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Klasea , traditionally treated as a section in Serratula , is now widely accepted at the generic level. A classification of the genus is presented here, accommodating the 46 species in ten sections based on nuclear ribosomal DNA external and internal transcribed spacer sequence data and morphology. New combinations for five species and ten subspecies are published, and a new hybrid species is described. The genus ranges from the Iberian Peninsula and north Africa through southern and eastern Europe, west and central Asia to the Himalayas, and the Far East of Russia and China. The ancestral area is in west Asia, most probably eastern Anatolia and northern and western Iran. In this region, representatives of all sections are present. The largest section Klasea diversified most likely in the mountains of central Asia. A key to all Klasea species is provided.  © 2006 The Linnean Society of London, Botanical Journal of the Linnean Society , 2006, 152 , 435–464.  相似文献   

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We applied the Cocktail method to a large data set of 4 117 relevés of all Slovak vegetation types with the aim to create formalised definitions of all Slovakian mire plant associations. We defined 21 groups of species with the statistical tendency of joint occurrences in vegetation. These groups differed substantially in their position along the pH/calcium gradient. We further defined 24 plant associations according to presence and/or absence of certain groups and/or strong dominance of some species. Only six traditional plant associations were not possible to be reproduced this way. We applied our formalised definitions to the regional data set of mires from the surrounding of the Vysoké Tatry Mts. Combined with frequency-positive fidelity index this method has led to the classification of the majority of vegetation plots into ten associations. When the vegetation types obtained from Cocktail-based classification and from cluster analysis were compared with respect to measured pH and conductivity in the study region, 82% of pairs differed significantly either in pH or in water conductivity in the former classification and 69% in the latter one.  相似文献   

4.
We evaluated the effectiveness of integrating discrete return light detection and ranging (LiDAR) data with high spatial resolution near-infrared digital imagery for object-based classification of land cover types and dominant tree species. In particular we adopted LiDAR ratio features based on pulse attributes that have not been used in past studies. Object-based classifications were performed first on land cover types, and subsequently on dominant tree species within the area classified as trees. In each classification stage, two different data combinations were examined: LiDAR data integrated with digital imagery or digital imagery only. We created basic image objects and calculated a number of spectral, textural, and LiDAR-based features for each image object. Decision tree analysis was performed and important features were investigated in each classification. In the land cover classification, the overall accuracy was improved to 0.975 when using the object-based method and integrating LiDAR data. The mean height value derived from the LiDAR data was effective in separating “trees” and “lawn” objects having different height. As for the tree species classification, the overall accuracy was also improved by object-based classification with LiDAR data although it remained up to 0.484 because spectral and textural signatures were similar among tree species. We revealed that the LiDAR ratio features associated with laser penetration proportion were important in the object-based classification as they can distinguish tree species having different canopy density. We concluded that integrating LiDAR data was effective in the object-based classifications of land cover and dominant tree species.  相似文献   

5.
Aim We modelled the relationship of breeding evidence for five species of forest songbirds (ruby-crowned kinglet (Regulus calendula) Blackburnian warbler (Dendroica fusca), black-throated blue warbler (Dendroica caerulescens), bay-breasted warbler (Dendrioca castanea) and Connecticut warbler (Oporornis agilis)) and a variety of macro-climate variables to examine the importance of climate as a factor determining distribution of breeding in these species and to assess the usefulness of spatial predictions generated from these models. Location Modelling was conducted over the entire province of Ontario, Canada, an area of ≈900,000 km2. Methods Data on the distribution of breeding in the province was derived from the Breeding Bird Atlas of Ontario. We used logistic regression to model the relationship between the probability of breeding (assessed in 10 km×10 km blocks) and estimates of a variety of climate variables at the same scale. Models were selected that had the least number of explanatory variables while at the same time having close to the best possible classification accuracy. Results The final models for these five species had from one to six explanatory variables and an overall concordance of 70.4% to 86.3% indicating a good classification accuracy. Results from subsampling 50% of the original data ten times indicate that (1) the classification accuracy of the model for data used to generate the model is not very sensitive to the specific observations used to generate the model (2) the classification accuracy of test data is close to the classification accuracy of the model data and (3) the classification accuracy of the test data is not dependent on the specific observations used to generate the model. We generated a spatial prediction of the probability of occurrence of each species for Ontario using the relationships defined by the logistic regression models and using 1 km gridded estimates of the necessary climate variables. These probability maps closely matched the maps of observed evidence of breeding from the Atlas. Main conclusions Although mechanisms controlling breeding distribution cannot be determined using this method, we can conclude that (1) macro-climate is an important factor directly and/or indirectly determining distribution of breeding in these species and (2) spatial predictions of probability of breeding are accurate enough to be useful in predicting probability of breeding in unsampled areas.  相似文献   

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树种多样性是生态学研究的重要内容,树木的种类和空间分布信息可有效服务于可持续森林管理。但在复杂林分条件下,获取高精度分类结果的难度大。而无人机遥感可获取局域超精细数据,为树种分类精度的提高提供了可能。基于可见光、高光谱、激光雷达等多源无人机遥感数据,探究其在亚热带林分条件下的树种分类潜力。研究发现:(1)随机森林分类器总体精度和各树种的F1分数最高,适合亚热带多树种的分类制图,其区分13种类别(8乔木,4草本)的总体精度为95.63%,Kappa系数为0.948;(2)多源数据的使用可以显著提高分类精度,全特征模型精度最高,且高光谱和激光雷达数据显著影响全特征模型分类精度,可见光纹理数据作用较小;(3)分类特征重要性从大到小排序为结构信息,植被指数,纹理信息,最小噪声变换分量。  相似文献   

7.
掌握森林内树木种类及其分布情况对研究森林生态系统具有重要意义.为推广国产高分数据在森林树种分类方面的应用,同时探究不同时相、分类特征及分类器的组合对树种分类结果的影响,本研究利用3景高分二号影像构建了3种单时相和4种多时相,通过多尺度分割、C5.0特征优选及支持向量机(SVM)和随机森林(RF)两种分类器分别实现了不同时相及特征维度下面向对象的8个树种的分类,最终取得了总体精度在63.5~83.5%、Kappa系数在0.57~0.81的良好结果.结果表明: 时相的选择会对分类结果产生较大的影响,其中,基于多时相的结果往往优于单时相,多时相下不同影像组合间以及单时相间亦存在明显的精度差异;特征优选会对分类精度的提升起到积极作用,应予以足够重视;SVM在不同时相及特征维度下的表现均较为稳定,在单时相及分类特征难以直接区分树种的情况下应优先使用SVM,但使用SVM时应注意其易发生过拟合;RF不易发生明显的过拟合,但其对分类特征的质量依赖较大,并倾向于在良好的影像组合下取得较为优异的结果.  相似文献   

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采用RAPD和同工酶技术对川西北具有代表性的10份荞麦材料进行分析.结果表明,筛选出的15个RAPD引物扩增出388条带.其中352条具有多态性,多态性比率为90.72%;过氧化物同工酶分析获得15条酶带,酯酶同工酶获得10条酶带.3种方法聚类结果基本一致,10份材料可初步聚为4个类群.其中,与金荞亲缘关系相比,甜荞较近而苦荞较远;普格县野荞和齿翅野荞、细柄野荞亲缘关系较近,划为同类;阿坝野荞单独划为一类,对其在分类中的地位有待进一步研究.  相似文献   

10.
Aim: Introduction of a novel approach to the classification of vegetation data (species by plot matrices). This approach copes with a large amount of noise, groups irregularly shaped in attribute space and species turnover within groups. Method: The proposed algorithm (Isopam) is based on the classification of ordination scores from isometric feature mapping. Ordination and classification are repeated in a search for either high overall fidelity of species to groups of sites, or high quantity and quality of indicator species for groups of sites. The classification is performed either as a hierarchical, divisive method or as non‐hierarchical partitioning. In divisive clustering, resulting groups are subdivided until a stopping criterion is met. Isopam was tested on 20 real‐world data sets. The resulting classifications were compared with solutions from eight widely used clustering algorithms. Results: When looking at the significance of species fidelities to groups of sites, and at quantity and quality of indicator species, Isopam often achieved high ranks as compared with other algorithms.  相似文献   

11.
猕猴属五个种mtDNA多态性研究   总被引:17,自引:2,他引:15  
本文以10种限制性内切酶研究猕猴属5个种(Macaca mulatta.M.nemestrina.M.assemensis.M.thibetana,M arctoides)线粒体DNA进化。在13个个体中,共检出8种限制性类型。恒河猴种内存在广泛的线粒休DNA限制性片段长度多态性(RFLP)。结合日本猴(M.fuscata)的有关资料,构建了猕猴属6个种的分子系统树,并给出各个种的分化时间。结果表明,这6个种可分成4个类群,熊猴和藏酋猴、恒河猴和日本猴之间的遗传距离较近,可分别划为同一类群,红面猴与其他5种猴的遗传距离最远,在系统发生上分离最早。  相似文献   

12.
Molecular analyses are transforming our understanding of the evolution of scleractinian corals and conflict with traditional classification, which is based on skeletal morphology. A new classification system, which integrates molecular and morphological data, is essential for documenting patterns of biodiversity and establishing priorities for marine conservation, as well as providing the morphological characters needed for linking present‐day corals with fossil species. The present monograph is the first in a series whose goal is to develop such an integrated system. It addresses the taxonomic relationships of 55 Recent zooxanthellate genera (one new) in seven families (one new), which were previously assigned to the suborder Faviina (eight genera are transferred to incertae sedis). The present monograph has two objectives. First, we introduce the higher‐level classification system for the 46 genera whose relationships are clear. Second, we formally revise the taxonomy of those corals belonging to the newly discovered family‐level clade (restricted today to the western Atlantic and Caribbean regions); this revised family Mussidae consists of ten genera (one of which is new) and 26 species that were previously assigned to the ‘traditional’ families Faviidae and Mussidae. To guide in discovering morphologic characters diagnostic of higher‐level taxa, we mapped a total of 38 morphologic characters [19 macromorphology, eight micromorphology, 11 microstructure] onto a molecular tree consisting of 67 species [22 Indo‐Pacific and seven Atlantic species in the traditional family Faviidae; 13 Indo‐Pacific and ten Atlantic species in the traditional family Mussidae; 13 species in the traditional families Merulinidae (5), Pectiniidae (7), and Trachyphylliidae (1); two Atlantic species of traditional Montastraea], and trace character histories using parsimony. To evaluate the overall effectiveness of morphological data in phylogeny reconstruction, we performed morphology‐based phylogenetic analyses using 27 (80 states) of the 38 characters, and compared morphological trees with molecular trees. The results of the ancestral state reconstructions revealed extensive homoplasy in almost all morphological characters. Family‐ and subfamily‐level molecular clades [previously identified as XVII?XXI] are best distinguished on the basis of the shapes of septal teeth and corresponding microstructure. The newly revised family Mussidae (XXI) has septal teeth with regular pointed tips (a symplesiomorphy) and a stout blocky appearance. It has two subfamilies, Mussinae and Faviinae. The subfamily Mussinae is distinguished by spine‐shaped teeth and widely spaced costoseptal clusters of calcification centres. The subfamily Faviinae is distinguished by blocky, pointed tricorne or paddle‐shaped teeth with elliptical bases, transverse structures such as carinae that cross the septal plane, and well‐developed aligned granules. Defining diagnostic characters for the broader data set is more challenging. In analyses of taxonomic subsets of the data set that were defined by clade, morphological phylogenetic analyses clearly distinguished the families Mussidae (XXI) and Lobophylliidae (XIX), as well as the two subfamilies of Mussidae (Mussinae, Faviinae), with one exception (Homophyllia australis). However, analyses of the entire 67‐species data set distinguished the family Lobophylliidae (XIX), but not the Merulinidae (XVII) and not the newly defined Mussidae (XXI), although the subfamily Mussinae was recovered as monophyletic. Some lower‐level relationships within the Merulinidae (XVII) agree with molecular results, but this particular family is especially problematic and requires additional molecular and morphological study. Future work including fossils will not only allow estimation of divergence times but also facilitate examination of the relationship between these divergences and changes in the environment and biogeography. Published 2012. This article is a U.S. Government work and is in the public domain in the USA. Zoological Journal of the Linnean Society, 2012, 166 , 465–529.  相似文献   

13.
张石宝  魏兆祥   《广西植物》1997,17(2):162-165
本文对观赏植物异色芋(ColocasiaheterochromaH.LietZ.X.Wei)在昆明栽培环境下的生物学特性进行总结,为商品化栽培异色芋提供了理论依据,为其分类也提供了一定的有益补充。结果表明:一年生植株不开花,根茎也不产生分枝;二年生植株开花率为73.6%,根茎平均分枝3.6条。异色芋3月上旬开始萌动,7月中旬抽花梗,8月上旬开花,11月份地上部分枯萎,因此在昆明异色芋生育期约260d。  相似文献   

14.
O. Varis 《Hydrobiologia》1991,210(3):209-216
Canonical correlation analysis was used to study the associations between the most prevalent phytoplankton species and nine physical and chemical growth factors in a polyhumic Finnish lake. The analysis was made (a) to the ten species with the greatest mean biomass in the data over one growth season and (b) to the ten species providing the greatest canonical correlation with the growth factors. The latter species were detected using an exchange type procedure. The analysis showed strong associations within phyla. Especially the most problematic phylum with respect to the use of the lake, the cyanobacteria, had a pronounced mutual association, as they correlated negatively with the N/P ratio as positively with phosphorus.  相似文献   

15.
黑龙江省产10种蛇类血细胞的比较研究   总被引:1,自引:0,他引:1  
李殿伟  张志影  李淑兰  赵文阁 《四川动物》2007,26(2):401-403,I0008
本文用Wright染色法对黑龙江省产10种蛇类的血细胞形态学特征进行比较,测得数据用SPSS13.0软件统计。结果表明:10种蛇的各类血细胞形态和数量有较明显差别并有一定的属种特征,这可能与其进化地位和生态适应有关。  相似文献   

16.
鸢尾属部分种种子微形态特征与系统演化关系   总被引:3,自引:0,他引:3  
王玲  卓丽环 《植物研究》2006,26(3):286-290
用HITACHI S-520型扫描电子显微镜对鸢尾属植物10个种及1变种、1外类群的种子微形态进行观察、比较分析,探讨了鸢尾属植物部分种种子微形态特征分类学意义及系统演化关系。结果表明:鸢尾属植物种子表面微形态特征具有种的稳定性,与分布区无关;同一种的种子凹、凸面微形态差异很大,同一类群比较时应选择相同部位观察。所研究的鸢尾种都为网状(网纹或负网纹)文饰,种间差异明显,微形态特征可用于鸢尾属间、属下系的等级划分,但不适于种下等级鉴别。研究给出了鸢尾属植物种子表面纹饰的系统进化关系,证明了种子表面微形态对鸢尾属植物分类及系统演化关系具有重要意义。  相似文献   

17.
春黄菊族6属植物种子的微形态特征   总被引:3,自引:1,他引:2  
应用光学显微镜和扫描电镜对春黄菊族6属10种的种子微形态特征进行了比较观察。结果表明:10种种子在种子形态、表面纹饰、脐处的喙状突起、种子端的衣领状环等方面都表现出丰富的多样性,例如茼蒿的穴状和芫荽菊的细胞状纹饰等,具有明显的属级水平上的分类特征;在系和种级水平上,微形态特征虽有相似性,但仍具有一定的分类学价值,如龙蒿系圆头蒿的沟壑状纹饰和猪毛蒿系猪毛蒿的搓板状纹饰等。说明春黄菊族植物丰富的种子微形态特征在其系统分类中具有重要的参考价值;本研究结果支持栉叶蒿属、紊蒿属、茼蒿属独立成属的观点。  相似文献   

18.
In the first comprehensive floristic classification of Australian rainforests and monsoon forests, fresh insights made possible by the use of floristic as distinct from structural data are outlined. A set of 561 individual communities, on sites ranging from North Queensland westwards to the Kimberley region and southwards to Tasmania, is defined by the presence or absence of 1316 tree species, or 406 genera. The data have been subjected to numerical classification, first with respect to species, then to genera. The species classification first divides into three ‘ecofloristic regions’: A, temperate (microtherm) and subtropical (mesotherm) humid evergreen rainforests; B, tropical (megatherm) humid evergreen grading into highly seasonal raingreen (monsoon) forests; and C, subtropical (mesotherm) moderately seasonal humid/subhumid raingreen forests. The sites are further divided into eight ‘ecofloristic provinces’, for each of which a core area is identified and the ten most common diagnostic tree species listed for selected floristic elements, whose ecological relationships are briefly described. Gradients of quantitative thermal-moisture indices are added to standard climatic typology to provide a more flexible identification of local climates that characterize community-types of each province across a wide latitudinal/altitudinal range. Community disjuncts and outliers of a particular province are interpreted as the results of past environmental sifting (in which ecological factors are not entirely determinate), of previously more continuous rainforest vegetation. The genera classification first divides into humid eastern coastal and subhumid western and subcoastal sites, then four thermal types, and finally nine groups of floristic ‘paleo-provinces’. Where the species and genera classifications are not in substantial agreement, a wide-ranging generic element across the provinces in northern and northeastern Australia is interpreted in paleogeographic terms. The relict distribution of existing community types, as the result of climatic sifting of ancient floral stocks, is discussed in support of emerging ideas about the autochthony of Australian rainforests, especially those tropical types that are not intrusive. It is argued that the unique ecological relationships of Australian rainforests justify the most conservative uses of the relatively small remaining areas.  相似文献   

19.
We introduce a method to transform wing venation data to a numerical form so that the venation pattern can be analysed and compared regardless of wing size and displacement of the pattern. We use the method for assessing the intraspecific variation and asymmetry within the individual of relative positions of forewing veins in ten species of elachistid moths. Both the intraspecific variation and intra-individual asymmetry were found to be greater than the differences frequently used as systematic characters on various levels within Elachistidae, and to some extent in other Lepidoptera. At least in Elachistidae, major alterations to the current classification will have to be made. Wing characters subject to intraspecific variation should not be used to delimit groups unless they are based on examination of population samples and supported by other characters.  相似文献   

20.
Remote sensing classification has the potential to provide important information, such as tree species distribution maps, to ecologists, at a range of spatial and temporal scales. However, standard classification procedures often fail to provide the high accuracies required for many ecological applications. Previously, a modified remote sensing classification technique was used to provide very high classification accuracies for one or two classes (e.g. species) of interest. The aim of this paper was to demonstrate that the output from the method can be suitable for spatial ecological analyses, and to provide a generic simulation framework for assessing the adequacy of any given remote sensing classification for such analyses. Marked point pattern analysis (MPPA) was applied to tree species distribution data obtained for sycamore Acer pseudoplatanus and ash Fraxinus excelsior from a 400 ha ancient semi-natural woodland in southern England using the modified remote sensing classification method to test several hypotheses of ecological interest relating to the spatial distribution and interaction of these species. Monte Carlo simulation methods were then used to evaluate the data and data quality requirements of the MPPA to check that the classified tree species maps for sycamore and ash were adequate. Using the combined method the spatial distributions for sycamore and ash were found to be aggregated and inter-dependent at a range of spatial scales. Together, the remote sensing classification and simulation approaches provide the basis for exploiting more fully the potential of remote sensing to provide information of value to ecologists.  相似文献   

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