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1.
广西金钟山鸟类保护区鸟类多样性初步研究 总被引:7,自引:0,他引:7
本文共记录到金钟山鸟类274种,分别隶属于18目57科,其中陆生鸟类251种,水鸟23种;以留鸟为主,共157种;候鸟、旅鸟分别为104种、13种;东洋种为优势类群,共有171种,古北种和广布种分别为4种、27种。这些鸟类中有国家重点保护鸟类39种,中国特有种鸟类3种,列入世界自然保护联盟红皮书名录中的鸟类5种,列入中国濒危动物红皮书名录中的鸟类20种,列入CITES附录中的鸟类34种。本文还对金钟山鸟类保护区的5种不同生境类型的鸟类种类组成作了比较,结果表明灌丛+农田的鸟种多样性指数最高,为3.04;水域的鸟种多样性指数最低,为2.14。 相似文献
2.
W. B. RUDMAN 《Zoological Journal of the Linnean Society》1977,61(4):351-397
Six species of Hypselodoris and three species of Chromodoris axe described from the coast of East Africa. Three species of Hypselodoris and one species of Chromodoris are new species. Two species of Chromodoris from the tropical West Pacific are also described. The eleven species fall into three groups of similarly coloured species.
Hypselodoris nigrostriata and a new species of Hypselodoris are compared with H. infucata, H. festiva, H. obscura and two unnamed species from the literature. It is concluded that all these are distinct species.
H. nigrolineata and two new species, are compared with H. lineata and H. hilaris and all are considered distinct.
H. regina, Chromodoris quadricolor, C. africana, C. elisabethina, C. magnified and a new species of Chromodoris, are compared with C. westraliensis and two unnamed species from the literature. All these species are considered distinct.
All other names for forms falling into these three colour groups are considered synonyms of one or other of the above named species. Full synonymies are given. 相似文献
Hypselodoris nigrostriata and a new species of Hypselodoris are compared with H. infucata, H. festiva, H. obscura and two unnamed species from the literature. It is concluded that all these are distinct species.
H. nigrolineata and two new species, are compared with H. lineata and H. hilaris and all are considered distinct.
H. regina, Chromodoris quadricolor, C. africana, C. elisabethina, C. magnified and a new species of Chromodoris, are compared with C. westraliensis and two unnamed species from the literature. All these species are considered distinct.
All other names for forms falling into these three colour groups are considered synonyms of one or other of the above named species. Full synonymies are given. 相似文献
3.
4.
What do the biodiversity experiments tell us about consequences of plant species loss in the real world? 总被引:1,自引:0,他引:1
Jan Lep 《Basic and Applied Ecology》2004,5(6):529-534
Experiments where the diversity of species assemblage is manipulated are sometimes used to predict the consequences of species loss from real communities. However, their design corresponds to a random selection of the lost species. There are three main factors that limit species richness: harshness of the environment, competitive exclusion, and species pool limitation. Species loss is usually caused by increasing effects of these factors. In the first two cases, the species that are excluded are highly non-random subsets of the potential species set, and consequently, the predictions based on random selection of the lost species might be misleading. The data show that the least productive species are those being recently excluded from temperate grasslands and consequently, species loss is not connected with decline of productivity. The concurrent species loss in many communities, however, means also a reduction of the available diaspore pool on a landscape scale, and could result in increased species pool limitation in other communities. 相似文献
5.
Peter R. Thompson William F. Fagan Phillip P. A. Staniczenko 《Ecology and evolution》2020,10(7):3293-3304
Designing an effective conservation strategy requires understanding where rare species are located. Because rare species can be difficult to find, ecologists often identify other species called conservation surrogates that can help inform the distribution of rare species. Species distribution models typically rely on environmental data when predicting the occurrence of species, neglecting the effect of species' co‐occurrences and biotic interactions. Here, we present a new approach that uses Bayesian networks to improve predictions by modeling environmental co‐responses among species. For species from a European peat bog community, our approach consistently performs better than single‐species models and better than conventional multi‐species approaches that include the presence of nontarget species as additional independent variables in regression models. Our approach performs particularly well with rare species and when calibration data are limited. Furthermore, we identify a group of “predictor species” that are relatively common, insensitive to the presence of other species, and can be used to improve occurrence predictions of rare species. Predictor species are distinct from other categories of conservation surrogates such as umbrella or indicator species, which motivates focused data collection of predictor species to enhance conservation practices. 相似文献
6.
Species concepts and species delimitation 总被引:7,自引:0,他引:7
De Queiroz K 《Systematic biology》2007,56(6):879-886
The issue of species delimitation has long been confused with that of species conceptualization, leading to a half century of controversy concerning both the definition of the species category and methods for inferring the boundaries and numbers of species. Alternative species concepts agree in treating existence as a separately evolving metapopulation lineage as the primary defining property of the species category, but they disagree in adopting different properties acquired by lineages during the course of divergence (e.g., intrinsic reproductive isolation, diagnosability, monophyly) as secondary defining properties (secondary species criteria). A unified species concept can be achieved by treating existence as a separately evolving metapopulation lineage as the only necessary property of species and the former secondary species criteria as different lines of evidence (operational criteria) relevant to assessing lineage separation. This unified concept of species has several consequences for species delimitation, including the following: First, the issues of species conceptualization and species delimitation are clearly separated; the former secondary species criteria are no longer considered relevant to species conceptualization but only to species delimitation. Second, all of the properties formerly treated as secondary species criteria are relevant to species delimitation to the extent that they provide evidence of lineage separation. Third, the presence of any one of the properties (if appropriately interpreted) is evidence for the existence of a species, though more properties and thus more lines of evidence are associated with a higher degree of corroboration. Fourth, and perhaps most significantly, a unified species concept shifts emphasis away from the traditional species criteria, encouraging biologists to develop new methods of species delimitation that are not tied to those properties. 相似文献
7.
Although jellyfish blooms are a focus of recent research, the roles that the developmental stages of species play are underestimated.
Planulae, polyps and ephyrae are inconspicuous and often overlooked. The importance of production of ephyrae from the sessile
polyps has become more apparent. Our objective was to establish an identification system for early ephyrae of scyphozoan species
in plankton samples. We studied ephyrae of 18 species. Standard measurements were introduced and the variability of marginal
lappets analysed. Characters differentiating the 18 species are described. Photographs and drawings of each species are presented
as a catalogue of ephyrae of these species. We developed a key for identification of the 18 species. 相似文献
8.
ALAN J. KOHN 《Zoological Journal of the Linnean Society》1964,45(304):151-167
Twenty-three species of Conus were described by authors other than Linnaeus between 1766 and 1786. Of these, 3 are Eocene species from England described by Solander in Brander (1766), and the remainder are Recent. Chemnitz (1777) described one valid species. Of the 10 species described by Born (1778), 7 are valid, 2 are junior synonyms of Linnaean species, and 1 is a nomen dubium. Solander in [Lightfoot] (1786) described 5 species, of which 3 are valid and 2 are junior synonyms of Linnaean species. Lightfoot (1786) described 4 species, of which 1 is valid and 3 are junior synonyms of Linnaean species.
Holotypes of 7 species and lectotypes of 3 species exist, and representatives of lecto-types of 10 species have been selected. All of these types are illustrated photographically.
Between 1758 and 1786, 60 species of Conus were described, of which 45 are now considered valid. Of these, 42 are Recent. 相似文献
Holotypes of 7 species and lectotypes of 3 species exist, and representatives of lecto-types of 10 species have been selected. All of these types are illustrated photographically.
Between 1758 and 1786, 60 species of Conus were described, of which 45 are now considered valid. Of these, 42 are Recent. 相似文献
9.
A new argument that species are individuals has recently been presented based on the way species names are used and systemic logic. The alternate idea that species are a categorical item, i.e., collections of individuals, was rejected. We wanted to evaluate this approach by establishing concepts that apply to individuals in order to examine if they are also applicable to a species viewed as a categorical item. It is our thinking that if species are not such, then concepts applicable to individuals will not be applicable to species so viewed. Individuals and species are similar in the presence of conceptual boundaries, unidirectional change and the presence of past and future time. These are all central, and salient, biological phenomena. But, these are concepts that apply also to populations which, for the most part, are not the same as species. Thus, these considerations infer that species, when viewed as a collection of individuals, do not share relevant concepts with individuals. Our conclusion is that a species is a 'unity' rather than an 'individual'. 相似文献
10.
Mark Ridley 《Biology & philosophy》1989,4(1):1-16
The correct explanation of why species, in evolutionary theory, are individuals and not classes is the cladistic species concept. The cladistic species concept defines species as the group of organisms between two speciation events, or between one speciation event and one extinction event, or (for living species) that are descended from a speciation event. It is a theoretical concept, and therefore has the virtue of distinguishing clearly the theoretical nature of species from the practical criteria by which species may be recognized at any one time. Ecological or biological (reproductive) criteria may help in the practical recognition of species. Ecological and biological species concepts are also needed to explain why cladistic species exist as distinct lineages, and to explain what exactly takes place during a speciation event. The ecological and biological species concepts work only as sub-theories of the cladistic species concept and if taken by themselves independently of cladism they are liable to blunder. The biological species concept neither provides a better explanation of species indivudualism than the ecological species concept, nor, taken by itself, can the biological species concept even be reconciled with species individualism. Taking the individuality of species seriously requires subordinating the biological, to the cladistic, species concept. 相似文献
11.
Mel Chih-Yu Chu 《American journal of botany》1974,61(7):681-692
A comparative study of the leaves of 31 species of Lycopodium was made. The pattern of tracheids varies with the species. Usually they exhibit annular, helical, reticulate, modified or transition forms; none of the species have advanced phylogenetically beyond the scalariform tracheid stage. Mucilage canals have been found in four species. Tracheids are enclosed by a few to several layers of oblique ended, elongated parenchyma cells in most species, but an endodermis is absent. Vascular bundles are encircled by fiber cells in three species. The mesophyll of most species consists of identically shaped cells, although palisade-like tissue has been observed in a few species. The epidermal cells vary from elongated to isodiametric and have either undulated or smooth anticlinal walls, which are deeply pitted in some species. The outer epidermal walls are usually thick and heavily cutinized. Stomates are distributed on both surfaces in 18 species, on the abaxial surface in 11 species, and on the adaxial side in only two species. Most stomates are practically isodiametric in surface view, broader than epidermal cells, usually parallel to the vein, and at the same level as the adjacent epidermal cell. A typical guard cell has a prominent outer ledge and a less developed inner ledge of cutin in most species. Six groupings are suggested, based on similarity of leaf structure and the known chromosome numbers. 相似文献
12.
《农业工程》2019,39(6):443-450
Pakistan has rich history of indigenous folk medicine, and of the 6000 species of higher plants found in the country 12% are used in medicinal formulations. This immensely important knowledge of folk practices to cure different ailments has been learned after centuries and is mostly verbally communicated. Therefore, a field study was designed to investigate the plant biodiversity and accumulate the indigenous knowledge about the uses of plants of Tehsil Oghi, District Mansehra, Pakistan. A total of 141 local inhabitants were interviewed through a structured questionnaire followed by multivariate approaches to evaluate the data based on the Principle Component Analysis (PCA) and Detrended Correspondence Analysis (DCA). Plants specimen were preserved, mounted and labeled on the herbarium sheets, cataloged and deposited for voucher numbers in Herbarium, Government Post Graduate College, Mansehra, Pakistan. In present study, a total 104 species belonging to 88 genera and 54 families were recorded from the study area; herbaceous growth form dominated the study area with 56 species, followed by trees with 30 species and shrubs 14 species. Among all 54 families, Rosaceae species were dominant with 12 species, followed by Asteraceae with 8 species. Out of the reported 104 species, 94 plant species are medicinal, 22 plant species are edible fruits, 37 plant species are fuel wood, 24 plant species are timber wood, 38 plant species are fuel wood, 9 plant species are vegetables, while 34 plant species are ornamental. The present study revealed the importance of the flora of this unexplored area and also provides the baseline study for future biological, phytochemical and pharmacological experimentations. 相似文献
13.
Exotic invaders of the meso-oligohaline zone of estuaries in the Netherlands: why are there so many?
Wim J. Wolff 《Helgoland Marine Research》1998,52(3-4):393-400
The numbers of exotic species introduced into brackish waters (5–20 psu) and high-salinity waters (> 20 psu) in the Netherlands are hypothesized to reflect species richness in such waters elsewhere in the world. Notwithstanding the fact that species numbers in brackish waters all over the world are lower than in high-salinity waters, the numbers of introduced species in these waters in the Netherlands are about equal. Alternative hypotheses to explain this phenomenon are: (1) because most ports are situated in brackish regions, brackish-water species stand a better chance of being transported; (2) because brackish-water species are more tolerant of conditions in ballast water tanks, these species have a better chance of being transported alive than high-salinity species; and (3) because brackish waters have few species, it is easier for an introduced species to establish itself in brackish waters. None of the latter three hypotheses can be rejected and probably they all play a part in explaining the phenomenon. The third hypothesis, however, seems most likely. 相似文献
14.
W. B. RUDMAN 《Zoological Journal of the Linnean Society》1983,78(2):105-173
Eleven species of Chromodoris, two species of Hypselodoris, three species of Mexichromis and one species of Noumea are described from the Indo-West Pacific, of which four species of Chromodoris and one of Mexichromis are new species. All species have a colour pattern dominated by red, purple or black spots. All previously described species with similar colour patterns, from both the Indo-West Pacific and other regions, are discussed. 相似文献
15.
1IntroductionWildlifetradeisamain~mpetustoutilizewildlife.Thechangeinspeciesandvolumein-volvedinthewildlifetrademayreflectconservationstatus,dynamicsandexploitedlevelofwildliferesources.Thestudyonwildlifetradeisthetheoriticalbasisonwhichproposalsastolimittradeonrareorendangeredspeciescanbemade,andwithwhichfuturemonitoringofthetradecanbecompared.Theresultalsocanbeusedtoevaluateconservationeffectsofprotectionmeasuresandlawsforbiodiversityconservation.Itisofgreatsignificanceinguid-ingsustainable… 相似文献
16.
西双版纳片断热带雨林30多年来植物种类组成及种群结构的变化 总被引:6,自引:0,他引:6
通过对西双版纳景洪曼仰广的“龙山”片断热带雨雨林30年前后植物区系组成和样方调查资料的对比研究,探讨了30年来该“龙山”片断热带雨林植物区系组成、生活型及群落生态成分和乔木树种的种群变化规律。在植物区系组成上,已确认有种子植物7科53属55种从该片断雨林中消失。在消失的这55种植物中,属于群落顶级成分的有18种,属于耐阴的林下和层间植物有30种,喜阳种类有2种,广生态幅的随遇种有5种。初步得出该龙山热带雨林随着30多年的片断化,8.8%的科,26.8%的属和22.4%的种类消失或被后来的成分替换了。在生活型及群落生态成分变化上,群落中小高位芽及一年生植物相对增加,阳性植物明显增加,阴生(耐阴)植物明显减少,亦即雨林固有成分减少,非雨林成分增加。在乔木树种的种群变化上,过去该片断雨林的优势成份,绝大多数现在仍存在,多数仍在优势种之列,少数优势种衰退了,少数变得更优势。首先消失的种类,或为先锋树种(短命)或为种群数量很少的树种。 相似文献
17.
中国台湾和大陆蹄盖蕨属植物的生物地理学比较 总被引:1,自引:0,他引:1
蹄盖蕨属Athyrium Roth是个典型的东亚属,全世界估计约有160种,主要分布在亚洲东部的亚热带高山,少数在温带其他地区,中国有117种,是其分布中心。台湾和大陆的蹄盖蕨属植物关系尤为密切,是研究海峡两岸植物地理关系的一个很好的材料。台湾已知共计有蹄盖蕨类植物32种,包括狭义蹄盖蕨27种,介蕨2种,蛾眉蕨1种,假蹄盖蕨1种,假冷蕨1种,即使将待查实的4种蹄盖蕨除去,至少还有28种。其中除去7种大陆不产外, 21种均和大陆共有,占75%。况且,这7种与大陆种形态相近,是否同种异名、亚种或姊妹种关系还有待进一步研究;在台湾和大陆共有的16种狭义蹄盖蕨中有7种是台湾-西南间断分布。这不仅说明了台湾的蹄盖蕨属类植物和大陆的关系密切、有着共同的起源,而且说明台湾高地的植物区系和西南高地关系最为密切。运用生物系统学和分子系统学的方法研究和测定海峡两岸共有种种内、姊妹种或近缘种之间的遗传学关系(如:遗传一致度),进一步了解并量化台湾和大陆植物区系之间的历史和地理关系是必要的。 相似文献
18.
Threatened and endemic species: are they good indicators of patterns of biodiversity on a national scale? 总被引:5,自引:1,他引:4
Endemic and/or threatened species are often targeted to set conservation priorities. It is tempting to assume that a reserve network focusing on these species will be an effective umbrella for overall species richness of a country. For South Africa and Lesotho we tested whether complementary networks selected for threatened and/or endemic bird species satisfactorily represent all bird species, both in terms of capturing areas where other species are present or areas where they are more abundant (and, presumably, more viable). We found that areas selected for threatened and endemic species perform considerably better than areas selected at random. However, they do not guarantee the representation of overall bird species diversity, particularly not in peak abundance locations. Although nationally threatened and endemic species are important conservation targets, our results indicate that reserve networks focusing solely on these species may not be sufficient to preserve overall species diversity in a country. 相似文献
19.
Fernando Gómez 《分类学与生物多样性》2013,11(3):267-275
This study reviews the trends in the lifestyle, habitat distribution and trophic diversity of the 2377 described species of dinoflagellates (Dinophyceae). Most of the dinoflagellates inhabit marine waters, whereas 17% of the total species have colonized continental waters. Dinoflagellates are dominated by planktonic species, while benthic forms represented 8% of the species. From the total number of species, 49% are heterotrophic (devoid of plastids), while 51% of the species have been reported with plastids (that does not strictly imply autotrophy). All the basal dinoflagellates (ellobiopsids, Duboscquodinida, Syndiniales) are heterotrophic, with the exception of a few Noctilucales (Spatulodinium). The continental waters are highly dominated by plastid-containing species (88%), while in marine environments there is a slight dominance of heterotrophic species (58%). Most of the dinoflagellates are free-living forms; only 7% of the total species are parasites. The dinokaryotic parasites appear in separate clades, and about 40% of them contain plastids. The beneficial or mutualistic symbionts (21 species, 1%) are photosynthetic species dispersed into at least three clades. 相似文献
20.
为了解鸟类多样性现状,制定科学有效的栖息地保护管理对策,于2006年5~7月利用样线法对内蒙古桦木沟自然保护区鸟类物种多样性进行了调查,并分析了群落结构。结果显示,保护区内有17目44科127种鸟类,其中有国家Ⅰ级重点保护鸟类1种,国家Ⅱ级重点保护鸟类14种。居留型组成为90种夏候鸟、27种留鸟、10种旅鸟。不同生境类型中的鸟类群落多样性指数以草原湿地最高,均匀性指数以林地和疏林较高。提出保护区在制定鸟类多样性保护对策时应全面考虑各类栖息地的生态作用。 相似文献