Variability and ecology of the alpine dwarf shrub community Loiseleurio-Cetrarietum

Summary Variation in the dwarf shrub community Loiseleurio-Cetrarietum from Mt. Patscherkofel, Austria, was investigated using polar ordination, principal component analysis, hierarchical cluster analysis, and multiple correlation analysis. Comparison was made with existing data (relevé tables) from the Alps. In addition to phytosociological methods the canopy structure and the morphological variability of the dominant species Loiseleuria procumbens were studied. The result of the namerical phytosociological analyses yield 3 clusters representing: 1) A dense Loiseleuria carpet, 2) a Loiseleuria carpet damaged by erosion and 3) an open Loiseleuria community on skeletal soils. The first two communities can be combined as one type because of their canopy structure in the form of dense intertwined individual plants and because of the morphological uniformity of Loiseleuria, although in the second group there are species growing on erosion gaps and showing close floristic connections to the third group. The comparison of 140 relevés from the Alps proves that the Loiseleurio-Cetrarietum is characterized only by the dominance of Loiseleuria procumbens while the abundantly occurring lichens change in their species composition along the gradient of wind, and elevation. The open Loiseleuria community at the most extreme habitats (cluster 3) is regarded as a new association. Not only floristic but also physiognomical, morphological and ecophysiological evidence led to this conclusion. The name Gymnomitrio-Loiseleurietum (ass. prov.) is proposed. This plant community shows floristic and ecological correlations to the Diapensia-Loiseleuria-Cesiolichen community known from Scandinavia.Nomenclature of species follows Ehrendorfer (1973) (vascular plants), Poelt (1974) (lichens) and Gams (1973) (mosses).For PCA, hierarchical cluster analysis, and multiple correlation analysis, computer programs from the data bank system (AFO-data) of the Alpine Forschungsstelle Obergurgl, Austria were used. I am indebted to Dr. S. Pamer and P. Moser for their invaluable help. For polar ordination a separate program was developed (language: Simula, author: Dr. G. Knecht). I am also indebted to Dr. H. Hilscher for the translation of the text.     

瑞典河漫滩草甸植被的数量分类和排序

本文用目前各国学者广泛使用的一些数量分类和排序方法对瑞典河漫滩草甸样地资料进行了分类和排序。所用的方法包括多元等级聚合分类(TABORD程序),多元等级分划分类(TWINSPAN程序),PCA排序(ORDINA程序),RA和DCA排序(DECORANA程序)。研究结果表明可以把28个样地分为6个群落类型,它们的分布格局是与土壤水分梯度密切相关的。此外本文还对数量分类和排序方法在植物群落学研究中的应用以及所用方法的比较进行了讨论。     

A coenocline of the high-ranked syntaxa of ruderal vegetation

Two sets comprising 1419 and 1350 phytosociological relevés of ruderal vegetation classified into 9 and 7 orders, respectively, from an area in the Podunajská ní zina Lowland, western Slovakia were ordinated using correspondence and detrended correspondence analyses. The paper describes a coenocline of the high-ranked syntaxa contained in the data sets, and discusses some issues of the classification of the syntaxa involved.The Bidentetalia and Potentillo-Polygonetalia should be considered a special category of synanthropic vegetation as habitat moisture (flooding and waterlogging) play the controlling role in the formation of structural and dynamical patterns within these communities. The latter factor complex is responsible for the clear separation of these orders from the other syntaxa included in the ordinations. The coenocline of terrestrial ruderal vegetation units has the following sequence along the CA axis 1: Poo-Polygonetalia, Sisymbrietalia, Eragostrietalia, Onopordetalia, Agropyretalia repentis, Artemisietalia vulgaris and Glechometalia hederaceae.Various complexes of soil factors and anthropogenic disturbance are operational along the concatenation (a series of portions composing the coenocline). The factor complex includes soil compaction, trampling disturbance, nutrient status, soil texture and moisture, and solar irradiation. Step-by-step ordination and interpretation of concatenated portions of the coenocline proved to be useful in the analysis of complex data sets.Abbreviations CA = correspondence analysis - DCA = detrended correspondence analysis - PCA = principal components analysis     

The high-rank syntaxa of the rock-cliff and scree vegetation of the mainland Greece and Crete

A revision was undertaken of the high-rank syntaxa of the vegetation occurring in rock fissures, ledges and screes of mainland Greece and Crete. All published phytosociological relevés available were collected and subjected to numerical classification and ordination. Four orders (Androsacetalia vandelii, Onosmetalia frutescentis, Potentilletalia speciosae andPetromaruletalia pinnatae) comprising 8 alliances (one of them new) were distinguished within theAsplenietea trichomanis (rock fissures, clefts, and ledges). The scree vegetation was classified partly within theThlaspietea rotundifolii (Drypidetalia spinosae with 2 alliances) and partly within theDaphno-Festucetea (Saturejo-Scutellarietalia—a new order, with 2 alliances). Ordination revealed clear differences in floristic composition of the alliances distinguished. The studied chasmophytic vegetation of Greece contains a very high proportion of endemics which serve as diagnostic species of the syntaxa. Further, an analysis of chorological species spectra suggested that the chorological homogeneity of a syntaxon should be considered an important diagnostic feature at high-syntaxon levels.     

Revision of the central Mediterranean xerothermic cliff vegetation

Questions

What are the syntaxonomic and synchorological patterns of the xerothermic chasmophytic vegetation in the central part of the Mediterranean Basin? What are the diagnostic species of the high‐rank syntaxa of Asplenietalia glandulosi, Onosmetalia frutescentis and Centaureo dalmaticae‐Campanuletalia pyramidalis?

Location

Mediterranean coastal and subcoastal areas of southern France, Italy, Malta, Slovenia, Croatia, Bosnia and Herzegovina, Montenegro, Albania and of mainland Greece.

Methods

The data set of 1,261 published relevés was analysed using hierarchical clustering (Flexible Beta method), involving a series of data transformations. Indicator species analysis was used to select the best dendrogram solution and identify diagnostic taxa of the main clusters. The dendrogram was interpreted from a syntaxonomic point of view, using nomenclatural type relevés as a basis. The NMDS ordination was performed in order to visualize the floristic relationships among associations and high‐rank syntaxa. MRPP was used to test for differences among alliances.

Results

The classification revealed four main clusters of relevés representing the chasmophytic vegetation of southern France, Sardinia and the northwestern part of Italy (Asplenienalia glandulosi/Asplenietalia glandulosi), the southwestern part of Italy and Malta (Tinguarrenalia siculae/Asplenietalia glandulosi), the Adriatic Basin area (Centaureo dalmaticae‐Campanuletalia pyramidalis) and the southern Balkans (Onosmetalia frutescentis). The NMDS ordination confirmed the overall pattern, while MRPP showed significant differences among the alliances of the above‐mentioned orders and suborders. The lists of diagnostic taxa of the high‐rank syntaxa were revised according to a supra‐national perspective.

Conclusions

The new syntaxonomic scheme provides a comprehensive overview of the chasmophytic vegetation of the central part of the Mediterranean Basin. This scheme mostly matches the recently published EuroVegChecklist, but also exhibits important novelties concerning the syntaxonomic position of some alliances (Dianthion rupicolae, Centaureion pentadactyli, Arenarion bertolonii and Caro‐Aurinion), and the floristic and chorological relationships among high‐rank syntaxa, with new revised sets of diagnostic taxa. This revision might be useful for further small‐scale phytosociological studies.

     

Numerical taxonomy of some taxa of the genus Fucus in the Iberian Peninsula

A study of morphological variation patterns in three Iberian Fucus species has been carried out. Data on 36 features from 113 specimens have been studied by numerical methods (PCA, discriminant analysis and ANOVA).The PCA ordination displayed a continuous trend of variation in the following Fucus species: F. ceranoides, F. vesiculosus and F. spiralis. However, no obvious morphological discontinuities have been observed. In addition, three varieties of F. spiralis and five of F. vesiculosus have been identified.At the varietal level discriminant functions could be used for identifying 93–100% of the individuals within F. vesiculosus and 72–91% of F. spiralis.The most discriminating diagnostic character appeared to be the midrib size, as detected by ANOVA procedures.Some qualitative characters, such as presence of vesicles, dioecious-monoecious character and receptacle edge shape, frond and receptacle shape, have been also important for discriminating specific and infraspecific taxa.A nomenclatural discussion of varietal taxa is also included.     

Classification of schoenus communities in South and Southeast Sweden

Summary The Schoenus phytocoenoses of South and South-eastern Sweden have been sampled by 189 relevés of standard areas (4 m²) and divided into clusters using the TABORD program on two homotoneity levels. Two Schoenus associations and five potential nuclei of associations, mainly Schoenus nigricans phytocoena, have been distinguished.The species have been divided into twelve groups on the basis of similarities in distribution amongst phytocoena and assumed environmental preferences. Acidophilous or indifferent species together with common mire species are characteristics of the Oxycoccus-Schoenus ferrugineus association, while basiphilous and wet-meadow species are typical of the Primula-Schoenus ferrugineus association and the Fissidens-Schoenus nigricans phytocoenon. The Primula-Schoenus ferrugineus association is characterized by species associated with Tofieldietalia and Eriophorion latifolii, while in the Oxycoccus-Schoenus ferrugineus association also Scheuchzerio-Caricetalia and Oxycocco-Sphagnetalia species play an important rôle. Another difference between the two associations is that hemicryptophytes and helomorphes dominate in the Primula-Schoenus ferrugineus association, while in the Oxycoccus-Schoenus ferrugineus association dwarf shrubs, hydrophytes and hydromorphes are rather common.The properties of the homotoneity and diversity indices used are compared and their compatibility is discussed.     

A phytosociological survey of the boreal forest (shape Vaccinio-Piceetea) in North America

A survey of syntaxa of vegetation of North American boreal forests (class Vaccinio-Piceetea) is presented. This phytosociological survey, carried out combining the Braun-Blanquet method with numerical syntaxonomical analyses (cluster and correspondence analysis), describes the associations of the North American boreal forests, which have several species, varieties or vicariant species in common with their Eurasian counterparts, and can be placed in the class Vaccinio-Piceetea. By means of tabular and multivariate analyses, 2084 North American relevés were compared with 3273 relevés from European, Japanese and Korean boreal forest, to describe and typify 4 orders, 10 alliances and 37 associations. Diagnostic tables, ordination, clustering, and climatic, edaphic and biogeographical data were used to show floristic affinities among these syntaxa and interpret their distribution areas. Syntaxa were briefly characterized by their floristic composition, physiognomy, succession, zonation, and biogeographical distribution.     

Validation of the Finnish forest types by numerical methods illustrated by means of two sets of relevé data

Examples show that two clustering programs (GROUPAGE, TABORD) group the forest vegetation into clusters with about the same results as obtained by a traditionally working plant sociologist assigning it to the Finnish forest site types. The best result is achieved by using both of these programs together with an additional ordination program (ORDINA). The differences when all three analyses are taken into account depend on the fact that there are often some transitional relevés in the material. In a few cases a new type determination for the relevé might be justified. The clustering methods show often groupings into smaller units (variants) inside the types, units which are rarely used in the Finnish forest type system.     

中国特有植物短丝木犀(Osmanthus serrulatus Rehd.)群落结构及其环境解释

为了解环境因子对短丝木犀植物群落的影响,研究了四川省宝兴县东拉山短丝木犀植物群落地区的环境因子、TWINSPAN分类、物种和多样性指数与环境因子的DCCA排序。结果表明:1)TWINSPAN将东拉山短丝木犀24个植物群落里划分为12个群落类型,分类结果在空间上反映了东拉山植物群落的演替变化趋势。2)短丝木犀植物群落生长在土壤含水量较高、郁闭度较高,并处于西南和南坡向的沟边。短丝木犀群落的主要伴生物种为鹅耳枥Carpinus turczaninowii、宝兴木姜子Litsea moupinensis、领春木Euptelea pleiosperma、云锦杜鹃Rhododendron fortunei、宝兴过路黄Lysimachia baoxingensis、糙苏Phlomis umbrosa和铁角蕨Asplenium trichomanes。3)DCCA排序结果验证了TWINSPAN分类结果的合理性,同时指出影响东拉山短丝木犀植物群落类型及空间分布的重要环境因子是土壤有机质和腐殖质含量。     

Longitudinal distribution of Trichoptera in the Loire River (France): simple ordination methods and community structure

The longitudinal distribution of Trichoptera at 37 sampling sites along 800 km of the Loire River (France) was analyzed in order to better understand large-scale changes in community structure occurring on a stream continuum. Different simple ordination methods — centered PCA and Correspondence Analysis — were performed to investigate these changes. Both analyses showed that a major change occurs in the community in the upper reaches of the Loire River between the Serre de la Fare and Vorey sampling sites with the appearance of Hydropsyche contubernalis and H. Exocellata. Even though other changes in community structure could exist, revealed either by Correspondence Analysis at the first sampling sites (crenal), or by PCA at sampling sites influenced by dams, this Trichoptera community appears to be stable enough in the latter part of the Loire River with the addition of a few species, Hydropsyche bulgaromanorum, Ecnomus tenellus and E. deceptor, rather than changes in species. The results are discussed in the light of different concepts in stream ecology, and the validity of such data analyses to describe some community patterns.     

珠穆朗玛峰自然保护区小叶金露梅灌丛群落数量分类和排序及其多样性垂直格局

根据野外样方调查数据,采用双向种指示分析(TWINSPAN)和典范对应分析(CCA),对珠穆朗玛峰国家级自然保护区小叶金露梅灌丛群落进行分类和排序,并分析物种多样性沿海拔梯度的分布格局。结果表明:(1)该区域24个样地中,记载的维管束植物共有23科45属80种,出现频度较高的种有小叶金露梅(Potentilla parvifolia)、高山嵩草(Kobresia pygmaea)、木根香青(Anaphalis xylorhiza)、垫状点地梅(Androsace tapete)、藏沙蒿(Artemisia wellbyi)、垫状雪灵芝(Arenaria pulvinata)和柴胡红景天(Rhodiola bupleuroides)等。(2)经TWINSPAN等级分类将该区域小叶金露梅灌丛24个样地划分为10个群丛类型。(3)样地和物种CCA二维排序结果表明,海拔和坡位是影响该区域小叶金露梅灌丛群落和物种分布格局的主要环境因子。(4)该区域小叶金露梅灌丛群落物种丰富度、Shannon-Wiener指数和Simpson指数均随海拔升高呈下降的趋势,而Pielou指数呈上升的趋势。(5)样地中优势种小叶金露梅的盖度和高度沿海拔梯度呈显著下降趋势。     

On the delimitation of the Mesobromion and Xerobromion in Belgium and French Lorraine

Within a broader study of the chalk and limestone grasslands in Belgium, Luxemburg and northern France, the limestone grasslands of the Meuse valley in Belgium and in French Lorraine were investigated. Floristic data as well as environmental variables were taken into account for the delimitation of species and relevé groups. Discriminant analysis and canonical correlation analysis proved to be very helpful in the interpretation of the detected groups as well as for the reconsideration of interrelationships between recognised syntaxa. The present results are consistent with the hypothesis that the limestone grasslands in French Lorraine, even those previously assigned to the Xerobromion, belong to the Mesobromion, and that the limestone grasslands in Belgium belong either to the Mesobromion or to the Xerobromion in an impoverished form.     

Pre-climax epiphyte communities of bryophytes and lichens in Mediterranean forests from the Central Plateau (Spain)

The pre-climax epiphytic communities of forests from the Spanish Mediterranean region (Central Plateau) were studied by numerical and traditional floristic methods. One hundred phytosociological relevés were analyzed through a classical numerical approach based on hard partitions improved by PCoA — Principal Coordinates Analysis — ordinations. Two groups easily related to two different suballiances included in Frullanion dilatatae Lecointe 1975, Ulotenion crispae (Barkman 1958) Lecointe 1975 and Fabronienion pusillae Barkman 1958 were detected. Two new syntaxa within the ass. Ortotrichetum lyellii (Allorge 1922) Lecointe 1975 are proposed. Phytogeography, syntaxonomy and ecology of these communities are discussed.     

Clusla: A computer program for the clustering of large phytosociological data sets

Summary CLUSLA, a computer program for the clustering of very large phytosociological data sets is described. It is an elaboration of Janssen's (1975) simple procedure. The essence of the program is the creation of clusters, each starting with one relevé, as the relevés are entered in the program. Each new relevé that is sufficiently distinct from already existing clusters is considered a new cluster. The fusion criterion is the attainment of a certain level of (dis-) similarity between relevé and cluster. Bray and Curtis' dissimilarity measure with presence-absence data was used.The program, written in FORTRAN for an IBM 370–158 system, can deal with practically unlimited numbers of relevés, provided the product of the number of primary clusters and the number of species does not exceed 140.000. We adopted maxima of 100 and 1400 respectively.After the primary clustering round a reallocation is performed. Then a simple table is printed with information on the significance of occurrence of species in clusters according to a chi-square approach. The primary clusters can be treated again with a higher fusion threshold; or approached with more elaborate methods, in our case particularly the TABORD program.The program is demonstrated with a collection of 6072 relevés with 889 species of salt marsh vegetation from the Working-Group for Data-Processing.Contribution from the Working Group for Data-Processing in Phytosociology, International Society for Vegetation Science. Nomenclature follows the Trieste system, which will be published later.The authors are very grateful to Drs. Jan Janssen, Mike Dale, László Orlóci and Mike Austin for their comments on drafts of the program, and to Wil Kortekaas for her help in the interpretation of the tables.     

Contribution to the knowledge on relic Stipa spp.-dominated ultramafic grasslands of the Central Balkans

The heterogeneity of the ultramafic vegetation of the Central Balkans is rather great. Although this vegetation has been continuously investigated, some gaps are still to be filled. For example, the lack of available data on ultramafic vegetation of the Republic of Macedonia is evident. In that light, we have investigated different relic Stipa species-dominated dry grasslands over ultramafic bedrock. Twenty relevés were made and compared to the similar vegetation types (i.e. Potentilla visianii, Centaureo kosaninii-Bromion fibrosi, “Thymion jankae”, Saturejo-Thymion and Alyssion heldreichii) by means of numerical analyses. We distinguished one new association and one informal community, providing them with diagnosis and lists of diagnostic, constant and dominant species. We also determined their syntaxonomic positions and relations to ultramafic syntaxa from the neighboring countries.     

Rupicolous vegetation of the betic ranges (south Spain)

On rupicolous vegetation (cl. Asplenietea trichomanis) of the Betic ranges in south Spain. The endemic alliance Saxifragion camposii developed in the upper zones of this area is here thoroughly examined. Phytosociological tables with records of all the syntaxa and biogeographical, ecological and floristic data among others are shown. Finally, as a result of a profound syntaxonomical discussion and the last data available the synopsis of this alliance is completed with four new associations: Hieracio texedensi-Moehringietum tejedensis, Athamanto hispanicae-Sideritetum stachydioidis, Sileno andryalifoliae-Saxi-fragetum camposii, Jasiono minutae-Saxifragetum rigoi.

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Resumen Se estudia la vegetación rupícola (cl. Asplenietea trichomanis) de las Cordilleras Béticas, emplazadas en el sur de España. En los territorios más elevados de estas se desarrolla la alianza endémica Saxifragion camposii, cuya revisión completa se realiza en este trabajo. Se aportan tablas fitosociológicas de todos los sintáxones, así como datos de tipo biogeográfico, ecológico, florístico, etc. Como resultado de una profunda discusión sintaxonómica y con los nuevos datos disponibles, se completa el esquema de la mencionada alianza con cuatro asociaciones nuevas (ver resumen en inglés).

     

Effect of streaked shearwaterCalonectris leucomelas on species composition ofPersea thunbergii forest on Kanmurijima Island,Kyoto Prefecture,Japan

The effects of trampling and burrowing by streaked shearwaters were studied on thePersea thunbergii forest in Kanmurijima Is. The vegetation data were analysed using both the phytosociological tabulation method and principal component analysis (PCA). The vegetation ordination on the first axis reflected the environmental gradient from light to heavy disturbance by the streaked shearwater, and the vegetation ordination on the second axis represented the gradient from the latter phase of forest succession to retrogressive succession. The position of the three vegetation groups in the ordination diagram successfully explained the relation between the habitat and the species composition. The disturbance caused by activities of the streaked shearwater such as burrowing and trampling causes a decrease of species, especially character species of Camellietea japonicae, and also causes retrogressive succession: patches ofMallotus japonicus develop and many heliophytes occur.     

Host races and sympatric speciation in small ermine moths, Yponomeutidae

The amount of genetic differentiation at various levels of evolutionary divergence (conspecific populations, sibling species and non-sibling species) in Yponomeuta was determined. Genetic distances between siblings or non-siblings were found to cover a wide range. It is concluded that such estimates do not give much information on the speciation process itself. Inbreeding coefficients were calculated for populations of Y. padellus from a total of six host plants. The grand mean F _ST value is 0.030±0.012. F _ST values for populations sampled from Crataegus, the common food plant of Y. padellus, are 2–3.5 times smaller than those for populations from the other food plants taken together. Host race formation, as measured by significant differences in allozyme frequencies between sympatric populations on two or more food plants, was investigated in four areas. Host race formation seems to occur in Y. padellus and sympatric speciation is a likely event.

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Résumé Le degré de différenciation génétique en allozymes à des niveaux divers de divergence évolutive (populations conspécifiques, sibling species et non-sibling species) d'Yponomeuta a été déterminé. Les distances génétiques entre des sibling species ou des non-sibling species sont très larges. Il en est conclu que de telles estimations ne fournissent pas beaucoup d'informations sur le phénomène de spéciation même. Des coéfficients de reproduction consanguine (F _ST) ont été calculés pour des populations d'Y. padellus provenant de six plantes-hôtes. La valeur moyenne F _STest .030±.012. Les valuers de F _ST des populations recueillies sur Crataegus, (plante-hôte habituelle d'Y. padellus), sont inférieures 2–3.5 fois à celles des populations de l'ensemble des autres plantes-hôtes. L'apparition de races en fonction de l'hôte, mesurée par les différences importantes dans de fréquences des allozymes entre populations sympatriques sur plusieurs plantes-hôtes, a été examinée dans quatre régions. Il apparaît ainsi que la formation de races en fonction de l'hôte se produit chez Y. padellus et que la spéciation sympatrique est un évènement très vraisemblable.

     

Numerical phytosociology of the subalpine belt of the Kazbegi region,Caucasus, USSR

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.