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Marginal associations, i.e. floristically impoverished associations at the margin of the distribution area of a higher syntaxon, form a problem in vegetation classification, because true character species are lacking. We propose a new approach for the classification of such marginal associations, making use of the notion of 'chorological tension zones'. In the absence of true character species, the species from other syntaxa of the same formation can be used as such. Our proposal is to use the species group from every formation-true class only once within every marginal alliance, to limit the number of possible marginal associations. This approach is illustrated in a classification of the retamoid thickets in the Netherlands. On the basis of a numerical-subjective classification of the relevant species in the scrub layer and the evaluation of relevant literature, we conclude that the broom and gorse thickets in the Netherlands can be assigned to the Cytisetea scopario-striati Rivas-Mart. 1974, which is represented by four associations, each of which is characterised by the species of other scrub classes. The Ulici europaei-Sarothamnion scoparii Doing ex Weber 1997 is represented by the Rubo plicati-Sarothamnetum scoparii Weber 1987 and the Crataego monogynae-Cytisetum scoparii R. Haveman, I. de Ronde & J.H.J. Schaminée ass. nov., the Ulici europaei-Cytision striati Rivas-Mart., Báscones, Díaz, Fern. Gonz. & Loidi 1991 by the Frangulo alni-Ulicetum europaei De Foucault 1988 and the Rubo ulmifolii-Ulicetum europaei J.-M. Géhu ex R. Haveman, I. de Ronde & J.H.J. Schaminée ass. nov. This classification is based on a restricted dataset though, and a revision, based on a larger dataset from a wider region has to prove the tenability of the classification.
Transitional between the Pannonian Basin and the Eastern Carpathians the Transcarpathian Ukraine (Transcarpathia) has a diverse geology including Quaternary sediments, volcanites, limestones and flysch, and its climate at low altitudes is relatively warm and humid. We conducted a field survey in June 2016 focusing on mesophilous forest vegetation along a transect covering almost the whole lowaltitudinal part of Transcarpathia. We recorded 54 relevés in the field and further digitized 22 relevés from literature. Using classification analysis, we distinguished three clusters of oak-hornbeam forests (alliance Carpinion betuli; 1–3) and three clusters of scree and ravine forests (alliance Tilio platyphylli-Acerion; 4–6): (1) Slightly wet Pannonian oak-hornbeam forests occurring in the lowland part of the region (Circaeo-Carpinetum); (2) Mesophilous oak-hornbeam forests (Carici pilosae-Carpinetum); (3) Xero-mesophilous oak-hornbeam forests (a drier subtype of the Carici pilosae-Carpinetum and the association Primulo veris-Carpinetum); (4) Mesophilous scree forests (Phyllitido-Aceretum); (5) Forests of steep slopes (Aceri-Tilietum) and transitions to mesophilous oak-hornbeam forests (Carici pilosae-Carpinetum); (6) Cool and wet scree and ravine forests (Arunco dioici-Aceretum pseudoplatani). Using indirect ordination analysis, three environmental variables (altitude, heat load index and slope) were identified as factors of significant influence on the species composition. These factors well distinguish oak-hornbeam forests from scree and ravine forests.
Dry open rocky grassland vegetation on shallow ultramafic soils in the Central Balkans represents typical secondary grasslands, which have developed mainly in the zone of thermophilous mixed deciduous broadleaved and pine forests. Although all relevant national and regional syntaxonomic reviews classify these rocky grasslands within the distinct order Halacsyetalia sendtneri, the syntaxonomic position of the order in different systems of classification has varied in the past. Considering this as well as the fact that there have been no synoptic works on this specific vegetation type, we gathered all available data on the order Halacsyetalia sendtnerii from the serpentinites of the Western and Central Balkan Peninsula for its critical evaluation. The results obtained in our analyses allowed us to propose a new syntaxonomic concept, which is partly in accordance with previously published syntaxonomic schemes. Two alliances can be distinguished: Centaureo kosaninii-Bromion fibrosi and Potentillion visianii, for which the diagnoses, diagnostic and constant taxa are given. Furthermore, we discussed the syntaxonomic position of the order Halacsyetalia sendtneri with respect to the classes Festuco-Brometea and Koelerio-Corynephoretea, as within the analysed associations, many taxa diagnostic for the class Koelerio-Corynephoretea were registered. The thermophytic pioneer grasslands and therophyte sward communities included in the alliance Thymion jankae nomen. inval., characterised by the absence of typical species of the order Halascyetalia sendtneri and presence of taxa diagnostic for the class Koelerio-Corynephoretea, are temporarily left within the order Halacsyetalia sendtneri. Finally, we provided nomenclatural adjustments for the analysed associations when necessary, although a conclusive judgement regarding all the associations currently included within the analysed order can only be made after more detailed field surveys including data on cryptogams as well as joint analyses including all floristically and ecologically similar syntaxa (e.g. Astragalo-Potentilletalia, Festucetalia valesiacae).
Thermophilous deciduous forests of Quercetalia pubescentis are widespread in Bosnia and Herze-govina (B&H), where they occupy about 11% of the national territory and account for about 20% of the total forest area. This paper provides their formalized classification and nomenclatural revision, based on 274 relevés from the literature and 399 relevés collected during intensive field research. The Cocktail method was used for supervised classification, which resulted in 17 associations recognized for B&H. Additionally, one new association emerged after semi-supervised classification of relevés not classified by Cocktail. The following associations were recognized, and characterized by species composition, ecology and distribution: 1. Querco pubescenti-Carpinetum orientalis; 2. Rusco aculeati-Carpinetum orientalis; 3. Carici hallerianae-Quercetum pubescentis; 4. Cruciato glabrae-Carpinetum orientalis; 5. Seslerio autumnalis-Quercetum pubescentis; 6. Aristolochio luteae-Quercetum pubescentis; 7. Asparago tenuifolii-Quercetum pubescentis; 8. Seslerio autumnalis-Ostryetum carpinifoliae; 9. Rusco aculeati-Ostryetum carpinifoliae; 10. Querco pubescenti-Ostryetum carpinifoliae; 11. Quercetum frainetto-cerridis; 12. Fraxino orni-Quercetum cerridis; 13. Lathyro nigri-Quercetum petraeae; 14. Aceri obtusati-Quercetum petraeae; 15. Cytiso hirsuti-Quercetum petraeae; 16. Festuco drymejae-Quercetum petraeae; 17. Potentillo micranthae-Quercetum petraeae; 18. Seslerio autumnalis-Quercetum petraeae. The validity and legitimacy of associations were checked and they were validated and corrected as needed, strictly following the rules of the International Code of Phytosociological Nomenclature. A complete list of synonyms has been given for every association, with an indication of the article of the Code according to which the name must be rejected. The associations were assembled into four groups, following the criterion of dominant species in a tree layer, in order to present differences and similarities in floristic composition between associations of the same type, i.e., dominated by the same tree species. An ecogram was drawn displaying the relative ecological range of each association along soil pH and moisture gradients. The largest number of associations (13) occurs in the Mediterranean region; the Dinaric and Pre-Pannonian regions each harbour ten associations, while there are only five associations in the Transitional Illyrian-Moesian region. Seven syntaxa previously reported for thermophilous deciduous forests of B&H were not recognized during the analysis. A list is given of all nomina nuda that could not be resolved and ascribed to synonymy with accepted associations.
Ziel der Arbeit ist eine zusammenfassende floristisch-pflanzensoziologische Darstellung der Wälder des Saarlandes. Der Schwerpunkt liegt dabei auf den Verbänden Carpinion betuli, Tilio platyphylli-Acerion pseudoplatani, Fagion sylvaticae und dem Deschampsio flexuosae-Fagion. Das Quercion robori-petraeae sowie das Quercion pubescenti-petraeae werden ebenfalls beschrieben und interpre-tiert. Hier besteht allerdings weiterer Untersuchungsbedarf, um die standörtlichen wie floristisch-soziologischen Details noch besser heraus zu arbeiten.
Das Aufnahmematerial (539 Aufnahmen) stammt von Dr. Erhard Sauer (erhoben in den 1960er und 1970er Jahren im Rahmen der forstlichen Standortkartierung) und vom Autor selbst (erfasst zwischen 2003 und 2014). Alle Vegetationsaufnahmen wurden nach der Methode von Braun-Blanquet erfasst. Zur Beschreibung und Interpretation der Waldgesellschaften im Untersuchungsgebiet werden zudem die vorliegenden Arbeiten aus Teilgebieten des Saarlandes mit herangezogen. Synsystematisch folgt der Autor im Wesentlichen Oberdorfer und Härdtle et al., in dem die azidophilen Buchenwaldgesellschaf-ten der Ordnung Quercetalia robori-petraeae zugeordnet werden.
Das gesamte Gesellschaftsspektrum weist mit seinen diagnostischen Arten auf die ausgesprochen subatlantische Klimatönung des Untersuchungsgebietes hin. Die Luzulo-Fagenion- sowie die Quercion roboris-petraeae-Gesellschaften werden der westlichen Teucrium scorodonia-Vikariante zugerechnet. In den wärmeliebenden Carpinion-Gesellschaften des West-Saarlandes kommen bereits die mediterran-atlantisch verbreiteten Arten Dioscorea communis und Viola alba vor und in den Tilio-Acerion-Gesellschaften Polystichum setiferum, ebenfalls eine submediterran-subatlantische Art. Floristisch gut charakterisierte Kalk-Buchenwälder in submontan-montaner Höhenlage gibt es im Saarland nicht, weshalb Hordelymo-Fagetum und Carici-Fagetum nur fragmentarisch ausgebildet sind. Das schwer-punktmäßig subkontinental verbreitete Galio-Carpinetum beschränkt sich im subatlantisch getönten Untersuchungsgebiet auf extrazonale wärmeliebende Standorte.
Dry grasslands are highly diverse vegetation types of great importance for livestock production in rural Balkan areas. We analysed a large data set of phytosociological relevés of dry grasslands (Festuco-Brometea and Festucetea vaginatae classes) in Serbia to produce the first overview of its classification, distribution, environmental conditions and biodiversity patterns. Phytocoenological relevés from relevant literature sources and our own investigations were stored in the Vegetation Database of Serbia (EU-RS-002) and the Balkan Dry Grassland Database (EU-00-013). After heterogeneity-constrained random resampling, the final dataset contained 1,897 relevés and 1,323 species. Species composition was classified hierarchically by the beta flexible method. We used species ecological indicator values for the estimation of the ecological conditions. Floristic and vegetation diversity and the conservation relevance of various dry grassland types, based on an assessment of endemic and protected species, were analysed. We identified 11 clusters, which were well characterised by their species composition and ecology. The first three clusters included loess and sand steppe grasslands mostly found in the Pannonian part of Serbia (Festucion rupicolae and Festucion vaginatae). The next three clusters consisted of Balkan ultramafic rocky grasslands of the order Halacsyetalia sendtneri, Balkan submediterranean mountain steppe grasslands on calcareous substrates, belonging to the order Astragalo-Potentilletalia and grasslands of the Balkan alliance Saturejion montanae on limestone. The third group of relevés comprised Balkan alliances of dry grasslands on deep soils, the Chrysopogono-Danthonion and sub-continental steppes of the alliance Festucion valesiacae in hilly areas of Serbia, mostly in the thermophilous oak zone. According to ordination analysis (DCA), the main floristic gradient was largely determined by temperature and moisture. The Festuco-Brometea class exhibited high floristic diversity (1,323 plant species) and very high conservation relevance in view of the large number of Balkan endemic species (204). A total of 233 species and subspecies protected by national legislation within the studied vegetation were recorded.
Cryophytic steppes in the Minusinskaya intermountain basin containing plant species that are predominantly distributed in the alpine zone such as Androsace dasyphylla, Dryas oxyodonta, Festuca sphagnicola, Kobresia myosuroides, K. filifolia, Minuartia verna, Oxytropis bracteata, Sagina saginoides, Papaver nudicaule, Patrinia sibirica, Pedicularis lasiostachys, Pulsatilla ambigua, Saussurea schanginiana, which are considered remnants of the Pleistocene vegetation. Based on 89 relevés, we classified cryophytic steppes using the Braun-Blanquet method within two phytosociological classes: Central Asian steppes of the Cleistogenetea squarrosae and West Palearctic steppes of the Festuco-Brometea. Three associations (Androsaco dasyphyllae-Caricetum pediformis, Pulsatillo patentis-Caricetum pediformis and Bupleuro multinervi-Helictotrichetum desertori) with three subassociations and three variants were described with respect to their phytosociological affinities and ecology. DCA ordination showed floristic differences between syntaxa, while correlations of DCA axes and floristic and environmental variables detected substrate type and temperature regime as presumably main drivers for vegetation differentiation. Another driver for vegetation differentiation seems to be continentality of the climate. Small scale distribution of cryophytic steppes were mapped using satellite images with resolution of 1.8 m. Cryophytic steppes always occupy only small areas in landscapes, on convex parts of undulated microrelief of mountain slopes and summits characterised by drought in summer and deep soil freezing in winter. These special micro-ecological conditions play an essential role for the existence of alpine flora in the Minusinskaya intermountain basin.
A phytosociological survey of weed (segetal) vegetation in Slovakia was performed. A total of 508 relevés were sampled in 2002–2008. The aims of this study were to determine the actual distribution of the segetal communities, to analyze their floristic structure, and to evaluate their relationships to selected environmental factors. Thirteen plant communities of the class Stellarietea mediae were distinguished by cluster analysis; 11 communities were included in the subclass Violenea arvensis (Lathyro tuberosi-Adonidetum aestivalis, Consolido-Anthemidetum austriacae, Euphorbio exiguae-Melandrietum noctiflori, Veronicetum trilobae-triphyllidi, Lamio amplexicauli-Thlaspietum arvensis, Taraxacum sect. Ruderalia community, Spergulo arvensis-Scleranthetum annui, Myosotido-Sonchetum arvensis, Echinochloo-Setarietum pumilae, Galinsogo-Setarietum, and Stachyo annui-Setarietum pumilae) and two in the subclass Sisymbrienea (Portulacetum oleraceae and Setario viridis-Erigeronetum canadensis). Communities were characterized by diagnostic, constant, and dominant species and their structure, ecology, and distribution were estimated. The species composition of these communities was documented in synoptic and association tables. DCA ordination and analysis of variance was used to determine the main environmental factors of floristic differentiation and to determine ecological and structural differences among the communities. The analyses showed that the most important factors affecting floristic composition and classification of the weed communities are their time of development (agroecophase), the type of crops and altitude.
Bramble scrubs are among the least known and understood vegetation types in Europe. In the Dutch National Vegetation Overview, three associations belonging to the Lonicero-Rubion silvatici were distinguished, viz. the Rubetum grati, Rubetum silvatici, and Rubetum pedemontani. During several vegetation mapping projects and Rubus excursions, a distinct type of bramble scrub was recorded repeatedly in the Campine in the province Noord-Brabant in the southern part of the Netherlands. In this paper, this scrub is described as a new association, the Rubetum taxandriae Haveman, de Ronde & Weeda, with R. taxandriae, R. campaniensis, and R. baronicus as character species, and R. insectifolius as regional character species. Variation, ecology and distribution of this new association are given and discussed, and two subassociations are distinguished. The differences with the Rubetum silvatici, to which this community was believed to belong, are discussed. Based on an earlier analysis of the centres of diversity of the genus Rubus in the Netherlands, it is supposed that the Rubetum silvatici in its circumscription in the Dutch National Vegetation Overview can be divided in more regionally distributed communities, partly as subassociations of the Rubetum silvatici, partly as independent associations.
In the lower siliceous uplands of Central Europe, various types of nutrient-poor grasslands are widespread and grow intermingled. These species-rich grasslands, often dominated by taxa of the Festuca ovina aggregate, comprise various phytosociological classes. They are remnants of a historic rural lands - cape and are of conservation importance. Few studies on such grasslands are available and there has been disagreement in assigning them to appropriate habitat types or syntaxa. We investigated such nutrient-poor grasslands in the lower Aar valley (Middle Hesse, Rhenish Massif). We surveyed 104 vegetation plots distributed throughout the valley and identified syntaxa to (sub)association level. We carried out supervised classification combining cluster analysis, a priori assignment to classes based on prevailing diagnostic species, and regional refinement based on phi-value maximisation of the units. As a result, we classified five associations within four classes: Polytricho piliferi-Festucetum tenuifoliae/Galio harcynici-Deschampsietum flexuosae and Festuco rubrae-Genistelletum sagittalis (Calluno- Ulicetea), Jasiono montanae-Festucetum ovinae (Koelerio-Corynephoretea), Gentiano-Koelerietum pyramidatae (Festuco-Brometea) and Arrhenatheretum elatioris (Molinio-Arrhenatheretea). Ecologically, soil acidity (resulting from Ca concentrations of the bedrock) was the main cause of floristic dissimilarity of the grasslands and thus community differentiation. Many stands grew on soils with intermediate pH and showed a peculiar mixture of basiphilous and acidophilous species. We conclude that (i) our approach of supervised classification yields convincing reproducible results when a syntaxonomic system is adapted top-down to a geographically restricted area, (ii) nutrient-poor siliceous grasslands dominated by taxa of the Festuca ovina aggregate can be well assigned to ecologically meaningful syntaxa, and (iii) the nutrient-poor siliceous grasslands of the Lahn-Dill Highlands are of high conservation relevance and in urgent need of protection.