Plant species richness and diversity of the serpentine areas on the Witwatersrand

Soil chemistry can play an important role in determining plant diversity. Serpentine soils are usually toxic to many plant taxa, which limits plant diversity compared to that on adjacent non-serpentine soils. The usually high concentrations of toxic metals in serpentine soils are considered to be the edaphic factors that cause low diversity and high endemism. This paper aimed primarily to determine whether there is a relationship between serpentine soil chemistry and species richness on the Witwatersrand and to compare species richness of the serpentine areas with that of adjacent non-serpentine areas as well as with the species richness of the serpentine areas in the Barberton Greenstone Belt. The alpha- and beta-diversity of the Witwatersrand serpentine and non-serpentine areas was also investigated. A secondary aim of this study was to determine which of the non-serpentine taxa were more common on the serpentine than off the serpentine, which taxa were more common off the serpentine than on the serpentine and which taxa were equally common on and off serpentine soils. There was no significant difference in alpha-diversity between the serpentine and the adjacent non-serpentine areas, but beta-diversity is higher between serpentine plots than between non-serpentine plots. Although soil factors do affect species richness and diversity of plants on the Witwatersrand to a limited extent, the concentrations of soil chemicals in serpentine soils are not sufficiently different from those in non-serpentine soils to significantly influence the species richness and diversity of the serpentine soils. The high, but similar, diversity on serpentine and non-serpentine soils on the Witwatersrand indicates that soil factors do not play a significant role in determining diversity on potentially toxic soils in the area.     

Distribution of the endemic Balkan flora on serpentine I. – obligate serpentine endemics

Serpentine (ophiolithic) substrate covers large areas in the Balkans, more so than in any other part of Europe. These areas extend from north to south mainly in the mountainous central regions and represent specialized habitats for basiphilous-calcifugal plants. Biodiversity in the area is high, with a great number of interesting local and regional endemics. The high number of endemics indicates the importance of serpentine habitats as centres for floristic differentiation and speciation. The number of Balkan endemics growing on serpentine is c. 335 taxa (species and subspecies) of which 123 are obligate. Their distribution is presented in 50 × 50 km UTM squares as adopted in the Atlas Florae Europaeae project coordinated at Helsinki. The richest (in number of taxa) squares are situated in NW Greece (Epirus), the island of Evvia, N Albania together with SW Serbia, and N Greece (Vourinos). They indicate important centres of plant diversity in the Balkans, areas to be noted for conservation strategy. Features responsible for the distribution and abundance of these obligate serpentine endemics include: 1) edaphic isolation in relation to type of bedrock (lime, dolomite, marble, schist, etc.), 2) mountain island isolation (Smolikas, Vourinos, Ostrovica, etc.), 3) island isolation (Evvia) and 4) continuous long-term isolation without interruption or disturbance of speciation.     

Diversity,geographic variation and conservationof the serpentine flora of Tuscany (Italy)

The specialised flora of serpentine outcrops in Tuscany (Italy) is analysed in terms of species richness and geographic variation, in order to identify main centres of diversity and provide a basis for conservation programmes. Five edaphic groups are distinguished, among which obligate endemics, serpentine-preferential taxa, facultative basiphilous and facultative calcifuge serpentinophytes. Relatively low diversity (87 taxa) and high taxonomic distinctiveness (28.7% of endemics plus preferentials) underscore the insular condition of the ophiolitic outcrops. Hemicryptophytes and chamaephytes are the dominat life-forms, in line with the mainly continental character revealed by the phytogeographical analysis. Presence/absence of the taxa in 10 serpentine island systems was assessed using literature and original field data. Number of species and surface of the areas are significantly correlated. Cluster analysis identifies five groups of areas, while ordination indicates the species which are more effective in determining the floristic differences among the areas. Cecina valley, Monte Ferrato, Murlo hills and upper Tiber valley are the main centres of endemism and taxonomic diversity. However, the positive relationship between floristic and geographic distances and the remarkable proportion of species with frequency < 50% highlights a considerable among-area variation. To ‘catch’ such variation, a network of distant protected sites appears more effective than to search for single areas with high diversity. At least one site in each of the five clusters should be included in a ‘Important Plant Area’ network which would ensure the conservation of such a peculiar component of the Italian vascular flora.     

Niche analysis of orchids of serpentine and non-serpentine areas: Implications for conservation

Orchids are known for their species richness, intriguing ecology, rarity and the fact that they grow in almost all terrestrial ecosystems. Although numerous studies about their ecology have been carried out concerning calcareous areas, little is known about orchids that occur in serpentine habitats. The aim of this study was to investigate the ecological preferences of orchids in serpentine and non-serpentine areas on the model of the Valjevo Mountain Range (W Serbia). Niche analysis of orchids was performed using outlying mean index analysis. Data concerning geographical coordinates, altitude, habitat type, inclination, bedrock type, light regime, soil moisture, acidity, nitrogen and temperature were used as explanatory variables. Data of 33 orchid taxa from 407 localities were analysed. The most important gradients that govern orchid distribution were geological bedrock, light regime and temperature. The results have shown that only Anacamptis morio and Gymnadenia conopsea have statistically significantly larger populations on serpentine compared with non-serpentine bedrocks. This study highlights the importance of serpentine habitats as orchid habitats, bearing in mind the occurrence of rare species and species which were found exclusively in serpentine habitats.     

Climatic and spatial patterns of diversity in the serpentine plants of California

Abstract . The insular distribution of distinctive substrates, such as outcrops of serpentine rock, may either promote plant diversity by enhancing opportunities for speciation or reduce diversity by increasing rates of extinction. To examine the relationship between diversity and the spatial structure of habitats, we studied large‐scale patterns of diversity in the flora of serpentine in California. We used multiple linear regressions on geographical information system (GIS)‐derived data for 85 subregions of the state to analyse the climatic and spatial correlates of plant species richness. The diversity of plants endemic to serpentine declined from north to south and from the coast inland, in association with decreasing rainfall; the same trends were seen in the total flora, but the trends were stronger in serpentine endemics. Diversity of serpentine endemics increased with the area of serpentine and decreased with the mean isolation of serpentine patches in a subregion. The diversity of endemics was not correlated with the number of serpentine patches or their mean perimeter‐to‐area ratio. We conclude that patchiness in this terrestrial habitat does not appear to promote diversity, even at the large spatial scale associated with speciation and endemism.     

Composition, geographical affinities and endemism of the Iberian Peninsula orchid flora

The orchid flora of the Iberian Peninsula is relatively well known, but its biogeographical and diversity patterns have until now remained unanalysed. This work compares the richness of this flora with that of 27 other territories in different continents and at different latitudes, with the aim of establishing whether it is richer or poorer than might be expected. Latitude was found to be an excellent predictor of regional orchid species richness. With 122 taxa, the orchid flora of the Iberian Peninsula is more or less as diverse as that of other Mediterranean areas of similar latitude (e.g. France, Greece or Italy), but more diverse than other European or indeed North African orchid floras. In this study, the Iberian orchid species were assigned to eight monophyletic clades and the global distribution of these are mapped to establish continental affinities between the floras. A recent floristic account on the Iberian orchids was also used to assign the orchid taxa to habitats, and the relationship between the number of endemisms and their habitats was analysed. The patterns of endemism differed in different habitats. Very high levels of endemism were found in habitats peculiar to the Mediterranean Basin, indicating the relict status of its orchid flora.     

湖北兰科植物多样性及其区系地理特征

湖北植被尤其是鄂西地区,在近代以来备受植物学家的关注。该研究基于植物标本、文献资料与野外调查成果,整理出湖北兰科植物名录,结合湖北的地形与气候特征分析了湖北兰科植物的分布格局、区系及多样性特征。结果表明:湖北兰科植物主要分布在西南、西北、东北及东南部山区,以鄂西山地最为丰富,中南部江汉平原最少,900~1 200 m中海拔地段丰富度最高;物种多样性由南至北、由西至东呈递减趋势,鄂西南与鄂西北之间具有最大相似性;除拟兰亚科(subfam.Apostasioideae)外的5个亚科湖北均有分布,计有15族54属141种,单种属和寡种属分别占总属数的50.00%和33.33%;湖北兰科植物东亚分布成分占40.43%,中国特有种占总种数的41.84%,东亚区系主体突出,中国特有成分所占比例较大,其中中国—日本成分占优势;温带属性较强,亚热带向温带过渡特征明显,有25个热带分布属及27个温带分布属,热温比为0.93,种级水平的热带分布类型占8.51%,温带分布类型占91.49%;一些稀缺种在台湾与湖北的间断分布,表明两者植物区系有较强的关联性;湖北兰科植物区系与西南及横断山区联系密切,是与东部地区植物区系交流的中转站。     

Centres of plant endemism in China: places for survival or for speciation?

Aim This study aimed to identify the ‘centres of endemism’ of the Chinese spermatophyte flora in order to indirectly detect the locations of past glacial refugia. The role of these areas as places for plant survival (‘plant museums’) and/or areas for plant evolution and speciation (‘plant cradles’) was also assessed. Location China. Methods Distribution patterns of 555 plant endemic taxa, taken as a representative sample of the Chinese endemic flora, were mapped on a 1° × 1° latitude/longitude grid. For each grid cell, species richness (total count of species) and weighted richness (down‐weighting each species by the inverse of its range) were calculated. Grid cells within the top 5% of highest values of weighted richness were considered centres of endemism. Based on available information, all plant taxa included in this study were classified into palaeoendemics and neoendemics, and their distributional patterns were represented separately. Results Twenty areas of endemism were identified in central and southern China, roughly corresponding to mountain ranges, including the Hengduan and Daxue Mountains, the Yungui Plateau, central China Mountains, the Nanling Mountains, eastern China Mountains, and Hainan and Taiwan. Although almost all centres of endemism contained both palaeoendemic and neoendemic taxa, considerable differences in their respective numbers were recorded, with the majority of neoendemics on the eastern fringe of the Tibetan Plateau (Hengduan Mountains sensu lato) but more palaeoendemics towards the east. Main conclusions Owing to their varied topography, the mountainous regions of central and southern China have provided long‐term stable habitats, which allowed palaeoendemics to persist and facilitated the process of speciation. Contrasting patterns between the palaeoendemics and neoendemics within refugia might be attributable to the geological and tectonic history of specific areas. The eastern fringe of the Tibetan Plateau clearly constitutes the ‘evolutionary front’ of China, probably as a result of the uninterrupted uplift of the plateau since the late Neogene. In contrast, the tectonic stability of central and southern China during the Tertiary may have facilitated the persistence of relict plant lineages.     

Genetic Diversity of Bacterial Communities of Serpentine Soil and of Rhizosphere of the Nickel-Hyperaccumulator Plant <Emphasis Type="Italic">Alyssum bertolonii</Emphasis>

Serpentine soils are characterized by high levels of heavy metals (Ni, Co, Cr), and low levels of important plant nutrients (P, Ca, N). Because of these inhospitable edaphic conditions, serpentine soils are typically home to a very specialized flora including endemic species as the nickel hyperaccumulator Alyssum bertolonii. Although much is known about the serpentine flora, few researches have investigated the bacterial communities of serpentine areas. In the present study bacterial communities were sampled at various distances from A. bertolonii roots in three different serpentine areas and their genetic diversity was assessed by terminal restriction fragment length polymorphism (T-RFLP) analysis. The obtained results indicated the occurrence of a high genetic diversity and heterogeneity of the bacterial communities present in the different serpentine areas. Moreover, TRFs (terminal restriction fragments) common to all the investigated A. bertolonii rhizosphere samples were found. A new cloning strategy was applied to 27 TRFs that were sequenced and taxonomically interpreted as mainly belonging to Gram-positive and -Proteobacteria representatives. In particular, cloned TRFs which discriminated between rhizosphere and soil samples were mainly interpreted as belonging to Proteobacteria representatives.This revised version was published online in November 2004 with corrections to Volume 48.     

Can a benthic diatom community complement chemical analyses and discriminate between disturbed and undisturbed saline wetland habitats? A study of seven soda pans in Serbia

Soda pans are protected in the European Union as Natura 2000 areas in the category of “Pannonic saline steppes and marshes”. There are at least six soda pans of reference status in Serbia and only a half have strict legal protection. The number of similar, but disturbed (modified) habitats that could be reconstructed is still unknown. We conducted sampling in five natural and two disturbed soda pans aiming to compare a difference in physical and chemical water properties and benthic diatom communities. In addition, we tried to apply recently developed Diatom Index for Soda Pans (DISP) and Trait-based index (TBI) to test the applicability of taxonomic and trait-based approaches in ecological status assessment of soda pans in the southern part of the Carpathian Basin. In contrast to natural soda pans, lower pH and nutrients levels were recorded in disturbed pans. A total of 86 taxa of benthic diatoms, including 11 new for diatom flora of Serbia, were identified. A lower species richness and Shannon index was recorded in natural soda pans. Nitzschia austriaca, N. supralitorea, Navicula veneta and N. wiesneri were dominant diatoms in soda pans of the reference status. Both diatom indices were in average lower in disturbed pans, and this difference was statistically significant for DISP index. We concluded that two indices, supplemented with indicator values for some local diatom species, can be a promising tool for soda pan conservation in this part of the Carpathian Basin.

     

Continental scale patterns of biodiversity: can higher taxa accurately predict African plant distributions?

The distribution maps of a total of 3563 species, which represent 8.9% of the known African angiosperm flora, were entered into cells representing a one-degree latitude–longitude grid of Sub-Saharan Africa. The computer programme WORLDMAP was used to explore continental scale patterns of biodiversity. The maps were used to assess the use of higher taxa as a surrogate measure for predicting patterns of species richness. Genera were found to predict species richness distributions most closely, with higher taxa (families, orders, subclasses) exhibiting progressively worse correlations. However in two areas, the Cape Region of South Africa and coastal Cameroon, there was a higher species to genus ratio than in other areas of Africa. In the Cape Region this meant that generic richness failed to predict species richness. Hotspots, defined as the 5% of grid cells with the highest scores for richness and range-size rarity, were identified for species and higher taxa. Whilst a high percentage of species richness hotspots were predicted by higher taxa, there were important exceptions like the Cape Region. Species range-size rarity hotspots were not well predicted by higher taxa. Hotspots of higher taxa (families and orders) do not therefore accurately predict the location of species hotspots. Higher taxa appear to provide a powerful and accurate tool that can be used to predict large scale patterns of species biodiversity in Sub-Saharan Africa. However care must be taken when using taxa higher than genera, especially if selecting areas of highest conservation priority. The special case of the Cape Region indicates the danger of extending predictive generalizations as the ecological mechanisms that promote and retain species may not be the same in all places. © 2002 The Linnean Society of London, Botanical Journal of the Linnean Society , 138 , 225–235.     

Orchid biogeography and factors associated with rarity in a biodiversity hotspot,the Southwest Australian Floristic Region

Aim The causes of orchid diversification and intrinsic rarity are poorly resolved. The Orchidaceae of the Southwest Australian Floristic Region use a diversity of pollination strategies and sites of mycorrhizal infection, and occupy a diversity of habitats. We combined a biogeographic analysis with analysis of factors associated with rarity to establish: (1) the landscape features correlated with taxon turnover and speciation, and (2) the possible role in taxon rarity of geographic region, pollination strategy, edaphic habitat and site of mycorrhizal infection. Location Southwest Australian Floristic Region. Methods The distributions of 407 orchid taxa (species and subspecies) were mapped at the quarter‐degree scale using 13,267 collections in the Western Australian Herbarium. This database was used to map taxon richness, for a biogeographic analysis and to quantify rarity of taxa. Using herbarium records, rarity was expressed as mean abundance, mean distribution and incidence of rarity based on abundance and distribution for each genus. We tested for differences in rarity of species between pollination strategies, edaphic habitats and sites of mycorrhizal infection. Results Taxon richness was highest in the High Rainfall Province. Biogeographic provincial boundaries for orchids were aligned with rainfall, while district boundaries tended to follow geological formations. When rarity was defined as either low abundance or small distribution, the greatest number of rare taxa occurred in areas of high taxon richness and naturally fragmented edaphic environments. For both abundance and distributional extent, sexual deception had a significantly higher incidence of rarity than food‐rewarding taxa. There was no significant difference in rarity with site of mycorrhizal infection. Main conclusions While large‐scale edaphic and climatic variation are correlated with orchid taxon turnover and speciation in a similar fashion to the flora in general, the processes responsible for patterns of diversity may differ. Fragmented edaphic environments appear to be associated with a higher incidence of rare species due to limited dispersal/colonization opportunities or radiations of taxa in allopatry. The high incidence of rarity in sexually deceptive taxa could be due to either low fruit set or the risk of specializing on a single pollinator species.     

Urban domestic gardens (I): Putting small‐scale plant diversity in context

Abstract. As part of a larger survey of biodiversity in gardens in Sheffield, UK, we examined the composition and diversity of the flora in two 1‐m² quadrats in each of 60 gardens, and compared this with floristic data from semi‐natural habitats in central England and derelict urban land in Birmingham, UK. Garden quadrats contained more than twice as many taxa as those from any other habitat type. Ca. 33 % of garden plants were natives and 67 % aliens, mainly from Europe and Asia. A higher proportion of garden aliens originated from Asia and New Zealand than in the UK alien flora as a whole; 18 of the 20 most frequent plants in garden quadrats were natives, mostly common weeds. Garden quadrats showed no evidence of ‘nestedness’, i.e. a tendency for scarce species to be confined to the highest diversity quadrats. Conversely, species in all semi‐natural and derelict land data sets were significantly nested. Compared to a range of semi‐natural habitats, species richness of garden quadrats was intermediate, and strikingly similar to the richness of derelict land quadrats. Although species accumulation curves for all other habitats showed signs of saturation at 120 quadrats, gardens did not. Correlations between Sørensen similarity index and physical distance were insignificant for all habitat types, i.e. there was little evidence that physical distance played any part in structuring the composition of the quadrats in any of the data sets. However, garden quadrats were much less similar to each other than quadrats from semi‐natural habitats or derelict land.     

<Emphasis Type="Italic">Cardamine plumieri</Emphasis> (<Emphasis Type="Italic">Brassicaceae</Emphasis>) confirmed to the Flora of Serbia

The south-European Cardamine plumieri Vill. (sect. Pteroneurum subsect. Cryptopterum) is confirmed for the Flora of Serbia. Several populations were discovered in the central and western part of country, exclusively on the serpentine bedrocks. Morphological, chorological and ecological characteristics of C. plumieri was studied.     

Fungal Diversity Is Not Determined by Mineral and Chemical Differences in Serpentine Substrates

The physico-chemical properties of serpentine soils lead to strong selection of plant species. Whereas many studies have described the serpentine flora, little information is available on the fungal communities dwelling in these sites. Asbestos minerals, often associated with serpentine rocks, can be weathered by serpentine-isolated fungi, suggesting an adaptation to this substrate. In this study, we have investigated whether serpentine substrates characterized by the presence of rocks with distinct mineral composition could select for different fungal communities. Both fungal isolation and 454 pyrosequencing of amplicons obtained from serpentine samples following direct DNA extraction revealed some fungal taxa shared by the four ophiolitic substrates, but also highlighted several substrate-specific taxa. Bootstrap analysis of 454 OTU abundances indicated weak clustering of fungal assemblages from the different substrates, which did not match substrate classification based on exchangeable macronutrients and metals. Intra-substrate variability, as assessed by DGGE profiles, was similar across the four serpentine substrates, and comparable to inter-substrate variability. These findings indicate the absence of a correlation between the substrate (mineral composition and available cations) and the diversity of the fungal community. Comparison of culture-based and culture-independent methods supports the higher taxonomic precision of the former, as complementation of the better performance of the latter.     

Latitudinal patterns and regionalization of plant diversity along a 4270‐km gradient in continental Chile

According to the global latitudinal diversity gradient, a decrease in animal and plant species richness exists from the tropics towards higher latitudes. The aim of this study was to describe the latitudinal distribution patterns of Chilean continental flora and delineate biogeographic regions along a 4270‐km north–south gradient. We reviewed plant lists for each of the 39 parallels of continental Chile to build a database of the geographical distribution of vascular plant species comprising 184 families, 957 genera and 3787 species, which corresponded to 100%, 94.9% and 74.2% of the richness previously defined for Chile, respectively. Using this latitudinal presence–absence species matrix, we identified areas with high plant richness and endemism and performed a Cluster analysis using Jaccard index to delineate biogeographic regions. This study found that richness at family, genus and species levels follow a unimodal 4270‐km latitudinal distribution curve, with a concentration of richness in central Chile (31–42°S). The 37th parallel south (central Chile) presented the highest richness for all taxonomic levels and in specific zones the endemism (22–37°S) was especially high. This unimodal pattern contrasts the global latitudinal diversity gradient shown by other studies in the Northern hemisphere. Seven floristic regions were identified in this latitudinal gradient: tropical (18–22°S), north Mediterranean (23–28°S), central Mediterranean (29–32°S), south Mediterranean (33–37°S), north temperate (38–42°S), south temperate (43–52°S) and Austral (53–56°S). This regionalization coincides with previous bioclimatic classifications and illustrates the high heterogeneity of the biodiversity in Chile and the need for a reconsideration of governmental conservation strategies to protect this diversity throughout Chile.     

New chorological data for flora of the Pannonian region of Serbia

The northern part of Serbia, known as Pannonian Serbia, is a lowland region. The autochthonous (indigenous) flora is classified as either steppe, forest-steppe, sand dune or salt flat. Most of the area has been developed agriculturally, thereby reducing the amount of land containing preserved habitats. The flora of this region was collected over a period of several years, supplying new data on the distribution of numerous plant species. The first data on the distribution of flora in Pannonian Serbia for Humulus scandens and Ophris scolopax subsp. Cornuta is presented in this study. The local regions cited were the first time precisely recorded regions were made after a period of over 100 years, for Cardamine impatiens, Monotropa hypopitys subsp. hypopitys, Ononis pusilla, Globularia punctata, Gymnadenia odoratissima and Carex brevicollis. The groups, Peucedanum carvifola and Galium tenuissimum, quite rare in the northern part of Serbia, were found at new localities. In order to present the data, the authors used the method of indirect mapping on UTM grid, with 10 × 10 km as the basic unit. This method is compatible with the edition Atlas Florae Europaeae.     

Endemicity and evolutionary value: a study of Chilean endemic vascular plant genera

This study uses phylogeny‐based measures of evolutionary potential (phylogenetic diversity and community structure) to evaluate the evolutionary value of vascular plant genera endemic to Chile. Endemicity is regarded as a very important consideration for conservation purposes. Taxa that are endemic to a single country are valuable conservation targets, as their protection depends upon a single government policy. This is especially relevant in developing countries in which conservation is not always a high resource allocation priority. Phylogeny‐based measures of evolutionary potential such as phylogenetic diversity (PD) have been regarded as meaningful measures of the “value” of taxa and ecosystems, as they are able to account for the attributes that could allow taxa to recover from environmental changes. Chile is an area of remarkable endemism, harboring a flora that shows the highest number of endemic genera in South America. We studied PD and community structure of this flora using a previously available supertree at the genus level, to which we added DNA sequences of 53 genera endemic to Chile. Using discrepancy values and a null model approach, we decoupled PD from taxon richness, in order to compare their geographic distribution over a one‐degree grid. An interesting pattern was observed in which areas to the southwest appear to harbor more PD than expected by their generic richness than those areas to the north of the country. In addition, some southern areas showed more PD than expected by chance, as calculated with the null model approach. Geological history as documented by the study of ancient floras as well as glacial refuges in the coastal range of southern Chile during the quaternary seem to be consistent with the observed pattern, highlighting the importance of this area for conservation purposes.     

Diversity and endemism of angiosperms in the Gulf of Guinea islands

The richness of flowering plants (1666 native taxa) and the originality of the flora of the islands of the Gulf of Guinea are remarkable. The flora of Bioko shows the highest diversity in terms of families, genera and species of angiosperms but, due to its proximity to the mainland, the level of endemism is relatively low. The number of endemics in the four islands has suffered a decrease in the last years, due to taxonomic changes. Currently, 176 endemic taxa of angiosperms are recognized. Most of the endemic taxa are under-collected and information is lacking on their biology and distribution, hence the need for inventory work on the flora of the islands. A measure of the similarity between the floras of the islands can be given by determination of genera in common. The results are comparable to those obtained with Exell and Wild's quotient of affinity and show a great similarity between neighbouring islands. The presence of afromontane elements and several palaeoendemics in the mountain rain forest of the islands is notable and makes the study of its flora a priority for research.     

Current biogeographical roles of the Kunlun Mountains

Large‐scale patterns of biodiversity and formation have garnered increasing attention in biogeography and macroecology. The Qinghai‐Tibet Plateau (QTP) is an ideal area for exploring these issues. However, the QTP consists of multiple geographic subunits, which are understudied. The Kunlun Mountains is a geographical subunit situated in the northern edge of the QTP, in northwest China. The diversity pattern, community phylogenetic structures, and biogeographical roles of the current flora of the Kunlun Mountains were analyzed by collecting and integrating plant distribution, regional geological evolution, and phylogeography. A total of 1911 species, 397 genera, and 75 families present on the Kunlun Mountains, of which 29.8% of the seed plants were endemic to China. The mean divergence time (MDT) of the Kunlun Mountains flora was in the early Miocene (19.40 Ma). Analysis of plant diversity and MDT indicated that the eastern regions of the Kunlun Mountains were the center of species richness, endemic taxa, and ancient taxa. Geographical origins analysis showed that the Kunlun Mountains flora was diverse and that numerous clades were from East Asia and Tethyan. Analysis of geographical origins and geological history together highlighted that the extant biodiversity on the Kunlun Mountains appeared through species recolonization after climatic fluctuations and glaciations during the Quaternary. The nearest taxon index speculated that habitat filtering was the most important driving force for biodiversity patterns. These results suggest that the biogeographical roles of the Kunlun Mountains are corridor and sink, and the corresponding key processes are species extinction and immigration. The Kunlun Mountains also form a barrier, representing a boundary among multiple floras, and convert the Qinghai‐Tibet Plateau into a relatively closed geographical unit.