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1.
The paper presents the results of phytosociological research conducted on the vegetation of rock clefts and ledges in the Pamir-Alai Mountains (Tajikistan, Middle Asia). During the field studies, done in 2010–2012, 101 phytosociological relevés were taken. Plant species were recorded according to the Braun-Blanquet cover-abundance scale. Communities of calcareous rock clefts and ledges with small soil amounts from several ranges (Zeravshan Mts, Hissar Mts, Hazratishokh Mts, Darvaz Mts, Rushan Mts and Vanch Mts), inhabiting mainly the alpine and subnival zone, have been described. A synopsis of the rock communities of the Pamir-Alai is proposed. In the examined vegetation plots 77 vascular plant and 6 moss species were noted. The most frequent were: Achoriphragma pinnatifidum, Artemisia rutifolia, Asperula albiflora, Campanula incanescens, C. lehmanniana, Parietaria judaica, Pentanema albertoregelia, Poa relaxa and Stipa zeravshanica among vascular plants and Brachythecium albicans and Bryum caespiticum among mosses. Most of them are narrow endemics of Tajikistan or Middle Asia. The collected material presents most of the variability among the phytocoenoses of large crevices and rock ledges in limestone massifs in the alpine and subnival zones. As a result of field research and numerical analyses, 7 associations have been distinguished: Achoriphragmetum pinnatifidi, Asperulo albiflorae-Stipetum zeravshanicae, Inuletum glaucae, Paraquilegietum anemonoidis, Pentanemetum albertoregeliae, Rhinactinidietum popovii and Saussureaetum ovatae. The distinctiveness of habitat and species composition of Middle Asiatic rock communities makes it necessary to distinguish a new suballiance, Pentanemenion albertoregeliae, within the Asperulo albiflorae-Poion relaxae alliance. The main factors determining the species composition of classified associations seem to be the elevation above sea level and exposition. Alpine rock communities are one of the most unique and interesting plant formations in the moutainous areas of Pamir-Alai. Despite not being species-rich they often harbour many specialists adapted to harsh and extreme environments, especially in areas of Mediterranean-like climate.  相似文献   

2.
Arnica montana, a characteristic plant of nutrient-poor grasslands, has strongly declined during the last decades, particularly at lower altitudes. To gain insights into the underlying reasons for this decline, we recorded differences in size, stage structure and reproductive traits between 21 colline populations of A. montana in the Ardennes-Eifel region (280–600 m a.s.l.) and 10 montane populations in the Vosges Mountains (1,200 m a.s.l.). Community composition of the Violion caninae vegetation at colline sites and Nardion strictae vegetation at montane sites indicated that temperature and moisture were the main abiotic factors differentiating between low and high altitudinal relevées. The proportion of flowering rosettes decreased with altitude, indicating a shift from sexual reproduction to clonal growth. In contrast to expectation, Ellenberg values for nutrient availability as well as the proportion of young rosettes and population size did not differ between colline and montane populations. However, population size decreased with nutrient availability, indicating eutrophication as the reason for population decline. In small populations, plant density, the proportion of flowering rosettes, the number of flowerheads per rosette and the number of seeds per flowerhead were lower, indicating less suitable conditions. Thus, preventing further eutrophication in both colline and montane populations will be crucial for the conservation of the species. Reduced reproduction may not be important for the population dynamics of this clonal plant in the short term, but could affect genetic diversity and survival in the long term.  相似文献   

3.
This study provides a view of vegetation types dominated by Sesleria species in the Western Carpathians (Sesleria caerulea, S. heufleriana, S. tatrae, and S. uliginosa). We also took into account characteristics/traits such as plant life forms, autochthonous status, endemism, and ploidy level occurring within each relevé in our data set. Altitude and Ellenberg indicator values derived for each relevé were considered as well. Eight vegetation types/formations/habitats were recognized in a data set of 942 phytosociological relevés: (1) synanthropic vegetation, (2) rock fissures and screes, (3) alpine grasslands and heaths, (4) mesic grasslands and pastures, (5) springs and fens, (6) forests, (7) xerophilous shrubland, and (8) high-mountain scrubs (krummholz). Results corroborated and clearly emphasized that Sesleria caerulea has the widest ecological amplitude of all studied species because the species occurred among all studied vegetation types. Sesleria tatrae was present only in several vegetation types occurring from montane to alpine vegetation belts in the highest mountains. Sesleria heufleriana and S. uliginosa were recorded only in low-altitude areas. The difference between them lies mainly in the dampness of each locality. Sesleria heufleriana was frequently found in xerophilous communities, whereas S. uliginosa preferred humid habitats of springs and fens.  相似文献   

4.
5.
This paper reports a phytosociological study on managed hay meadow communities in the main mountains of the Spanish Central Range. Multivariate techniques (Cluster analysis and CA-ordination) were applied in the classification of the relevés and ordination of vegetation units and species. Clusters were related to the following associations: Agrostio castellanae–Arrhenatheretum bulbosi, Festuco amplae–Cynosuretum cristati, and F. amplae–Agrostietum castellanae. The scattergram suggested that the dynamic patterns between communities are associated with soil nutrient content and moisture. We propose a new subassociation: F. amplae–A. castellanae gaudinietosum fragilis that includes Salmantincensean Agrostis castellana communities growing in regions with lower supramediterranean thermotype.  相似文献   

6.
Stipa zeravshanica M. Nobis sp. nov. from the western Pamir Alai Mts (Tajikistan) is described and illustrated. Morphologically, the new species is similar to S. gracilis, but it is easily distinguishable by pilose (vs. glabrous) lower part of the awn, and generally somewhat longer ligules of the vegetative shoots. Epidermal patterns of the lemma in S. zeravshanica and three other closely related taxa, namely S. gracilis, S. himalaica and S. orientalis, were examined by means of SEM. The main macro‐morphological and micro‐morphological characteristics differentiating all mentioned species are presented. Additionally, a lectotype for S. gracilis is designated. Based on phytosociological relevés prepared during field investigation in the western Pamir Alai Mts, a new plant association Asperulo albiflorae–Stipetum zeravshanicae, occurring on shelves and rocky crevices is also described.  相似文献   

7.
The montane and subalpine forests of a mountain range in northwestern Montana were investigated using phytosociological and numerical methods. Twelve associations and two subassociations were identified, of which eight are described here for the first time. The forest vegetation of valleys and lower slopes is strongly affected by repeated fire and is placed in the new orderCalamagrostio-Pseudotsugetalia glaucae, which includes temperate, low elevation forests in inland regions of northwestern North America. These forests bear only weak resemblance to forests traditionally assigned to the classVaccinio-Piceetea, and occupy the habitats filled by broad-leaved forests elsewhere at temperate latitudes. Montane and subalpine forest vegetation is moister and has longer snow duration and a shorter growing season. Upper montane vegetation more closely resembles that of other temperate montane forests of the classVaccinio-Piceetea.  相似文献   

8.
Heathland vegetation of northern Spain, included in theCalluno-Ulicetea, was studied using a set of 802 phytosociological relevés. The existing syntaxonomy has been tested and most of the types (associations and subassociations) fit satisfactorily with the observed groupings. Two main problems were encountered within theUlex dominated communities of the Cantabrian fringe and the Castilian-Cantabrian heathland communities. Both groups of communities were subject to ordination in order to clarify relationships between them. For the former group, ordination suggests that three associations can be distinguished: theUlici-Ericetum vagantis (lowlands up to the submontane belt), theVaccinio-Ulicetum gallii for the communities of higher altitudes (montane belt) and theUlici-Ericetum ciliaris (hygrophilous heathlands). The Castilian-Cantabrian heathlands show a variable Mediterranean influence and have a dispersed distribution due to lithological conditions. This results in the distinction of two new associations, viz. theArctostaphylo crassifoliae-Daboecietum cantabricae (marly, water-retaining soils) and theEricetum scopario-vagantis (sandy soils). A complete classification of theCalluno-Ulicetea in the studied area and short ecological and biogeographical diagnoses are given.  相似文献   

9.
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   

10.
This paper describes the vegetation of the Carson Desert (Nevada, USA) based on a phytosociological analysis of its major plant associations, as determined by the Braun-Blanquet method. Diagnostic tables, climatic, edaphic, and biogeographical data were used to establish floristic affinities among identified plant communities and to interpret their distributions in zonal gradients. Their syntaxonomic positions in the classes Allenrolfeetea occidentalis and Artemisio tridentatae–Juniperetea osteospermae, and in the new class Sarcobatetea vermiculati were also established. Three associations (Atriplici confertifoliae–Sarcobatetum baileyi, Atriplici canescentis–Psorothamnetum polydenii, and Suaedo moquinii–Sarcobatetum vermiculati) are described here for the first time along with the order Sarcobatetalia vermiculati and the alliance Sarcobation vermiculati.  相似文献   

11.
We conduct a study of the dry forest in areas of scant rainfall in the Dominican Republic; these are sites with particular endemic habitats, as the samples reveal a high rate of local and insular endemic species, with 84 (24.85%) endemisms. This work covers dry forests rich in coarse spiny plants and includes a statistical (multivariate analysis), phytosociological and catenal study of the vegetation. We analyse the floristic composition, ecology, distribution and richness in endemisms of each association. The bioclimatic analysis reveals the different thermotypes and ombrotypes on the island, and locates the proposed plant associations in the infra- and thermotropical thermotypes, and in the arid, semiarid and dry ombrotypes. As a result of this phytosociological analysis, we propose the new alliance Harrio nashii–Acacion skleroxylae and four plant associations: Harrisio nashii–Prosopidetum juliflorae, Crotono poitaei–Erythroxyletum rotundifolii, Lonchocarpo pycnophylli–Cylindropuntietum caribaeae and Neoabbottio paniculatae–Guaiacetum officinali; these associations connect catenally with the subhumid forest and mangrove swamps.  相似文献   

12.
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   

13.
C. Blasi  G. Pelino 《Plant biosystems》2013,147(3):357-385
Abstract

The vegetation communities of the karst-tectonic basins of the Majella massif alpine belt were studied using the phytosociological methods, and analysed from coenological, synchorological and syntaxonomical viewpoints. During the field-work, 115 relevés were performed using the phytosociological approach of Braun-Blanquet, and these relevés were further subjected to multivariate analyses. Eight clusters of relevés resulted from the numerical classification. The plant communities identified in the study area were ascribed to the following five associations, two sub-associations and one community type: Leontopodio – Seslerietum juncifoliae (ass. nova); Helianthemo – Festucetum italicae (ass. nova); Gnaphalio – Plantaginetum atratae; Taraxaco – Trifolietum thalii gnaphalietosum magellensis (subass. nova); Luzulo italicae – Nardetum, Carici – Salicetum retusae; Saxifrago – Papaveretum julici, Saxifrago – Papaveretum androsacetosum (subass. nova), Plantago atrata and Leontodon montanus community. The distribution of these communities within the karst basins was found to be related to variations in topographic and geomorphological parameters, such as altitude, slope, soil availability and stoniness. All the new associations proposed in this paper belong to the suballiance Leontopodio – Elynenion and to the alliance Seslerion apenninae, both of which are endemic to the central Apennines. In order to compare the plant community types identified within the Majella massif to similar associations found in the rest of the Apennine chain, synoptic tables were constructed. Finally, a comparative phytogeographical analysis of the alpine belt vegetation of the Apennines, Dinarides, southern Balkans and eastern Alps is presented.  相似文献   

14.
Arbuscular mycorrhizal (AM) fungal spore communities and distribution patterns were surveyed in montane scrub grassland, alpine steppe, and alpine meadow sites at altitudes ranging from 3,500 to 5,200 m a.s.l. on the Tibetan Plateau. Thirty-two representative soil samples were collected from the root zone of the dominant and common plant species in late May 2004. Twenty-three AM fungal species representing six genera (Acaulospora, Entrophospora, Glomus, Pacispora, Paraglomus, and Scutellospora) were detected and species richness varied from 5.3 ± 0.8 to 10.5 ± 2.5 per site. Some AM fungal species were restricted to one vegetation type and Glomus mosseae, Glomus intraradices, and Scutellospora calospora were detected in all three vegetation types. Glomus species were found to be the most frequent and abundant in all three vegetation types. Acaulospora occurred mostly in the alpine steppe and alpine meadow. Scutellospora occurred mostly in montane scrub grassland. At the species level, Glomus mosseae was dominant in the montane scrub, Acaulospora laevis and Pacispora scintillans were dominant in the alpine steppe, and Acaulospora laevis, Pacispora scintillans, and Glomus claroideum dominated the alpine meadow. It was evident from the distribution pattern of AM fungi in the different vegetation types that the abundance and diversity of AM fungal species were lowest in the montane scrub grassland than the other two plant communities. Climatic conditions, especially temperatures, and intensity of land use may be the most important factors influencing the AM fungal community.  相似文献   

15.
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   

16.
Question: Can GIS and GPS technology be used to quantify the hydrological regime of different plant communities on turloughs (groundwater dependent calcareous wetlands)? Location: Skealoghan turlough, County Mayo, Ireland. Methods: Plant communities were mapped and digitised with GIS software and a digital elevation model of the site was constructed from differential GPS data. Together with records of water level fluctuations on the site from May 2001 to May 2004, these data were used to calculate hydrological variables for each plant community. Hierarchical cluster analysis was used to identify groups of plant communities with similar hydrological regimes. Results: 15 plant communities were mapped at Skea loghan, with the Cirsio‐Molinietum and Ranunculo‐Potentilletum anserinae being the dominant phytosociological associations. Skealoghan is subject to large temporal and spatial variation in its hydrological regime and fluctuations in water level are intrinsically linked to rainfall. The spatial variation in flooding can be linked to the vegetation zones. Conclusions: GIS and DGPS technology can be used to quantify the hydrological regime of different plant communities on turloughs. Since the hydrological regime is a major environmental factor controlling the vegetation composition of the site, the maintenance of natural flooding regimes is a vital component for the conservation and management of the diverse vegetation mosaic at Skealoghan turlough.  相似文献   

17.
ABSTRACT

A phytosociological study of the shrubland communities which colonise abandoned terraced olive groves in the Tyrrhenian district of Central Italy is presented here. The vegetational analysis was carried out using the Braun Blanquet phytosociological approach. Two main types of shrubland communities characterising distinct environmental conditions occur within abandoned terraced olive groves. On the one hand, there are those scrub types which tend to occupy the central part of the terrace; on the other hand, there are the scrubs types which develop along the stone walls bordering the terrace. Different phytosociological associations, sub-associations, and variants ranging from Pistacio-Rhamnetalia alaternii to Prunetalia spinosae are recognised and described. In the warm dry areas, both Myrto-Lentiscetum and Rhamno-Euphorbietum dendroidis occur. Also, a new Oleo-Ceratonion sub-association (Myrto-Lentiscetum spartietosum junceii) is presented here for the first time. In the inner zones of the study area, a range of aspects characterising a new Pruno-Rubion ulmifolii community type (Roso-Rubetum ulmifolii ass. nova) are identified.  相似文献   

18.
Abstract

In this paper, evidence for the presence of Festuca pallens Host in Italy is presented for the first time. This species is typical of the submontane and lower montane belt of the Gran Sasso d'Italia, a limestone massif of the Apennine chain (central Italy). In the Apennines this species occurs where subcontinental bioclimatic conditions and very shallow and subalcaline soils with abundance of calcareous debris prevail. From a phytosociological point of view, Festuca pallens seems to mainly characterise chamefitic Bromus erectus or Stipa capillata communities belonging to the xerophitic fringe of the Brometalia erecti grasslands.  相似文献   

19.
Abstract. The typology and distribution are discussed of hitherto poorly known Mediterranean-type maquis vegetation from the eastern stretch of the coastal fringe of the Cantabrian Mountains. 51 phytosociological relevés of maquis with Arbutus unedo (‘madroñales’) and Quercus coccifera (kermes oak shrubland or ‘coscojares’) were submitted to Correspondence Analysis and table rearrangement. The results are discussed and interpreted in the light of actual biogeographical and palaeohistorical knowledge. A sharp division between (uniform) acidophilous and (diversified) basophilous communities was revealed. On the basis of the phytosociological classification four new syntaxa are described: the associations Ulici gallii-Arbutetum unedonis, Phillyreo latifoliae-Arbutetum unedonis - with two subassociations: arbutetosum unedonis and viburnetosum tini - and the association Genisto occidentalis-Quercetum cocciferae.  相似文献   

20.
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