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Aim: Our knowledge of Pleistocene refugia and post‐glacial recolonization routes of forest understorey plants is still very limited. The geographical ranges of these species are often rather narrow and show highly idiosyncratic, often fragmented patterns indicating either narrow and species‐specific ecological tolerances or strong dispersal limitations. However, the relative roles of these factors are inherently difficult to disentangle. Location: Central and south‐eastern Europe. Time period: 17,100 BP – present. Major taxa studied: Five understorey herbs of European beech forests: Aposeris foetida, Cardamine trifolia, Euphorbia carniolica, Hacquetia epipactis and Helleborus niger. Methods: We used spatio‐temporally explicit modelling to reconstruct the post‐glacial range dynamics of the five forest understorey herbs. We varied niche requirements, demographic rates and dispersal abilities across plausible ranges and simulated the spread of species from potential Pleistocene refugia identified by phylogeographical analyses. Then we identified the parameter settings allowing for the most accurate reconstruction of their current geographical ranges. Results: We found a largely homogenous pattern of optimal parameter settings among species. Broad ecological niches had to be combined with very low but non‐zero rates of long‐distance dispersal via chance events and low rates of seed dispersal over moderate distances by standard dispersal vectors. However, long‐distance dispersal events, although rare, led to high variation among replicated simulation runs. Main conclusions: Small and fragmented ranges of many forest understorey species are best explained by a combination of broad ecological niches and rare medium‐ and long‐distance dispersal events. Stochasticity is thus an important determinant of current species ranges, explaining the idiosyncratic distribution patterns of the study species despite strong similarities in refugia, ecological tolerances and dispersal abilities. [ABSTRACT FROM AUTHOR]

Aims: Oak–hornbeam forests and related vegetation types (phytosociological order Carpinetalia betuli) are widespread in temperate western Eurasia. However, their national classification systems are poorly compatible, and a broad‐scale classification based on numerical analyses is lacking. Therefore, we aimed to establish a unified formalized classification system based on a large data set of vegetation plots covering the entire range of these forests. Location: Europe, Anatolia, Caucasus and northern Iran. Methods: We compiled a data set of 15,817 vegetation plots from the European Vegetation Archive and the Hyrcanian Forest Vegetation Database, using the formal definition of the EUNIS habitat type T1E Carpinus and Quercus mesic deciduous forest. We classified the data set using TWINSPAN. Biogeographically and ecologically similar plot clusters were merged into oak–hornbeam forest types, which were interpreted as alliances. We also developed expert systems for automatically classifying vegetation at the alliance level for both the EuroVegChecklist (EVC) system and the revised classification. In addition, we calculated ordinations to show the major gradients in the species composition of the data set. Results: We present a revised classification system of the order Carpinetalia betuli with nine alliances, including basic descriptions of their species composition, distribution, ecology and syntaxonomy. The analyses largely supported the biogeographic concept of classification, analogous to EVC. Compared to EVC, we recognized an additional alliance Physospermo verticillati‐Quercion cerridis (southern Italy) but found no support for the alliances Astrantio‐Carpinion, Erythronio‐Carpinion and Scillo‐Quercion. The greatest difference in species composition was found between the southern and northern‐northeastern Carpinetalia types. Expert systems for the revised classification system (~89% of plots classified) and the EVC system (~72%) are also included. Conclusions: We provide the first comprehensive overview of alliances of the order Carpinetalia betuli across its whole distribution range. The associated expert systems allow consistent application of the classification of these forests in nature conservation, habitat monitoring, and biodiversity and ecological research.We provide the first formal classification for oak–hornbeam forests and related vegetation types (phytosociological order Carpinetalia betuli) across Europe and adjacent areas. It includes both traditional and revised classifications of this vegetation. Furthermore, we developed expert systems for vegetation‐plot assignment to vegetation types, which can be applied in research and biodiversity conservation, monitoring and management. [ABSTRACT FROM AUTHOR]

The occurrence and origin of dry grasslands and their rich biota in the moderately humid Central‐European climate have fascinated scientists for over a century. Modern palaeoecological and phylogeographical data support earlier hypotheses that these grasslands are late Pleistocene relicts and can therefore be considered part of the Eurasian forest–steppe biome. However, it is still unclear which factors fostered the maintenance of steppe patches in Central Europe throughout the Holocene. Here, we provide an overview of the main hypotheses, which stress, respectively, the effects of climate, edaphic conditions and disturbances. We then develop a general conceptual framework on how these three factors interact to form forest–steppe mosaics. We thereby emphasize the role of topography as a crucial control on forest–steppe patterns at the landscape scale. Topography is related to several mechanistic drivers that influence vegetation processes, such as near‐surface microclimate and soil formation. Consequently, topographic variation allows both forest and steppe patches to occur beyond their macroclimatic niche, favouring the development of forest–steppe mosaics. To illustrate our framework, we demonstrate the interactive effect of macroclimate and topography on the occurrence of steppe patches at 108 selected Central European forest–steppe sites. Although we developed our framework focusing on the current distribution of Central European forest–steppe, we suggest that it contributes to the understanding of similar transitions between temperate forest and steppe biomes in the past as well as elsewhere in the world. [ABSTRACT FROM AUTHOR]

The floodplain of the rivers Danube, March/Morava and Thaya/Dyje in eastern Austria and western Slovakia harbours a great diversity of meadows, reed swamps and sedge-bed communities. However, the grasslands along the Danube have not been adequately addressed by any study up to now, and a transnational revision of the alluvial grasslands is completely lacking. In this third part of a series focusing on the syntaxonomy of the Pannonian grasslands of Austria, we present a detailed classification of the grassland and marsh vegetation of the Danube and March-Thaya floodplain. We compiled all available relevés from the study area belonging to the classes Phragmito-Magnocaricetea, Molinio-Arrhenatheretea and Festuco-Brometea. In total, our data set comprised 2119 relevés, of which 355 were from Slovakia. We conducted a TWINSPAN classification and, based on a provisional syntaxonomic interpretation of the clusters, assigned all relevés to classes, orders, alliances and associations using the total cover of the diagnostic species in each relevé as the assignment criterion. We identified 42 associations and five provisional communities belonging to 14 alliances. Our revision includes substantial changes to previous overviews, in particular regarding the alluvial grasslands of the March-Thaya floodplain. We merge Lathyro palustris-Gratioletum, Gratiolo-Caricetum suzae, Cnidio-Violetum pumilae, Serratulo-Plantaginetum altissimae and "Silaetum pratensis" into only two associations (Gratiolo-Caricetum suzae and Cnidio-Violetum pumilae, alliance Deschampsion), which are differentiated along the moisture gradient. The Ophioglosso-Caricetum tomentosae is revealed as a geographical vicariant of the Cnidio-Violetum pumilae, replacing the latter along the Danube. The Agropyro-Alopecuretum pratensis is newly reported for Austria. The mesic Festuca rupicola grasslands along the March/Morava (previously named "Serratulo-Festucetum commutatae") are included in the Colchico-Festucetum rupicolae (Cirsio-Brachypodion). Ranunculo bulbosi-Arrhenatheretum, Pastinaco-Arrhenatheretum, Festuco rupicolae-Brometum and Polygalo-Brachypodietum (the latter in a new subass. selaginelletosum helveticae) are confirmed as widespread grassland types in the Danube floodplain, and the Teucrio botryos-Andropogonetum (Festucion valesiacae) is split into two subassociations. Moreover, we report four grassland types dominated by Elymus repens and Calamagrostis epigejos, provisionally treated as rankless communities, which have been neglected by all previous authors. [ABSTRACT FROM AUTHOR]

Aim: The steppe grasslands of eastern Central Europe are exceptionally species rich and valuable from a nature conservation point of view. However, their historical biogeography is still poorly understood. Here we use the regional diversity of habitat specialists and chloroplast DNA data to investigate potential long-term refugia of steppe species in this region. Location: Pannonian Basin and adjacent regions; SW Russia. Taxon: Vascular plants. Methods: After identifying habitat specialists of the three main steppe types (meadow steppes, grass steppes and rocky steppes), we compiled their regional presence--absence in grid cells of 75 km x 75 km. We analysed the dependency of habitat specialist diversity to climate, topographic heterogeneity and geographical distance to potential refugia. For genetic analysis, we sampled three or four habitat specialists of each steppe type and used cpDNA markers to investigate intraspecific diversity and geographical distribution of haplotypes. We also tested for correspondence between the number of habitat specialists and haplotype diversity. Results: Climate and topography explained between 40% and 63% of the variance in habitat specialist diversity. Adding geographical distance to potential refugia increased the explained variance in the models for all steppe types. Chloroplast haplotypes featured a complex pattern across the study area. Several species showed a strong geographical differentiation, suggesting migration waves from multiple refugia with only limited subsequent genetic intermixture. Maximum haplotype diversity in a region showed a better correlation with the number of habitat specialists per steppe type than mean haplotype diversity. Main conclusions: We can clearly reject the scenario of a late-Holocene immigration of steppe species from areas outside the Pannonian Basin. Most species must have been present in the region since at least the early Holocene, highlighting the importance of the lower mountain ranges surrounding the Pannonian Basin as long-term refugia for European steppe species. Dispersal limitation and resulting migration lags seem to have a strong influence on the distribution of steppe species in Central Europe. [ABSTRACT FROM AUTHOR]

The fourth edition of the International Code of Phytosociological Nomenclature (ICPN) was prepared by the Steering Committee of the IAVS Working Group for Phytosociological Nomenclature (GPN). The edition consists of 14 Definitions, 7 Principles, 53 Articles, and 7 Appendices. When compared with the previous edition, the main amendments are: (a) the acceptance of electronic publications (Art. 1); (b) the introduction of binding decisions (Definition XIV, Principle II, Articles 1, 2b, 3c, 29b, 40, 42, 44, Appendices 6 and 7); (c) the mandatory use of the English or Latin terminology for syntaxonomic novelties (Definition II, Principle II, Articles 3d and 3i); (d) the introduction of autonyms for the main ranks when the corresponding secondary ranks are created (Articles 13b and 24); (e) the automatic correction of the taxon names (name‐giving taxa) used in the names of syntaxa in accordance with the International Code of Nomenclature for algae, fungi, and plants (ICN) (Article 44); (f) the possibility to mutate the name of a syntaxon in using other correct, alternative names for the name‐giving taxa (Article 45); (g) the introduction of inadequate names, a new category of rejected names (Definition V, Articles 43 through 45); and (h) the introduction of a conserved type (Definition XIII, Article 53). The fourth edition of ICPN was approved by the GPN on 25 May 2019 and becomes effectively binding on 1 January 2021. [ABSTRACT FROM AUTHOR]

Aims: The forest vegetation of Turkey has been studied extensively using the Braun-Blanquet approach, but mostly in rather small areas which were not sufficient to provide an integrative phytosociological interpretation. In this study, we formed a regional forest vegetation database and aimed to construct a hierarchical syntaxonomic system using numerical methods. Study area: The Western Euxine province of the Euro-Siberian phytogeographic region of Turkey, extending from the province of Sinop in the east to the Istranca Mountains in the west. Methods: Vegetation data consist of 1526 relevés and 872 species. The dataset was split into coniferous forests and deciduous-mixed forests. For the delimitation of these categories, all relevés where the total cover of deciduous trees reached at least 1/3 of the total cover of tree layer were defined as deciduous-mixed forests, while relevés with a total cover of deciduous trees less than 1/3 were defined as coniferous forests. Classification of these forests was carried out using TWINSPAN. Diagnostic species of vegetation units were defined using both the phi coefficient and constancy ratio. For tree species, the ratio of average cover was taken instead of constancy ratio. The vegetation units were further evaluated using DCA ordination and comparison of environmental variables. Results: The classification of deciduous-mixed forests resulted in 21 units differentiated by edaphic, climatic or phytogeographic factors. These communities were assigned to three classes (Quercetea pubescentis, Carpino-Fagetea, Alno-Populetea), four orders and five alliances. The oak-hornbeam forests of Turkey were described as a new alliance Trachystemono orientalis-Carpinion betuli since there was no valid alliance name available. For coniferous forests, eight communities were determined which are classifed in three classes (Quercetea ilicis, Erico-Pinetea, Vaccinio-Piceetea), three orders and three alliances. Mesic fir forests were assigned to a new alliance Lonicero caucasicae-Piceion orientalis within a new order Abieti nordmannianae-Piceetalia orientalis. Conclusions: In separating coniferous and deciduous-mixed forests prior to the numerical classification, we were able to achieve a classification in good accordance with the current syntaxonomic system used in Europe. The proposed system of higher syntaxa, which is mainly based on the dominant tree species, will provide a more stable and objective framework for future studies on biodiversity, nature conservation and sustainable forest management. Moreover, we provide an overview of the associations corresponding to each vegetation unit. [ABSTRACT FROM AUTHOR]

A historical overview of the phytosociological method in Europe is presented. Some methodological and procedural differences in the application of the Braun-Blanquet approach, from the selection of the sampling plots to the assignment of relevés to existing or newly described units, are briefly compared. The main advantages and limitations of the phytosociological vegetation classification are reviewed and discussed, also in light of their applications for vegetation mapping and monitoring. [ABSTRACT FROM AUTHOR]

The annual Editorial of Phytocoenologia 2018 reflects on the topical coverage of the journal in the years 2015-2017. All continents except Antarctica were present, but contributions from Europe and Asia dominated, South America and Africa were moderately represented and North America and Australia underrepresented. In terms of vegetation types temperate grasslands and forests were the most frequent study subjects, while aquatic and weed communities were hardly addressed at all. We highlight the classification of the petrifying springs in Ireland (Lyons & Kelly 2017, Phytocoenologia 47: 13-32) as a prototypic study we would like to be published in the journal and thus acknowledge the authors with the Editors' Award 2017. Also the two permanent sections, Ecoinformatics (with Long and Short Database Reports) as well as Phytosociological Nomenclature (with nomenclatural proposals and nomenclatural revisions) are important and much used parts of Phytocoenologia. [ABSTRACT FROM AUTHOR]

Questions What are the main floristic patterns in European beech forests? Which classification at the alliance and suballiance level is the most convincing? Location Europe and Asia Minor. Methods We applied a TWINSPAN classification to a data set of 24 605 relevés covering the whole range of Fagus sylvatica forests and the western part of Fagus orientalis forests. We identified 24 'operational phytosociological units' (OPUs), which were used for further analysis. The position of each OPU along the soil pH and temperature gradient was evaluated using Ellenberg Indicator Values. Fidelity of species to OPUs was calculated using the phi coefficient and constancy ratio. We compared alternative alliance concepts, corresponding to groups of OPUs, in terms of number and frequency of diagnostic species. We also established formal definitions for the various alliance concepts based on comparison of the total cover of the diagnostic species groups, and evaluated alternative geographical subdivisions of beech forests. Results The first and second division levels of TWINSPAN followed the temperature and soil pH gradients, while lower divisions were mainly geographical. We grouped the 22 OPUs of Fagus sylvatica forests into acidophytic, meso-basiphytic and thermo-basiphytic beech forests, and separated two OPUs of F. orientalis forests. However, a solution with only two ecologically defined alliances of F. sylvatica forests (acidophytic vs basiphytic) was clearly superior with regard to number and frequency of diagnostic species. In contrast, when comparing groupings with three to six geographical alliances of basiphytic beech forests, respectively, we did not find a strongly superior solution. Conclusions We propose to classify F. sylvatica forests into 15 suballiances - three acidophytic and 12 basiphytic ones. Separating these two groups at alliance or order level was clearly supported by our results. Concerning the grouping of the 12 basiphytic suballiances into ecological or geographical alliances, as advocated by many authors, we failed to find an optimal solution. Therefore, we propose a multi-dimensional classification of basiphytic beech forests, including both ecological and geographical groups as equally valid concepts which may be used alternatively depending on the purpose and context of the classification. [ABSTRACT FROM AUTHOR]

Questions What are the main floristic patterns in the Pannonian and western Pontic steppe grasslands? What are the diagnostic species of the major subdivisions of the class Festuco-Brometea (temperate Euro-Siberian dry and semi-dry grasslands)? Location Carpathian Basin (E Austria, SE Czech Republic, Slovakia, Hungary, Romania, Slovenia, N Croatia and N Serbia), Ukraine, S Poland and the Bryansk region of W Russia. Methods We applied a geographically stratified resampling to a large set of relevés containing at least one indicator species of steppe grasslands. The resulting data set of 17 993 relevés was classified using the TWINSPAN algorithm. We identified groups of clusters that corresponded to the class Festuco-Brometea. After excluding relevés not belonging to our target class, we applied a consensus of three fidelity measures, also taking into account external knowledge, to establish the diagnostic species of the orders of the class. The original TWINSPAN divisions were revised on the basis of these diagnostic species. Results The TWINSPAN classification revealed soil moisture as the most important environmental factor. Eight out of 16 TWINSPAN groups corresponded to Festuco-Brometea. A total of 80, 32 and 58 species were accepted as diagnostic for the orders Brometalia erecti, Festucetalia valesiacae and Stipo-Festucetalia pallentis, respectively. In the further subdivision of the orders, soil conditions, geographic distribution and altitude could be identified as factors driving the major floristic patterns. Conclusions We propose the following classification of the Festuco-Brometea in our study area: (1) Brometalia erecti (semi-dry grasslands) with Scabioso ochroleucae-Poion angustifoliae (steppe meadows of the forest zone of E Europe) and Cirsio-Brachypodion pinnati (meadow steppes on deep soils in the forest-steppe zone of E Central and E Europe); (2) Festucetalia valesiacae (grass steppes) with Festucion valesiacae (grass steppes on less developed soils in the forest-steppe zone of E Central and E Europe) and Stipion lessingianae (grass steppes in the steppe zone); (3) Stipo-Festucetalia pallentis (rocky steppes) with Asplenio septentrionalis-Festucion pallentis (rocky steppes on siliceous and intermediate soils), Bromo-Festucion pallentis (thermophilous rocky steppes on calcareous soils), Diantho-Seslerion (dealpine Sesleria caerulea grasslands of the Western Carpathians) and Seslerion rigidae (dealpine Sesleria rigida grasslands of the Romanian Carpathians). [ABSTRACT FROM AUTHOR]

In this paper we present nomenclatural adjustments and validations of syntaxa of the forest vegetation of Europe. We introduce a new, valid name of the class of nemoral coniferous or mixed forests ( Asaro europaei-Abietetea sibiricae) replacing the deciduous Carpino-Fagetea in the easternmost Europe and Siberia. We describe two new orders for birch and birch-poplar woodlands, formerly included in the Betulo pendulae-Populetalia tremulae. We validate the names of two alliances for the deciduous forests of the Southern Urals and the name of an alliance for hemiboreal forest swamps. The suballiance Ostryo-Tilienion, coined to accommodate the xerothermophilous ravine forests of SE Europe, is here elevated to the rank of alliance. Finally, we validate the name Quercion alnifoliae (evergreen oak forests of Cyprus). [ABSTRACT FROM AUTHOR]

Questions The vegetation of high-alpine and subnival scree habitats in Iranian mountains has been poorly investigated so far despite the large variety of narrowly distributed vascular plant species and the expected vulnerability of these ecosystems to global warming. Which plant communities occupy these ecosystems and what is their syntaxonomic position? Which environmental factors determine the species composition of these habitats? Location Alborz and Azerbaijan Mountains in N and NW Iran. Methods A total of 141 phytosociological relevés were collected from 3200 to 4800 m a.s.l. This data set was classified using TWINSPAN, and the numerical classification was translated into a syntaxonomic system. Floristic differences between vegetation types were evaluated with detrended correspondence analysis ( DCA). We determined the means and SD of measured environmental and vegetation parameters for all associations. Differences in the major environmental parameters among associations and alliances were analysed using ANOVA and post-hoc tests. Moreover, we determined the mean cover percentage of life forms in all associations. Results All high-alpine and subnival scree communities are arranged in one class ( Didymophyso aucheri- Dracocephaletea aucheri), two orders ( Physoptychio gnaphalodis- Brometalia tomentosi, Didymophysetalia aucheri), three alliances ( Elymo longearistati- Astragalion macrosemii, Erigerontion venusti, Didymophysion aucheri) and ten associations, which are new to science, except for one association. The territory of the class extends from Alborz to NW Iran and probably to E Anatolia, Transcaucasia and the Zagros Mountains. Altitude, aspect and edaphic qualities are the major ecological factors influencing the species composition and vegetation mosaic. Conclusions Our study introduces a formal syntaxonomic classification of the scree vegetation at high altitudes in Iran, thus providing a scheme for ongoing ecological surveys and monitoring programmes to assess the impacts of climate warming and of human land use on these unique ecosystems. [ABSTRACT FROM AUTHOR]

The post-glacial migration of European beech Fagus sylvatica has been addressed by many studies using either genetic or fossil data or a combination of both. In contrast to this, only little is known about the migration history of beech forest understorey species. In a review of phytosociological literature, we identified 110 plant species which are closely associated with beech forest. We divided the distribution range of European beech forests into 40 geographical regions, and the presence or absence of each species was recorded for each region. We compared overall species numbers per region and numbers of narrow-range species (species present in <10 regions). A multiple regression model was used to test for the explanatory value of three potential diversity controls: range in elevation, soil type diversity, and distance to the nearest potential refuge area. A hierarchical cluster analysis of the narrow-range species was performed. The frequency of range sizes shows a U-shaped distribution, with 42 species occurring in <10 regions. The highest number of beech forest species is found in the southern Alps and adjacent regions, and species numbers decrease with increasing distance from these regions. With only narrow-range species taken into consideration, secondary maxima are found in Spain, the southern Apennines, the Carpathians, and Greece. Distance to the nearest potential refuge area is the strongest predictor of beech forest species richness, while altitudinal range and soil type diversity had little or no predictive value. The clusters of narrow-range species are in good concordance with the glacial refuge areas of beech and other temperate tree species as estimated in recent studies. These findings support the hypothesis that the distribution of many beech forest species is limited by post-glacial dispersal rather than by their environmental requirements. [ABSTRACT FROM AUTHOR]

Question: How different are lists of diagnostic species of vegetation units, derived using various fidelity measures, in different contexts and with presence/absence versus cover data? Methods: Six different fidelity measures were calculated for vegetation units of two classified data sets covering contrasting types of Central European vegetation (beech forest and dwarf shrub vegetation). Both statistical and non-statistical fidelity measures were used, and either species presence/absence or cover was considered. Each measure was calculated on four hierarchical levels and within two different contexts, either within the whole data set or within the next higher level of hierarchical classification. Average similarities of the diagnostic species lists derived from various combinations of fidelity measures and contexts were calculated and visualized using principal coordinate analysis (PCoA). Results: The correlations between fidelity values derived from non-statistical and statistical measures were rather weak. Nevertheless, diagnostic species lists calculated for the same syntaxon by different measures usually had several species in common. Average similarity between pairs of fidelity measures or contexts (based on the Sørensen similarity index) ranged from 0.21 to 0.92. PCoA clustered individual combinations of fidelity measures and contexts mainly according to the context and the use of presence/absence versus cover data, rather than according to the fidelity measures. Conclusions: The strongest impact on the lists of diagnostic species was not the fidelity measure itself but the context of its application and the use of presence/absence or cover data. Despite the weak correlation between individual fidelity values, traditional (non-statistical) and statistical measures produce quite similar lists of diagnostic species, provided that the context of the analysis is the same. Both approaches have their advantages and disadvantages, and the choice of the appropriate algorithm should depend on the focus of the study. [ABSTRACT FROM AUTHOR]

A TWINSPAN classification of a representative set of 3026 relevés of spruce and fir forests from the Eastern Alps (Austria) is presented. Ecological features of relevé clusters and species groups are described by means of Ellenberg indicator values, site factors and stand characteristics. The most important floristic discontinuity in the data set separates acidophilous communities on mostly silicate substrates from basiphilous communities on mostly carbonate substrates. Further divisions reflect a combined gradient of temperature, nutrient regime and shading. This is supported by the correlation of average Ellenberg values of sample plots with DCA axes. A qualitative comparison between TWINSPAN clusters and a syntaxonomic system widely used in the Austrian Alps is drawn. The two orders Piceetalia excelsae and Athyrio-Piceetalia largely coincide with the clusters of the first level of divisions. Alliances are partly reproduced by TWINSPAN. Clusters on the fifth and fourth level of division mostly correspond to associations. However, a considerable portion of the lower level clusters is of a transitional type. Out of thirteen fir and spruce associations described for the Austrian Alps, five associations are not reproduced by TWINSPAN, i.e. Bazzanio-Piceetum, Veronico-Piceetum, Adenostylo alliariae-Abietetum, Asplenio-Piceetum and Carici-Piceetum. Three associations are split on the second level of division, i.e. Larici-Piceetum, Luzulo nemorosae-Piceetum and Calamagrostio variae--Piceetum. [ABSTRACT FROM AUTHOR]

• Glacial survival of Astragalus onobrychis within the Pannonian region. • Pleistocene E–W expansion from the Pontics/Caucasus into Pannonian region (8x). • Younger, smaller-scaled postglacial W–E migration across the Pannonian region. • Long-term stable populations in Dobruja, N Balkan & Central Pontic subregions. • High genetic uniqueness of S Pannonian, N Balkan and N Caucasus populations. Steppe grasslands represent important refuges for rare species in the Pannonian region of eastern Central Europe. Nevertheless, little is known about their regional continuity and potential (post)glacial in-situ survival. Biogeographical studies assume potential source areas for the postglacial (re)colonisation of the Pannonian region in the Western and Central Pontics including the Black Sea coast. However, south-exposed slopes surrounding the Hungarian plain may have also played an important role as small-scale refugia. Using cpDNA sequence markers (atpI-H , rpL16, ycf1) and 190 individuals representing 25 populations, we investigated the genetic diversity and biogeographical history of Astragalus onobrychis within different subregions of its European distribution. We aimed at answering questions about the glacial survival, (post)glacial expansion and/or recent decline of the species throughout this area. A TCS network showed 108 haplotypes, which were divided into two unconnected clusters, representing different ploidy levels. We found octoploid populations widely distributed from the Pannonian region and Transylvania to more eastern areas in the Western Pontics and the Northern Caucasus. On the contrary, di- and tetraploid populations occur in the Dobruja and the Northern Balkan Peninsula, but also in the Central Pontic and the Southern Pannonian subregions. Four main cpDNA haplotype groups basically showed a geographical pattern; the Pannonian region being best-defined. We found high haplotype and moderate to high nucleotide diversity within most populations/subregions. Equilibrating these two genetic diversity measures indicates a long-term – probably glacial – (diploid) persistence of A. onobrychis in the Southern Pannonian subregion, areas along the Black Sea coast, the Northern Balkan Peninsula and the Central Pontic subregion. However, the octoploid lineage likely originated more to the east and expanded to Western Pontic areas and the Pannonian Basin probably already during Pleistocene. [ABSTRACT FROM AUTHOR]

Pleistocene climate fluctuations had profound influence on the biogeographical history of many biota. As large areas in high mountain ranges were covered by glaciers, biota were forced either to peripheral refugia (and possibly beyond to lowland refugia) or to interior refugia (nunataks). However, nunatak survival remains controversial as it relies solely on correlative genetic evidence. Here, we test hypotheses of glacial survival using two high alpine plant species (the insect‐pollinated Pedicularis asplenifolia and wind‐pollinated Carex fuliginosa) in the European Alps. Employing the iDDC (integrative Distributional, Demographic and Coalescent) approach, which couples species distribution modelling, spatial and temporal demographic simulation and Approximate Bayesian Computation, we explicitly test three hypotheses of glacial survival: (a) peripheral survival only, (b) nunatak survival only and (c) peripheral plus nunatak survival. In P. asplenifolia the peripheral plus nunatak survival hypothesis was supported by Bayes factors (BF> 100), whereas in C. fuliginosa the peripheral survival only hypothesis, although best supported, could not be unambiguously distinguished from the peripheral plus nunatak survival hypothesis (BF = 5.58). These results are consistent with current habitat preferences (P. asplenifolia extends to higher elevations) and the potential for genetic swamping (i.e., replacement of local genotypes via hybridization with immigrating genotypes [expected to be higher in the wind‐pollinated C. fuliginosa]). Although the persistence of plants on nunataks during glacial periods has been debated and studied over decades, this is one of the first studies to explicitly test the hypothesis instead of solely using correlative evidence. [ABSTRACT FROM AUTHOR]

Deciduous forests form the dominant natural vegetation of Europe today, but were restricted to small refugia during Pleistocene cold stages, implying an evolutionary past shaped by recurrent range contractions and expansions. Cold‐stage forest refugia were probably widespread in southern and central Europe, with the northwestern Balkan Peninsula being of particular importance. However, the actual number and location of deciduous forest refugia, as well as the connections between them, remain disputed. Here, we address the evolutionary dynamics of the deciduous forest understorey species Euphorbia carniolica as a proxy for past forest dynamics. To do so, we obtained genomic and morphometric data from populations representing the species' entire range, investigated phylogenetic position and intraspecific genetic variation, tested explicit demographic scenarios and applied species distribution models. Our data support two disjoint groups linked to separate refugia on the northwestern and central Balkan Peninsula. We find that genetic differentiation between groups started in the early Pleistocene via vicariance, suggesting a larger distribution in the past. Both refugia acted as sources for founder events to the southeastern Alps and the Carpathians; the latter were likely colonised before the last cold stage. In line with traditional views on the pre‐Pleistocene origin of many southeastern European deciduous forest species, the origin of E. carniolica was dated to the late Pliocene. The fact that E. carniolica evolved at a time when a period of continuous forestation was ending in much of Eurasia provides an interesting biogeographical perspective on the past links between Eurasian deciduous forests and their biota. [ABSTRACT FROM AUTHOR]

Aims: This is the first attempt to describe the diversity of the thorn-cushion and snowbed vegetation of the high mountains of NW Iran. Our main aim was to identify plant communities occurring in these habitats, and to clarify their syntaxonomic position. We also explored the key environmental factors influencing the species composition of these communities. Study area: Sahand Mts. (3707 m a.s.l.), Sabalan Mts. (4810 m a.s.l.) and Bozqush Mts. (3302 m a.s.l.) in NW Iran. Methods: A total of 166 phytosociological relevés were sampled at elevations ranging from 2800 to 3700 m a.s.l. The data set was classified using the TWINSPAN algorithm, and the result of the numerical classification was interpreted through a syntaxonomic system. Floristic differences were evaluated using a Detrended Correspondence Analysis. Results: We distinguished two alliances of thorncushion grasslands: Astragalion polyanthi all. nov. on windswept sites (including three associations) and Astragalion sahendi all. nov. on sites with longer snow cover duration (including two associations). Snowbed communities were classified into seven associations and assigned to the previously described alliance Taraxaco brevirostris-Polygonion serpyllacei. Conclusions: The duration of snow cover (i.e. the time of snowmelt) strongly determines the distribution of the studied communities. Among other ecological factors affecting the species composition are elevation, aspect, slope inclination and soil structure. [ABSTRACT FROM AUTHOR]

Forest understories play a vital role in ecosystem functioning and the provision of ecosystem services. However, the extent to which environmental conditions drive dominant ecological strategies in forest understories at the continental scale remains understudied. Here, we used ~29 500 forest vegetation plots sampled across Europe and classified into 25 forest types to explore the relative role of macroclimate, soil pH and tree canopy cover in driving abundance‐weighted patterns in the leaf economic spectrum (LES) and plant size spectrum (PSS) of forest understories (shrub and herb layers). We calculated LES using specific leaf area (SLA) and leaf dry matter content (LDMC) and PSS using plant height and seed mass of vascular plant species found in the understories. We found that forest understories had more conservative leaf economics in areas with more extreme mean annual temperatures (mainly Fennoscandia and the Mediterranean Basin), more extreme soil pH and under more open canopies. Warm and summer‐dry regions around the Mediterranean Basin and areas of Atlantic Europe also had taller understories with heavier seeds than continental temperate or boreal areas. Understories of broadleaved deciduous forests, such as Fagus forests on non‐acid soils, or ravine forests, more commonly hosted species with acquisitive leaf economics. In contrast, some coniferous forests, such as Pinus, Larix and Picea mire forests, or Pinus sylvestris light taiga and sclerophyllous forests, more commonly hosted species with conservative leaf economics. Our findings highlight the importance of macroclimate and soil factors in driving trait variation of understory communities at the continental scale and the mediator effect of canopy cover on these relationships. We also provide the first maps and analyses of LES and PSS of forest understories across Europe and give evidence that the understories of European forest types are differently positioned along major axes of trait variation. [ABSTRACT FROM AUTHOR]

Aims: The effect of biogeographical processes on the spatial turnover component of beta‐diversity over large spatial extents remains scarcely understood. Here, we aim at disentangling the roles of environmental and historical factors on plant taxonomic and phylogenetic turnover, while controlling for the effects of species richness and rarity. Location: European beech (Fagus sylvatica) forests in Europe. Methods: We aggregated plant species occurrences from vegetation plots in spatial grid cells of 0.25º × 0.25º to calculate the spatial turnover component of taxonomic (TBDturn) and phylogenetic (PBDturn) beta‐diversity for each cell. We also calculated the deviation of PBDturn given TBDturn (PBDdev‐turn), which measures the importance of phylogenetic turnover after factoring out taxonomic turnover. Beta‐diversity was calculated for each grid cell as the mean pairwise dissimilarity between the focal cell and all other cells. We used structural equation modeling (SEM) to examine the relationships between environmental (climate, soil pH, and distance from the geographical distribution limit of beech) and historical (distance from beech glacial refugia) predictors and beta‐diversity metrics. Results: We found a geographically consistent variation in taxonomic and phylogenetic turnover. Overall, TBDturn and PBDturn increased significantly toward more extreme climatic conditions, on more acidic soils, and toward the margins of beech distribution. The effects of environmental variables and the distance from glacial refugia on beta‐diversity metrics were mediated by species richness and rarity. Phylogenetic turnover was low in relation to taxonomic turnover (i.e., high PBDdev‐turn) in areas closer to glacial refugia. Conclusions: Continental‐scale patterns of beta‐diversity in European beech forests are the result of complementary ecological and evolutionary processes. In general, beech forests are taxonomically and phylogenetically more distinct in climatically marginal areas of their European range. However, the spatial variation of beta‐diversity in European beech forest flora is still strongly characterized by the distribution of groups of closely related species that evolved or survived in glacial refugia. [ABSTRACT FROM AUTHOR]

The Caucasus harbours unique forest vegetation so far only little studied using the Braun-Blanquet approach. This study is mostly based on a dataset (N = 110) of original phytosociological relevés of oak-hornbeam and ravine forests in the Eastern Greater Caucasus, Georgia. Their unsupervised classification produced seven communities. Five belong to oak-hornbeam forests (order Lathyro-Carpinetalia caucasicae). Of the zonal Caucasian alliance Crataego-Carpinion, the association Corno australis-Carpinetum inhabits valleys of the Greater Caucasus, and Clinopodio umbrosi-Carpinetum is confined to the warm Eastern Greater Caucasus promontories. The association Astrantio maximae-Carpinetum of the alliance Astrantio-Carpinion represents distinctive Caucasian montaneoak-hornbeam forests. The other two communities, documented by a few relevés, were described at the community level only. Within ravine forests (order Aceretalia pseudoplatani), we introduce a new Caucasian alliance Pachyphragmo macrophyllae-Tilion begoniifoliae with two associations. Valeriano tiliifoliae-Ulmetum glabrae comprises Caucasian montane ravine forests whereas Hedero pastuchovii-Aceretum velutini inhabits the foothills of the Eastern Greater Caucasian. To provide a broader context of the recognized communities, an expanded dataset (N = 231) of original relevés and previously published relevés of Georgian deciduous forests was analysed. It indicated a major turnover in species composition following biogeographical patterns presumably driven by macroclimate and vegetation history. [ABSTRACT FROM AUTHOR]

An introduction to the journal, which features a series of articles devoted to the classification of European grasslands, is presented.

Climate and land‐use change jointly affect the future of biodiversity. Yet, biodiversity scenarios have so far concentrated on climatic effects because forecasts of land use are rarely available at appropriate spatial and thematic scales. Agent‐based models (ABMs) represent a potentially powerful but little explored tool for establishing thematically and spatially fine‐grained land‐use scenarios. Here, we use an ABM parameterized for 1,329 agents, mostly farmers, in a Central European model region, and simulate the changes to land‐use patterns resulting from their response to three scenarios of changing socio‐economic conditions and three scenarios of climate change until the mid of the century. Subsequently, we use species distribution models to, first, analyse relationships between the realized niches of 832 plant species and climatic gradients or land‐use types, respectively, and, second, to project consequent changes in potential regional ranges of these species as triggered by changes in both the altered land‐use patterns and the changing climate. We find that both drivers determine the realized niches of the studied plants, with land use having a stronger effect than any single climatic variable in the model. Nevertheless, the plants' future distributions appear much more responsive to climate than to land‐use changes because alternative future socio‐economic backgrounds have only modest impact on land‐use decisions in the model region. However, relative effects of climate and land‐use changes on biodiversity may differ drastically in other regions, especially where landscapes are still dominated by natural or semi‐natural habitat. We conclude that agent‐based modelling of land use is able to provide scenarios at scales relevant to individual species distribution and suggest that coupling ABMs with models of species' range change should be intensified to provide more realistic biodiversity forecasts. [ABSTRACT FROM AUTHOR]

Aim: Current species‐richness patterns are sometimes interpreted as a legacy of landscape history, but historical processes shaping the distribution of species during the Holocene are frequently omitted in biodiversity models. Here, we test their importance in modelling current species richness of vascular plants in forest and grassland vegetation. Location: Western Carpathians and adjacent regions. Taxon: Vascular plants. Methods: Numbers of all species and of habitat specialists were extracted from plot records of forest and grassland vegetation. For each plot, environmental and historical data were derived from thematic maps. Historical data related to the persistence of (a) temperate taxa during the Late Glacial and Early Holocene, (b) open‐landscape taxa during the Middle Holocene and (c) taiga taxa during the Late Holocene were based on 112 fossil pollen profiles. Boosted regression trees were used to model spatial patterns in species richness. Results: Historical variables always appeared among the best predictors of current species richness. In light forests, species richness highly mirrored both the Late Glacial (12.5% contribution) and Middle‐Holocene (8.6%) landscape history. The latter factor became an important predictor also for species richness of steppe grasslands (8.3%) along with temperature seasonality (11.9%). Species richness of dark coniferous forests was best predicted by the Late‐Holocene occurrence of taiga forests (14.8%), which had an even stronger effect on the richness of habitat specialists (20.5%). Main conclusions: Landscape changes since the Last Glacial Maximum are important predictors of current plant species richness. The historical effects were found to be habitat specific and, because they may interact with recent environmental conditions and anthropogenic pressures, they often show a nonlinear relationship with species richness. We provide one possible direction of incorporating past landscape changes to the models of species richness. [ABSTRACT FROM AUTHOR]

The annual editorial of Phytocoenologia 2019 brings bittersweet news about plot-based vegetation classification. On the one hand, the editorial of our Special Issue "Classification Approaches" (issue 48(2)) reported noticeable gaps in several regions of the world. On the other hand, articles in recent Phytocoenologia reach more and more of these underrepresented regions and extend to previously rarely classified plant formations. Our last issues 48(1-4) included several papers applying vegetation classification to address a number of ecological and socio-economical questions. We highlight the classification of steppe vegetation in Pamir Alai and Tian-Shan Mountains in Middle Asia (Nowak et al. 2018, Phytocoenologia 48: 369-391) and acknowledge the authors with the Editor's Award 2018. Our Ecoinformatics Section attracts many submissions, but we regret that in 2018 we did not publish any paper in the Phytosociological Nomenclature Section. [ABSTRACT FROM AUTHOR]

Abstract: Aim: We investigate whether (1) environmental predictors allow to delineate the distribution of discrete community types at the continental scale and (2) how data completeness influences model generalization in relation to the compositional variation of the modelled entities. Location: Europe. Methods: We used comprehensive datasets of two community types of conservation concern in Europe: acidophilous beech forests and base‐rich fens. We computed community distribution models (CDMs) calibrated with environmental predictors to predict the occurrence of both community types, evaluating geographical transferability, interpolation and extrapolation under different scenarios of sampling bias. We used generalized dissimilarity modelling (GDM) to assess the role of geographical and environmental drivers in compositional variation within the predicted distributions. Results: For the two community types, CDMs computed for the whole study area provided good performance when evaluated by random cross‐validation and external validation. Geographical transferability provided lower but relatively good performance, while model extrapolation performed poorly when compared with interpolation. Generalized dissimilarity modelling showed a predominant effect of geographical distance on compositional variation, complemented with the environmental predictors that also influenced habitat suitability. Main conclusions: Correlative approaches typically used for modelling the distribution of individual species are also useful for delineating the potential area of occupancy of community types at the continental scale, when using consistent definitions of the modelled entity and high data completeness. The combination of CDMs with GDM further improves the understanding of diversity patterns of plant communities, providing spatially explicit information for mapping vegetation diversity and related habitat types at large scales. [ABSTRACT FROM AUTHOR]

Abstract: Asexual taxa often have larger ranges than their sexual progenitors, particularly in areas affected by Pleistocene glaciations. The reasons given for this ‘geographical parthenogenesis’ are contentious, with expansion of the ecological niche or colonisation advantages of uniparental reproduction assumed most important in case of plants. Here, we parameterized a spread model for the alpine buttercup Ranunculus kuepferi and reconstructed the joint Holocene range expansion of its sexual and apomictic cytotype across the European Alps under different simulation settings. We found that, rather than niche broadening or a higher migration rate, a shift of the apomict's niche towards colder conditions per se was crucial as it facilitated overcoming of topographical barriers, a factor likely relevant for many alpine apomicts. More generally, our simulations suggest potentially strong interacting effects of niche differentiation and reproductive modes on range formation of related sexual and asexual taxa arising from their differential sensitivity to minority cytotype disadvantage. [ABSTRACT FROM AUTHOR]

Questions Which are the main vegetation types of lowland hay meadows and pastures in Western and Central Europe? What are the main environmental gradients that drive patterns of species composition? Is it possible to classify these grasslands to phytosociological alliances that reflect management practices? Location Western and Central Europe (excluding the Alps and Carpathians). Methods A database of 21 400 vegetation plots of mesic grasslands across Western and Central Europe was compiled. After geographically stratified resampling, semi-supervised classification based on the K-means algorithm was applied to assign a subset of plots into 32 a priori association-level vegetation types and to search for new types within the subset of non-assigned plots. The vegetation plots assigned into the final vegetation types were submitted to another K-means classification to show the grouping into higher-level vegetation types. Results A total of 36 associations were distinguished in the resampled subset of 8277 vegetation plots and were grouped into four large groups: (1) eutrophic and intensively managed hay meadows and permanent pastures; (2) nutrient-rich grasslands developed from recently abandoned fields or managed under irregular practices of mowing and manuring; (3) non-eutrophic lowland and submontane hay meadows; (4) extensively managed pastures and Atlantic grazed hay meadows. A PCoA of the associations of these four groups showed that extensively managed pastures were floristically more similar to non-eutrophic hay meadows than to permanent intensively managed pastures, which was more obvious in the Atlantic region than in Central Europe. Species composition of the lowland hay meadows was clearly differentiated according to biogeographic sectors. Other floristic differences were related to climate, altitude, soil base status and topography. Conclusions This analysis challenges the traditional concept of mesic grassland alliances separating hay meadows from pastures. New classification should be based mainly on the differences in management intensity rather than in management practice. Consequently, nutrient-poor extensive pastures, which currently are not considered in the European Habitats Directive, should receive the same conservation attention as low-intensive hay meadows, because both types of vegetation can be equally species-rich and do not differ substantially in floristic composition from each other. [ABSTRACT FROM AUTHOR]

Aims We study the high-mountain grasslands growing on siliceous substrata of the Iberian Peninsula to determine floristic patterns and affinities that best define the structure and phytosociological classification of this vegetation. Location Cantabrian Range, Sierra Nevada, Sistema Central, Sistema Ibérico and the Pyrenees. Methods We analysed 1484 relevés representing 25 phytosociological associations of high-mountain grasslands on siliceous substrata previously described in the study area. A first classification using noise clustering produced a large noise group containing over 50% of the relevés. We then carried out a DCA to check the relative position of the noise group components with respect to the whole pool, and a K-means combined with species indicator analysis to obtain a more precise delimitation of clusters through their representative species. Results We considered 17 groups as the optimum number of clusters when considering K-means and the corresponding indicator species. Pyrenean alpine vegetation separated first, showing a homogeneous pattern with a set of diagnostic taxa organized around two groups that coincide with one European class ( Juncetea trifidi) and two alliances: Festucion eskiae in chionophilous environments and Festucion supinae in chionophobous habitats. The rest of the data correspond to the Iberian class Festucetea indigestae, recognized in three alliances corresponding to three territories: the Cantabrian Range, Central Iberian Peninsula (Sistema Central and Sistema Ibérico) and Sierra Nevada. Four groups were extracted from the Cantabrian Range, which correspond to temperate (two groups) and Mediterranean (two groups) plant communities included in Teesdaliopsio-Luzulion. Two groups from Sierra Nevada - one oro- ( Thymion serpylloidis) and another cryoromediterranean ( Ptilotrichion purpurei) - were separated later on. Some relationships were found between the oromediterranean communities in the Central Mountains (Sierra de Guadarrama) and Sierra Nevada. This highlights the mediterranean character of this central Iberian mountain, compared to the rest of the central ranges (four groups representing cryoromediterranean vegetation) that were independently separated by the analysis and have a more submediterranean character. All are included in Jasionion carpetanae. Conclusions The Pyrenees and the Cantabrian Range show relationships in high-mountain vegetation but also differences since the Cantabrian Range has a major influence of Mediterranean taxa in their plant communities. Central Iberian mountains showed relationships with the other Mediterranean mountains through the presence of species of the Festuca indigesta gr. and other endemic taxa. The particular pattern of Sierra Nevada - very patchy and with lower cover values - hindered the separation of groups, but two groups were finally detected in the analysis based on the altitudinal gradient. [ABSTRACT FROM AUTHOR]

Both, agricultural intensification and abandonment caused a strong decline in plant species richness in semi-natural grasslands in Central Europe within the last decades. At a global scale, the Convention on Biological Diversity targeted at halting the decline of biodiversity by the end of 2010. Agri-environmental schemes (AES) have been developed at the national level to reach this biodiversity target in agricultural areas. We evaluated the effectiveness of Austrian agro-environmental schemes on species-rich grasslands within the UNESCO Biosphere Reserve Wienerwald. We found a general decrease of vascular plant species richness at 95 sites, from an average of 43 species in 1990/92 to 31 species in 2011. The average decrease of species classified as threatened according to the national Red List from 12 to 7 and the parallel increase of widespread, nitrophilous species indicates a reduced conservation value of observed meadows. Species losses did not differ between mesic meadows of the Arrhenatherion type (EU habitat type 6510) and more nutrient-poor, semi-dry Brometalia grasslands (EU habitat type 6210), indicating the sensitivity to changes in agricultural management regimes even for more intensively used grassland types. AES decelerated this overall trend but could not stop biodiversity losses over the past two decades. Although the maintenance of grassland management through AES prevented biodiversity loss in areas which otherwise would have been abandoned, adaptations of the Austrian AES are desirable to effectively conserve biodiversity at agricultural sites. [ABSTRACT FROM AUTHOR]

This annual Editorial of 2017 summarizes the developments of the journal Phytocoenologia in the two years following its re-launch in 2015. Both the Editorial Team and the topics and regions of publications are very diverse. Starting with 2015, Impact Factors and CiteScores profoundly improved compared to the previous years, which, together with some other measures, has rendered Phytocoenologia an increasingly attractive publication venue. Narrowing the scope of Phytocoenologia explicitly down to "vegetation survey and classification" was arguably one of the cornerstones of recent success. The bibliometric analyses have also allowed us to demonstrate that both in absolute numbers and with regard to the proportion of such papers, Phytocoenologia can now be considered the leading journal in the field of vegetation classification worldwide. The citation network of Phytocoenologia includes a wide array of journals, although many remain to be covered in the Web of Science, to the bibliometric disadvantage of Phytocoenologia. We shortly present the four Editors' Choice articles of 2016 and a selection of some other outstanding contributions of that volume. The Editors' Award 2016 goes to Rui B. Elias and colleagues for their combination of vegetation classification and distribution modelling to derive a map of the natural vegetation of the Azores. In conclusion, the Editors aim to provide a service to vegetation ecologists worldwide by maintaining and further improving the qualities of Phytocoenologia. [ABSTRACT FROM AUTHOR]

Aims Vegetation classification consistent with the Braun-Blanquet approach is widely used in Europe for applied vegetation science, conservation planning and land management. During the long history of syntaxonomy, many concepts and names of vegetation units have been proposed, but there has been no single classification system integrating these units. Here we (1) present a comprehensive, hierarchical, syntaxonomic system of alliances, orders and classes of Braun-Blanquet syntaxonomy for vascular plant, bryophyte and lichen, and algal communities of Europe; (2) briefly characterize in ecological and geographic terms accepted syntaxonomic concepts; (3) link available synonyms to these accepted concepts; and (4) provide a list of diagnostic species for all classes. Location European mainland, Greenland, Arctic archipelagos (including Iceland, Svalbard, Novaya Zemlya), Canary Islands, Madeira, Azores, Caucasus, Cyprus. Methods We evaluated approximately 10 000 bibliographic sources to create a comprehensive list of previously proposed syntaxonomic units. These units were evaluated by experts for their floristic and ecological distinctness, clarity of geographic distribution and compliance with the nomenclature code. Accepted units were compiled into three systems of classes, orders and alliances (EuroVegChecklist, EVC) for communities dominated by vascular plants ( EVC1), bryophytes and lichens ( EVC2) and algae ( EVC3). Results EVC1 includes 109 classes, 300 orders and 1108 alliances; EVC2 includes 27 classes, 53 orders and 137 alliances, and EVC3 includes 13 classes, 24 orders and 53 alliances. In total 13 448 taxa were assigned as indicator species to classes of EVC1, 2087 to classes of EVC2 and 368 to classes of EVC3. Accepted syntaxonomic concepts are summarized in a series of appendices, and detailed information on each is accessible through the software tool EuroVegBrowser. Conclusions This paper features the first comprehensive and critical account of European syntaxa and synthesizes more than 100 yr of classification effort by European phytosociologists. It aims to document and stabilize the concepts and nomenclature of syntaxa for practical uses, such as calibration of habitat classification used by the European Union, standardization of terminology for environmental assessment, management and conservation of nature areas, landscape planning and education. The presented classification systems provide a baseline for future development and revision of European syntaxonomy. [ABSTRACT FROM AUTHOR]

Correlative species distribution models have long been the predominant approach to predict species' range responses to climate change. Recently, the use of dynamic models is increasingly advocated for because these models better represent the main processes involved in range shifts and also simulate transient dynamics. A well-known problem with the application of these models is the lack of data for estimating necessary parameters of demographic and dispersal processes. However, what has been hardly considered so far is the fact that simulating transient dynamics potentially implies additional uncertainty arising from our ignorance of short-term climate variability in future climatic trends. Here, we use endemic mountain plants of Austria as a case study to assess how the integration of decadal variability in future climate affects outcomes of dynamic range models as compared to projected long-term trends and uncertainty in demographic and dispersal parameters. We do so by contrasting simulations of a so-called hybrid model run under fluctuating climatic conditions with those based on a linear interpolation of climatic conditions between current values and those predicted for the end of the 21st century. We find that accounting for short-term climate variability modifies model results nearly as differences in projected long-term trends and much more than uncertainty in demographic/dispersal parameters. In particular, range loss and extinction rates are much higher when simulations are run under fluctuating conditions. These results highlight the importance of considering the appropriate temporal resolution when parameterizing and applying range-dynamic models, and hybrid models in particular. In case of our endemic mountain plants, we hypothesize that smoothed linear time series deliver more reliable results because these long-lived species are primarily responsive to long-term climate averages. [ABSTRACT FROM AUTHOR]

Aim Emerging polyploids may depend on environmental niche shifts for successful establishment. Using the alpine plant Ranunculus kuepferi as a model system, we explore the niche shift hypothesis at different spatial resolutions and in contrasting parts of the species range. Location European Alps. Methods We sampled 12 individuals from each of 102 populations of R. kuepferi across the Alps, determined their ploidy levels, derived coarse-grain (100 × 100 m) environmental descriptors for all sampling sites by downscaling WorldClim maps, and calculated fine-scale environmental descriptors (2 × 2 m) from indicator values of the vegetation accompanying the sampled individuals. Both coarse and fine-scale variables were further computed for 8239 vegetation plots from across the Alps. Subsequently, we compared niche optima and breadths of diploid and tetraploid cytotypes by combining principal components analysis and kernel smoothing procedures. Comparisons were done separately for coarse and fine-grain data sets and for sympatric, allopatric and the total set of populations. Results All comparisons indicate that the niches of the two cytotypes differ in optima and/or breadths, but results vary in important details. The whole-range analysis suggests differentiation along the temperature gradient to be most important. However, sympatric comparisons indicate that this climatic shift was not a direct response to competition with diploid ancestors. Moreover, fine-grained analyses demonstrate niche contraction of tetraploids, especially in the sympatric range, that goes undetected with coarse-grained data. Main conclusions Although the niche optima of the two cytotypes differ, separation along ecological gradients was probably less decisive for polyploid establishment than a shift towards facultative apomixis, a particularly effective strategy to avoid minority cytotype exclusion. In addition, our results suggest that coarse-grained analyses overestimate niche breadths of widely distributed taxa. Niche comparison analyses should hence be conducted at environmental data resolutions appropriate for the organism and question under study. [ABSTRACT FROM AUTHOR]

Aim The rate of climate change might exceed the migration capacity of plants, particularly where habitats became fragmented by human land use. Except for some tree species, the extent to which habitat fragmentation decreases migration rates has nevertheless been little evaluated. Here, we compare simulated migration rates of understorey herbs, which comprise the big part of temperate forest plant diversity, under varying levels of fragmentation at a continental scale. Location Europe. Methods We combined simulations of demography and seed dispersal to simulate migration of 16 hypothetical forest herb species through a virtual, continuously forested landscape of 50 × 50 km and through 1179 50 × 50 km regions spanning most of the European Union's territory plus Norway and Switzerland. Each region was subdivided into a 250-m raster of sites, which were rated as suitable to a species if covered by forest according to current land cover maps and future land cover scenarios. The 16 hypothetical species were defined by combinations of those trait values that control demographic and dispersal processes. Results In continuous forests, simulated migration rates of the 16 species varied between ~95 and ~225 m/y. Current forest fragmentation was predicted to reduce migration rates to about 70% on average across the continent, but to below 25% in many parts of western and southern Europe. Under future land use, migration rates might slightly increase in economically marginal regions. Main conclusions Our results indicate that even on a continuously forested continent most understorey herbs would be unable to track climate warming and that habitat fragmentation will reduce migration rates to values an order of magnitude lower than expected climate velocities in parts of Europe. We conclude that, instead of concentrating conservation efforts in protected areas, facilitating the movement of species through the average countryside should become a conservation priority. [ABSTRACT FROM AUTHOR]

The role of competition for light among plants has long been recognised at local scales, but its importance for plant species distributions at larger spatial scales has generally been ignored. Tree cover modifies the local abiotic conditions below the canopy, notably by reducing light availability, and thus, also the performance of species that are not adapted to low-light conditions. However, this local effect may propagate to coarser spatial grains, by affecting colonisation probabilities and local extinction risks of herbs and shrubs. To assess the effect of tree cover at both the plot- and landscape-grain sizes (approximately 10-m and 1-km), we fit generalised linear models (GLMs) for the plot-level distributions of 960 species of herbs and shrubs using 6935 vegetation plots across the European Alps. We ran four models with different combinations of variables (climate, soil and tree cover) at both spatial grains for each species. We used partial regressions to evaluate the independent effects of plot- and landscape-grain tree cover on plot-level plant communities. Finally, the effects on species-specific elevational range limits were assessed by simulating a removal experiment comparing the species distributions under high and low tree cover. Accounting for tree cover improved the model performance, with the probability of the presence of shade-tolerant species increasing with increasing tree cover, whereas shade-intolerant species showed the opposite pattern. The tree cover effect occurred consistently at both the plot and landscape spatial grains, albeit most strongly at the former. Importantly, tree cover at the two grain sizes had partially independent effects on plot-level plant communities. With high tree cover, shade-intolerant species exhibited narrower elevational ranges than with low tree cover whereas shade-tolerant species showed wider elevational ranges. These findings suggest that forecasts of climate-related range shifts for herb and shrub species may be modified by tree cover dynamics. [ABSTRACT FROM AUTHOR]

Aim Phylogenetic diversity patterns are increasingly being used to better understand the role of ecological and evolutionary processes in community assembly. Here, we quantify how these patterns are influenced by scale choices in terms of spatial and environmental extent and organismic scales. Location European Alps. Methods We applied 42 sampling strategies differing in their combination of focal scales. For each resulting sub-dataset, we estimated the phylogenetic diversity of the species pools, phylogenetic α-diversities of local communities, and statistics commonly used together with null models in order to infer non-random diversity patterns (i.e. phylogenetic clustering versus over-dispersion). Finally, we studied the effects of scale choices on these measures using regression analyses. Results Scale choices were decisive for revealing signals in diversity patterns. Notably, changes in focal scales sometimes reversed a pattern of over-dispersion into clustering. Organismic scale had a stronger effect than spatial and environmental extent. However, we did not find general rules for the direction of change from over-dispersion to clustering with changing scales. Importantly, these scale issues had only a weak influence when focusing on regional diversity patterns that change along abiotic gradients. Main conclusions Our results call for caution when combining phylogenetic data with distributional data to study how and why communities differ from random expectations of phylogenetic relatedness. These analyses seem to be robust when the focus is on relating community diversity patterns to variation in habitat conditions, such as abiotic gradients. However, if the focus is on identifying relevant assembly rules for local communities, the uncertainty arising from a certain scale choice can be immense. In the latter case, it becomes necessary to test whether emerging patterns are robust to alternative scale choices. [ABSTRACT FROM AUTHOR]

Highlights: [•] Historical patch size is a better species richness predictor than current size. [•] Habitat quality variables are better predictors than size variables. [•] High quality areas in the landscape are more important than extensively used areas. [•] Grassland specialists do not benefit from linear structures in the surroundings. [•] Conservation should achieve a network of high-quality grassland patches. [ABSTRACT FROM AUTHOR]

Question How does the plant species composition of Pontic- Pannonian salt-rich habitats vary on a large geographical scale? Do the floristic differences between Pannonia and the Balkans correspond to the current phytosociological classification? Location Pannonia ( Hungary, Slovakia, Austria, Czech Republic, Croatia, Serbia, Romania) and the Balkans ( Bulgaria, Macedonia, Greece). Methods Two thousand four hundred and thirty-seven relevés from halophytic and sub-halophytic habitats were classified using a modified TWINSPAN. The crispness of classification was checked. DCA and CCA with climate data as explanatory variables were applied. Results The classification was best interpreted at the level of 15 clusters. The vegetation changed along the salinity gradient from sub-halophytic grasslands (including Trifolion resupinati alliance of the Molinio- Arrhenatheretalia class and Beckmannion eruciformis and Festucion pseudovinae p. p. alliances of the Festuco- Puccinellietea class) and reed beds ( Bolboschoenion maritimi p. p. alliance; the Phragmito- Magnocaricetea class), through steppe and wet inland halophytic vegetation ( Festucion pseudovinae p. p. , Puccinellion limosae, Pucinellion convolutae, Bolboschoenion maritimi p. p. and Juncion gerardii of the Festuco- Puccinellietea class) towards the extreme halophytic vegetation of the Thero- Salicornietea, Crypsietea and Juncetea maritimi classes. This gradient was longer in the Balkan region, where it spanned from the sub-mediterranean salt-rich grasslands to the extremely halophytic vegetation at the Black Sea coast. The second most important gradient coincided with the water regime. Some vegetation types appeared to be confined to either the Pannonian or the Balkan region (especially within dry sub-halophytic and steppe halophytic grasslands), while others were distributed across the entire study area. The above-mentioned pattern did not always correspond with current classification systems. Conclusions Variation in salt-rich vegetation predominantly follows the salinity and water regime gradients. Geographical variation, generally coinciding with climatic and historical effects, is also important, especially in drier salt-rich habitats. Our large-scale analysis of the floristic variation of salt-rich habitats might be useful for the unification of classification systems that differ substantially between the countries involved. In addition, the analysis may be useful for adjustment of a classification system in the poorly explored Balkan region, where particular vegetation types were identified with, or delimited from, Central European vegetation types without detailed comparative analysis until now. [ABSTRACT FROM AUTHOR]

Background: The divergent glacial histories of southern and northern Europe affect present-day species diversity at coarsegrained scales in these two regions, but do these effects also penetrate to the more fine-grained scales of local communities? Methodology/Principal Findings: We carried out a cross-scale analysis to address this question for vascular plants in two mountain regions, the Alps in southern Europe and the Scandes in northern Europe, using environmentally paired vegetation plots in the two regions (n = 403 in each region) to quantify four diversity components: (i) total number of species occurring in a region (total γ-diversity), (ii) number of species that could occur in a target plot after environmental filtering (habitat-specific γ-diversity), (iii) pair-wise species compositional turnover between plots (plot-to-plot b-diversity) and (iv) number of species present per plot (plot a-diversity). We found strong region effects on total γ-diversity, habitatspecific γ-diversity and plot-to-plot b-diversity, with a greater diversity in the Alps even towards distances smaller than 50 m between plots. In contrast, there was a slightly greater plot a-diversity in the Scandes, but with a tendency towards contrasting region effects on high and low soil-acidity plots. Conclusions/Significance: We conclude that there are strong regional differences between coarse-grained (landscape- to regional-scale) diversity components of the flora in the Alps and the Scandes mountain ranges, but that these differences do not necessarily penetrate to the finest-grained (plot-scale) diversity component, at least not on acidic soils. Our findings are consistent with the contrasting regional Quaternary histories, but we also consider alternative explanatory models. Notably, ecological sorting and habitat connectivity may play a role in the unexpected limited or reversed region effect on plot adiversity, and may also affect the larger-scale diversity components. For instance, plot connectivity and/or selection for high dispersal ability may increase plot a-diversity and compensate for low total γ-diversity. [ABSTRACT FROM AUTHOR]

The article discusses the impact of rise in temperature on ecology. More species of plants and animals are moving towards higher elevated lands. The ecologists are focusing on several aspects related to this trend which includes declining fauna in lowlands, effects on mountaintop and gaps between elevational ranges. Studies states that species are also found moving towards lowlands. It states that climate change or warming affects species distribution as it changes abiotic conditions also.

. Question: Are there effects of long-term deposition of airborne nitrogen and sulphur on the forest floor vegetation from permanent plots collected in 1993 compared to 2005. Location: Northern limestone Alps in Austria. Methods: Single species responses were analysed by correlating trends in cover-abundance values, as derived from marginal models, with Ellenberg indicator values. Changes in the species composition of plots were analysed by correlating changes in mean Ellenberg indicator values with the displacement of plots within a multidimensional scaling ordination. Results: Trends in single species abundance were positively correlated with indicator values of soil pH but were independent of nutrient availability. A general trend towards the homogenisation of vegetation, due to convergent time vectors of the relevés, became obvious. Oligotrophic sites previously situated at the distal ends of ordination axes shifted towards the centre since they were enriched by species preferring mesotrophic conditions. The bulk of plots with intermediate site conditions hardly showed any trends. A concomitant analysis demonstrated that temporal changes in species composition exceed the variation in cover abundance estimates among different field botanists. Conclusions: N deposition can lead to a homogenisation of forest floor vegetation. Larger limestone areas with diverse soil conditions, such as the Northern limestone Alps in Austria, as a whole are thus negatively affected by airborne N deposition. Nevertheless, the vegetation was at least as strongly affected by an increase of basiphilous species as a result of decreasing S deposition. [ABSTRACT FROM AUTHOR]

Question: What is the variation in species composition of Central European semi-dry grasslands? Can we apply a training-and-test validation approach for identifying phytosociological associations which are floristically well defined in a broad geographic comparison; can we separate them from earlier described Associations with only a local validity? Location: A 1200 km long transect running along a gradient of increasing continentality from central Germany via Czech Republic, Slovakia, NE Austria, Hungary to NW Romania. Methods: Relevés with > 25% cover of Brachypodium pinnatum and/or Bromus erectus were geographically selected from a larger database. They were randomly split into two data sets, TRAINING and TEST, each with 422 relevés. Cluster analysis was performed for each data set on scores from significant principal coordinates. Different partitions of the TRAINING data set were validated on the TEST data set, using a new method based on the comparison of % frequencies of species occurrence in clusters. Clusters were characterized by statistically defined groups of diagnostic species and values of climatic variables. Results: Species composition changed along the NW-SE gradient and valid clusters were geographically well separated. Optimal partition level was at 11 clusters, six being valid: two clusters Germany and the Czech Republic corresponded to the Bromion erecti; two clusters from the Czech Republic and Hungary to the Cirsio-Brachypodion, and two clusters were transitional between these two alliances. Conclusion: The training-and-test validation method used in this paper proved to be efficient for discriminating between robust clusters, which are appropriate candidates for inclusion in the national or regional syntaxonomic overviews, and weak clusters, which are specific to the particular classification of the given data set. [ABSTRACT FROM AUTHOR]

In the phytosociological literature, there are numerous different approaches to the designation of diagnostic species. Frequently, this results in discrepancies between the lists of diagnostic species published for one and the same community. We examined different approaches to determining diagnostic species using as an example Picea abies forests within the broader context of all Central European forests. Diagnostic species of spruce forests were determined from a data set of 20,164 phytosociological relevés of forests from the Eastern Alps, Western Carpathians, and the Bohemian Massif, which included 3,569 relevés of spruce forests. Phi coefficient of association was used to measure species fidelity, and species with the highest fidelities were considered as diagnostic. Diagnostic species were determined in four ways, including (A) comparison of spruce forests among the three mountain ranges, (B) comparison between spruce forests and other forests, performed separately in each of the mountain ranges, (C) simultaneous comparison of spruce forests of each of the mountain ranges with spruce forests of the other two ranges and with the other forests of all ranges, (D) comparison of spruce forests with the other forests, using pooled data sets from the three mountain ranges. The sets of diagnostic species of spruce forests yielded in comparisons A and B were sharply different; the set resulting from comparison C was intermediate between the first two and comparison D resulted in similar diagnostic species as comparison B. In comparison A, spruce forests of the Eastern Alps had a number of diagnostic species, while the spruce forests of the other two mountain ranges had only few diagnostic species. In comparison B, by contrast, the number and quality of diagnostic species decreased from the Bohemian Massif to the Eastern Alps. This exercise points out that lists of diagnostic species published in phytosociological literature are dependent on the... [ABSTRACT FROM AUTHOR]

An Correction to this paper has been published: https://doi.org/10.1007/s12224-021-09391-x [ABSTRACT FROM AUTHOR]

We assessed the relationships between site size, habitat quality, landscape factors (fragmentation, landscape diversity) and species richness in communities of Collembola in 50 small dry grassland habitat patches in an agricultural landscape of eastern Austria. Grasslands in that region were once widespread and extensive, but have become increasingly fragmented and isolated. We hypothesized that dry grassland springtails species richness is significantly correlated with site variables (soil properties, habitat quality) and that the size of grassland sites is positively correlated with species richness. We used pitfall traps in 50 dry grasslands in differently structured agricultural landscapes and tested total abundance and three species richness measures: (1) the number of dry grassland specialist species; (2) total number of dry grassland species and (3) overall species richness. In the multivariate correlation models, we found that all species richness measures were significantly related to the plant species richness, a shape parameter of the sites, soil properties such as humus, temperature, sand and gravel content and the landscape variable reflecting isolation (distance to the nearest large dry grassland area). This landscape variable indicates that neighbouring grasslands are influencing the species richness of the sites. This may be a result of passive wind dispersal across the landscape or historic connection of the small sites with much larger dry grasslands. The size of the site did not show any significant correlation with total, dry grassland specialist, dry grassland generalist or generalist species richness. The small size of Collembola might explain these findings, because they have high population densities even in small patches. [ABSTRACT FROM AUTHOR]