首页 | 本学科首页   官方微博 | 高级检索  
文章检索
  按 检索   检索词:      
出版年份:   被引次数:   他引次数: 提示:输入*表示无穷大
  收费全文   6篇
  免费   0篇
  2021年   1篇
  2019年   1篇
  2016年   1篇
  2008年   1篇
  2007年   1篇
  1987年   1篇
排序方式: 共有6条查询结果,搜索用时 109 毫秒
1
1.
Juniperus excelsa is one of the specific tree species in the mountainous areas of Iran. It forms the mountainous forests of Irano-Turanian vegetation region. Despite the considerable spread of J. excelsa in Iran, there is no detailed and valid published study on the phytosociology of Iranian juniper stands. The aim of this research is to identify these associations and their characteristics in Alborz mountains in the north of Iran. To this goal, a set of data including floristic data according to Braun-Blanquet method, and important environmental characteristics, were collected. To classify the vegetation, TWINSPAN was used and phytosociology tables were analysed with JUICE software. Diagnostic species were determined by measuring the degree of fidelity and using statistically meaningful measurements. According to the results, the vegetation was classified into six associations and five subassociations. Among them are Cotoneastro nummulariis-Juniperetum excelsae ass. nov., Lonicero ibericae-Juniperetum excelsae ass. nov., Rhamno pallasii-Juniperetum excelsae ass. nov., Rhamno p.-Juniperetum e. ajugetosum chamaecisti subass. nov., Rhamno p.-Juniperetum excelsae gypsophiletosum aretioidis subass. nov., Amygdalo lycioidis-Pistacietum atlanticae hymenocratretosum bituminosoris Kashipazha et al. 2007, Feruletum ovinae ass. nov., Artemisio aucheri-Astragaletum veri Asri 2004, and Artemisio aucheri-Onobrychidetum cornutae ass. nov. The introduced juniper associations were placed in class Junipero-Pistacietea Zohary 1973 and order Juniperetalia excelsae nov.  相似文献   
2.
Silene bitlisensis O.Tugay & Ertugrul from the Green Line Afforestation Zone (B9: Bitlis Province) is a new species described and illustrated here. It is closely related to S. caramanica Boiss. & Heldr. var. ilarslanii Aytaç & Dural, from which it mainly differs in its habit, leaf, and floral features.  © 2008 The Linnean Society of London, Botanical Journal of the Linnean Society , 2008, 156 , 463–466.  相似文献   
3.
South-West and Central Asia are major centres of diversity in the genus Heliotropium . On the basis of detailed taxonomic studies and information gathered from the literature, a synopsis of 61 known species of Heliotropium and two species of Arguzia in the area is given. Iran, with 32 species and 14 (sub)endemic species, has the highest diversity. The photosynthetic pathways of 42 taxa were determined using the isotope composition method. Except for H. marifolium Retz s.l. and H. rariflorum Stocks, all remaining species analysed showed δ13C values characteristic for C3 photosynthesis. Evidently, by contrast with the families Chenopodiaceae and Polygonaceae, the Irano-Turanian area is not an authochthonous region of developing C4 species in Heliotropium . The distribution maps of 57 taxa are provided and their biogeographical importance is discussed in order to elucidate the distribution patterns in South-West Asia. In the Irano-Turanian region, the Irano-Anatolian province of Zohary, which extends from central Anatolia to the western Himalaya, is a very large and vaguely defined phytochorion that should be split into smaller units. The consideration of southern Iran and adjacent Pakistan as part of the Sudanian or Saharo-Sindian regions ( sensu either Zohary or Léonard) cannot be accepted, because most endemic species in this area are either typical Irano-Turanian or isolated relicts. Furthermore, it is concluded that the Saharo-Sindian flora is not an autochthonous flora; most species are of transgressive origin from the surrounding phytochoria. Finally, a new species, Heliotropium ziegleri Akhani, is described from Iran.  © 2007 The Linnean Society of London, Botanical Journal of the Linnean Society, 2007, 155 , 401–425.  相似文献   
4.
5.
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   
6.
Acanthophyllum squarrosum and two closely related species, A. heratense and A. laxiusculum (Caryophyllaceae), form a complex that covers parts of subalpine steppes of the Irano-Turanian (IT) region. In this study, we explored the genetic structure and phylogeography of this complex based on partial sequences of two chloroplasts (psbA–trnH and rpl32–trnL (UAG)) and two nuclear (EST24 and nrITS) DNA regions. We analysed 80 individuals from eight populations and detected 12 chloroplast haplotypes, 16 and eight nuclear alleles in EST24 and nrITS sequences, respectively. Phylogenetic trees and haplotype networks did not show distinct genetic groups in the complex and this could be explained by incomplete lineage sorting or introgression between species. Divergence time analysis revealed a Quaternary origin for A. squarrosum complex at approximately 1.8 million years ago (Mya) and the neutrality test results indicated that this complex experienced a recent population expansion. AMOVA analysis of the chloroplast regions showed a significant genetic differentiation among populations and low genetic differentiation within populations, but opposite results were found with nuclear markers, implying introgression between A. squarrosum complex populations.  相似文献   
1
设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号