The distribution,diversity, and conservation status of Cycas in China

As ancient gymnosperm and woody plants, cycads have survived through dramatic tectonic activities, climate fluctuation, and environmental variations making them of great significance in studying the origin and evolution of flora biodiversity. However, they are among the most threatened plant groups in the world. The principal aim of this review is to outline the distribution, diversity, and conservation status of Cycas in China and provide suggestions for conservation practices. In this review, we describe the taxonomy, distribution, and conservation status of Cycas in China. By comparing Chinese Cycas species with its relatives worldwide, we then discuss the current genetic diversity, genetic differentiation of Cycas, and try to disentangle the potential effects of Quaternary climate changes and topographical events on Cycas. We review conservation practices from both researchers and practitioners for these rare and endangered species. High genetic diversity at the species level and strong genetic differentiation within Cycas have been observed. Most Cycas species in southwest China have experienced population retreats in contrast to the coastal Cycas's expansion during the Quaternary glaciation. Additionally, human activities and habitat fragmentation have pushed these endangered taxa to the brink of extinction. Although numerous efforts have been made to mitigate threats to Cycas survival, implementation and compliance monitoring in protection zones are currently inadequate. We outline six proposals to strengthen conservation measures for Cycas in China and anticipate that these measures will provide guidelines for further research on population genetics as well as conservation biology of not only cycads but also other endangered species worldwide.     

江西九岭山脉种子植物区系研究

九岭山脉植物区系发生历史悠久,对研究我国早期种子植物演化、动植物迁徙、物种分布格局均具有重要作用。为探讨九岭山脉种子植物区系成因和濒危保护植物的保护利用,该文通过野外调查、标本采集和鉴定,结合经典植物地理学方法,对该山脉种子植物区系进行了研究。结果表明:(1)九岭山脉共有野生种子植物211科956属2928种,占江西种子植物1064属4028种的比例分别为89.8%和72.69%。(2)该植物区系的热带成分科占该地区种子植物总科数(不含世界分布科)的81.35%,但缺乏典型热带成分科,区系中的热带性属和温带性属数量接近,显示该植物区系由热带性质向温带性质过渡,这与九岭山脉地处重要的气候和生态交错地带有一定关联。(3)该地区共分布中国特有植物6科33属41种,特有属主要为古特有属,体现了该植物区系起源的古老性,推断该山脉在第四纪冰期环境较为稳定,为众多植物提供了“避难所”。(4)该地区的种子植物中有30科63属109种为国家重点保护植物,其中,国家I级保护植物15种,极危植物3种、濒危植物11种、易危植物20种。该山脉中的九岭山、官山和大围山已有相应的自然保护区发挥生态保护作用,而其余的山地则未建立有效保护,应对相关濒危植物所在区域加以监管,可采取就地保护或迁地保护等措施,建立相关的种质资源库,确保濒危保护植物的可持续利用。     

陕西汉中天坑群维管植物多样性及区系分析

对陕西汉中典型天坑生物多样性进行调查，并在系统收集天坑周边生物多样性研究成果与资料的基础上，对该区维管植物多样性区系进行初步研究。结果表明，汉中天坑群区域有被子植物940种，裸子植物20种，蕨类植物73种。该区植物区系以温带成分为主，兼具热带成分，展示了明显的由暖温带向亚热带过渡的特点，且区系具有一定的古老性。天坑群已发现30种珍稀濒危植物，是现存珍稀濒危植物的“避难所”。该研究对探究天坑群地区生态资源可持续发展利用、天坑生物多样性的保育以及恢复重建等方面具有重要意义。     

广西木论国家级自然保护区植物物种多样性初步研究

广西木论国家级自然保护区位于我国滇黔桂植物区和华南植物区的交错地带，是古北极与古热带两大植物区系交接过渡的中心地带，在我国生物多样性保护区域中占据不可替代的地位。为摸清广西木论国家级自然保护区植物物种多样性，该文基于历史文献整理、野外调查、标本采集和鉴定以及数据统计分析，对该保护区维管束植物物种多样性组成及其特点进行了研究。结果表明：(1)该区共有维管束植物1 735种，包括石松类和蕨类植物218种、种子植物1 517种，具有较丰富的维管束植物多样性组成以及较复杂的植物区系成分。(2)该区共有中国特有植物486种、广西特有植物56种、岩溶特有植物262种，具有显著的植物特有性。(3)该区共有国家重点保护野生植物68种、广西重点保护野生植物153种、我国极小种群野生植物4种、受威胁植物108种、列入《濒危野生动植物种国际贸易公约》(CITES)附录植物144种，具有较高程度的植物珍稀濒危性。综上表明，该区是我国重要的岩溶植物基因库，具有极其重要的保护价值。该研究结果为自然保护区的建设和管理、植物保护和利用以及其他科研工作的开展提供了重要依据。     

Conservation challenges in a threatened hotspot: agriculture and plant biodiversity losses in Baja California,Mexico

Modern agricultural practices pose serious threats to biodiversity worldwide. Species losses from habitat conversion are well documented, but indirect impacts such as reduced water availability to adjacent ecosystems are less known. San Quintín is an important agricultural valley in the mediterranean climate region of Baja California, Mexico. The region is also a hotspot of plant species richness and endemism. Plant species in the region are here analyzed by comparison of the contemporary flora to historical botanical collections to identify extirpations. Historical collections indicate that habitat loss to agriculture has been a direct cause of species losses. As importantly, the unsustainable extraction of groundwater has apparently led to salt water intrusion, resulting in the loss of 22 native plant taxa, including 13 rare plants. Seventy-eight percent of all the vernal pool taxa have been lost from the flora (including 85 % of the rare taxa) and 11 % of plants of riparian and pond habitat (including 25 % of the rare taxa) are no longer found in the region. Unsustainable agricultural practices continue to threaten fragile coastal ecosystems and are a serious challenge to current and future conservation efforts. Ironically, these same practices frequently result in abandonment of cultivated areas. Owing to indirect impacts, conservation of biodiversity and large-scale agricultural operations are even less compatible on a regional scale than indicated by direct impacts. It is vital that sustainable agricultural practices be adopted locally and globally to avoid further losses of biodiversity.     

Effectiveness of mowing for the flora diversity preservation: a case study of steppe-like grassland in Croatia (NATURA 2000 site)

Intensive human activities have resulted in a critical reduction of grasslands in Croatia, one of the richest Europian countries in terms of biodiversity. Sub-Pannonic steppic grasslands are very rare, only few occur in the continental part of Croatia and most of them are protected as NATURA 2000 sites. We studied vascular flora of the Sub-Pannonic stepic grassland with the aim to examine the changes in plant communities 15 years from the mowing application. Results showed that hand mowing once per year at the end of vegetation season increased the species diversity as well as the number of medium and low growth taxa. The critically endangered, nearly threatened and vulnerable species remained preserved. The occurrence of trees, shrubs and invasive species as a consequence of succession and anthropogenic influences could be important threat for steppe-like grassland flora. From a conservation point of view infrequent mowing regime could be an effective management tool, although it needs to be adapted to regional and local circumstances for maintaining high biodiversity of steppe-like grasslands and valuable plant species.     

Aquatic plants diversity in arid zones of Northwest China: patterns, threats and conservation

We investigated aquatic plant diversity by conducting the field investigation and collecting the published data in the arid regions of Northwest China. Two hundred and twenty four taxa of vascular aquatic plants representing 64 genera and 34 families occur in this area, 8.48% of which are endemic. Among these, 1 genus and 6 species were new state records and 1 family, 9 genera and 29 species were new area records. Typhaceae, Potamogetonaceae, Juncaginaceae and Haloragaceae were the most frequent families (considering relative frequency of occurrence), whereas Cyperaceae, Potamogetonaceae and Ranuncnlaceae are the most species-rich. The most frequent genera were Typha, Potamogeton, and Triglochin, and the most species-rich were Potamogeton, Eleocharis and Scirpus. The most frequent species are Triglochin palustre, Myriophyllum spicatum, Potamogeton pectinatus and Typha angustifolia. Aquatic plants diversity is distributed unevenly in the region. The maximum species occurs in Dzungarian basin while the least species in Hexi corridor. The aquatic flora in arid zone of China is not distinctive although some endemic species are found, most species are widely distributed. Local aquatic plants diversity can be influenced by many factors such as hydrological alteration, habitat loss, over-grazing, high human population pressure, global climate change, an inappropriate economic development policy. Among them, the largest threat to aquatic plants biodiversity may be habitat loss due to hydrological alteration. In order to conserve the aquatic plants biological resources and biodiversity in this region, some strategies and measures must be suggested including strengthening scientific research and biodiversity education in the local people, balancing economic development and ecological conservation, and enhancing governmental assistance and subsidy to the local residents.     

湖北后河国家级自然保护区生物多样性及其保护对策 Ⅰ.生物多样性现状及其研究

湖北后河国家级自然保护区位于湖北、湖南交界处的五峰县境内,属武陵山东段余脉山地,为我国地势的第二阶梯向第三阶梯的过渡地带,是我国三大物种特有中心之一的川东-鄂西特有中心和第三纪古植物的孑遗中心的重要组成成分之一。该区拥有丰富的生物多样性,尤以第三纪孑遗珍稀濒危植物集中分布群落为典型特征。该区地貌复杂,海拔落差大,微生境复杂多变,拥有从低山河谷常绿阔叶林到亚高山灌丛或草甸等多种生态系统和多种植被类型。目前已知该区有陆生脊椎动物25目74科306种,占湖北省总种数的63.5%和全国总种数的13.0%,其中有51种国家重点保护野生动物和70种湖北省级重点保护动物;已知该区维管植物有194科819属2088种,占湖北省总种数的34.4%和全国总数的7.5%,属国家特有、珍稀濒危或重点保护的植物约有70余种;已知藓类植物33科90属192种和叶附生苔类植物3科7属7种,分别占全国总种数的9.8%和4.2%。该区不仅拥有丰富的动植物区系成分多样性,而且具有高度的群落物种多样性和经济类型多样性。尽管该区的生物多样性研究得到长足发展,但主要集中在物种种类的调查与区系成分研究和少数群落格局物种多样性研究,而遗传多样性方面的研究十分欠缺。物种多样性研究也不平衡,昆虫类和苔藓植物的调查刚起步,真菌资源、淡水鱼类等尚未开展研究。     

我国近30年来植物迁地保护及其研究的综述

从20世纪80年代起,中国植物园与世界植物园同步挑起了植物迁地保护的历史重担,使植物园的数量迅速增加至近200个,收集保存了占中国植物区系2/3的20000个物种,并在稀有濒危植物迁地保护原理与方法的科学研究上获得了新的进展。然而,中国植物园的布局与世界的植物园一样,物种越丰富的地区,已建立的植物园越少;在保存的物种中,不仅忽视了遗传多样性的保护,而且有约1/3的国家重点保护种类主要因适应性问题而生长不良、出现生殖障碍,甚至死亡。为了提高我国植物迁地保护的有效性,本文就《中国稀有濒危植物保护名录》的修订与公布、《中国植物保护战略》的制定,以及我国植物园协调机制的建立、植物迁地保护网络系统的完善、稀有濒危植物迁地保护的规范等问题进行讨论。     

Patterns of plant invasions in China: Taxonomic,biogeographic, climatic approaches and anthropogenic effects

This study was aimed to determine the patterns as well as the effects of biological, anthropogenic, and climatic factors on plant invasions in China. About 270 volumes of national and regional floras were employed to compile a naturalized flora of China. Habit, life form, origin, distribution, and uses of naturalized plants were also analyzed to determine patterns on invasion. Correlations between biological, anthropogenic and climatic parameters were estimated at province and regional scales. Naturalized species represent 1% of the flora of China. Asteraceae, Fabaceae, and Poaceae are the dominant families, but Euphorbiaceae and Cactaceae have the largest ratios of naturalized species to their global numbers. Oenothera, Euphorbia, and Crotalaria were the dominant genera. Around 50% of exotic species were introduced intentionally for medicinal purposes. Most of the naturalized species originated in tropical America, followed by Asia and Europe. Number of naturalized species was significantly correlated to the number of native species/log area. The intensity of plant invasion showed a pattern along climate zones from mesic to xeric, declining with decreasing temperature and precipitation across the nation. Anthropogenic factor, such as distance of transportation, was significantly correlated to plant invasions at a regional scale. Although anthropogenic factors were largely responsible for creating opportunities for exotic species to spread and establish, the local biodiversity and climate factors were the major factors shaping the pattern of plant invasions in China. The warm regions, which are the hot spots of local biodiversity, and relatively developed areas of China, furthermore, require immediate attentions.     

Plant invasions on small Mediterranean islands: An overview

Biological invasions have become one of the main drivers of habitat degradation and a leading cause of biodiversity loss in island ecosystems worldwide. The spread of invasive species poses a particular environmental threat on the islands of the Mediterranean Basin, which are hot spots of biodiversity and contain rare habitats and endemic species, especially on small islands, which are highly vulnerable to biodiversity loss. Following a recent survey, in this paper we aim to provide an overview of the present-day non-native vascular flora of small Mediterranean islands based on a sample of 37 islands located in the middle of the Mediterranean Sea, off the coast of Italy. By comparing the current data with those gathered during a previous survey conducted in the same study area, we also aim to highlight the main changes that have occurred in non-native plant species diversity, establishment and distribution in recent years and to present a first general overview of the most prominent plant taxa in the island’s introduced flora, focusing on those most responsible for these changes and those that pose the greatest environmental threats. We recorded 203 non-native plant species, 147 of which have established on at least one of the islands investigated. Overall, we detected a sharp increase in the number of species, in their levels of establishment and in the extent of their distribution within the study area in recent years. This may be explained by the intensification of research on plant invasions, as well as to new introduction, escape, establishment and invasion events on the islands in recent decades. The most remarkable plants detected include acacias and succulents, two groups that appear to be emerging very rapidly and to be posing new threats to the conservation of the islands’ natural environment, especially the genus Carpobrotus, whose spread into natural habitats containing rare and endemic taxa is seriously threatening biodiversity on both a local and global scale. On the whole, our results show that the plant invasion phenomenon in the study area has in recent years intensified considerably. As this process seems likely to continue, we should expect more establishment events in the future and the further spread of species that are already present. This is of particular conservation concern on the islands investigated in this survey, which are rich in endemisms, but have been facing deep socio-economic and environmental transformations in these last decades as a consequence of the abandonment of traditional management practices and the development of tourism. Our study thus confirms that plant invasions on Mediterranean islands are a serious environmental problem that threatens biodiversity conservation not only in the Mediterranean biogeographic region, but also on the global scale, and highlights the need to further increase efforts aimed at preventing, controlling or mitigating the effects of plant invasions in island ecosystems.     

Ex situ conservation of plant diversity in Romania: A synthesis of threatened and endemic taxa

Romania hosts a relatively high species diversity, including 3,829 vascular and 979 non-vascular spontaneous plant taxa. Multiple national red lists exist, with the number of taxa assessed as threatened varying greatly between them, from 548 to 1,438, and with number of taxa assigned to a given threat category also varying between the different sources. A composite list including all taxa mentioned in at least one of the selected red listings from Romania is required in order to compensate for this lack of consensus and to assess their ex situ conservation status. In this study, we synthesized data from the national red lists and counted 1,220 spontaneous vascular plant species and 201 subspecies, of which 77 are endemic and 76 subendemic for Romania. In addition, 18 non-red-listed endemics and 14 subendemics have been added, bringing the total to 1,453 threatened and (sub)endemic plant taxa, representing almost 38% of the total native vascular flora of Romania. Despite the large network of protected areas in Romania, many taxa are still being threatened with extinction in the region mainly due to anthropogenic pressure. Several ex situ conservation measures have been employed to assure a more substantial buffer against plant extinction in the wild, supported by thorough and adequate conservation strategies and multiple means to reintroduce taxa back to their natural habitats. Consequently, our second aim was to evaluate the ex situ conservation status of these threatened and (sub)endemic plants from Romania, focussing on both conventional methods (cultivation in botanic gardens, seed banking) and biotechnological approaches (in vitro tissue culture, medium-term storage and cryostorage). Of the 1,453 taxa included in our list, 642 (44.2%) are conserved by ex situ approaches. Of these, 524 are harboured in the most important botanic gardens throughout Romania, while 156 are currently held in long-term seed banks locally or in the Millennium Seed Bank of the Royal Botanic Garden, Kew (UK). Conversely, only 64 taxa from the list are preserved at the national level through in vitro cultures, and cryopreservation protocols have been developed for only 8 taxa. Overall, more than half of the threatened and (sub)endemic vascular flora from Romania remains unprotected outside the classical in situ conservation measures. For red-listed bryophytes, only 0.6% are preserved in national ex situ collections. Moreover, some aspects related to population genetic studies and the genetic stability of ex situ conserved plants are also briefly discussed, as essential prerequisites for applied biodiversity conservation programs. Finally, considering the distribution range of targeted taxa, we included a synthesis of biotechnological approaches at both national and international level. Our study presents not only a first assessment of the ex situ conservation status of national red listed flora, but also, to our knowledge, the most comprehensive and updated overview of the rare, threatened and (sub)endemic taxa from Romania. This evaluation will provide a supporting tool for national decision- and policy-making actions for biodiversity conservation, using both in situ and ex situ approaches. We also highlight the need for an updated red list for the Romanian flora that accurately follows the IUCN assessment criteria and protocols.     

湖北后河国家级自然保护区生物多样性及其保护对策Ⅰ.生物多样性现状及其研究*

湖北后河国家级自然保护区位于湖北、湖南交界处的五峰县境内,属武陵山东段余脉山地,为我国地势的第二阶梯向第三阶梯的过渡地带,是我国三大物种特有中心之一的川东-鄂西特有中心和第三纪古植物的孑遗中心的重要组成成分之一。该区拥有丰富的生物多样性,尤以第三纪孑遗珍稀濒危植物集中分布群落为典型特征。该区地貌复杂,海拔落差大,微生境复杂多变,拥有从低山河谷常绿阔叶林到亚高山灌丛或草甸等多种生态系统和多种植被类型。目前已知该区有陆生脊椎动物25目74科306种,占湖北省总种数的63．5％和全国总种数的13．0％,其中有51种国家重点保护野生动物和70种湖北省级重点保护动物;已知该区维管植物有194科819属2088种,占湖北省总种数的34．4％和全国总数的7．5％,属国家特有、珍稀濒危或重点保护的植物约有70余种;已知藓类植物33科90属192种和叶附生苔类植物3科7属7种,分别占全国总种数的9．8％和4．2％。该区不仅拥有丰富的动植物区系成分多样性,而且具有高度的群落物种多样性和经济类型多样性。尽管该区的生物多样性研究得到长足发展,但主要集中在物种种类的调查与区系成分研究和少数群落格局物种多样性研究,而遗传多样性方面的研究十分欠缺。物种多样性研究也不平衡,昆虫类和苔藓植物的调查刚起步,真菌资源、淡水鱼类等尚未开展研究。     

海南文昌维管植物区系特征分析

采用全面踏查结合文献研究的方法,对海南文昌地区维管植物组成、区系成分、分布区类型进行了研究。结果显示,文昌地区共计有维管束植物201科777属1397种,其中蕨类植物31科46属67种,种子植物170科731属1330种;野生种子植物634属1183种(包括珍稀濒危植物25种,海南特有种49种)。在属级水平上,文昌植物区系以热带成分占绝对优势,热带、亚热带成分占非世界分布总属数的93.23%。在种级水平上,热带亚洲成分和中国特有成分是该地区植物区系的主要组成部分,其中热带亚洲分布及其变型的分布种最多,占非世界广布种的47.26%;中国特有种占非世界广布种的12.01%。此外,村落风水林保存了大量当地珍稀植物和古树名木,对当地生物多样性保护具有重要意义,建议当地政府加强对村落风水林的保护。     

广西武鸣县种子植物区系研究

为了解广西武鸣县野生种子植物区系特征, 对其野生种子植物资源进行调查。结果表明,广西武鸣县有野生种子植物2 542种,隶属于184科898属,以被子植物占优势,裸子植物贫乏。从科属组成上看,以大科、单种属和寡种属为主体。科、属和种分布区类型丰富,含典型的热带亚热带成分,兼具温带成分,呈热带至亚热带过渡性质。与邻近地区比较,武鸣县植物多样性比较丰富,植物区系成分与广西横县最相近。因此,武鸣县种子植物多样性丰富、热带性质明显、地理成分多样、起源古老,同时聚集了一些特有植物和珍稀濒危植物,体现出北部湾植物区系的特征。     

宁夏野生维管植物编目

物种编目是区系研究、生物多样性监测和珍稀濒危生物保护的基础。宁夏维管植物编目对该区植物多样性保护和资源植物开发利用具有重要意义。本文在《宁夏植物志(第二版)》的基础上, 结合多年野外实地调查数据和相关文献资料, 按照APG Ⅳ分类系统修订了宁夏野生维管植物名录。结果显示: 宁夏有野生维管植物127科597属1,754种, 排名前10的优势科分别是菊科、禾本科、豆科、蔷薇科、毛茛科、苋科、唇形科、莎草科、石竹科和伞形科, 这10科共有物种939种, 占宁夏野生维管植物总数的53.53%; 科的组成以物种数小于20种的科为主, 属主要以小于5种的属为主; 2007年至今累计发现新记录植物230种; 宁夏有珍稀濒危植物25科44属65种; 外来归化、逸生及入侵植物9科22属28种。就国土面积和地理位置而言, 宁夏野生维管植物较为丰富。本研究结果可为《宁夏植物志(第三版)》修订和生物多样性监测与保护提供基础数据。     

神农架北坡堵河源自然保护区植物多样性研究

为建立自然保护区,保护神农架北坡堵河源地区丰富的生物多样性资源,并为神农架地区植物起源、植被演替以及生物多样性和濒危物种状况深入、准确评价提供基础数据,2002年,采用路线调查与标准地调查相结合的方法,结合历史资料,对堵河源地区的野生植物资源进行了实地野外调查研究,分析了植物区系和植物多样性及其受威胁状况。结果表明:(1)该保护区具有丰富的植物物种多样性,有维管束植物174科730属1733种(含亚种、变种),其中,国家重点保护野生植物有23种;(2)该区植物区系成分具有复杂性、多样性,拥有中国种子植物分布区类型属级水平的全部类型,但明显偏重于温带性质。且植物区系起源古老,有中国特有分布属37个,其中,古特有属27个;(3)该区具有丰富的植被类型,包括4个植被型组,8个植被型,26个群系,具有较高的保护和科研价值。同时针对保护区植物多样性受威胁状况,提出了植被恢复、加强防火设备设施建设、生态移民、保护珍稀濒危植物及社区共管是保护植物多样性的有效措施。     

The Atlantic elements in the Swiss flora: distribution, diversity, and conservation status

The purpose of this study was to examine the composition, distribution, ecology, and conservation status of the Atlantic elements of the Swiss flora. About 195 Atlantic and 80 Mediterranean–Atlantic vascular plant species of the European flora have been used as the basis for our analysis. The complete list of 3,143 taxa has been used as the reference for the Swiss flora. The distributions of the species are illustrated in coincidence maps based on the computer database of the Data Centre of the Swiss Flora in Geneva, Switzerland. Our study demonstrates clearly that the Atlantic flora of Europe requires a new biogeographical appraisal. The Swiss flora comprises 66 Atlantic and Mediterranean–Atlantic taxa, which are taxonomically and ecologically highly diverse. Switzerland contains 44% of all European Sub-Atlantic plants. This confirms the Sub-Atlantic geographical position of Switzerland. Only one Eu-Atlantic species growing in Switzerland, Vicia orobus, can be classified as native with certainty. This species is critically endangered and merits the highest conservation priority. Although a very alpine country, Switzerland has a relatively large number of Mediterranean–Atlantic species. The Atlantic and Mediterranean–Atlantic plants are a very threatened group in Switzerland, with wetland plants the most imperilled ecological group. Electronic supplementary material  The online version of this article (doi:) contains supplementary material, which is available to authorized users.     

江西三清山种子植物中国特有属的物种多样性分析

通过多年调查,发现江西三清山分布有中国特有属37属(其中3属为华东特有属),含40种,隶属于30科,占中国种子植物特有属总数的13.75%,占华东地区种子植物特有属总数的53.62%,占江西种子植物特有属总数的66.07%,是江西乃至华东特有属的生物多样性最丰富的地区之一。三清山分布的中国特有属区系以双子叶植物占优势,生活型以落叶木本和多年生草本为主,地理分布与华东各山地关系最密切,属种起源以原始、孤立为特色,并有许多珍稀濒危保护物种。     

黄土高原地区种子植物区系特征

黄土高原在中国植物区系分区上属于泛北极植物区,中国-日本森林植物亚区的华北地区黄土高原植物亚地区,是东西、南北旱生、中生和水生植物交汇和聚集区域。计有种子植物147科864属3224种,其中裸子植物7科13属41种,被子植物140科851属3183种,具有中国特有属32个,黄土高原地区特有属4个,特有种164个。黄土高原地区种子植物区系的基本特征为:植物种类相对丰富,在全国植物区系上占有重要地位;植物区系起源古老,原始类群丰富;地理成分复杂多样,以温带成分占优势;与周边地区区系的联系广泛,是多种成分汇集和过渡的地区;特有性程度相对低,稀有濒危植物丰富。