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1.
Due to their numerous endemic/sub‐endemic and rare plant species, rocky outcrops and cliffs, particularly those occurring at the timberline and forest/steppe ecotones of the Hyrcanian area, are considered as among the most important and fragile ecosystems in Iran. As a representative of such ecosystems, one of the last remnants of relatively undisturbed timberline and ecotone areas of the central Hyrcanian region was selected for phytogeographical, floristic and vegetation analyses. The flora and vegetation of rocky outcrops and crevices at altitudes of 2500–3000 m a.s.l. was surveyed by 40 relevés of 25 m2 surface area. A total of 215 vascular plants belonging to 55 families and 150 genera were identified in the different vegetation types. Hemicrytophytes (55.8%) were the dominant life form and Euro–Siberian/Irano–Turanian biregional plants (28.2%) were the most common chorotype at the study sites. A phytogeographical analysis indicated that Euro–Siberian elements (including Hyrcanian endemics) precede other uniregional chorotypes in the timberline and upper‐mountain parts of the central Hyrcanian area. The Caucasus, an important biodiversity hotspot close to Iran, has a considerable number of taxa in common with the Irano–Turanian floristic regions. Five vegetation types were identified using a modified TWINSPAN procedure and subsequently analysed by indirect gradient analysis applying both species‐related (species richness, life form and phytogeographical elements) and topographic/bedrocks features of the studied relevés. The analysis revealed that the vegetation of the area is mainly affected by altitude, heat index, northness, slope inclination and bedrock features.  相似文献   

2.
The vascular flora of the Siahrud-e Rudbar protected area was investigated in the years 2007 and 2008. It is a sylvatic area in the Guilan province with a total area of approximately 28 289 hectares. A total of 711 plant specimens were collected and 616 species,subspecies,and varieties,belonging to 373 genera and 101 families were identified. Of these,14 species( 2. 3%) are endemic to Iran. The documented flora exhibited many typically Hyrcanian species,including Hyrcanian endemics. The global phytogeographical affinities of the species were as follows:Euro-Siberian 21. 2%,Iran-Turanian Euro-Siberian 16. 8%,Pluriregional 11. 7%,Iran-Turanian 10. 6%,and Cosmopolite 5. 5%.  相似文献   

3.
The Saharo–Sindian regional zone encompasses the flat and arid areas of North Africa, the Arabian Peninsula, southern Iran and the deserts of Pakistan and west India. There are some scattered mountains situated within this area, like Hoggar in Sahara, Saint Catherine in Sinai and Genu and Homag in southern Iran. These highlands serve as interglacial refugia for cold adapted plant species. In the present study, phytogeographical patterns and relationships of the flora of Genu and Homag mountains are described and discussed in relation to the phytogeography of the flora of low‐lying Hormoz Island. According to a chorological assesment of the flora, Genu and Homag mountains belong to the Irano–Turanian region with 59% of the species restricted to this area. In contrast, the surrounding lowland plains are part of the Saharo–Sindian area with a rather high proportion of widespread species (17%) and Somalia–Masai‐linking elements (20%). It is noteworthy that several Turanian enclaves also occur in the lowland zone. Furthermore, the distributional patterns imply that the mountainous Irano–Turkestanian region is an integrated area which is supposedly distinct from the Turanian lowland areas in the north and from the Saharo–Sindian lowland areas in the south. On the other hand, the expansive floras of Turanian and Saharo–Sindian regions are linked to each other. Endemic species in lowland areas in south Iran are mostly either frost sensitive vicariants of cold adapted Turanian species or of Saharo–Sindian origin, while the highland endemics in the area trace their origins to the Irano–Turkestanian region.  相似文献   

4.
Anatomical features of basal leaves, pedicels and tepals of 22 species of Gagea belonging to four sections (Platyspermum, Plecostigma, Gagea and Didymobulbos) are investigated. Anatomical characters are mapped onto a molecular phylogenetic tree and their evolution is evaluated. The systematic importance of the anatomical characters is discussed. Anatomical characters are more systematically useful in the Irano‐Turanian taxa than in Euro‐Siberian taxa. The presence of collenchyma and/or sclerenchyma and the pentagonal outline of the transverse section of the basal leaf is found in Irano‐Turanian taxa of section Platyspermum and is mostly absent in Euro‐Siberian taxa. A diagnostic key based on combined anatomical characters is provided. The level of variation in anatomical characters is greater in the basal leaf than the pedicel and lowest in the tepals. Convergent evolution in anatomical characters is associated with ecological shifts between sunny, open, dry habitats and closed, humid habitats. © 2010 The Linnean Society of London, Botanical Journal of the Linnean Society, 2010, 164 , 155–177.  相似文献   

5.
Tertiary‐relict Hyrcanian (Caspian) forest along the shores of the southern Caspian Sea is a center of biodiversity. Still, there is little information on plant diversity patterns in this area. This study evaluated plant diversity, variation in life forms, and geographical distribution of the zonal vegetation types and their relationships with environmental variables, in the educational and experimental forest of Kheyrudkenar, an important protected area in the central Hyrcanian forest of northern Iran. For this purpose, 226 vegetation plots of 400 m2 were laid out along two altitudinal transects from the lowlands (100 m a.s.l.) to the timberline (2000 m a.s.l.). Four vegetation types were identified using modified TWINSPAN, indirect and direct gradient analyses. Species‐related (species diversity indices, life form and phytogeographical elements) and environmental variables (climate, topographic and soil variables) were calculated and subjected to one‐way ANOVA among the vegetation types. Both constrained (CCA) and unconstrained (DCA) ordination analyses showed an almost identical variation of the floristic composition along their axes and demonstrated that there are two main gradients in the Hyrcanian forest. Elevation together with annual precipitation and mean annual temperature were the most important factors controlling the floristic composition in the area. Topographic features such as slope inclination and heat index were found to be important within an elevation zone/vegetation type. Soil physical and chemical properties were of secondary importance for the separation of the vegetation types. This knowledge will be useful for forest management and conservation practices in the Hyrcanian area with its distinct and unique flora and vegetation.  相似文献   

6.
Euphorbia acanthodes Akhani is described as a new gypsophilous species from south-west Iran. The affinity, morphological and carpological features, and habitat of the species are discussed. A list of a further 36 interesting endemic species of south-western Iran and adjacent areas is given with notes on their affinities and distribution. These include Centaurea gudrunensis Boiss. & Hausskn., as a new record from Iran. The specific status of Pteropyrum naufelum Al-Khayat is confirmed and it is suggested that P. noëanum Boiss. ex Meisn. is synonymous with P. aucheri Boiss. The biogeographic importance of the so-called 'Persian foothills', and biodiversity conservation status of the area are discussed, together with distribution maps of 12 species. It is concluded that the majority of the endemic species in the southern and south-western parts of Iran are Irano–Turanian or have their origins in the Irano–Turanian region. Therefore, it is questionable to consider the area as part of either the Saharo–Sindian, Sudanian or Sudano–Zambezian regions.  © 2004 The Linnean Society of London, Botanical Journal of the Linnean Society , 2004, 146 , 107–121.  相似文献   

7.
Little is known about the soil seed bank and the influence of plant communities on the interaction between the seed bank and aboveground vegetation in the Hyrcanian temperate deciduous forest. We surveyed species composition and diversity of the persistent soil seed bank and the aboveground vegetation in six community types in old-growth Hyrcanian Box tree (Buxus hyrcana) stands in northern Iran. Fifty-two species with an average of 3,808 seeds/spores m−2 germinated; forbs accounted for 64% of the seed bank flora. Thirty-four species in the aboveground vegetation were not presented in the seed bank, 32 species in the seed bank were not found in the vegetation, and 20 species were in both. The dominant tree species were Diospyros lotus and Alnus subcordata with an average of 17 and 4.6 seeds m−2, respectively. Our results suggest that (1) vernal geophytes and shade-tolerant perennials are not incorporated in the seed bank, (2) early successional species are well represented in the seed bank, (3) plant community type has significant impacts on seed bank densities, and seed bank richness and diversity were significantly related to presence/absence of Box tree in the aboveground vegetation. The persistent seed bank contained species that potentially have a negative impact on the regeneration of forests, thus forest managers should retain old-growth Hyrcanian Box tree stands to conserve disturbance-sensitive indicator forest species.  相似文献   

8.
A revision of the Iranian Bolboschoenus was made based on studies of herbarium material and cultivated plants. Fruit features (fruit shape and pericarp anatomy) were used as the main distinguishing characters; style branching, inflorescence structure and the colour of floral scales were considered as accompanying distinguishing characters. The following taxa were recognized: Bolboschoenus glaucus (Lam.) S. G. Sm., B. affinis (Roth) Drobov, B. schmidii (Raymond) Holub, B. planiculmis (F. Schmidt) T. V. Egorova and B. maritimus (L.) Palla. Taxonomical difficulties, especially in the B. affinis group and B. maritimus are discussed. Bolboschoenus glaucus was found in all of the phytogeographical regions of Iran, and it is more frequent than any other Bolboschoenus species. Bolboschoenus planiculmis is very rare in the Irano–Turanian and Hyrcanian regions and grows only in human‐influenced habitats; it might be introduced as a weed in rice fields. Bolboschoenus maritimus, B. affinis and B. schmidii occur in the Irano–Turanian region only rarely. Bolboschoenus maritimus reaches the southeastern border of its distribution area in this region. All these species typically grow at higher altitudes. Great morphological variability in inflorescence structure was found in some species (especially in B. glaucus), which may be partly explained as a response to habitat conditions and partly by genotypic diversity.  相似文献   

9.
In this paper a critical annotated checklist of 256 endemic and near endemic species belonging to 152 genera and 50 families of flowering plants known from Hyrcanian relict forests is presented. Distribution maps of taxa, elevational range, number of known records, chorotypes, life forms, IUCN threat categories and habitat types are also provided. The chorotypes are categorized into eight main patterns: 1) the Omni-Hyrcanian pattern(OH), 2) West Hyrcanian pattern(WH), 3) Manjil-Rudbar pattern(MR...  相似文献   

10.
A total of 393 species (sub type included) in 267 genera, 97 families were reported in Nanji Island, the main island of Nanji Islands National Nature Reserve. After eliminating all the cultivated and invasive species, there were still 304 species in 210 genera and 81 families belonging to wild vascular plants; To better understand the floristic characteristics of Nanji, we applied analysis in 3 levels: At family level, the largest families in pteridophyte were ranked as Pteridaceae、Thelypteridaceae、Lygodiaceae、Dryopteridaceae; In seed plants, almost the largest ones were Cosmopolitan, while the small ones dominented the most, quantitatively and proportionately; The characteristic families of seed flora were consisted of Liliaceae、Amaryllidaceae、Urticaceae、Verbenaceae, cause they got high ratio of VFICS/WFIW; At genus level, the Pantropical Distribution (3810%)、the North Temperate Distribution (1630%) and the East Asia distribution (1131%) formed the main part of seed flora; The proportion of the category of temperate distribution and tropical distribution was 6072% and 3928% respectively; Took 6 other sites as reference, through cluster analysis and R/T ratio comparisons, It was proved that Nanji Island were most similar to that of Wuyanling of Zhejiang Provience but showed more tropical affinities; At species level, wild seed plants can also be divided into 9 areal subtypes, The Yangtze River & Southern Proviences sub type dominented at 5390%, following by South China sub type at 2078%. The results showed that Nanji Island had a distinctive transitional characteristics of flora from north to south China with more tropical biological properties, thus the floristic division of Nanji should on the southern margin area of east China.  相似文献   

11.
On the basis of new floristic works a distribution map of the genusCousinia is given and discussed. The generic distribution area ofCousinia is nearly identical with the Irano-Turanian Region, but most of the 662 species are concentrated on the Iranian and Turkestanian mountain regions. Here, both in the eastern and in the western parts of the distribution area, four centres of diversity with high numbers of—mostly endemic—species are found: The western Tienshan (61 species), Pamiro-Alaj (169), NE-Afghanistan (80), NW-Afghanistan (44); Kopetdagh (66 in Iran, 33 in Turkmenia), Elburz (66), the northern part of Zagros (44), Azerbaijan (36). The outlines of the generic area are formed by genetic-historical and by climatic factors. The distribution patterns ofCousinia species confirm the close connections between the Iranian and the Turkestanian mountains as centres of origin and conservation of palaeo-xeromorphic mountain floras, contrasting with the Turanian lowland flora.Dedicated to Prof.K. H. Rechinger on the occasion of his 80th birthday.  相似文献   

12.
The first survey of vascular epiphytes was conducted using ground based inventory assisted by single rope technique in the recently established Bulong Nature Reserve, Xishuangbanna, China. Results indicated that vascular epiphytes were abundant and diverse there. On a total of 77 phorophytes in six plots (96 trees were examined in total, covered ca. 02ha area), 1756 individuals were recorded and were identified to 103 species (47 genera, 14 families). Compared with other regions, the epiphytes were as diverse as Paleotropics, and more diverse than temperate zone, but significantly less than the Neotropics. Orchids and ferns comprised 60%, 24% of the total flora, respectively, while others only took up 16%. The highest species richness and richest life form diversity was found in the middle canopy zone from 10 to 15m (51% of total species), where also supported high individual abundance (19% of total individuals). Besides the middle canopy, the most abundant zone of epiphyte individuals was detected at the base of the trunk (zone 0-5m, 24% of total individuals and 37% of total species), indicating another important niche for epiphytes in this forest environment. Primary hemiepiphytic figs were rare in the area and were not found on the surveyed host trees, while hemiepiphytic Araliaceae species (Schefflera elliptica and Tupidanthus calyptratus) were popular.  相似文献   

13.
海南岛尖峰岭地区种子植物区系组成及地理成分研究   总被引:14,自引:4,他引:10  
黄世能  张宏达  王伯荪   《广西植物》2000,20(2):97-106
尖峰岭地区位于海南岛西南部 ,面积约 470 km2 ,有种子植物 1 83科、90 6属、2 0 87种及变种。区系组成及地理成分分析结果表明 ,本区种子植物区系有如下特征 :(1 )科属种的组成较为丰富 ,但属内种系较贫乏、分化程度弱 ;(2 )地理成分复杂 ,以热带成分、热带亚洲成分占优势 ,特有成分也相对较丰富 ,是海南岛整体区系的重要组成部分 ;(3)区系有一定邃古性 ,本质上是华夏植物区系不可分割的一部分。  相似文献   

14.
对新疆天山大峡谷地衣进行调查研究,查阅相关资料,初步对该地区地衣进行分类和整理。结果表明:该区地衣有81种,隶属5目,15科,26属,其中地卷属,石蕊属和蜈蚣衣属种类最多,分别占14.81%,12.35%和9.87%。我们将新疆天山大峡谷地理区系划分为世界广布区、环北极广布区、欧亚-北美分布区、环北极-高山分布区、环北方分布区、欧亚-北非分布区、地中海-西亚和中亚分布区、北温带分布区和中国特有等9种类型。研究还发现该地区岩树枝及树皮生地衣与朽木生地衣占主导地位。  相似文献   

15.
该研究于2019-2021年4次对安徽大别山北坡进行苔藓植物野外考察和标本采集,对采集到的1 517份标本鉴定以及文献整理,统计分析该区苔藓植物物种组成、区系地理组成;并与华东、华中、华北等地的苔藓植物区系地理组成进行比较,以明确大别山北坡苔藓植物区系的归属问题。结果表明:(1)安徽大别山北坡共有苔藓植物80科180属482种(包括种以下单位);该次调查增加了12科40属206种,其中安徽省新记录种9个。(2)发现受威胁苔藓植物2种——滇西高领藓(Glyphomitrium minutissimum)属于极危(CR),瘤根真藓(Bryum bornholmense)属于易危(VU)。(3)大别山北坡苔藓植物区系拥有3个世界性单种科,14个世界性单种属,且有34个世界性寡种属(2~6种),该区单种属和寡种属(48属)占该区总属数的26.67%,表明该区苔藓植物起源古老。(4)大别山北坡苔藓植物区系地理成分复杂多样,以北温带成分(26.43%)和东亚成分(24.89%)为主,热带亚洲成分(14.54%)次之。(5)安徽大别山北坡苔藓植物区系与华东(西天目山、清凉峰、阳际峰)区系的关系最为密...  相似文献   

16.
Based on the investigation of 1ha plot, the primitive monsoon forest on the valley of lower Luzhi River in Yunnan was studied. The height of the community is 15-20m, and tree layers are divided into 2 layers, which is dominated by deciduous tree species Lannea coromandelica and evergreen tree species Cipadessa cinerascens. One hundred and sixteen vascular plant species were recorded from the plot, including 36 tree species, 14 shrub species, 43 herbaceous species, 43 liana species and 2 epiphyte species. Shannon Wienner index is 22824 and Simpson index is 08321 from the 1ha plot. Total 1764 trees individuals with DBH ≥1cm were recorded in the plot. This community is dominated by phanerophytes. The forest is dominated by the microphyllous species which makes up 3932% of the total. The forest is also dominated by the species with simple leaves (make up 7350%), papery leaves (make up 6923%), none caudate leaves (make up 8120%) and entire leaves (make up 6752%). The species/area curve shows that it is flatten at 2000m2, which is suggested to be the minimum sampling area for the forest. This community could be recognized as Lannea coromandelica Cipadessa cinerascens formation.  相似文献   

17.
Iran is a mountainous country. Zagros and Alborz mountains reach altitudes of more than 4,000 m. Alpine regions are above timber-line, which is not easy to recognize, since aridity is prominent in most regions. The alpine zone in Alborz lies between 3,000 and 4,000 m, the nival zone is above 4,000 m, locally varying by some hundred meters. A first evaluation of vascular flora shows that 682 species belonging to 193 genera and 39 families are known from the alpine zone of Iran. The alpine zone is commonly characterized by many species of hemicryptophytes and thorny cushions. Species numbers decline very strongly with increasing altitude. In this paper biogeographical patterns of the alpine flora of Iran have been discussed and distribution maps of 44 species are illustrated. New data indicate a transitional situation of the Iranian mountains between Anatolia/Caucasus and the Hindu Kush, but with a strong own element with high endemism and remarkable relict species. Ca. 58% of the alpine flora of Iran are endemic and subendemic. The Zagros Mountains harbor high endemism which justify considering this area as a separate floristic province. Based on the evaluation of published data from 682 known alpine species ca. 160 species have been known only by one record, 110 species by 2–3 records and 87 endemic species have been known only based on the type location. These plants need a strong conservation and protection management since the fragile ecosystems are often very restricted, small and very isolated, nonetheless grazing and overgrazing are still common threats.  相似文献   

18.
白鹤(Leucogeranus Leucogeranus)是国家Ⅰ级重点保护野生动物,唯一一种极度濒危(CR)鹤类,分布和种群数量是评估其濒危程度的重要参数。无人机调查作为目前生态学研究的一个重要调查方法,为查明白鹤的越冬分布、种群数量及幼鸟比例,于2022年1月使用地面监测结合无人机调查的方法在江西、山东、安徽、湖南、湖北等地的湖泊和农田中开展越冬白鹤调查。野外调查共记录白鹤5607只,网络信息检索在调查区域外的8个地点记录白鹤9只,合计记录越冬白鹤5616只。其中江西鄱阳湖记录到越冬白鹤4813只,占总数的85.7%,主要分布在康山垦殖场、五星垦殖场和成新垦殖场;山东黄河三角洲记录到越冬白鹤625只,占总数的11.1%。安徽、湖南、湖北分别记录到越冬白鹤34,63和72只。对部分群体的白鹤幼鸟数量进行统计,4680只白鹤中,记录到幼鸟674只,幼鸟比例为14.4%,其中湖南越冬白鹤幼鸟比例最高,达28.6%,山东越冬白鹤幼鸟比例最低,为11.5%。调查刷新了白鹤种群数量,证实了山东黄河三角洲是目前除江西鄱阳湖外最重要的白鹤越冬地,缓解了白鹤越冬期过度集中的压力。基于本研究结果,我们...  相似文献   

19.
越南蒲马特国家自然保护区植物区系特征   总被引:1,自引:0,他引:1  
蒲马特国家公园位于越南中部的义安省,国际著名的生物多样性极为丰富的Annamite山系的核心地区。基于植物标本鉴定,在蒲马特国家公园保护区内记录有维管束植物184科,771属,2018种(包括变种和亚种)。该植物区系占整个越南植物区系的21 %,其中的木兰亚纲植物占该植物区系总种数的90 .98 %,总属数的90 .4 %及总科数的83 .7 %。含种数最多的科包括茜草科(37属/129种) ,大戟科(36/99) ,兰科(34/73) ,樟科(11/66) ,桑科(10/54) ,蝶形花科(24/51) ,壳斗科(4/50) ,紫金牛科(5/48)及芸香科(14/45)等。在种子植物地理成分组成上,有11个科的分布区类型及14属分布区类型,其中,热带分布型分别占总科数的85 .6 %和总属数的90 .1 %,并且在其热带分布属中,热带亚洲成分占总属数的31 .4 %。这些特征显示,蒲马特国家公园植物区系是典型热带性质的植物区系,属于热带亚洲植物区系的一部分。  相似文献   

20.
A key to and new findings on the Astragalus sect. Erioceras, are given for the 10 species of this section, which occur within the area covered by the flora of Iran. One species, Astragalus neo-sytinii , is described as a new species. A. sympileicarpus is reported as a new record for the flora of Iran. A. viridis is transferred from A. sect. Erioceras to sect. Xiphidium Sect. Acantherioceras is reduced to the level of subsection. The differences between that section and closely related sections are discussed.  相似文献   

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