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Abstract. Sand dune vegetation along the coast of the Mexican states of Tabasco and Campeche was sampled by means of 1501 releves and the data were analyzed with classification and ordination programs. 36 community types were distinguished, which were grouped into 10 higher-order groups. The communities are described in a sequence reflecting the main vegetation zonation. Beach, embryo dune and foredune community groups include 12 community types, the sheltered zone includes 16 types and the fixed dunes 8 types. The ordination results reveal one main vegetation gradient corresponding to the increase in mean distance from the shoreline and elevation, and being covariant with species richness, mean vegetation cover and mean vegetation height. Additional differences are related to the geographical transition between the Gulf and Caribbean coastal vegetation and environmental conditions, mainly type of sand, occurring in the study area. Siliceous sand and a Gulf climate are characteristic for most of Tabasco, and calcareous sand and a Caribbean-type climate are characteristic for Campeche. Disturbance caused by coconut plantations, cattle grazing and tourism favours the invasion of ruderal species from waste places behind the dunes, which attain local dominance in the dunes described here. Consequently some separate community types had to be distinguished. The distribution of community types is analyzed in the context of the transitions between calcareous and siliceous substrates in the study area. 相似文献
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Short-lived plant communities of ruderal habitats in North Korea were studied using the Zürich-Montpellier approach. TheBeckmannio eruciformis-Potentilletum costatae, theDaturo tatulae-Siegesbeckietum pubescentis, theHumulo japonicae-Chenopodietum albi and theCosmo-Humulion japonicae were described as new. 相似文献
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Abstract. A syntaxonomic study of the major plant communities in neotropical North American deserts (Sonoran, Mojave and Baja California Deserts) is presented. The field method of the Braun-Blanquet approach was combined with a numerical syntaxonomical analysis (cluster analysis and principal coordinate ordination). 21 associations are described for the first time: Ambrosio chenopodifoliae-Larreetum tridentatae, Acamptopappo sphaerocephali-Larreetum tridentatae, Hymenocleo monogyrae-Baccharidetum glutinosae, Bergerocacto emoryi-Agavetum shawii, Burseretum hindsianomicrophyllae, Cercidio microphylli-Carnegieetum giganteae, Bursero microphyllae-Cyrtocarpetum edulis, Hymenocleo salsolae-Daleetum spinosae, Echinocereo engelmannii-Agavetum deserti, Euphorbio californicae-Fouquierietum diguetii, Fouquierio splendentis-Larreetum tridentatae, Agavo cerulatae-Idrietum columnaris, Mascagnio macropterae-Lysilometum candidae, Maytenetum phyllanthoidis, Opuntio basilaris-Larreetum tridentatae, Prosopidetum torreyanae, Roso minutifoliae-Aesculetum parryi, Opuntio taponae-Agavetum subcerulatae, Tidestromio oblongifoliae-Atriplicetum hymenelytrae, Eurotio lanatae-Larreetum tridentatae and Yucco validae-Fouquierietum diguetii. Some associations include subassociations. Ecological, biogeographical and floristic bioclimatic data are given for each association. 相似文献
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Vřa Komárková 《Plant Ecology》1980,42(1-3):149-163
Summary A mid-latitude, Northern Hemisphere alpine vegetation in the Colorado Rocky Mountains was suitable for analysis by syntaxonemie and numerical methods, which interpreted the Braun-Bianquet association data, distributed by habitat and vegetation dominance types, correspondingly. Classification and ordination yielded complementary, interpretable results, which combined were more informative than results of either technique alone. Syntaxonomic results can faeilitate the interpretation of numerical results; the syntaxonomic relationships can be clarified by the results of numerical analysis.Alliances and orders of the Braun-Blanquet hierarchy, and their diagnostic taxa groups were derived by numerical methods from an association/taxa matrix. On the basis of this matrix, numerical methods demonstrated some of the environmental gradient complexes controlling the compositional variation. The compositional distinctiveness and uniformity of orders and alliances parallel environmental distictiveness and uniformity.The following attributes of the sampled vegetation and environment were probably responsible for the successful combination of syntaxonomic and numerical results: 1. The sampled area as a geographically limited universe, characterized by relative environmental, biotic, and historical distinctiveness and uniformity, 2. The wide range, high diversity, and clear denfinition of habitat and vegetation dominance types. Because it effectively summarizes and simplifies field data, syntaxonomy can play an important role in building local vegetatio models.Most of the figures in this paper are from a book version of a University of Colorado, Department of Environmental, Population, and Organismic Biology, Ph. D. thesis which was produced at the Institute of Arctic and Alpine Research. I would like to thank Dr. P.J. Webber, the thesis advisor, for his support, for suggesting the numerical methods, and for computer programs which were written by W.F. Reid. Vicki Dow, Marilyn Joel, and Karen Sproul drafted the majority of figures. I am grateful to Gwen Archer for editorial help. 相似文献
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Use of ecological groups in analysis and classification of plant communities in a section of western Quebec 总被引:1,自引:0,他引:1
A plant community analysis and classification were done for an integrated ecological study, in the lake Abitibi region, Quebec. Two levels of vegetation analysis were used: the ecological group level and the community level. Species were first grouped according to their sociological affinities. The ecological significance of those groupings was studied by principal component analysis, with the inclusion of abiotic variables, and by the study of ecological profiles. Secondly, the concurrent use of ecological groups permitted the definition and characterization of noda. The relationships between the noda, in the space defined by the ecological groups, were analyzed by principal coordinate analysis on which is superimposed the shortest spanning tree. Those combined analyses permitted the identification of 35 community types which vary mainly according to surficial deposits (organic or mineral), drainage, relative richness of soils in bases, flooding, presence of bedrock outcrops. fire perturbations and microclimate. Those variations are discussed according to the exlusive or non-exclusive character of the ecological groups. 相似文献
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Summary The classical syntaxonomical treatment of the European Spartina communities as published in the series Prodrome of the the European plant communities, is compared with the results of a numerical treatment, based on largely the same set of relevés. 576 relevés, selected from the total salt marsh data set were subjected to agglomerative clustering with relocation with the similarity ratio as similarity measure. The resulting numerical system was compared with the syntaxonomical hierarchy. The correlation between both systems is close. The numerical units are slightly more heterogeneous because no purification occurred, which implies relevés to be left out of consideration. One new syntaxon, Spartinetum townsendii asteretosum tripolii, could be suggested from the results of the numerical treatment. Perspectives for the development of a numerical syntaxonomy are stressed.Communication number 40. 相似文献
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松林节肢动物群落结构相似性分析 总被引:7,自引:4,他引:7
应用系统聚类、模糊聚类和主成分分析法,研究湿地松纯林、湿地松一木荷混交林 和湿地松-大叶相思混交林节肢动物群落结构的相似性.结果表明,2种混交林节肢动物群 落结构比较相似,而纯林与混交林相异;林冠层亚群落与灌木一草本届亚群落的结构也不 相同.分析结果能较好地反映不同林分和不同层次的节肢动物群落结构的差异性与连续 性.模糊聚类的分析方法优于系统聚类. 相似文献
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Natalia E. Koroleva 《植被学杂志》1994,5(6):803-812
Abstract. A phytosociological survey of the tundra vegetation of the Kola Peninsula, Russia according to the Braun-Blanquet approach is presented. The areas examined comprise the treeless zones along the shores of the White Sea and the Barents Sea as well as mountain areas above the timberline. Plant communities were assigned to five alliances: Loiseleurio-Diapension on dry, wind-swept habitats on summits and wind-eroded sites in the lowland; Phyllodoco-Vaccinion myrtilli on well-drained soils with intermediate snow cover and moisture status, mostly in the lowlands and lower belts of mountain tundra; Nardo-Caricion bigelowii comprising early snowbed and Salicion herbaceae late snowbed communities; Adenostylion alliariae comprising mesophilous tall-herb communities along mountain springs and in wind-protected and well-drained sites near the sea shore. A DCA-ordination showed that two major gradients determine the varation in tundra vegetation, altitude and topography, which are connected to variation in snow cover. The syntaxa described are well-differentiated, although they form a syntaxonomical continuum. 相似文献
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Abstract. Phytosociology is a subdiscipline of plant ecology that describes the co‐occurrence of plant species in communities. Gradient analysis and classification are its complementary tools. Various peculiarities and anachronisms of Central European phytosociology conceal its similarity with Anglo‐American approaches. Phytosociology deserves to be updated as a part of modern vegetation science that can build on a vast heritage of high‐quality data and the tools to store and analyse them in ways that go beyond syntaxonomy. By providing a context to more specialized pure and applied research, it has a crucial role to play in understanding community structure, ecosystem functioning and biological evolution. 相似文献
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甘肃河西走廓不同生境中鼠类群落结构初步研究 总被引:12,自引:0,他引:12
本文对河西走廓不同生境中鼠类群落的物种组成和多样性进行了初步研究,在6种生境中进行了定量调查和采集,共获13种标本,隶于6(亚)科9属,其中古北界种类占优势。多样性分析结果表明:6种生境的物种丰富度指数RMargaler在.6139-1.9689之间。Shannon-Wiener指数(H')为1.0695-1.5607,Pielou旨数(J')和Simpson指数(D)分别为0.7242-0.9735和0.2768-0.4683,不同生境的丰富种数量(N1)变化趋势与H'相似,而非常丰富种数量(N2)的变化趋势为:半莫荒灌丛生境>山地草原生境>戈壁荒漠生境>农田生境>森林生境>山地半荒漠灌丛生境。降水对不同生境类型中鼠类群落物种组成和多样性起直接的限制作用,同时海拔和人类干扰也是影响的因素。 相似文献
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This paper reports on the syntaxonomical structure, the ecological, physiognomical and phytogeographical differentiation of wetland forests in Latvia dominated by Picea abies and Fraxinus excelsior. Data were collected following the Braun-Blanquet approach and treated by the GROUPAGE, TWINSPAN and CANOCO programs. Spruce forests (Sphagno girgensohnii-Piceetum var. Crepis paludosa, S.g.-P. myrtilletosum) form a well-defined community mostly in shallow and medium deep (0.2–1.3 m) peatland. Assemblages of spruce wetlands in NEE Europe point to amazing similarity and little variation from NE Poland and Fennoscandia over the Baltic States to the central parts of Russia. Ash-dominated wetlands (Carici elongatae-Alnetum, Carici remotae-Fraxinetum) refer only to particular localities of the country and lie on wet mineral, gleyey soils, usually along brooks and on undulating ground rich in subsoil streams, mostly in sites without an evident accumulation of peat. In Latvia, these reach the northernmost limit of distribution and are poorer in species compared with the ash wetlands of Central Europe. 相似文献
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三峡库区消涨带植物群落的数量分析 总被引:23,自引:0,他引:23
运用双向指示种分析法(TWINSPAN)和除趋势对应分析法(DCA)对三峡库区消涨带植物群落进行了数量分类和排序分析。TWINSPAN将122个样方分成19类,可归为4个植被型,分类结果反映了植物群落与环境梯度间的关系,并在DCA分布图上得到较好的验证。DCA分布图的对角线基本反映了水淹时间长短和土壤湿度高低,表明水淹时间和土壤湿度是该区域植物群落组成和空间分布的主要限制性影响因子。对消涨带不同部位植物群落的物种组成和分布规律的分析为筛选耐水淹物种、进行三峡水库消涨带的植被恢复提供了物种参考。 相似文献
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A three-dimensional compositional pattern in the epiphytic lichen vegetation in Tasmanian cool temperate rainforest is demonstrated using the robust ordination technique, hybrid multidimensional scaling (HMDS). The first two dimensions are correlated with the age of the host tree (and the concomitant change in bark texture) and wetness of the substrate. No measured environmental variable is related to the third dimension, which is tentatively attributed to a gradient in the constancy of the microclimate. Patterns of richness of lichen growth forms and the cover of bryophytes are correlated with the three putative environmental gradients. Possible successional trends between 12 community groups derived by numerical classification are described with respect to changes in substrate age, wetness and microclimatic constancy. Temporal variation of these factors due to tree growth, together with the slow establishment and long persistence of some lichen species, make succession in epiphytic communities very complex. This study demonstrates the value of HMDS in identifying compositional patterns and generating hypotheses about the causal ecological factors. The existence of the postulated microclimatic constancy gradient was not appreciated before the analysis and its discovery illustrates the risk of relying on constrained ordination methods, such as canonical correspondence analysis.Abbreviations HMDS
Hybrid multidimensional scaling
- NMDS
Non-metric multidimensional scaling 相似文献
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中条山中段木本植物群落植物种多样性分析 总被引:11,自引:1,他引:11
采用样方法取样,依据重要值指标运用双向指示种分析(TWINSPAN)法,将山西中条山中段植被群系分成16个群丛。应用丰富度指数(R1、R2)、Simpson指数(λ),Shannon-Weiner指数(H′)和均匀度指数(E1、E5)研究了16个群丛的植物种多样性。结果表明:群系植物种多样性指数的大小受立地生境和人为活动的综合影响;森林群落的植物种多样性指数明显高于灌丛群落;群落植物种多样性在空间上的差异不仅决定于物种丰富度指数,更与各物种间的均匀度指数密切相关;进而影响不同层次的物种多样性对群落总体物种多样性的贡献。 相似文献
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IAHOPA, an overlay program package performing intersection analysis and information analysis has been applied to a large data set of relevés of beech woods in the Apennines (Italy) completed by several authors following the Braun Blanquet approach. The results have been treated by several numerical methods testing classification efficiency and predictivity. Ecological indicator values have been used to test for predictivity. The classification proposed by Gentile has been confirmed in its main lines. However 2 new associations (Polysticho-Fagetum and Digitali-Fagetum) and 12 new subassociations are described. Furthermore the Veronico-Fagetum Montacchini 1972 has been recognized also for the Apennines. The clusters corresponding to the association level could be classified in two main alliances: Geranio nodosi-Fagion and Geranio striati-Fagion as suggested by Gentile, however their syntaxonomical justification should be based on numerical comparisons of the data from the entire area of European beech woods. 相似文献