Large-scale phytogeographical patterns in East Asia in relation to latitudinal and climatic gradients

Aim This paper aims at determining how different floristic elements (e.g. cosmopolitan, tropical, and temperate) change with latitude and major climate factors, and how latitude affects the floristic relationships between East Asia and the other parts of the world. Location East Asia from the Arctic to tropical regions, an area crossing over 50° of latitudes and covering the eastern part of China, Korea, Japan and the eastern part of Russia. Methods East Asia is divided into forty‐five geographical regions. Based on the similarity of their world‐wide distributional patterns, a total of 2808 indigenous genera of seed plants found in East Asia were grouped into fourteen geographical elements, belonging to three major categories (cosmopolitan, tropical and temperate). The 50°‐long latitudinal gradient of East Asia was divided into five latitudinal zones, each of c. 10°. Phytogeographical relationships of East Asia to latitude and climatic variables were examined based on the forty‐five regional floras. Results Among all geographical and climatic variables considered, latitude showed the strongest relationship to phytogeographical composition. Tropical genera (with pantropical, amphi‐Pacific tropical, palaeotropical, tropical Asia–tropical Australia, tropical Asia–tropical Africa and tropical Asia geographical elements combined) accounted for c. 80% of the total genera at latitude 20°N and for c. 0% at latitude 55–60°N. In contrast, temperate genera (including holarctic, eastern Asia–North America, temperate Eurasia, temperate Asia, Mediterranean, western Asia to central Asia, central Asia and eastern Asia geographical elements) accounted for 15.5% in the southernmost latitude and for 80% at 55–60°N, from where northward the percentage tended to level off. The proportion of cosmopolitan genera increased gradually with latitude from 5% at the southernmost latitude to 21% at 55–60°N, where it levelled off northward. In general, the genera present in a more northerly flora are a subset of the genera present in a more southerly flora. Main conclusions The large‐scale patterns of phytogeography in East Asia are strongly related to latitude, which covaries with several climatic variables such as temperature. Evolutionary processes such as the adaptation of plants to cold climates and current and past land connections are likely responsible for the observed latitudinal patterns.     

中国西南干旱河谷植被的区系地理成分与空间分异

根据对云南、四川、甘肃三省九条主要河流干旱河谷的植物群落调查数据, 对我国西南干旱河谷维管束植物区系的科、属分布区类型进行划分, 并分析其地理分布格局。结果表明: (1)西南干旱河谷区的植物区系地理成分复杂, 联系广泛, 共包含11个科级和15个属级分布区类型; 总体上, 科、属两级热带/温带成分比例分别为3.06和1.77, 显示了强烈的热带区系亲缘及温带区系的后期影响; 与地中海-西亚至中亚植物区系存在一定联系; 其东亚成分和中国特有成分比例低于亚热带区系平均水平, 且中国-喜马拉雅成分比例高于中国-日本成分。(2)从西南向东北方向, 植物区系的热带性质逐渐减弱, 温带性质逐渐增强; 科、属水平区系成分与古地中海-中亚区系的相似性逐渐增强; 东亚和中国特有成分比例增加; 南盘江与元江的干旱河谷植物区系之间存在中国-日本和中国-喜马拉雅成分的分界线。(3)根据干旱河谷植物属区系成分的比例构成将怒江、澜沧江和元江与其他流域分开, 显示了长江溯源侵蚀和水系合并对西南诸河流植物区系发育的影响。     

A biogeographical study on tropical flora of southern China

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.     

Observations on the formation of Chinese desert floras

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.     

Biogeographical Divergence of the Flora of Yunnan,Southwestern China Initiated by the Uplift of Himalaya and Extrusion of Indochina Block

The floral composition of Yunnan is conspicuously linked to the biogeographical history of this extremely species-rich province in southwestern China. The floristic compositions of three representative regions in Yunnan were compared to reveal their variation with geography. From southern Yunnan, 4150 native species (including subspecies and varieties) from 1240 genera and 183 families of seed plants were recognized. From central Yunnan 3389 native species from 1095 genera and 167 families of seed plants were recognized. From northwestern Yunnan 6807 native species from 1296 genera and 166 families of seed plants were recognized. Although these three floras across Yunnan are similar in familial composition, similarities between the floras of southern and northwestern Yunnan are low at the generic and specific levels. The flora of northwestern Yunnan is dominated by families and genera with cosmopolitan and north temperate distributions, while the flora of southern Yunnan is dominated by tropical families and genera. Northwestern Yunnan is composed largely of temperate genera, of which the highest proportion has a north temperate distribution. In contrast, southern Yunnan has mainly tropical genera, of which most have a tropical Asian distribution. The flora of central Yunnan is a combination of southern and northwestern Yunnan. These three floras might be derived from a common Tertiary tropical or subtropical East Asian flora, but the geological history of each region has influenced its flora, and they have remained divergent since the late Tertiary. The flora of northwestern Yunnan has evolved with the uplift of the Himalayas and by gradual proliferation of mainly cosmopolitan and north temperate floristic elements, while the flora of southern Yunnan has evolved with extrusion of the Indochina block and the influence of mainly tropical Asian elements.     

Phytogeographical patterns of genera of endemic flora in relation to latitudinal and climatic gradients in China

This paper aims at detecting the relationships between phytogeographical patterns of genera of Chinese endemic seed plants and latitude or climatic factors. The landmass of China was divided into four latitudinal zones, each of c. 8°. Based on a total of 1664 indigenous genera of Chinese endemic seed plants which were grouped into fifteen geographical elements, belonging to three major categories (cosmopolitan, tropical and temperate) and which were absent or present in 28 provinces in China, we analyzed the phytogeographical patterns of genera of Chinese endemic seed plants and detected the relationships between them and main climatic factors. Our results showed that the proportion of tropical genera decreases with the increase in latitude; the proportion of temperate genera increases with the increase in latitude; and the proportion of cosmopolitan genera increased gradually increased gradually with latitude. There are a slow decrease in the proportion of tropical genera and slow increase in the proportion of temperate genera at latitudes 35°–40°. Alternatively, the tropical genera and the temperate genera have the same proportion at latitude c. 25°. These changes and issues about the different genera also appeared in main climate factors. In general, the genera present in a more northerly flora are a subset of the genera present in a more southerly flora. In summary, the large-scale patterns of phytogeography of endemic flora in China are strongly related to latitude, which covary with several climatic variables such as temperature.     

A Numerical Study on the Floristics of the Zhoushan Archipelago

The Zhoushan Archipelago, one of the famous fishing grounds in China, is lo cated in the northern part of the Donghai Sea, at the mouth of the Hangzhou Bay (Fig. 1). The flora of the archipelago was botanically little known. After 1972, several botanical ex plorations to the archipelago were conducted by Qiu L.-Q. of the Shanghai Museum of Natu ral History, and nearly one thousand numbers of plant specimens were collected. From these specimens, we have identified about 500 species of seed plants. The present paper deals with a numerical taxonomic study of the floristic affinities of seed plants of the Zhoushan Archipelago by means of both cluster and principal component analyses (PCA). The total distribution realm of the Zhoushan floristic elements is divided into 18 regions, which were used as Operational Taxonomic Units (OTU). The 348 native species and infrasp ecific taxa (see Appendix 1, excluding cultivated plants, ruderals and exotics) of seed plants were used as characters of the OTUs, A normal cluster analysis using UPGMA gave rise to phenogram (Fig. 1). The phenogram provides a great amount of information regarding the floristic affinities between Zhoushan and the other regions. In the PCA, method of inverse analysis was used and has brought forth two diagrams of dimensional program (Fig. 2a,b). These diagrams give some hints of the distributional trends of geographical elements and floristic affinities. The result of the above analyses shows that the floristics of the Zhoushan Archipelago is the most closely related to those of its neibouring regions, for instance, Zhejiang mainland, Jiangsu and some other regions of eastern China. Though rich in island elements, the archipelago has almost no endemic species. The short distance between the archipelago and the mainland, which has favored mutual exchange of plants, and the severe destruction of the original forest vegetation, may account for this phenomenon. The floristic similarities between Zhoushan and Taiwan of China and between the archipelago and Japan are not so remarkable. This may be due to both the climatical difference and geographical barriers existing between these floristic regions. Yet the presence of a number of linking plants confined to these floras, such as Rhaphiolepis integerrima, Anodendron salicifolium, and Eurya japonica, etc., suggests that these regions should be considered as being of the common tertiary origin. The mountain forest flora of Zhoushan is more closely related to those of southern regions than to those of northern regions of China, From the point of view of floristic regionalization, it is appropriate to consider the flora of the Zhoushan Archipelago as a part of the northern subregion of the mid-subtropical region.     

安徽珍稀濒危植物区系探讨

在深入调查的基础上,对安徽珍稀濒危植物区系组成和地理成分进行了详细的统计分析,探讨了该区系的组成特点及地理分布特征。结果表明,该区系属温带亚热带性植物区系,具有珍稀濒危物种丰富,古老、孑遗植物众多;地理成分复杂,区系联系广泛;过渡性质明显,温带亚热带成分占优;特有现象显著,华东区系特征典型等基本特征。在植物区系亲缘上,该区系隶属东亚植物区、中国-日本森林植物亚区、华东地区,与华中植物区系关系密切,受西南植物区系影响深刻。     

安徽省鹞落坪自然保护区植物区系的数量分析

鹞落坪自然保护区是大别山中植物的集中分布地,植物区系成分丰富,也是我国北亚热带生物多样性保护的关键区域。其地理成分以北温带、泛热带、东亚三种为主,显示出区系成分的过渡特征。以植物地理成分为指标,对鹞落坪与全国其它14个山地的植物区系的模糊聚类分析,表明了华东与华中植物区系无明显的分界线,大别山成为联系这两大植物区系的纽带。     

广西拉沟自然保护区种子植物区系研究

通过调查统计,广西拉沟自然保护区共有野生种子植物153科594属985种.种子植物区系组成丰富,地理成分复杂,具有中亚热带向南热带过渡性质.在科、属水平上对植物区系特性进行了统计分析,热带性质均强于温带性质,属的成分以泛热带分布、热带亚洲分布为主.与邻近地区植物区系相比较,拉沟自然保护区与广西大瑶山自然保护区相似性较高,与广西花坪自然保护区相似性较低.     

云南不同地区和生境代表性热带植物区系的物种组成比较

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。     

海南五指山地区种子植物区系的特点

五指山地区共有种子植物 1 77科、82 1属、1 882种 (含变种 )。区系组成及地理成分分析表明 :该区系是海南岛区系的重要组成部分 ;其热带性质强烈 ,其中热带亚洲和泛热带成分最占优势 ,各占非世界属总数的 2 6.78%和 2 6.40 % ;讨论了该地区与邻近 6个不同纬度山区植物区系的关系 ,认为五指山区系与大陆区系联系紧密 ,本质上是华夏植物区系不可分割的一部分。     

辽西走廊白狼山保护区植物区系及其与邻近山地的关系

采用植物区系谱、排序分析、聚类模型和相关性等方法,研究了辽西白狼山植物区系属的地理组成以及与其它山地的相似关系,以揭示多个山地植物区系的相互关系及分布格局。结果表明:(1)白狼山自然保护区野生种子植物多样而丰富,共有101科394属790种;被子植物占总种数的98.35%,优势科现象明显,寡种属和单种属占优势,呈现一定残遗性;(2)属的地理成分以温带成分为主,共有273属,占总属数的81.3%,处于中国-日本森林植物亚区暖温带-温带过渡范围内,植物区系划归于华北植物区系平原山地亚地区。(3)相关分析表明,白狼山与努鲁儿虎山(r=0.999)、东灵山(r=0.998)之间的植物区系具有极显著相关关系;主坐标排序和聚类分析表明,白狼山种子植物属的分布区类型与努鲁儿虎山、东灵山、小五台山以及雾灵山等有着较大的相似性,不同纬度水热条件可能是影响植物区系地理分布格局的重要因素。     

中国沿海主要岛屿植物区系的性质及其相互关系与分布格局

通过植物区系谱、多样性指数、主坐标排序及聚类分析等方法,研究了中国沿海主要岛屿(从渤海、黄海、东海及南海海域,选取不同纬度所在地的岛屿)的植物区系性质、相互关系及分布格局,为沿海岛屿的生态保护和生物多样性保育提供依据。结果表明:(1)中国沿海主要岛屿植物区系地理成分表现出纬向分异性,温带成分比例随着纬度降低呈递减趋势,而各种热带成分比例呈递增的分布格局,这与不同海岛所处位置气候的纬向地带性基本一致;(2)不同沿海岛屿植物区系的Shannon指数(1.887~2.197)和Simpson指数(0.780~0.865)均无显著差异,而区系间Pearson相关系数(0.199~0.997)则有明显的差异;(3)通过聚类分析和主坐标排序生成的树状图和最小生成树,可将22个岛屿划分为5个集合,揭示了沿海岛屿植物区系属的类似性和南北纬度分布格局。     

柳州市龙潭、都乐公园植物区系特点

柳州市龙潭—都乐公园植物区系是广西中部一个被破坏后经多年保护恢复起来的岩溶石山植物区系。总面积9平方公里,共有维管束植物152科455属675种。由于处于中亚热带向南亚热带过渡的气候带上,气候温和,阳光充足,雨量充沛,植物的地理成分复杂,但以亚热带和热带成分占优势;特有种、属少,但岩溶成分较明显;由于岩溶生态条件影响,与(?)岗植物区系相比,属的相似性比率略高于与大瑶山植物区系的比率。按吴征镒教授对中国植物区系的划分,它应属于泛北极植物区、中国—日本森林植物亚区、滇黔桂地区的一个小区。     

罗霄山脉种子植物区系及其南北分化特征

本文基于野外调查和文献资料整理, 对罗霄山脉种子植物区系及其自北向南5条中型山脉之间的区系过渡性特征进行了系统分析。结果表明: (1)该区域内野生种子植物有179科1,107属4,314种; 区系表征科主要以亚热带山地为现代分布中心。科的区系组成为: 单型科25科, 寡种科61科, 单型属465属, 寡种属432属, 呈现出区系特征上的孑遗性, 也显示出本地区系成分与典型热带成分及典型温带成分间存在密切交流。(2)科的地理成分共分为10个类型, 以热带性成分占明显优势, 热带性科83科及温带性科40科分别占非世界性科总数的67.48%和32.52%; 属的地理成分包括15个分布区类型, 以温带成分占优势, 温带性属534属及热带性属484属分别占非世界性属总数的52.46%和47.54%。属分布区类型以泛热带分布、热带亚洲分布、北温带分布、东亚分布为主, 体现出本地区与古热带植物区系及温带第三纪植物区系的紧密联系。(3)罗霄山脉5条山脉间区系组成呈现出明显的南北分异特征, 自北向南热带属与温带属比值逐渐增大, 北段幕阜山脉温带性成分明显占优势, 与华中区系关联密切, 而南段万洋山脉、诸广山脉热带性属较占优势, 分布有丰富的华南区系成分。罗霄山脉地区是重要的区系交流通道, 历史时期的气候波动是本地区现代区系分布格局形成的主要原因。     

广东郁南同乐大山自然保护区种子植物区系研究

通过野外调查与查阅资料,广东郁南同乐大山自然保护区共有野牛种子植物149科542属1 002种.种子植物区系组成丰富,区系地理成分复杂,以南亚热带和热带北缘植物区系地理成分为主.区内珍稀濒危植物多,特有现象较明显,植物区系起源古老.与其它邻近地区植物区系相比较,同乐大山自然保护区种子植物区系与广西龙虎山自然保护区、广东黑石顶自然保护区的相似性较高,与湖南武陵源的相似性较低.     

广州市流溪河森林公园植物区系的初步研究

本文从植物区系地理学的角度,讨论了流溪河森林公园植物区系的基本特征、科属地理成分、与邻近植物区系的联系．以及在中国植物区系研究中的作用．本区系位于泛北极植物区、中国－日本森林植物亚区、华南地区。初步分析结果表明,该区系的热带、亚热带成分占有明显的优势,并具有向古热带印度－马来西亚植物区系过渡的特点．本区系和鼎湖山、黑石顶区系联系密切．具有相似的典型南亚热带区系成分．研究流溪河植物区系的组成和特点．对于进一步研究华夏植物区系以及我国植物区系和其它植物区系的联系．均有一定的意义。     

西北地区木本植物区系多样性研究

西北地区在中国植物区系上属于泛北极植物区,其南部基本上控制在中国-日本植物亚区的华中地区内,区系成分以北亚热带成分占优势,中、东部主要控制在中国-日本植物亚区内的华北地区中的黄土高原地区内,以华北区系成分占优势,西南部主要属青藏高原植物亚区和中国-喜马拉雅植物亚区,区系成分以唐古特和横断山区系成分占优势,北部主要是亚洲荒漠植物亚区,区系成分是以古地中海成分占优势。本区有木本植物(不包括栽培植物)103科338属1729种(含种下等级),其中裸子植物6科17属57种,被子植物97科321属1672种,另外,具有中国特有属26个,土著特有种173个(含种下等级)。大科、大属在区系组成中起着非常重要的作用,该区木本植物区系包含有15个分布区类型及其17个变型,其中北温带分布、泛热带分布、东亚至北美间断分布、东亚分布等成分占有重要地位。其木本植物区系的主要特征为:种类比较丰富;分布不均,区域差异大;地理成分复杂,具有明显的温带性质;起源古老;土著特有种较多;区系联系广泛,多种区系成分的汇集、混杂和过渡。     

横县野生种子植物区系及与附近地区的比较研究

为了解广西横县野生种子植物区系特征,对横县野生种子植物进行了调查分析。结果表明,广西横县有野生种子植物1 269种,隶属于163科658属,以被子植物占优势,而裸子植物则贫乏。在科属种组成上,以大科、区域单型属和少型属为主;生活型组成反映亚热带常绿阔叶林群落特征,藤本植物种类丰富。种子植物地理成分均以热带成分为主,兼备亚热带和温带成分。与邻近地区相比较,横县种子植物区系与广东紫金县相似性较高,区系成分组成则与广东新会区、紫金县相近。因此,横县地区野生种子植物种类丰富,热带性质明显,呈热带至亚热带过渡性质,起源古老,具有一定特有现象,与广东地区联系密切。