A syntaxonomical synthesis of calcicolous forests dominated by Fagus sylvatica (Cephalanthero-Fagenion suballiance) in the Czech Republic was carried out using the Braun-Blanquet approach. Relevés included in the analyses were selected following formalized approach by using an expert-delimited group of 38 calcicolous and/or xerothermophilous species. Only one association Cephalanthero-Fagetum was distinguished, which usually occurs on limestone, calcareous sandstone and calcareous sandy marlite; however, can be found also on base-rich siliceous bedrock (e.g. basalt, phonolite). Based on TWINSPAN analysis, three subassociations were recognized within the Cephalanthero-Fagetum: (i) Cephalanthero-Fagetum seslerietosum caeruleae on shallow rocky soils with frequent dominance of Sesleria caerulea and presence of petrophytes, (ii) Cephalanthero-Fagetum typicum on dry, shallow soils with a significant presence of light-demanding, thermophilous, and calcicolous species, and (iii) Cephalanthero-Fagetum actaeetosum spicatae on deeper, sufficiently moist soils with an abundance of mesophilous, nitrophilous and acidophilous species. The name Cephalanthero-Fagetum actaeetosum spicatae is a new nomenclatural combination. The relationships between Cephalanthero-Fagetum and similar forest vegetation types containing xerothermophilous and/or calcicolous species in the Czech Republic are discussed. The main gradients in species composition of Cephalanthero-Fagetum subassociations were revealed by gradient analysis. The Ellenberg indicator values, altitude, slope, and ‘southness’ were used to interpret these gradients. Using unconstrained ordination analysis (DCA) the syntaxonomical interpretation indicated three relatively distinct groups. Moreover, further DCA analysis revealed the well-defined position of Cephalanthero-Fagetum within Czech beech forests. The results of the above delimitation of Cephalanthero-Fagetum were compared with the results based on Cocktail-defined species groups improved by similarity-based assignment of relevés (using frequency-positive fidelity index). When the Cocktail-based formulas for beech forests were applied to the relevés selected by our 38-species diagnostic group, the correspondence between these two approaches was only 36%. However, at the lower subassociation level, the highest correspondence occurred for Cephalanthero-Fagetum seslerietosum (84%). The reason for this high correspondence is that the species composition includes many specialists (i.e. good diagnostic species) and it occurs at the end of an ecological gradient. To sum up, it is possible to define vegetation units accurately using strict formulas, as opposed to the less rigorous ‘soft’ traditional approach. However, both approaches fail when defining central units.
Until now, Dryopteris remota was only recorded in the Czech Republic from the Moravian Karst, ca 70 years ago. This record is mentioned in some studies, but references to the data’s origin have always been missing. For this reason it was uncertain whether D. remota was still present in the Czech Republic. Recently, the records from the Moravian Karst were verified by re-examination of original herbarium specimens. In 2002 a specimen of D. remota was found for the first time in Bohemia, close to the village of Ktiš, on a slope of Malý Plešný hill in the foothills of the Bohemian Forest (S Bohemia). At this locality only one plant occurred on the boundary between Lonicera nigra-shrub and spruce-beech-fir forest, on a gneiss outcrop. Determination of the Czech specimens of D. remota was based on comparisons with macro- and micromorphological characters of both Alpine (Upper Austria) and Carpathian (West Ukraine) specimens, as well as descriptions in the literature. A detailed morphological description and comparison with similar taxa are included. A map of its distribution within the Czech Republic as well as a map of the distribution of D. remota worldwide is also presented. It is suggested that D. remota be designated a critically endangered plant species in the Czech Republic.
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.
Two new apomictic triploid (2n = 3x = 51) species from the Sorbus latifolia group, S. portae-bohemicae M. Lepší, P. Lepší, P. Vít et K. Boublík and S. albensis M. Lepší, K. Boublík, P. Lepší et P. Vít, putative hybridogenous species originated from a cross between S. danubialis and S. torminalis, are distinguished and described based on a taxonomic and chorological revision of Sorbus bohemica (a hybridogenous triploid species from the same parental combination). A number of contemporary biosystematic techniques, including molecular (nuclear microsatellite markers), karyological (chromosome counts, DAPI flow cytometry) and multivariate and geometric morphometrics were used to assess the variation of the species and justify their independent taxonomic status. All three species occur sympatrically in the České středohoří Mts (NW Bohemia). Sorbus bohemica is recorded from 31 localities, based on a revision of herbarium vouchers and field research. Recent field studies failed to verify five of these localities. Sorbus portae-bohemicae is a stenoendemic in the Porta bohemica gorge (situated ca 7 km WNW of Litoměřice) where it grows in open oak forests (Luzulo-Quercetum and transition vegetation type to Melampyro nemorosi-Carpinetum) on ENE-facing slopes and rocks. The only known population of S. portae-bohemicae consists of 14 adult individuals. Sorbus albensis occurs at 12 localities W to NW of Litoměřice. The total number of individuals is estimated at 600. Most are in acidophilous oak forests (Luzulo-Quercetum and its mesic derivatives), scree forests (Aceri-Carpinetum) or shrubby slopes (Pruno-Ligustretum, Antherico-Coryletum). Populations of the new taxa show little genetic variation and are phenotypically homogenous and well separated from other Bohemian hybridogenous Sorbus species. A distribution map of the three species is provided. Photographs of the type specimens and in situ fructiferous individuals of the new species are presented.