Towards unification of national vegetation classifications: A comparison of two methods for analysis of large data sets

Abstract. In European phytosociology, national classifications of corresponding vegetation types show considerable differences even between neighbouring countries. Therefore, the European Vegetation Survey project urgently needs numerical classification methods for large data sets that are able to produce compatible classifications using data sets from different countries. We tested the ability of two methods, TWINSPAN and COCKTAIL, to produce similar classifications of wet meadows (Calthion, incl. Filipendulenion) for Germany (7909 relevés) and the Czech Republic (1287 relevés) in this respect. In TWINSPAN, the indicator ordination option was used for classification of two national data sets, and the extracted assignment criteria (indicator species) were applied crosswise from one to the other national data set. Although the data sets presumably contained similar community types, TWINSPAN revealed almost no correspondence between the groups derived from the proper classification of the national data set and the groups defined by the assignment criteria taken from the other national data set. The reason is probably the difference in structure between the national data sets, which is a typical, but hardly avoidable, feature of any pair of phytosociological data sets. As a result, the first axis of the correspondence analysis, and consequently the first TWINSPAN division, are associated with different environmental gradients; the difference in the first division is transferred and multiplied further down the hierarchy. COCKTAIL is a method which produces relevé groups on the basis of statistically formed species groups. The user determines the starting points for the formation of species groups, and groups already found in one data set can be tested for existence in the other data set. The correspondence between the national classifications produced by COCKTAIL was fairly good. For some relevé groups, the lack of correspondence to groups in the other national data set could be explained by the absence of the corresponding vegetation types in one of the countries, rather than by methodological problems.     

Diversity,variability and habitat characteristics of the communities dominated by Sesleria species (Poaceae) in the Western Carpathians

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.     

An association-analysis of montane grasslands of Sri Lanka

Association-analyses were made of montane grasslands (patanas) of Sri Lanka using higher plant and soil microfungal data. Stand classifications derived from higher plants and microfungi were remarkably parallel and were in complete agreement with the tentative division of patanas into five major types. The ecological distinctiveness of the five patanas was further evident from the phytosociological affinities of species indicated by classifications of higher plants and microfungi. Multivariate analyses of higher plants and fungi from the same ecosystem are regarded as alternative approaches which provide more information together than alone.     

Nuovi micromiceti su Pandanacee

Abstract

Helianthemetea guttati communities are pioneer spring and early summer ephemeral grasslands, dominated by non-nitrophilous therophytes. In Continental Portugal, these communities have not yet been fully investigated, and thus the objectives of the present study are: (1) to identify community types in therophytic grasslands; (2) to recognize those communities that configure the European priority habitat 6220* (pseudo-steppe with grasses and annuals); (3) to establish environmental gradients underlying their spatial variation; (4) to assess how floristic composition is affected by land use factors. Vegetation sampling using phytosociological methodology was carried out on 80 grasslands. Modified Twinspan classification and canonical correspondence analysis (CCA) was applied for the classification and ordination of relevés whereas partial CCA (pCCA) and variation partitioning were used to assess the relative influence of individual land use factors. Some 270 species were identified across 11 community types whose floristic patterns were mainly explained by environmental gradients related to altitude and soil type while land use variables could only explain a small part of the floristic variation. Based on biogeography and the determination of diagnostic species, four phytosociological new associations and a new subassociation are proposed: Holco-Brachypodietum distachyi, Holco-Micropyretum tenellae, Micropyro-Anthoxanthetum aristati and Leontodonto-Vulpietum bromoidis vulpietosum membranaceae.     

研究报告: 第五版《世界卫生组织中枢神经系统肿瘤分类指南》下成人胶质瘤诊断及预后

目的 脑胶质瘤是最常见的恶性原发性中枢神经系统肿瘤,近年来分子病理的快速发展对胶质瘤诊断及分级带来了重要影响,在2021年发布的《世界卫生组织中枢神经系统肿瘤分类指南》（第五版）引入了更多分子指标对肿瘤的诊断和分级进行指导。本研究旨在临床队列中比较最新版指南和上一版指南对肿瘤诊断及预后评估的影响,以期为临床实践活动中新版指南的应用提供数据参考和依据。方法 回顾性纳入了癌症基因组图谱数据库512例胶质瘤样本,分别依据2016版和2021版《世界卫生组织中枢神经系统肿瘤分类指南》进行诊断、通过Kaplan-Meier进行生存曲线绘制和中位总生存期计算和生存差异分析。结果 对512例样本分别完成了上一版指南和最新版指南的诊断及分级。在新版指南下分别有53和72例异柠檬酸脱氢酶（IDH）突变型和IDH野生型的胶质瘤诊断级别升级为了4级,且这些诊断级别升高的胶质瘤的预后更差。结论 最新版指南较上一版指南可对胶质瘤进行更为精准地分类及分级,在有条件的情况下应尽快依据最新版指南开展诊断及分级。     

Rilevamento Cartografico Della Vegetazione Della Conca di Bormio (Valtellina) Presentazione della Carta Fitosociologica all'1:5.000

Abstract

Account on the Cartography of the Vegetation of the Basin of Bormio (Valtellina). Presentation of the phytosociological Map 1:5000. — The authors illustrate the features of the new phytosociological map of the basin of Bormio (Valtellina). The chief types of vegetation of the region are outlined.     

A phytosociological study of the macrophytic vegetation of running waters in western lower saxony (Federal Republic of Germany)

A survey was carried out of the macrophytic vegetation in running waters of Western Lower Saxony. Three hundred and eighty-two phytosociological relevées were classified by common table work to 30 vegetation types of different phytosociological validity. The vegetation types are described and floristically characterized. Most of them belong to the complex Sparganium emersum community, which is characterized by the dominant occurrence of the nymphaeid species Sparganium emersum Rehm., Nuphar lutea (L.) Sm., Sagittaria sagittifolia L. and Potamogeton natans L., but magnopotamid-, parvopotamid-, batrachiid- and pleustophyte-dominated communities also occur. Similarity between the different vegetation types was checked by multivariate techniques, one classification technique (minimum variance clustering) and one ordination technique (principal components analysis). Additionally, syndynamical relations between the types were studied by observing the vegetation changes of 46 sample points within 2 years. The relations between different vegetation types are shown by combination of the different approaches. Finally, some more general statements are made regarding the handling of such data sets, as well as the consequences of the results for the classification of macrophytic vegetation in Central European rivers.     

The Balkan wet grassland vegetation: a prerequisite to better understanding of European habitat diversity

The knowledge of broad-scale floristic variation in wet grasslands, which are endangered throughout Europe, is still limited and some regions have remained unexplored so far. In addition, hitherto published phytosociological studies were concentrated at the national level and therefore national vegetation classifications are not consistent with each other. In order to overcome these shortcomings of traditional phytosociology, we gathered original data from Bulgaria and analysed them together with the data from Central Europe. We further analysed major compositional gradients within Bulgarian wet grasslands and changes in species richness along them. We sampled 164 wet grassland vegetation plots throughout Bulgaria. We further prepared a restricted data set of wet grasslands from Central-European phytosociological databases. Both data sets were merged and classified by modified TWINSPAN. Four distinct vegetation types were differentiated. Even if they correspond with traditional alliances, which are primarily drawn as geographically defined units in Western and Central Europe (sub-Mediterranean Trifolion resupinati, sub-continental Deschampsion cespitosae and Molinion caeruleae and sub-oceanic Calthion palustris), they all occur in Bulgaria. When more precise classification was applied, two types of sub-Mediterranean wet grasslands and one high-altitude type of Calthion grasslands were detected solely in Bulgaria. DCA analysis showed that altitude is a dominant gradient controlling variation in Balkan wet grasslands. The second DCA axis was interpreted as the gradient of nutrient availability. Species richness shows skewed-unimodal trends along both major gradients, with the highest species richness in intermittently wet nutrient-limited grasslands. Tukey post-hoc test of altitudinal differences amongst vegetation types is significant for all pairs of clusters, suggesting that altitudinal differentiation is responsible for co-occurrence of nearly all European types of wet grasslands in Bulgaria. Our results suggest that (1) climate is an important factor for the diversity of wet grasslands; (2) Balkan vegetation of middle altitudes matches with that of Central Europe, whereas that of the lowest altitudes corresponds rather to the sub-Mediterranean region and high mountains are specific; (3) upward shift of Central-European vegetation types in southern Europe, so often described in forest vegetation is also evident for grassland vegetation and (4) the high diversity of Balkan vegetation is determined by a diverse relief enabling confluence of habitats possessing different climatic conditions.     

Are habitat types compatible with floristically‐derived associations?

Abstract. The habitat type system developed by R. Daubenmire has been widely adopted throughout the western United States. Habitat types result from a site classification derived from the classification of late seral plant communities using selected indicator species. It has been suggested that the classification of late successional vegetation used to derive habitat types does not substantially differ from phytosociological classification in the sense of Braun‐Blanquet approach, and that habitat types can be adopted in their present form into floristically‐based vegetation classifications. Despite the many commonalities between the two systems, however, the classification methods, and specifically the use of indicator species in the habitat type system, yield a significantly different classification than the phytosociological approach. This is demonstrated in the comparison of a habitat type classification with the results of a recent phytosociological classification of forest vegetation in the northern Salish Mountains of Montana.     

A phytosociological analysis of abandoned terraced olive grove shrublands in the Tyrrhenian district of Central Italy

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.     

Syntaxonomical revision of the Triseto flavescentis-Polygonion bistortae alliance in the Carpathians

Abstract

This phytosociological study of the Carpathian species-rich mesophilous mountain hay meadows (Triseto flavescentis-Polygonion bistortae alliance, Molinio-Arrhenatheretea class) presents the first unified large-scale classification system in four countries: Slovakia, Poland, Romania and Ukraine. The starting dataset contained relevés of the Molinio-Arrhenatheretea, Mulgedio-Aconitetea and Nardetea strictae classes. Numerical classification and semi-supervised classification by K-means method were used for the analyses. An electronic expert system and diagnostic species for grassland vegetation served for identification of a priori groups in K-means method. The final dataset contained 612 relevés. Altitude, climatic data and Ellenberg indicator values were used for ecological differentiation of syntaxa. The main gradients in floristic composition were analysed by Detrended Correspondence Analysis. Finally, the eight well-differentiated associations and one newly described association were determined: Campanulo glomeratae-Geranietum sylvatici, Geranio sylvatici-Trisetetum flavescentis, Crepido mollis-Agrostietum capillaris, Geranio-Alchemilletum crinitae, Alchemillo-Deschampsietum caespitosae, Phyteumo (orbicularis)-Trifolietum pratensis, Astrantio-Trisetetum flavescentis, Trollio altissimi-Knautietum dipsacifoliae and Violo declinatae-Agrostietum capillaris ass. nova. The differences in vegetation diversity of mountain hay meadows between particular countries were confirmed: Alchemillo-Deschampsietum caespitosae occurs in all studied territories, Campanulo glomeratae-Geranietum sylvatici occurs predominantly in Slovakia and the newly described association Violo declinatae-Agrostietum capillaris ass. nova could be found only in Ukraine.     

Correlation between macrophyte vegetation and some water properties in the irrigation system of the Lower river Po Plane

Abstract

The distribution of macrophytic plant communities, defined by phytosociological numerical methods, in the irrigation system of the Lower river Po Plane was correlated with water characteristich. Water samples were collected periodically within phytocoena well-characterized from the phytosociological viewpoint. Nymphaeid-dominated communities (all. Nymphaeion) usually occur in deeper waters than elodeid- myriophyllid-, and ceratophyllid-dominated vegetation types (all. Potamogetonion). Hydrochemically, all of the studied waterbodies can be classified as rich in electrolytes and in bicarbonates. The distribution of phytocoena reflects a gradient in nutrient content: the Nymphoidetum peltatae characterizes waters moderately rich; the Myriophyllum spicatum community and the Trapetum natantis fairly rich; the Potamogetonetum pectinati and the Ceratophyllum demersum community very rich in nutrients.     

Un indice che stima il peso dei caratteri per classificazioni monotetiche

Abstract

An « index weighing » characters for monothetic classifications. — The Author, according to the classification principles of maximization, presents an index in order to value in what measure characters may be considered good for monothetic classifications. The index is given by the ratio between the average similarity within a set of entities exhibiting the character whose importance we want to ascertain and the average similarity that such entities have with those not exhibiting it.     

The Pinus halepensis Mill. forests in the central-eastern European Mediterranean basin

The Pinus halepensis Mill. forest vegetation of the central-eastern European Mediterranean basin (France, Italy, Croatia, Albania, Greece) is described here. This study was carried out considering published and unpublished phytosociological data, with the organisation of a systematic classification (syntaxonomic scheme) of the order Pinetalia halepensis according to the principal floristic variations, at multiple spatial scales and according to the physiognomic–structural, floristic, ecological and biogeographical characteristics. Five alliances and 25 associations are recognised.     

Local ranges of phytosociological associations: are they reflected in numerical classification?

In the tradition of European phytosociology, delimitations of vegetation units such as associations are mostly based on data from small areas where more detailed vegetation sampling has been carried out. Such locally delimited vegetation units are often accepted in large-scale synthetic classifications, e.g. national vegetation monographs, and tentatively assigned to a small geographical range, forming groups of similar (vicarious) vegetation units in different small areas. These vicarious units, however, often overlap in species composition and are difficult to recognize from each other. We demonstrate this issue using an example of the classification of dry grasslands (Festuco-Brometea) in the Czech Republic. The standard vegetation classification of the Czech Republic supposes that the majority of accepted associations (66 out of 68) have a restricted distribution in one of the two major regions, Bohemia or Moravia. We compared the classification into traditional associations with the numerical classification of 1440 phytosociological relevés from the Czech Republic, in order to test whether the traditionally recognized associations with small geographical ranges are reflected in numerical classification. In various comparisons, the groups of relevés identified by numerical analysis occupied larger areas than the traditional associations. This suggests that with consistent use of total species composition as the vegetation classification criterion, the resulting classification will usually include more vegetation units with larger geographical ranges, while many of the traditional local associations will disappear.     

Ginkgo,a multivariate analysis package

Abstract. The Ginkgo software is a subset of the VegAna (for Vegetation edition and Analysis) package that contains three programs named Quercus, Fagus and Yucca. Ginkgo is a multivariate analysis tool; it is oriented mainly towards ordination and classification of ecological data. Quercus is a relevé table editor; it handles community data to perform a phytosociological analysis. Fagus is a floristic citation editor; it can handle data coming from field surveys, bibliographic sources or collections. Yucca is a cartographic tool; it allows plotting distributions of taxa or syntaxa. VegAna is produced by the Department of Vegetal Biology, University of Barcelona. The general project is directed by Xavier Font I Castell, the Ginkgo module by Francesc Oliva I Cuyàs. Programmers are Miquel De Cáceres and Richard Garcia. This review deals primarily with Ginkgo.     

Syntaxonomical study of Italian wall vegetation

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.