Semi-dry grasslands are of high nature conservation interest both at national and European scales due to their high biodiversity and species richness. For effective conservation, however, the variation in floristic composition and distribution of these grasslands need first to be described. In Hungary, there is currently no comprehensive survey and classification of semi-dry grasslands. Therefore, the aim of this study was to (i) describe the variation in species composition of Hungarian semi-dry grasslands by a country-scale cluster analysis based on a large database; (ii) describe the types (clusters) and compare these descriptions with those in the phytosociological literature, and finally (iii) formulate a new syntaxonomical system for Hungarian semi-dry grasslands. For this analysis 699 relevés were selected in which the percentage cover of at least one of the grasses Brachypodium pinnatum, Bromus erectus, Danthonia alpina, Avenula adsurgens, A. pubescens or A. compressa reached >10%. A geographical stratification of the dataset was performed and then it was split randomly into two equal parts (training and test datasets). Following outlier exclusion and noise elimination, clustering was performed separately for both datasets. The optimal number of clusters was determined by validation. The number of valid clusters was the highest at the level of ten clusters, where seven clusters appeared to be valid. The valid clusters are separated geographically; however, there are considerable overlaps in the species compositions. According to our results, all the grasslands belong to the Cirsio-Brachypodion alliance. The seven valid clusters are assigned to five main groups of semi-dry grasslands in Hungary: 1. Brachypodium pinnatum (and partly Bromus erectus) dominated, species rich meadow-steppe-like grasslands occurring on deep loess in central Pannonia, identified as Euphorbio pannonicae-Brachypodietum Horváth 2009; 2. Brachypodium pinnatum dominated mountain grasslands restricted to the Bükk Mountains; identified as Polygalo majoris-Brachypodietum Wagner 1941; 3. mostly Bromus erectus dominated grasslands on shallow, calcium/rich soils of the Dunántúl region, proposed as a new association Sanguisorbo minoris-Brometum erecti Illyés, Bauer & Botta-Dukát 2009; 4. Brachypodium pinnatum and Danthonia alpina dominated stands occurring mainly in the Északi-középhegység Mts, characterized by species of nutrient poor soils, proposed as a new association Trifolio medii-Brachypodietum pinnati Illyés, Bauer & Botta-Dukát 2009; 5. transition towards meadows and successional stands dominated mainly by Brachypodium pinnatum.
The vegetation relevés stored electronically in the Czech National Phytosociological Database are reviewed. The database was established in 1996, with the central database located in the Department of Botany, Masaryk University, Brno (www.sci.muni.cz/botany/database.htm). On 15 November 2002 this central database contained 54,310 relevés from the Czech Republic, collected by 332 authors between 1922–2002. Ca. 54% of the relevés were taken from published papers or monographs, 21% from theses and the rest from various unpublished reports and field-books. These relevés include 1,259,008 records of individual plant species. Territorial coverage of the country by the reléves is irregular as the areas with attractive natural or semi-natural vegetation are more intensively sampled, with gaps in coverage of less attractive or poorly accessible areas. Most relevés are of broad-leaved deciduous forests (Querco-Fagetea), meadows (Molinio-Arrhenatheretea), dry grasslands (Festuco-Brometea), and marsh grasslands (Phragmito-Magnocaricetea). The quality of the data is discussed, such as researcher bias, preferential selection of sampling sites, spatial autocorrelation and missing values for some data elements.
This paper deals with the flora and vegetation of stony walls (wall tops, vertical wall surfaces) in East Bohemia. In total, 207 species of vascular plants and 60 mosses were identified in 114 recorded relevés. Flora of walls is composed of a high number of accidental species. Only two species (Poa compressa, Taraxacum sect. Ruderalia) were frequently recorded on walls. Differences in species’ traits (life strategy, life form, dispersal) and ecological requirements of plants (light, moisture) were analysed between vertical wall surfaces and wall tops. Due to high floristic heterogeneity, many communities can be classified only at the level of higher syntaxa. In total, 10 communities were reported on the studied walls. Communities on wall tops were dominated by Poa compressa, P. palustris subsp. xerotica, P. nemoralis subsp. rigidula, Conyza canadensis and Syringa vulgaris. Four communities dominated by Corydalis lutea, Cymbalaria muralis, Asplenium ruta-muraria and Cystopteris fragilis were identified on vertical wall surfaces. Their structure, species composition, ecology and distribution are briefly discussed.
A formalized and supervised phytosociological classification of Alnion glutinosae and Alnion incanae in the Czech Republic is presented. Three associations of Alnion glutinosae (Thelypterido palustris-Alnetum glutinosae, Carici elongatae-Alnetum glutinosae and Carici acutiformis-Alnetum glutinosae) and seven of Alnion incanae (Alnetum incanae, Stellario nemorum-Alnetum glutinosae, Pruno-Fraxinetum, Carici remotae-Fraxinetum, Piceo-Alnetum, Ficario-Ulmetum campestris and Fraxino pannonicae-Ulmetum) were distinguished by the Cocktail method using sociological species groups. Information about their syntaxonomy, species composition, ecology and distribution is presented. Ellenberg’s indicator values were used to show the main ecological gradients responsible for the variation in the vegetation of these communities. The most important factors affecting this variation were temperature (for Alnion incanae) and soil reaction, nutrient availability and moisture (for Alnion glutinosae).
Vegetation classification should reflect the major environmental and phytogeographical gradients that influence species composition. However, the importance of different gradients depends on the geographical scale of particular studies. Locally defined vegetation units usually reflect local gradients, such as disturbance and soil properties, while regionally defined units reflect macroclimatic patterns and different evolutionary and migration histories of large regions. The classification of Central European oak-hornbeam forests (Carpinion alliance) is an example of a widely accepted, broad-scale classification with geographically delimited associations. However, in some cases it fails to describe adequately local vegetation patterns. In the Czech Republic, six associations, based on a broad-scale regional classification, were traditionally distinguished: (1) Melampyro nemorosiCarpinetum – Hercynian association; (2) Primulo veris-Carpinetum – Pannonian association; (3) Carici pilosae-Carpinetum – Carpathian association; (4) Tilio-Carpinetum – Polonian association; (5) Stellario-Tilietum – local association of southern Bohemia; (6) Tilio-Betuletum – ecologically delimited and local association. The goal of this study was to evaluate, using a cluster analysis of a set of 601 geographically stratified relevés, whether the variation in species composition of oakhornbeam forests in the Czech Republic reflects the traditional geographically based classification. Hercynian, Pannonian and Carpathian types of oak-hornbeam forests were reproduced by cluster analysis. No support was found for the Polonian type and the two local associations, StellarioTilietum and Tilio-Betuletum. Instead, a distinct group confined to wet soils emerged. On the basis of this analysis, we suggest a classification that combines ecological and geographical principles and distinguishes four associations: (1) Hercynian (Melampyro nemorosi-Carpinetum or Galio sylvatici-Carpinetum); (2) Pannonian (Primulo veris-Carpinetum); (3) Carpathian (Tilio cordataeCarpinetum or Carici pilosae-Carpinetum); (4) Stellario holosteae-Carpinetum, which is a geographically delimited association of atlantic northwestern central Europe, defined ecologically by its occurrence on wet soils within the Czech Republic.
A new species of bramble, Rubus kletensis, of the section Corylifolii Lindley, series Sepincola (Focke) E. H. L. Krause occurring in South Bohemia and Upper Austria is described. The distance between the most distant localities exceeds almost 150 km. This distinct and relatively easily recognizable species grows in rather moist, eutrophic, synanthropic and sunny biotopes, and occurs most frequently in the vegetation of the class Galio-Urticetea, less frequently in that of the alliances Trifolion medii, Pruno-Rubion radulae, Sambuco-Salicion capreae, Berberidion and exceptionally in forest plantations and growths of pioneer saplings. A distribution map for this species and a list of all known localities are included, as well as a drawing of the species.
A new apomictic triploid (2n = 3x = 51) species belonging to the Sorbus latifolia group, S. milensis M. Lepší, K. Boublík, P. Lepší et P. Vít, putatively of hybridogenous origin between sexual Sorbus aria s.l. and S. torminalis, is described from the České středohoří Mts (northwestern Bohemia, Czech Republic). Several biosystematic techniques, including molecular (nuclear microsatellite markers), karyological (chromosome counts, genome size) and multivariate morphometrics were used to assess the variation in this species and justify its independent taxonomic status. The only known population of S. milensis consists of 38 adult and 19 juvenile individuals, is phenotypically homogenous and distinct from other Bohemian hybridogenous Sorbus species. All sampled individuals were karyologically uniform and showed little genetic variation. Sorbus milensis is a stenoendemic occurring on Milá hill (situated ca 9.5 km NNW of the town of Louny) where it grows on basaltic rocks, in ravines and on screes. The majority of the individuals grow in scree forests of the Tilio-Acerion alliance; other vegetation types include xeric scrub of the Prunion spinosae alliance and xerothermophilous grassland communities of the Festucion valesiacae alliance. A detailed distribution map for this species is provided as well as photographs of the type specimen.
A syntaxonomical revision of meadows of the Molinion caeruleae Koch 1926 alliance in the Czech Republic is presented. Of ten associations reported previously for the Czech Republic only two were distinguished using the Cocktail method – Molinietum caeruleae Koch 1926 and Junco effusi-Molinietum caeruleae Tüxen 1954. The former occurs on more base-rich soils, while the latter is found in more acidic habitats and characterized by the occurrence of species of Nardus grasslands. Results of this classification were compared with classifications of Molinion meadows for other countries of Central Europe. Main environmental gradients responsible for variation in species composition of Czech Molinion meadows were revealed by detrended correspondence analysis. For interpretation of these gradients correlations with Ellenberg indicator values and altitude were used. The main gradient positively correlates with soil base status, continentality, temperature and nutrients, and negatively with altitude.
Nutrient-rich terrestric habitats form small areas in the peaty alluvial plain of upper stream of the Vltava river. Their vegetation consists of birch and grey alder alluvial woodland, willow and bridewort scrub and tall grassland of sedges, grasses and forbs. A hypothesis that this vegetation is an Early Holocene relic is presented. The relict origin is supported by recent dynamics of habitats and vegetation, findings of palynology, palaeoecology and history of land use, and by the analogical composition and history of relict vegetation of northernmost Europe. The refugial effect of the habitat is suggested by stable conditions on high temporal and spatial scales, and by permanent reclaiming of open gaps along the stream.
Typology of dry-mesic oak forest vegetation of Slovakia is presented. Seven vegetation types were distinguished based on a Braun-Blanquetian relevé data analysis using a TWINSPAN classification algorithm. The identified vegetation types are related to seven syntaxa traditionally used by Central European phytosociologists: dry-mesic oak forest on sandy soils – Carici fritschii-Quercetum roboris, dry-mesic oak forest on heavy soils – Potentillo albae-Quercetum, dry-mesic oak forest on basic rocky substrates – Corno-Quercetum, dry-mesic oak forest on acidic substrates – Sorbo torminalis-Quercetum, dry oak forest on loess – Quercetum pubescenti-roboris, dry-mesic oak forest on loess – Convallario-Quercetum roboris, dry-mesic forest of Turkey oak – Quercetum petraeae-cerris. Detrended correspondence analysis was used to visualize the similarity of vegetation types. Some aspects of dry-mesic oak forest ecology, distribution and dynamics in Slovakia are discussed; their general retreat due to mesophilous tree species expansion is stressed.