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1.
It was established that there is little diversity of bryophytes in the derived savanna. Mosses were found in the sampling sites, whereas liverworts were rarely observed. The reproductive methods of four dominant sexually reproducing savanna mosses —Archidium ohioense, Bryum coronatum, Fissidens minutifolius andTrachycarpidium tisserantii were monitored over two consecutive rainy seasons. Protonemal and gametophyte production were noticed in the field in March/April, and capsule dehiscence and spore dispersal occurred in September/October. The sequential stages of development, starting with gametangial production and ending with the falling of the dehisced capsules, occurred within the rainy season. However,A. ohioense andT. tisserantii did not discharge their spores easily (cleistocarpous), unlike the stegocarpous speciesB. coronatum andF. minutifolius. Water availability and possibly high humidity may have contributed to growth. The short period between sex organ formation and dehiscence of capsule seen in these studies, compared with the longer period in some temperate mosses, may be an advantage for bryophytes in a savanna environment. 相似文献
2.
试论新南非语言政策的演变及其对教育的影响 总被引:1,自引:0,他引:1
文章以语言政策最近的发展为背景,讨论了与语言使用现实和执行相关的问题;以全南非语言委员会(PANSALB)遭遇的一些问题、公共场所语言使用情况、家庭使用语的分类以及学校里的教学指导语为案例进行阐释。这些案例表明了在执行语言政策和形成包容性的民族认同方面,南非依然困难重重。 相似文献
3.
广东省种子植物区系中有较丰富的地区特有属,如绣球茜草属、拟九节属、报春苣苔属、四数苣苔属、双片苣苔属、虎颜花属、梅兰属和异枝竹属等,另在两广交界地区分布有很多共特有属及中国特有属,形成了粤西南-桂东南特有现象中心,构成了中国南部植物区系的一个重要特征 相似文献
4.
窦奕晴 《沈阳大学学报:自然科学版》2006,18(6):81-83,105
分析了《走出非洲》一书中狮子的象征意义,认为它既是非洲草原的代表性动物,又是作者丹麦女作家凯伦.布里克森表达各种思想情感的媒介。狮子代表神秘、威猛和勇敢,但也以高贵和权威为特征。作者正是以狮子作为象征,充分地表述了她个人的爱情观、生活观和对高贵品质的理解。 相似文献
5.
张泽梅 《渝西学院学报(自然科学版)》2004,3(3):45-48
加快城镇化进程对渝东南民族地区的经济发展具有举足轻重的影响.本文通过对渝东南民族地区城镇化发展现状及存在问题的分析,提出了一些相应的建议和措施. 相似文献
6.
《Journal of Natural History》2012,46(4):893-902
Cytheridella tepida sp. nov., a freshwater ostracod, is described from Nigeria, West Africa. It has been compared with five extant species of the genus Cytheridella. Cytheridella tepida was collected from slow-flowing streams characterized by warm water. Some other ecological notes on its habitat are given. 相似文献
7.
This paper, which presents an annotated checklist of the ‘lower Nymphalidae’ (Libytheinae, Danainae, Satyrinae, Charaxinae), is the fourth in a series on the butterfly fauna of Mount Kilimanjaro. Four genera of lower Nymphalidae (Danaus, Amauris, Bicyclus, Charaxes), with a total of 11 included species, are known or believed to occur within the main forest zone, from c. 1800 to 2800 m. Of these, only three species of Charaxes (Charaxes berkeleyi, Charaxes ansorgei, Charaxes xiphares) may be restricted locally to this primary forest. The lower slopes fauna, below 1800 m, is considerably richer, with a total of 11 genera and 41 species listed (8 species of which extend into the forest zone). Possible additional species, dubious earlier records, problems with African subspecies of Danaus chrysippus, a need for more work on certain Satyrinae, and classification of the genus Charaxes are discussed. An identification key to the subfamilies of Nymphalidae, and the 19 genera of Libytheinae, Danainae, Satyrinae, Charaxinae that occur in Tanzania, together with a key to the adults of all the species of these four subfamilies considered to occur or have occurred on Kilimanjaro, with 206 colour images, are included as online Supplementary Information. 相似文献
8.
《Journal of Natural History》2012,46(6):1337-1346
The monotypic soft coral genus Malacacanthus has recently been rediscovered by means of scuba and is shown to be locally common and endemic in the shallow sublittoral of South Africa. Malacacanthus capensis (Hickson, 1900) is shown to be the proper taxonomic designation for the species. This species has previously been a problematic one due to the possession of several unusual morphological characteristics, including the total lack of sclerites and possession of a tough horny cuticle covering the stalk. The taxon is here shown to belong in the family Alcyoniidae by the possession of a full complement of mesenterial filaments, and not to the family Xeniidae as assigned by several previous authors. The species is here redescribed and the systematic status is revised. New observations on ecology and natural history from living colonies are also included. 相似文献
9.
《Journal of Natural History》2012,46(6):1543-1579
The species of the genus Labeo from the Lower Zaire river system have been revised on the basis of 284 preserved fishes, including type material of 18 nominal species cited or described from this region. Morphometrics, meristic counts, morphological observations and radiographs have been used for this study. All results obtained are supported by statistical analyses. From the 18 nominal species reported, only 12 species are recognized as valid. Two major groups were identified: one group has rows of conical papillae on the inner surface of lips; and the other group presents rows of transverse plicae on the inner surface of lips. The first group has two species: L. lineatus and L. weeksii. One synonymy is proposed: L. lineatus (partim) = L. weeksii. In the second group, 10 species have been identified: L. longipinnis, L. degeni, L. barbatus, L. macrostoma, L. falcipinnis, L. cyclorhynchus, L. parvus, L. greenii, L. nasus and L. sorex. One unidentified taxon apparently represents a species new to science, but this must be confirmed by a wider revision of the genus which is the subject of further research. Some synonymies in this group are proposed: L. brichardi (partim) = L. barbatus; L. lineatus (partim) = L. degeni. Other synonymies already established by Reid (1985), have been confirmed: L. lividus = L. barbatus; L. brichardi (partim) = L. macrostoma; L. variegatus = L. cyclorhynchus. One synonymy has been restored: L. velifer = L. longipinnis. Finally, one synonymy remains in question: L. chariensis = L. parvus. A key to species is provided. 相似文献
10.
《Journal of Natural History》2012,46(7):1143-1151
The Afrotropical genus Sisyrophanus Karsch is reviewed and a key is provided for the separation of the eight known species, including Sisyrophanus stylifer sp. nov. which is described from Burundi and Tanzania. 相似文献