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1.
Ladislav Mucina 《Plant Ecology》1989,81(1-2):107-115
Ruderal communities dominated by Onopordum acanthium are encountered in those regions of Europe with a dry and continental climate. Variability in the climate and local phytogeography within these regions is reflected in the floristic variability of the communities studied. A floristic cline within the communities was summarised by means of multivariate classification and ordination methods. Two associations distributed in temperate Europe and belonging to the Onopordetalia, the Onopordetum acanthii s.str. and Carduo acanthoidis-Onopordetum acanthii, were distinguished; The Carduo acanthoidis-Onopordetum is varied and occurs in several geographic races and sub-races. The Onopordetum acanthii s.str. is confined to deep inner-montane valleys with a continental climate. The other Onopordum acanthium communities described from Spain belong to the Scolymo hispanici-Onopordetalia nervosi.Abbreviations CA = correspondence analysis - CLC = complete linkage clustering  相似文献   

2.
Patterns of prevalence in communities of bacteria in free-living adult, juvenile, and feces of alpine accentors (Prunella collaris) were studied in the West Carpathian Mountains, Slovakia, in 2002–2003. A total of 27 species of bacteria belonging to 13 different genera were identified in cloacal and pharyngeal swabs taken from captured birds (n = 30) and/or in feces (n = 171). Forty-six percent of adult males, 75% of adult females, and 82% of juveniles sampled tested positive for one or more types of bacterium. A close association was found between the genera Hafnia, Bifidobacterium, and Pseudomonas. The prevalence of bacteria in accentors was found to vary among seasons and between years but was not, in general, site-specific. Enterococcus and Escherichia (and possibly Hafnia and Serratia) were most prevalent in summer, whereas Bacillus, Klebsiella, Pantoea, Pseudomonas, Staphylococcus, and Yersinia occurred more often during other seasons. Evidence is presented that anthropogenic food obtained as refuse probably has a significant effect on the gut flora of birds frequenting areas of high human use.  相似文献   

3.
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   

4.
L. Mucino 《Plant Ecology》1982,48(3):267-275
The ruderal communities of the orders Sisymbrietalia and Onopordetalia from the western part of Slovakia have been subjected to numerical classification and ordination. The ordination techniques proved to be a useful tool in the elucidation of the cluster pattern as well as in the detection of the main environmental variation underlying the floristic variation within the data. Results obtained with numerical techniques and traditional syntaxonomical classification have been compared. The similarity between these results is low at the level of the orders. This incompatability is explained by the differences in the weighting of the species in the course of the classification process and by the addition of non-floristical criteria that often occurs in syntaxonomical classification according to Braun-Blanquet. The highest value has been observed at the 3-clusters level (both orders and the Malvion neglectae). High similarity among the results of the numerical techniques have been observed, particularly in the group of space-dilating clusterings (Ward's method, Complete linkage clustering and MeQuitty's similarity analysis). Average linkage clustering produces the most diverse result. The Malvion neglectae appeared as a separate group in all numerical techniques adopted. This suggests the upranking of its syntaxonomical position. The Bromo-Hordeion murini turned out to be a very heterotoneous syntaxon.  相似文献   

5.
Forty Molinietalia communities were analyzed from the phytogeographical point of view in order to establish their distribution tendencies in Czechoslovakia in relation to the floristic regions of Hercynicum, Pannonicum and Carpaticum. Only few moist meadow communities of the Molinietalia order are found in the whole area under study; most of them have their distribution center in one of the floristic regions mentioned above. Eleven Calthion and two Molinion associations are confined to the Hercynicum, eight of them strictly. It is only in the Moravian and Slovak Pannonicum that all associations of the alliances Cnidion venosi and Veronico longifoliae-Lysimachion occur; they appear there together with two Molinion communities, the distribution of which is, however, a little wider. Three Calthenion communities show a still wider distribution, extending into the adjoining areas. One Calthenion community occurs in the Bohemian Pannonicum and its surroundings, two Calthenion associations have their distribution center in the Carpaticum, but they are not strictly confined to it.The author wants to express her thanks to Doc. Dr Miroslav Smejkal, CSc., for critical revision of the text.  相似文献   

6.
Cluster analysis and multidimensional scaling are used to revise the syntaxonomy of the Fagion illyricum alliance based on presence/absence data. The operational syntaxonomical units are associations and subassociations as suggested in the literature. The results of principal coordinates analysis and nonmetric multidimensional scaling are fairly congruent, whereas some differences occur between the dendrograms obtained by complete linkage and incremental sum of squares clustering. However, a joint evaluation of ordinations and the consensus classification derived from the cluster analysis results facilitates a meaningful revision of the formerly accepted division of the alliance. New low-level syntaxa, and some new names, including Aremonio-Fagion to replace the invalid alliance name of Fagion illyricum, are proposed and the removal of four associations from the alliance is suggested.  相似文献   

7.
Riverside vegetation dominated by Salix gracilistyla was analysed. In total, 77 phytocoenological relevés from Japan and both Korean Republics were compared. Based on 20 own relevés from Kumgang-san Mts (North Korea) a new association Artemisio feddei-Salicetum gracilistylae was described. It occupies alluvia of rivers and streams flooded for several times yearly. This species-rich community differs from the most similar, but species-poor association Salicetum gracilistylae Minamikawa 1963, described from Japan and known also from South Korea by numerous differential taxa.  相似文献   

8.
P. Pyšek  M. Šrůtek 《Plant Ecology》1989,81(1-2):199-208
A vegetational transect across a glacial valley was investigated. Structure and species composition, as well as influence of disturbance by biotic factors (grazing of sheep and cattle) and abiotic factors (topography, wind, water) are discussed.According to species composition and community structure, 4 main vegetation types were distinguished by comparing field data from phytosociological relevés with results of numerical treatments (3 methods of numerical classification and DCA ordination): 1) Chamaesciadium acaule-Polygonum viviparum, 2) Festuca cf. woronowii-Carex tristis, 3) Veratrum lobelianum-Taraxacum stevenii and 4) Rhododendron caucasicum-Vaccinium myrtillus communities.Species diversity (evenness, and number of species) was low in the ungrazed dwarf-shrub alpine communities, which were dominated by Rhododendron caucasicum, in comparison with the grazed meadow. The highest values of these characteristics were found in the transitions among the types.  相似文献   

9.
Mangal (tidal forest) communities vary with respect to position in the littoral sequence, and latitude. A previous classification of mangal from the southern and western coastlines of Australia has been subjected to a series of ordinations, in an attempt to produce a robust syntaxonomy. An iterative ordination process allowed for the progressive refinement of the syntaxonomic units. This process allows an ecologist to use critically a numerical technique to refine ecological assumptions developed from field work, and/or non-numerical analyses. Ordination analysis suggested a need for the classification to be refined, and allowed the construction of a final syntaxonomy. In conjunction with broad environmental data collected during the investigation, the ordinations allowed the development of some environmental perspectives. These suggested that littoral position is a stronger environmental influence on mangal communities than balance between salt and freshwater.  相似文献   

10.
Abstract

Thermophilous deciduous forest is widespread in northern mainland Greece and extends in patches further south to Peloponnisos and the bigger islands. In this paper, we provide a phytosociological survey of the plant communities of deciduous oak and mixed forest throughout Greece, based on about 370 relevés from the literature and more than 300 personal unpublished ones. Assocation names of the thermophilous deciduous forest are re-evaluated, and syntaxonomic conclusions added. The relevés are classified, and 13 associations and several additional subtypes described and presented in synoptic constancy tables. The following associations were recognized, and characterized by species composition, ecology and distribution: 1. Phillyreo–Carpinetum orientalis, 2. Dryopterido pallidae–Ostryetum carpinifoliae, 3. Tilio tomentosae–Castanetum; 4. Genisto carinalis–Quercetum petraeae, 5. Querco frainetto–Castanetum, 6. Cytiso villosi–Castanetum; 7. Lathyro laxiflori–Castanetum; 8. Symphyto ottomani–Quercetum frainetto, 9. Verbasco glabrati–Quercetum frainetto; 10. Huetio cynapioidis–Quercetum frainetto; 11. Digitali viridiflorae–Quercetum frainetto; 12. Geranio asphodeloidis–Quercetum frainetto; 13. Oenantho pimpinelloidis–Quercetum frainetto. Associations 12 are assigned to the alliance Fraxino orni–Ostryion, 46 and 813 to the Quercion frainetto (both Quercetalia pubescentis), 3 interim to the Tilio–Acerion, and 7 to the Quercetalia ilicis. The two Quercetalia pubescentis alliances co-occur in northern Greece; their habitats differ chiefly in terms of soil conditions, bedrock and topography, rather than in overall climatic character.  相似文献   

11.
Ring-width chronologies of Picea abies (L.) Karst. from ten sites in the Tatra Mountains, Poland, were developed to explore growth/climate responses in stands along an altitudinal gradient ranging from 839 to 1468 m a.s.l. There were positive relationships between current-year radial growth and mean monthly temperatures in March, April, June and July, but with increasing elevation, the strength of this correlation declined for March–April and increased for June–July temperatures. The mean monthly temperature in October of the previous year positively influenced radial growth of trees at all sites. Lower mean temperatures in January negatively affected growth of trees at the high-elevation sites. Trees at the low-elevation sites responded positively to a warm early spring, whereas trees at the high-elevation sites showed positive growth responses to higher summer temperatures. Growth of trees at the high-elevation sites was better explained by the temperature regime than was growth at the lower-elevation sites. Therefore, it is likely that these sites may be particularly sensitive to potential effects of temperature change.  相似文献   

12.
Two species of small rodents, Mastacomys fuscus and Rattus fuscipes, and one small dasyurid marsupial Antechinus swainsonii live sympatrically in the subalpine habitat of SE Australia. This paper describes the reproductive characteristics and ontogeny of M. fuscus, and shows that the three species have different reproductive strategies that, in part, are a reflection of their different phylogenies. Cold and snow in winter, and a short summer season, limit the length of time available for reproduction and development. The rodent species exhibit similar reproductive characteristics to those in alpine regions of Europe, North America and South Africa.  相似文献   

13.
Syntaxonomical study of Italian wall vegetation   总被引:1,自引:0,他引:1  
A syntaxonomical study of Italian wall vegetation based on classification and ordination of a large phytosociological data set from various authors (using the IAHOPA program) has confirmed the alliances Centrantho-Parietarion and Galio-Parietarion (order Parietarietalia judaicae, class Parietarietea judaicae), as already proposed by traditional syntaxonomy. The variation in humidity and the north-south geographical gradient are shown to be the most significant factors for the differentiation of this vegetation in Italy. The presence of some associations belonging to the class Asplenietea trichomanis (alliance Cystopteridion, Potentillion caulescentis and Centaureo-Campanulion) shows a strong connection with natural rock vegetation.  相似文献   

14.
Zielonka  Tomasz  Piątek  Grzegorz 《Plant Ecology》2004,172(1):63-72
This is a study of the colonization pattern of herbs and dwarf shrubs on rotten logs in subalpine spruce forests (Plagiothecio Piceetum) in the Tatra Mountains. On four study plots (total area 1.43 ha.) all dead logs were measured and the decomposition stage was estimated using the 8-degree scale. For each log the cover of all vascular species, bryophytes and lichens was determined according to the methods of classical phytosociology. Constancy and an index of coverage were calculated for all vascular species growing on logs. The total volume of logs was relatively high (93 m3 ha–1) and constituted 22% of the volume of living trees. Logs and stumps covered 411 m2 ha–1. These values are similar to those known from natural spruce forest from Carpathians and Scandinavia. The 8 stages of decomposition were equally represented, which indicates a constant supply of dead wood to the forest floor over time. The colonization of dead wood starts with lichens, followed by bryophytes and finally herbs and tree saplings. The first vascular plant colonists of dead logs appear at decay stage nr. 3 at least 20 years after tree death. The most suitable condition for most of the herb species corresponds to decay stage nr. 6 ca. 50 years after tree death. The herb cover is distinctively dominated by Vaccinium myrtillus. Simultaneously with herb species, tree seedlings colonize the logs. Constancy and abundance of Norway spruce saplings increases with advanced decomposition. It seems that the herb cover of logs does not hinder the regeneration of spruce.  相似文献   

15.
Abstract. A numerical syntaxonomic study of rupicolous vegetation of the Asplenietalia petrarchae in the Iberian Peninsula is described. The study is based on 37 local tables (OSUs) of different rupicolous communities from limestone cliffs found in the eastern half of the Iberian Peninsula. Three classification approaches were followed: (1) ‘hard partition’ techniques, (2) ‘fuzzy partition’ and (3) ordination partition. In order to find a direct solution, we tried an evaluation system based on the inertia associated with a CCA, Canonical Correspondence Analysis, and its relationships with the inertia of a similar CA, Correspondence Analysis. The most effective solutions were found through spatial partitions, and the best partition was obtained with CA considering five segments per axis. Among the fuzzy partitions the best solution was obtained with two clusters and a fuzziness value of 1.20. The best hierarchical partition was Complete Linkage with Chord Distance as a resemblance function. With the GRID procedure applied to the CA diagram, three different groups were distinguished. The first group is related to the Saxifragion boisseriano-reuterani, including five OSUs from Baetic ranges; the second group is very close to the Cosentinio-Lafuenteion rotundifoliae and includes 11 OSUs from thermo-mediterranean areas; the third group, including 21 OSUs basically related to meso-mediterranean areas, is strongly related to the Teucrion buxifolii.  相似文献   

16.
Summary Four Transsylvanian Geranion associations with their differentiating combination of ecological components are described. Emphasis on different floristic characteristics. of the Geranion or different class concepts may lead to classification into different higher syntaxonomical units. The hypothesis that the Geranium group species have their optimum in Transsylvania in forb communities of the Geranion type could be validated. The Geranion in Transsylvania is either a natural intrazonal community or a semi-natural, ephemeral community. Both are typical of calcareous soils on limestone, conglomerate or marl in the reach of a zonal vegetation of relatively mesophytic Quercetea pubescenti-petraeae, of Carpinion dacicum and of Fagion forests of the lower montane zone. The restricted habitat and/or time niche of Geranion communities is further explained by the palatability, the dissemination mechanism and the lack of competitive vigour against tuftgrassers of its constructive species.The authors want to express their gratitude to Miss Mieke Rats for being their cheerful driver during three weeks of field-work. They thank Drs. J. Louppen for help with the computerization of our data. They are greatly indebted to Prof. Dr. V. Westhoff for creating the basic conditions for the present study. They want to thank him especially for his stimulating interest. They are indebted to the directoon of the Grassland Research Station Mâgurele for permitting the collaboration and facilitating the research.  相似文献   

17.
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   

18.
A total of 31 suface sediment samples were collected from West Kunlun Mountain in south Xinjiang Autonomous Region in northwest China. These samples are from seven types of vegetation: Picea schrenkiana Fisch. et Mey. forest, Sabina Spach. woodland, sub-alpine steppe, alpine meadow, desert vegetion, cushion-vegetation and vegetation adjancent to glaciers. Pollen percentages and pollen concentrations were calculated in all samples. The dominant pollen types in the region are Chenopodiaceae, Artemisia, Picea, Ephedra, Gramineae, Cyperaceae, Rosaceae, Leguminosae, Compositae etc. In order to reveal the relationship between pollen composition and the vegetation type from which the soil sample was collected, principal component analysis and group average cluster analysis were employed on the pollen data. The results revealed that the major vegetation types in this region could be distinguished by pollen composition: a. Samples from desert vegetation were dominated by pollen of Chenopodiaceae (about 60195%). The percentages of all other pollen types were low. b. Picea forest samples were rich in Picea pollen (about 20%) Sabina forest had more Sabina pollen grains than other vegetation types (about 5%, others <1%). Pollen percentages of Artemisia, Chenopodiaceae and Ephedra were comparatively higher (each about 20%) in these samples from the two types of vegetations. C. Pollen percentages of Artemisia, Cyperaceae, Gramineae and Chenopodiaceae were high in both sub-alpine steppe and alpine meadow. But steppe containal more Artemisia and Chenopodiaceae (steppe 33.75% and 32.30%, meadow 15.57% and 19.48% in average), less Cyperaceae and Gramineae (steppe 2.58% and 7.60%, meadow 22.35% and 12.93% in average) than meadow. d. Samples from cushion-vegetation and vegetation adjacent to glaciers were mainly composed of pollen grains transported from other sites. It was not easy to distinguish them from other vegetation types. Principal component analysis and cluster analysis distinguish samples from Picea forest, Sabina woodland, sub-alpine steppe, alpine meadow and desert vegetation. Therefore we think it will be possible to apply the module to reconstruct past vegetation in this region and other similar regions. Regression analysis was also applied to reveal the relationships between pollen and plant percentages of Artemisia, Chenopodiaceae, Cyperaceae and Gramineae. The results indicated that a linear relationship existed between pollen and plant percentages for Artemisia, Chenopodiaceae and Cyperaeeae.  相似文献   

19.
Aspects of population dynamics in Halimione portulacoides communities   总被引:1,自引:0,他引:1  
Summary Studies on sample plots inHalimione portulacoides communities show that environmental disturbances, either natural or induced by man, start a sequence of partly overlapping density maxima inSuaeda maritima, Aster tripolium andPuccinellia maritima successively, before the originalHalimione community totally recovers. When succession time before recovering is long enough, there are tendencies in redundancy of this sequence stressing the unilinear character of the succession. Minor environmental impacts induce a longer time-lag period of theSuaeda density maximum, suggesting threshold values of these impacts for the species to maintain minimal population densities or to become locally extinct. This sequence of interim species starting after an environmental disturbance, suggests also a gradient character in various biological attributes, for instance in life-time, propagation, nutrient and genetic plasticity strategies. The mechanism described can therefore be interpreted as a complex of mostly well-adapted and well-integrated inherent species strategies capable of absorbing environmental shocks. It is suggested that in the salt-marsh ccosystem the pattern of spatial variation in densities and that of temporal variation in fluctuations of the three species populations under natural conditions reflect corresponding patterns of environmental disturbances in the vegetation taking into account a timelag associated with the magnitude of the impact concerned.Contribution to the Symposium on Plant species and plant communities held at Nijmegen, 11–12 November 1976, on the occasion of the 60th birthday of Professor Victor Westhoff.Nomenclature follows Heukels-van Ooststroom. Flora van Nederland, 18e druk, 1975. Wolters-Noodhoff, Groningen.The authors are greatly indebted to Dr K.F. Vaas (Yerseke) for reviewing the English text.Communication Nr. 160.  相似文献   

20.
Otto Wildi 《Plant Ecology》1989,83(1-2):179-186
The differentiation of river flood plain vegetation is predominantly determined by the inundation frequency and the type and age of the substrate. A comparison of data published in 1958 with recent relevés from all parts of Switzerland indicate that the hitherto known gradient- and group structure is disintegrating into multiple floristically isolated stands as a result of waterflow management constructions. In view of further vegetation mapping, a two-phase classification is proposed where the core of the gradients and groups is isolated and analysed first. The outliers are then re-attached to serve as possible indicators of the existence of variation not sufficiently described by the data. To structure the tedious analytical calculations involved, a hierarchical procedure has been developed.Abbreviations AOC = Analysis of concentration - CA = Correspondence analysis - PCA = Principal components analysis  相似文献   

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