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1.
Abstract. The peatlands of Atlantic Canada are classified in four plant alliances, consisting of 10 plant associations. The four plant alliances comprise the dry bog communities (Kalmio-Cladonion Wells 1981), wet bog communities (Scirpo-Sphagnion Wells 1981), hummock and ridge communities of slope and string fens (Betulo-Sphagnion Wells all. nov.), and poor, intermediate and rich fen plant communities (Scirpo-Myricion Wells 1981). Distribution maps are presented for relevés in each of the 10 associations. Based on species distributions, floristic regions are defined for peatlands in Atlantic Canada. Nutritional characteristics are also described for each plant association. pH and total soil concentrations of calcium, nitrogen and iron proved reliable in separating bog from fen. A boundary between ombrotrophic peatlands and minerotrophic peatlands is suggested, based on a soil pH of 4.0, total soil concentrations of 3.0 mg g?1 Ca, 4.0 mg g?1 Fe, 13.0 mg g?1 N and a Ca/Mg ratio of 2.5. Comparisons between the syntaxa for peatlands in Atlantic Canada and those in Europe are discussed for higher taxa. The possibility of establishing a new order (Chamaedaphno-Scirpetalia Wells ord. nov.) for peatlands in Atlantic Canada is also discussed.  相似文献   

2.
Abstract. The syntaxonomy of the perennial nitrophilous vegetation assigned to the Artemisietea vulgaris of the northern part of the Iberian Peninsula (Basque Country and surrounding areas) was revised. The study area is of biogeographic importance due to its transitional character - here, the ruderal vegetation of the Mediterranean and that of temperate Europe meet. Numerical ordination of the communities was performed in order to reveal systematic relations between the syntaxa. Two subclasses, Artemisienea vulgaris and Onopordenea, encompassing five orders, Convolvuletalia, Galio-Alliarietalia, Artemisietalia, Onopordetalia, Carthametalia lanati, and seven alliances with 12 associations and two rankless communities were distinguished.  相似文献   

3.
Abstract. A syntaxonomic study of trampled plant communities in North Korea is presented. Analytic and synthetic methods of the Braun-Blanquet approach together with a numeric-syntaxonomical analysis (cluster analysis and principal coordinate analysis ordination) were employed. With the exception of the Bryo-Saginetum japonicae, all the associations, such as the Artemisio asiaticae-Plantaginetum asiaticae, Plantagini depressae-Polygonetum avicularis, Polygono avicularis-Potentilletum costatae, Eragrostio multicaulis-Plantaginetum depressae, Euphorbio maculatae-Centipedetum minimae, Digitario pectiniformis-Eleusinetum indicae and Setario viridis-Chlorisetum virgatae, are described for the first time. Some communities also include a number of subassociations. Trampled communities are found along edges of paths and in cracks among paving stones. Soils vary from loamy to sandy and skeletal. A phenomenon of seasonality in expression of ruderal communities was observed in North Korea. It is assumed that this seasonality is controlled by pattern of precipitation showing distinct climatic seasons (e.g. pre-monsoon and post-monsoon periods). The ruderal vegetation seasonality is supposed to become more pronounced towards tropical regions. Several mesophilous or slightly hygrophilous European species occur frequently in North Korean trampled communities including Chenopodium glaucum, C. ficifolium and Potentilla supina. Their occurrence in trampled habitats is hypothesized as being related to high air humidity and associated wet climate.  相似文献   

4.
Abstract

The vegetation communities of the trampled habitats in the Plitvice Lakes National Park were studied during 2005 and 2006. With the numerical classification of the relevés, six clusters were obtained, corresponding to the following specific communities: cluster 1 – ass. MatricarioPolygonetum arenastri– the intensively trampled and grazed habitats; cluster 2 – ass. MatricarioPolygonetum arenastri– the only intensively trampled habitats; cluster 3 – ass. CoronopodoPolygonetum arenastri– very intensively trampled and grazed farmyards; cluster 4 –Trifolium fragiferum community – the trampled surfaces of moist habitats; cluster 5 – ass. Lolietum perennis– the moderately trampled surfaces of roads and yards; cluster 6 – ass. PrunelloRanunculetum repentis– trampled surfaces of forest roads. The first three clusters belong to the vegetation of intensively trampled habitats of the class Polygono arenastriPoetea annuae and the last three clusters belong to moderately trampled habitats of the class MolinioArrhenatheretea. In the analysis of the ecological factors it is established that separation of the relevés is influenced most greatly by the trampling intensity observed in the field, and of the Ellenberg indicator values, the most important are light, moisture, soil reaction and temperature. Using the analysis of the plant functional traits it is established that therophytes, annuals, biennials, species resistant to trampling and grazing, neophytes and archeophytes prevail in the intensively trampled habitats. In contrast, hemicryptophytes, perennials, and indigenous plant species prevail in the moderately trampled habitats. Representation of the C-S-R plant functional types shows also that trampling as a disturbance factor has a large influence on the differences in the relevés. In the intensively trampled habitats, there is a large proportion of ruderals, while in the moderately trampled habitats there is a large proportion of competitors.  相似文献   

5.
Woody perennial plants on islands have repeatedly evolved from herbaceous mainland ancestors. Although the majority of species in Euphorbia subgenus Chamaesyce section Anisophyllum (Euphorbiaceae) are small and herbaceous, a clade of 16 woody species diversified on the Hawaiian Islands. They are found in a broad range of habitats, including the only known C4 plants adapted to wet forest understories. We investigate the history of island colonization and habitat shift in this group. We sampled 153 individuals in 15 of the 16 native species of Hawaiian Euphorbia on six major Hawaiian Islands, plus 11 New World close relatives, to elucidate the biogeographic movement of this lineage within the Hawaiian island chain. We used a concatenated chloroplast DNA data set of more than eight kilobases in aligned length and applied maximum likelihood and Bayesian inference for phylogenetic reconstruction. Age and phylogeographic patterns were co‐estimated using BEAST. In addition, we used nuclear ribosomal ITS and the low‐copy genes LEAFY and G3pdhC to investigate the reticulate relationships within this radiation. Hawaiian Euphorbia first arrived on Kaua`i or Ni`ihau ca. 5 million years ago and subsequently diverged into 16 named species with extensive reticulation. During this process Hawaiian Euphorbia dispersed from older to younger islands through open vegetation that is disturbance‐prone. Species that occur under closed vegetation evolved in situ from open vegetation of the same island and are only found on the two oldest islands of Kaua`i and O`ahu. The biogeographic history of Hawaiian Euphorbia supports a progression rule with within‐island shifts from open to closed vegetation.  相似文献   

6.
Abstract. A survey of high-rank syntaxa of vegetation of European springs (class Montio-Cardaminetea) is presented. It shows the complexity of the class and the relations between the units. More than 1200 relevés were arranged into six phytosociological tables, each representing an alliance. A synoptic table comprising all alliances is presented. Bryo-phytes are the most important group in most of the communities, both regarding biomass and cover. The Adiantetea and the Montio-Cardaminetea are combined into one class. As to floristics and ecology, there are no obvious reasons to distinguish more than one order in this class. The vegetation of European springs is divided into six alliances: (1) Adiantion, split into two new suballiances, Adiantenion and Lycopodo-Cratoneurenion; (2) Cratoneurion commutati; (3) Cardamino-Montion - incl. three new suballiances: Mniobryo-Epilobienion hornemannii, Swertio-Anisothecienion and Cardamino-Montenion; (4) Dermatocarpion; (5) Epilobio nutantis-Montion; (6) Caricion remotae - incl. two new suballiances: Caricenion remotae and Cratoneuro filicini-Calthenion laetae. The alliances are floristically and ecologically characterized and their distributions in Europe shown on maps.  相似文献   

7.
Abstract. Effects of interspecific interactions on the organization of two trampled communities, Eragrostio ferrugineae - Plantaginetum asiaticae (EP) and Eleusino indicae - Digitarietum violascentis (ED), were examined by 4-yr field experiments. We compared changes in the relative abundance of the main component species of the communities in monoculture and mixed culture along a trampling gradient. At no trampling in mixed culture, Ambrosia artemisiifolia var. elatior and Erigeron annuus (roadside herbs, RH) predominated and excluded the trampled community species. Severe trampling markedly reduced the predominance of these roadside herbs, promoted Eragrostis ferruginea (a perennial grass of EP), but suppressed Eleusine indica (an annual grass of ED). These results suggest that the differentiation of trampled and roadside herb communities under heavy trampling are caused by asymmetric competition between their main species. Several species pairs showed a constant rank order of relative cover at high trampling levels. Pennisetum alopecuroides (a perennial grass of both RH and EP) and Eragrostis coexisted, indicating symmetric competition. Eragrostis and Plantago asiatica (a perennial herb of EP) or Poa annua (a winter-annual grass of both EP and ED) coexisted through separation in phenology. Eragrostis promoted the survival of Plantago by moderating unpredictable drought (commensalistic positive interaction). This suggests that community composition is maintained by several interspecific interactions.  相似文献   

8.
Abstract. The woody and shrubby riparian vegetation of the Mediterranean Region of Spain shows a progressive displacement from the Querco-Fagetea, typical of Central Europe, towards the Nerio-Tamaricetea, which has its maximum expression in North Africa. We studied the occurrence of 107 riparian plant communities on 52 locations in the Segura River Basin (SE Spain) and their presumed relation to variation in rainfall and temperature. On the basis of agglomerative clustering and Redundancy Analysis (RDA) three riparian vegetation complexes were identified and characterized by (a) Central European-related temperate communities, (b) predominantly North African riparian communities and (c) a combination of both community types, respectively. North African communities predominated in the lower stretches of the Segura Basin, probably due to the prevailing semi-arid bioclimate.  相似文献   

9.
Mires with attributes similar to the patterned fens of boreal continental regions have recently been reported from northern Scotland. This paper reports on the vegetation and water chemistry of 18 of these sites. Most of the 18 mires displayed remarkable uniformity in their vegetation, with Carex lasiocarpa being a main character species. Major variation of plant communities is associated with microtopographical niches, similar to those found on ombrotrophic mire systems and secondarily with pH and conductivity of surface waters. Nine vegetation noda are described and compared with existing phytosociological associations and National Vegetation Classification (NVC) communities. The dominant Sphagnum - Carex communities are intermediate between the Oxycocco-Sphagnetea and the Caricion lasiocarpae and are thus difficult to assign to existing associations or to NVC communities. Although there is a large variation in pH of surface waters (3.9–6.6), mean measurements for terrestrial and aquatic communities are 5.12 and 5.51 respectively. pH levels are comparable with poor fen systems elsewhere in Britain and slightly higher than patterned fens in continental regions of Europe and North America. The vegeta-tional and chemical attributes of these sites therefore confirm the existence of true patterned fen systems in the British Isles.  相似文献   

10.
Diversity indices (dominance and evenness) and ecological spatial structure (lifestyles and relative abundances) are important features of Changhsingian brachiopod communities prior to the end-Permian mass extinction (EPME) and could predict temporal and spatial extinction patterns during the EPME. In South China, Changhsingian brachiopod communities show higher diversity than other contemporaneous brachiopod communities in the world and have been reported from a variety of sedimentary environments. In this paper, brachiopods from 18 sections in South China were selected to divide communities and compare their ecological structure. Based on the results of network analysis, cluster analysis and quantitative data from the selected sections, we show that Changhsingian brachiopod communities in South China can be categorized into three assemblages along a marine depth gradient: the Neochonetes–Fusichonetes–Paryphella Assemblage from the shallow-water clastic-rock facies, Spinomarginifera–Peltichia–Oldhamina Assemblage from the shallow-water carbonate platform facies and Fusichonetes–Crurithyris Assemblage from the deep-water siliciclastic intracontinental basin facies. Compared with communities from carbonate platform facies, the communities from siliciclastic facies were characterized by high dominance, low evenness and low lifestyle diversity, which might be important biotic factors leading to earlier extinctions. After the extinction began in all environments, the whole earliest Triassic brachiopod community was first dominated by Fusichonetes and then by Crurithyris. These patterns of domination and replacement could be explained by morphological and ecological advantages. The domination of these two genera, which were already adapted to the oxygen and food-limited deep-water habitat, indicates that the cooler deep-water environment might have been a relatively less stressed habitat after the beginning of the EPME. This suggests that global warming might be the main trigger among the previously proposed synergistic environmental stresses, while anoxia might not, at least for the beginning of EPME.  相似文献   

11.
In Italy, woods dominated by Quercus petraea are well documented within local and regional phytosociological studies but a critical revision of their principal ecological-floristic components based on a comprehensive Italian data set was missing. We gathered 209 published and unpublished Italian phytosociological relevés, where Q. petraea was dominant, that were investigated by means of multivariate analysis. The ecological requirements of the resulting groups were indirectly calculated by means of Ellenberg indicator value, and a chorological analysis was performed. The fidelity coefficient (phi) for the diagnostic species of each group was calculated. According to our analysis, five different types of Q. petraea woods were found to be present in Italy. Each group was characterized by means of its floristic, ecological and chorological components. These resulting five groups were further compared with similar Q. petraea-dominated woods recorded in other European locations, as to the floristic and chorological components. We collected 57 synoptic tables of Q. petraea communities coming from all over Europe. This data set, together with the Italian relevés, was submitted to exploratory multivariate analysis using also the chorological information. According to these analyses, the Italian woods dominated by Q. petraea can be subdivided in two main clusters: the communities belonging to It-1 group (Alps) fell within the central European communities, distinguished by the predominance of large distribution and European chorotypes. All the other Italian groups of relevés resulted to be positioned in the cluster which includes central southern, central eastern and eastern European Q. petraea communities. From the syntaxonomical point of view, the results of this analysis allow to attribute the Italian Q. petraea woods to seven alliances of three different orders. The ecological similarities between Erythronio-Quercion petraeae and Erythronio-Carpinion betuli are highlighted and the distribution of Erythronio-Quercion petraeae is limited to northern Apennines, in particular, to slopes facing the Po Valley.  相似文献   

12.
We present a syntaxonomic account of the communities of the alliances of Oxytropido-Elynion Br.-Bl. 1949 and Festucion versicoloris Krajina 1933 from Western Carpathians. Both alliances comprise naked-rush, cushion form and dwarf-shrub heath communities typical of wind-exposed habitats occurring at the highest altitudes of the Tatra Mts. They represent a relic vegetation of the cold stages of the Pleistocene (probably Late Glacial Maximum) and they can be classified within the class of Carici rupestris-Kobresietea bellardii Ohba 1974. A set of relevés was subject to numerical-classification analysis. Floristics and ecology of the communities were characterised and the relationships to similar syntaxa were discussed. The Oxytropido-Elynion is restricted to the extreme ridge positions in the highest altitudes of the Belianske Tatry Mts. Five associations were distinguished, such as the Pyrolo carpaticae-Salicetum reticulatae, the Festuco versicoloris-Oreochloetum distichae, the Festucetum versicoloris, the Oxytropido carpaticae-Elynetum myosuroides and the Drabo siliquosae-Festucetum versicoloris. The Festucion versicoloris is limited to the mylonite zone of the alpine and subnival belt of the Vysoké Tatry and Západné Tatry Mts (and found as rare in the Nízke Tatry Mts). The stands of these communities prefer terraces of steep rocky faces and cliffs and stabilised small-grained screes below the cliffs. Within this alliance, three associations were described, including the Agrostio alpinae-Festucetum versicoloris, the Silenetum acaulis and the Salicetum kitaibelianae.  相似文献   

13.
V. Pietsch 《Plant Ecology》1985,59(1-3):97-109
On the basis of three selected examples chorological phenomena in waterplant communities of central, east and southern Europe are represented. Species of the Atlantic-oceanic floral element of the order Juncetalia bulbosi, like Pilularia globulifera, Eleocharis multicaulis and Deschampsia setacea are growing in markedly secondary sites near their eastern border, i.e. in the Lusatian district of central Europe, especially in sand, gravel and clay pits as well as in residue lakes of opencast mines. As a result of intensive recent human activities numerous new sites are being established now causing an expansion of their distribution area. With decreasing oceanity from the central part to the eastern border of the area a change in the floristic-sociological structure of the relevant plant communities and in the hydrochemical composition of the respective water bodies takes place. In western Europe the species grow in soft water poor in minerals, in the eastern part (central Europe) in mineral-rich, hard water with calcium and sulphate.At present Ceratophyllum submersum has a high frequency in the northeastern area in Mecklenburg. The sites are morainic lakes (kettle holes) and small waters and ponds near settlements, which are enriched in minerals and nitrales in consequence of the intensive agricultural use of inorganic fertilizers. Moreover the waters are alkaline and rich in minerals, especially bicarbonate and possess a high range of total hardness. The example of eight different sites of Aldrovanda vesiculosa illustrates a striking change of its diagnostic value in its disjunct north-south distribution. In the northern part of central Europe Aldrovanda is found in the communities of the Utricularietea intermedio-minoris, both in waters with a low acidity rich in sulphate and in alkaline waters rich in bicarbonate (Sphagno-Utricularion and Scorpidio-Utricularion respectively). In southern central Europe and in southeastern Europe Aldrovanda occurs in Lemnetea and Potametea communities. In northeastern Poland Aldrovanda is found together with Hydrilla verticillata, Chara mentosa, Myriophyllum verticillatum and Scorpidium scorpioides.
Die Sippennomenklatur richtet sich nach Rothmaler et al. (1970).  相似文献   

14.
Zusammenfassung Behandelt werden montane Trittpflanzengesellschaften (s. Tab. 1–3), ihre Gliederung und syntaxonomische Stellung. Gemeinsamen Besonderheiten entsprechend werden sie innerhalb der Plantaginetalia bzw. Agrostietalia in vikariierenden Verbänden/Unterverbänden, Alchemillo-Ranunculion, Poenion supinae, Alchemillo-Saginenion, zusammengefaßt.
Summary Plantaginetea communities of the montane belt of Central Europe (see table 1–3) are discussed as regards their systematical order and syntaxonomical arrangement. In accordance with the features they have in common they are classified within Plantaginetalia respectively Agrostietalia invicariant alliances/suballiances: Alchemillo-Ranunculion, Poenion supinae, Alchemillo-Saginenion.
Herrn Prof. Dr. Dr. h.c. E. Oberdorfer zum 75. Geburtstag.  相似文献   

15.
16.
Invasive plants are often associated with greater productivity and soil nutrient availabilities, but whether invasive plants with dissimilar traits change decomposer communities and decomposition rates in consistent ways is little known. We compared decomposition rates and the fungal and bacterial communities associated with the litter of three problematic invaders in intermountain grasslands; cheatgrass (Bromus tectorum), spotted knapweed (Centaurea stoebe) and leafy spurge (Euphorbia esula), as well as the native bluebunch wheatgrass (Pseudoroegneria spicata). Shoot and root litter from each plant was placed in cheatgrass, spotted knapweed, and leafy spurge invasions as well as remnant native communities in a fully reciprocal design for 6 months to see whether decomposer communities were species‐specific, and whether litter decomposed fastest when placed in a community composed of its own species (referred to hereafter as home‐field advantage–HFA). Overall, litter from the two invasive forbs, spotted knapweed and leafy spurge, decomposed faster than the native and invasive grasses, regardless of the plant community of incubation. Thus, we found no evidence of HFA. T‐RFLP profiles indicated that both fungal and bacterial communities differed between roots and shoots and among plant species, and that fungal communities also differed among plant community types. Synthesis. These results show that litter from three common invaders to intermountain grasslands decomposes at different rates and cultures microbial communities that are species‐specific, widespread, and persistent through the dramatic shifts in plant communities associated with invasions.  相似文献   

17.
Kobayashi  T.  Okamoto  K.  Hori  Y. 《Photosynthetica》1999,37(1):123-130
Field gas exchange and water potential in the leaves of a C3 dicot, Plantago asiatica L., and a C4 monocot, Eleusine indica Gaertn., which dominate in trampled vegetation in eastern Japan were surveyed during the growing periods for two consecutive years. Net photosynthetic rate (P N) of E. indica increased with photosynthetic photon flux density (PPFD) and leaf temperature (TL). P N was not saturated at PPFDs above 1500 μmol m−2 s−1 and at TL above 30 °C. On a sunny day in mid summer, maximum P N was two times higher in E. indica than in P. asiatica [42 vs. 20 μmol(CO2) m−2 s−1], but their transpiration rate (E) and the leaf water potential (ΨL) were similar. Soil-to-leaf hydraulic conductance, which probably plays a role in water absorption from the trampled compact soil, was higher in E. indica than in P. asiatica. The differences in photosynthetic traits between E. indica explain why E. indica communities more commonly develop at heavily trampled sites in summer than the P. asiatica communities. This revised version was published online in June 2006 with corrections to the Cover Date.  相似文献   

18.
The purpose of this study was to determine the conservation status of a Salix herbacea L. population, located in the N-Apennines (Italy), toward the southern edge of the species’ distribution. A 3 year-long study (1999–2001) was conducted to evaluate the effects of human trampling on Salix herbacea. Two stands, one trampled and one untrampled in the same site, were compared. The measured variables included: total vegetation cover; cover and female catkin number of Salix herbacea. The trampled stand showed a decrease in both Salix cover and sexual reproduction. We suggest possible conservation strategies to preserve the Salix herbacea trampled stand from its local extinction.  相似文献   

19.
Abstract. In this paper we analyse six communities with seven Mimosa species in the Tehuacán‐Cuicatlán valley, Mexico. All species are endemic to Mexico and four are endemic to the valley. Mimosa species are found in (1) the ‘matorral xerófilo’ (arid tropical scrub): Mimosa calcicola, M. lacerata, M. luisana, M. polyantha and M. purpusii, and (2) the ‘selva baja caducifolia’ (tropical deciduous forest): M. adenantheroides, Mimosa texana var. filipes. Most of them occur in similar soil environments, while M. polyantha and M. calcicola establish in particular soil conditions and only M. luisana establishes in two different sites showing a wider range of adaptation to soil characteristics. The communities studied include 24 plant families, 51 genera and ca. 70 species (5% of the total flora estimated in the valley). Heterogeneity was found among the communities. Our results point to the replacement of ‘matorral xerófilo’ and ‘selva baja caducifolia’ by ‘matorral espinoso’ (thorny scrub). Thorny species (e.g. Acacia cochliacantha, Mimosa spp.) are becoming the dominant/codominant elements in the communities. Within the communities, Mimosa species have a significant influence on soil pH, organic matter and electrical conductivity values. These species contribute to ameliorate soil nutrient conditions (OM, Ntot, P, Ca, Mg, Na and K contents) as well as other environmental factors (e.g. temperature, shade) under their canopy in degraded plant communities and may serve as ‘resource islands’.  相似文献   

20.
E. Krahulec 《Plant Ecology》1985,59(1-3):119-123
Two types of Nardus-rich communities may be distinguished in Europe according to their geographic pattern:I. Communities of high mountains showing discontinuous variation. Different florogenesis in island-like high mountains results in a number of alliances characteristic for particular mountain systems: Trifolion humilis Quézel 57 (Atlas, N Africa), Plantaginion thalackeri Quézel 53 (Sierra Nevada), Campanulo-Nardion Rivaz-Martinez 63 (mountains of the central Iberian peninsula), Nardion Br.-Bl. 26 (from Pyrenees, Auvergne to W and E Carpathians), Potentillo ternatae-Nardion Simon 58 (S Carpathians, Pirin, Rila), Jasionion orbiculatae Lakui 66 (Dinarids), Trifolion parnassi Quézel 64 (S Greece), Nardo-Caricion rigidae Nordhagen 37 (Iceland, Scotland, Scandinavia, W Sudeten).II. Communities at lower altitudes with continuous variation, where particular syntaxa are difficult to distinguish. Along the climatic gradient from a subatlantic to a subcontinental climate, a cline in floristic composition of the communities under discussion is found. Towards the eastern borderline, the communities are poorer in characteristic species. Here only one alliance is considered-Violion caninae Schwickerath 44. A Similar situation occurs along the altitudinal gradient in mountains. Only in mountains with a belt of alpine communities the montane Nardeta are saturated with alpine species. This thpe of communities was described as Nardo-Agrostion tenuis by Sillinger (1933).  相似文献   

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