tropical Asian distribution constitute the highest proportion, which implies tropical Asian or Indo‐Malaysia affinity. Floristic composition and geographical elements are conspicuous from region to region due to different geological history and ecological environments, although floristic similarities from these regions are more than 90% and 64% at the family and generic levels, respectively, but lower than 50% at specific level. These differences in the regional floras could be influenced by historical events associated with the uplift of the Himalayas, such as the southeastward extrusion of the Indochina geoblock, clockwise rotation and southeastward movement of Lanping–Simao geoblock, and southeastward movement of Hainan Island. The similarity coefficients between the flora of southern China and those of Indochina countries are more than 96% and 80% at family and generic levels, indicating their close floristic affinity and inclusion in the same biogeographically floristic unit.  相似文献   

18.
中国种子植物区系定量化研究 V.区系相似性   总被引:3,自引:0,他引:3  
本文总结了应用相似系数即关联系数进行植物区系相似性分析的现状,指出了存在的问题.然后,从集合论角度讨论了区系相似性、相似关系及其相似系数的实质.作者以为在区系相似性分析中应用R.R.Sokal和C.D.Michener(1958)提出的简单匹配系数比较适宜,同时亦能避免以往区系相似性分析中缺乏可比性及某些“表相”相似等问题.最后,还提出了总体相似系数和类型相似系数二个新概念,以便按照吴征镒教授关于中国植物区系研究的学术思想统一研究各个不同地区植物区系的相似性.对此,作者用了6个区系实例进行了演算说明.  相似文献   

19.
Aim Human activities have weakened biogeographical barriers to dispersal, increasing the rate of introduction of alien plants. However, their impact on beta diversity and floristic homogenization is poorly understood. Our goal is to compare the phylogenetic beta diversity of native species with that of two groups of alien species, archaeophytes and neophytes (introduced before and after ad 1500, respectively), across European urban floras to explore how biological invasions affect phylogenetic turnover at a continental scale. Location Twenty European cities located in six countries between 49 and 53° N latitude in continental Europe and the British Isles. Methods To compare the phylogenetic beta diversity of native and alien species we use the average phylogenetic dissimilarity of individual floras from their group centroid in multivariate space. Differences in phylogenetic beta diversity among different species groups are then assessed using a randomization test for homogeneity of multivariate dispersions. Results Across European urban floras, and when contrasted with natives, archaeophytes are usually associated with lower levels of phylogenetic beta diversity while neophytes tend to increase phylogenetic differentiation. Main conclusions While archaeophytes tend to promote limited homogenization in phylogenetic beta diversity, because of their diverse geographical origin together with short residence times in the invaded regions, neophytes are not promoting biotic homogenization of urban floras across Europe. Therefore, in spite of the increasing rate of alien invasion, an intense phylogenetic homogenization of urban cities is not to be expected soon.  相似文献   

20.
The biodiversity of floras has until recently been measured solely in terms of their species number or species density, with little regard to the breadth of phylogenetic diversity represented by the species. The latter is partly a function of the size of the flora, and partly of the pattern of distribution of the species into higher taxa. To determine whether floras differ in this respect, this study compares the frequency distribution of genus size in 20 island and regional floras. Certain floras (Cape Region, S.W. Australia, New Zealand, Hawaii) are found to have high concentrations of genera containing many species. Others are notably lacking in large genera (Java, Jamaica, Nepal, Niger), though this group tend to be family-rich. In floras with high endemism (Cape, New Zealand, Fiji, Jamaica, Hawaii), the level of endemism is consistently higher in larger genera. Possible reasons for the observed differences between floras are geographic and temporal isolation, level of habitat diversity, climatic history, volcanic, orogenic and tectonic events. Clusters of large genera may indicate recent speciation, possibly following the last glaciation. Genus size may be an important consideration when limited conservation resources have to be targetted to retain the maximum phylogenetic diversity in a threatened flora.  相似文献   

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