共查询到20条相似文献,搜索用时 15 毫秒
1.
2.
3.
井冈山地区珍稀濒危植物及其生存状况 总被引:1,自引:0,他引:1
开展国家珍稀濒危保护植物的考察、研究,对探讨区域生物多样性的性质、评价生态环境的状况和质量,提出适当的自然保护、管理对策等,均具有重要的指导意义.本文调查研究了井冈山地区珍稀濒危植物的种类、数量、分布、生长状况以及重要木本植物的群落特征,探讨了珍稀濒危植物的系统学与生物地理学特征.结果表明,井冈山地区有濒危苔藓植物2种,各类珍稀濒危野生维管植物199种.其中被《世界自然保护联盟濒危物种红色名录》收录50种,被《中国物种红色名录》收录160种,被《国家重点保护野生植物名录(第一批)》收录49种,被《濒危野生动植物种国际贸易公约附录》收录90种.本区珍稀濒危植物的种类和数量大体上与峨眉山相当,而远高于武夷山和太白山,在系统学与生物地理学上有重要意义,具有极高的保护价值.本区保存有较大面积的以珍稀濒危植物为优势种的群落,如资源冷杉(Abies beshanzuensis vat.ziyuanensis)、华榛(Corylus chinensis)、白豆杉(Pseudotaxus chienii)、南方红豆杉(Taxus wallichiana var.mairei)、福建柏(Fokienia hodginsii)、穗花杉(Amentotaxus argotaenia)、闽楠(Phoebe bournei)、马醉木Pieris japonica)、井冈山杜鹃(Rhododendron jinggangshanicum)等群落. 相似文献
4.
5.
6.
目的 中华花龟(Mauremys sinensis)是一种濒危野生动物,也是中国主要的养殖龟种.为了保护和可持续利用中华花龟,本文对其分类、生物学特性和资源保护现状进行总结和讨论.方法 通过研究分析文献,结合保护和养殖实践,进行系统的分析探讨.结果 中华花龟命名于1834年,现归隶龟鳖目地龟科拟水龟属,属于典型的淡水龟类,其最显著的特征是头颈部具有黑黄相间的细条纹.因其外部形态特征而得名花龟、珍珠龟和绿龟等.该龟分布广泛,见于殷商时代出头的动物遗骸之中,目前在中国分布于福建、广东、广西、香港、江苏、浙江、江西、海南岛和台湾岛,国外见于越南,并被引入韩国、美国的佛罗里达州和关岛等地.中国种群处于濒危状态,大规模的养殖和野外放归性保护行动对这一物种在海南岛的野生种群恢复奠定了基础.结论 中华花龟作为一种主要分布在中国的淡水龟,野外种群处于濒危状态.养殖技术的成熟和产业化发展,以及在海南的野外放归性保护行动能有效的促进这一资源的可持续发展. 相似文献
7.
A. Freese J. Benes R. Bolz O. Cizek M. Dolek A. Geyer P. Gros M. Konvicka A. Liegl & C. Stettmer 《Animal Conservation》2006,9(4):388-397
The knowledge of ecological requirements of declining butterflies of European woodlands remains limited, which hinders conservation management of their localities. This also applies for continentally threatened scarce fritillary Euphydryas maturna . On the basis of the largest data set on its habitat use ever collected in Central Europe, we analyse habitat requirements of its populations in Austria (A), the Czech Republic (Cz) and Germany (D). All studied populations inhabit open-canopy sites within woodlands, but larval survival decreases under full sun and preferred sites are relatively humid and sheltered. Nests of pre-hibernation larvae occur at terminal branches of Fraxinus excelsior , 1.5–3 m above the ground. Pre-hibernation mortality reaches 70% (Cz, D). Another limiting factor is quality of woodland vegetation: post-hibernation larvae consume a wide range of herbs and shrubs, and adult distribution is linked to nectar availability. The butterfly thus depends on highly heterogeneous early successional stages of deciduous woods, historically maintained by coppicing (Cz, D) and forest pasture (A). Restoration of these traditional methods offers the only chance for survival of E. maturna in Central Europe, and the butterfly may become a flagship for other threatened organisms of open-canopy woodlands. 相似文献
8.
L. V. Bardunov A. V. Verkhozina N. V. Dudareva S. G. Kazanovskii A. A. Kiseleva 《Contemporary Problems of Ecology》2008,1(4):445-448
The distribution and state of rare and endangered species of higher plants of Khamar-Daban, East Sayan, and adjacent territories has been analyzed. In general, the current state of these species is characterized as threatening. Recommendations on reinforcement of their protection are given. 相似文献
9.
Sterol compositions of six species of bryophytes were studied. The major sterols identified were campesterol, 22-dihydrobrassicasterol, sitosterol, clionasterol, stigmasterol, cholesterol, 24-methyl-5,22-cholestadienol and 24-methyl-5,7,22-cholestatrienol. The quantitative determinations of the α- and β-epimers of 24-methyl and 24-ethylcholesterols were made based on 220 MHz 1H NMR spectroscopy and capillary gas chromatography. Sterol compositions of bryophytes from other studies are reviewed, and possible sterol biosynthetic pathways in bryophytes are discussed. 相似文献
10.
The bryophytes comprise three phyla of embryophytes that are well established to occupy the first nodes among extant lineages in the land-plant tree of life. The three bryophyte groups (hornworts, liverworts, mosses) may not form a monophyletic clade, but they share life history features including dominant free-living gametophytes and matrotrophic monosporangiate sporophytes. Because of their unique vegetative and reproductive innovations and their critical position in embryophyte phylogeny, studies of bryophytes are crucial to understanding the evolution of land plant morphology and genomes. This review focuses on phylogenetic relationships within each of the three divisions of bryophytes and relates morphological diversity to new insights about those relationships. Most previous work has been on the mosses, but progress on understanding the phylogeny of hornworts and liverworts is advancing at a rapid pace. Multilocus multigenome studies have been successful at resolving deep relationships within the mosses and liverworts, whereas single-gene analyses have advanced understanding of hornwort evolution. 相似文献
11.
12.
Mitochondrial and nuclear DNA phylogeography of Crassostrea angulata, the Portuguese oyster endangered in Europe 总被引:4,自引:0,他引:4
The respective status of the Portuguese oyster, Crassostrea angulata, and the Pacific oyster, Crassostrea gigas, has long been a matter of controversy. Morphological and physiological similarities, homogeneity of allozyme allelic frequencies between populations of the two taxa and the demonstration of hybridization lead most authors to suggest that they should be regrouped within the same species. The risk of introgression and the present expansion of C. gigas aquaculture in Europe raises the question of the need for preservation of C. angulata in Europe, as only a few populations remain. We studied European and Asian populations of C. gigas and C. angulata using microsatellite and mitochondrial DNA markers to estimate their genetic diversity and differentiation. The analysis of genetic distances and the distribution of allelic and haplotype frequencies revealed significant genetic differences between taxa, showing two clusters: (1) C. gigas French and Japanese populations and (2) C. angulata Portuguese and Taiwanese populations. The Asian origin of the Crassostrea angulata taxa is therefore confirmed. Unlike previous studies based on allozymes, significant nuclear genome differences were noted between C. angulata and C. gigas. Despite the presumed history of the introduction of C. angulata into Southern Europe, these populations did not show any significant reduction of variability compared to Taiwanese populations. Any conservation plans for European C. angulata populations should take its non-native origin into account. They represent a valuable genetic resources for European breeding program. 相似文献
13.
14.
R. E. LONGTON 《Botanical journal of the Linnean Society. Linnean Society of London》1988,98(3):253-268
Physiological characteristics of polar bryophytes are discussed in relation to geographical distribution patterns, current polar climates, and the environmental history of the polar regions. The most significant attributes conferring fitness in contemporary polar environments appear to be phenotypic plasticity, opportunistic responses in CO2 , exchange, and poikilohydrous water relations leading to considerable tolerance of desiccation and frost. These features are widely distributed among bryophytes generally, and cannot be regarded as specific adaptations to polar conditions. This conclusion is consistent with the fact that most members of the polar bryophyte floras range widely in boreal forest, and in many cases also temperate regions. They are believed to have evolved under temperate conditions before the advent of polar environments during Tertiary climatic cooling, and they are characterized by an evolutionarily conservative life strategy. However, such species may show inherent, inter-population variation of an apparently adaptive nature in morphological or physiological characters. A small, contrasting assemblage of Arctic-endemic species, so far uninvestigated physiologically, shows high fertility and is suspected as being of more recent, possibly Pleistocene origin. 相似文献
15.
初步调查表明,福建永安安砂库区生态公益林有野生珍稀濒危植物21种,隶属14科19属。其中,国家一级保护植物1种,国家二级保护植物7种。这些珍稀植物资源种类丰富,组成多样,有显著的热带性质,起源古老,特有现象突出,并具有广泛用途和重要价值。 相似文献
16.
Ammonia-assimilating enzymes in bryophytes 总被引:1,自引:0,他引:1
R. Meade 《Physiologia plantarum》1984,60(3):305-308
Ammonia can be incorporated into amino acids by reductive amination of oxoglutarate, or by the glutamate synthase cycle via glutamine. The majority of plants possess the enzymes necessary for the operation of both these pathways although nitrogen is thought to be assimilated via the glutamate synthase cycle in most cases. Measurements of glutamate dehydrogenase, glutamine synthetase, and glutamate synthase activities are presented from a selection of bryophytes. The genus Sphagnum was found to be unique in lacking measurable glutamate dehydrogenase activity. The relevance of this in the nitrogen-poor acid bog is briefly considered. 相似文献
17.
N.G. Hodgetts 《Plant Ecology & Diversity》2013,6(2):375-385
Summary A brief overview is given of the importance of Scotland for Atlantic bryophytes within Europe and worldwide. The life strategies of Atlantic species are discussed and the main habitats of Atlantic bryophytes listed. A consideration of the use of distribution data to identify ‘hotspots’ and sites for conservation is made. Grimmia britannica A.J.E. Smith and Marsupella profunda Lindb. are added to the list of Atlantic species in Britain and Ireland. 相似文献
18.
Conducting tissues and phyletic relationships of bryophytes 总被引:9,自引:0,他引:9
Ligrone R Ducket JG Renzaglia KS 《Philosophical transactions of the Royal Society of London. Series B, Biological sciences》2000,355(1398):795-813
Internal specialized conducting tissues, if present, are restricted to the gametophytic generation in liverworts while they may occur in both generations in mosses. Conducting tissues are unknown in the anthocerotes. Water-conducting cells (WCCs) with walls perforated by plasmodesma-derived pores occur in the Calobryales and Pallaviciniaceae (Metzgeriales among liverworts and in Takakia among mosses. Imperforate WCCs (hydroids) are present in bryoid mosses. A polarized cytoplasmic organization and a distinctive axial system of microtubules is present in the highly specialized food-conducting cells of polytrichaceous mosses (leptoids) and in less specialized parenchyma cells of the leafy stem and seta in other mosses including Sphagnumn. A similar organization, suggested to reflect specialization in long-distance symplasmic transport of nutrients, also occurs in other parts of the plant in mosses, including rhizoids and caulonemata, and may be observed in thallus parenchyma cells of liverworts. Perforate WCCs in the Calobryales, Metzgeriales and Takakia, and hydroids in bryoid mosses, probably evolved independently Because of fundamental differences in developmental design, homology of any of these cells with tracheids is highly unlikely. Likewise, putative food-conducting of bryophytes present highly distinctive characteristics and cannot be considered homologous with the sieve cells of tracheophytes. 相似文献
19.
Phytogeography of Hong Kong bryophytes 总被引:7,自引:0,他引:7
Aim Hong Kong is in a biogeographically interesting location on the northern margins of the Asian tropics. This paper analyzes the phytogeography of Hong Kong's bryophyte flora for the first time. Location Hong Kong lies on the South China coast, 22°9′–22°37′ N, 113°52′–114°30′ E. It is one of the most densely populated places in the world, but because of the rugged topography only 20% of the total land area of 1100 km2 is urbanized. Although 130 km south of the Tropic of Cancer, it has a subtropical climate with distinct hot, humid and cool, dry seasons. Methods The analysis is based on a new and relatively complete inventory of Hong Kong's bryoflora. Each taxon was assigned to a phytogeographical pattern on the basis of its present worldwide distribution. Krober's percentage similarity was employed to evaluate the floristic affinities between different regions. Results The bryophyte flora consists of at least 360 species and twelve infraspecific taxa in 159 genera and seventy families, of which four taxa are locally endemic. The largest families are Lejeuneaceae (fifty‐one taxa), Fissidentaceae (28), Hypnaceae (21), Dicranaceae (20), Calymperaceae (18), and Sematophyllaceae (15). The largest genera are Fissidens (28), Cololejeunea (17), Lejeunea (10), Syrrhopodon (9), Frullania (8), and Macromitrium (8). Fourteen phytogeographical patterns are recognized. The East Asian pattern is the commonest (seventy‐three taxa, 19.6%), followed by Asian–Australian–Oceanian (45, 12.1%) and Temperate (44, 11.8%). Overall, a third of taxa have tropical distributions. The bryofloras of eleven regions were compared with that of Hong Kong. The most similar regions are Hainan Province, Taiwan Province, and Japan. Mosses and liverworts show very similar phytogeographical distributions. Main conclusions (1) The Hong Kong bryoflora is best described as northern marginal tropical, with a strong Eastern Asian and Temperate influence; (2) the region of closest phytogeographical affinity for which information is available is Hainan; (3) in comparison with vascular plants, vertebrates and those invertebrate groups for which there is information, the bryoflora has a relatively low proportion of tropical taxa; (4) the bryoflora of Hong Kong appears to be exceptionally rich for its small area. 相似文献