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.
Cyperus eragrostis Lam. was first recorded in the Czech Republic in an empty water reservoir at Jablonec nad Nisou (N Bohemia) in 1999. In this study, herbarium specimens of C. eragrostis in large herbaria in the Czech Republic were revised and the invasion of Europe by this species was reviewed. A brief description of C. eragrostis is given, distribution map of the temporal course of its invasion is presented and the species’ ecology in Europe characterized. Accompanying vegetation and results of the analyses of soil from the site are described. How the plant reached this locality remains unknown. The occurrence was only ephemeral as the only tussock was destroyed when the water reservoir was refilled.
The distribution of vascular plants in grid-cells and its relationship to the environmental correlates (driving factors) were studied using numerical methods (divisive classification and ordination). The first level of division in the classification distinguished forest and non-forest groups of grid-cells, and the second level four groups (containing predominantly species of base-rich forests at high altitudes, species of acidophilous mountain forests and small mountain grasslands, ruderal and meadows species at low altitudes, and species of thermophilous and basiphilous fringes and abandoned meadows). Within the study area, geographically consistent areas were delimited by correlating the groups, indicated by the divisive classification, with altitude and forest cover. Most differences in the Ellenberg indicator values for species in these groups for light, temperature, continentality, soil reaction and soil moisture were statistically significant. A number of variables were effective predictors (e.g. potential direct solar irradiation), physical geography (altitude, slope), land-cover (forest cover, area of urban zones) and geological bedrock were the key determinants of the species composition in the study area. However, even the most spatially correlated (according to Moran’s I measure) were the naturally contiguous variables such as topographical features (altitude, slope and aspect). Generally, the grid-cells at low altitudes contained more species due to the co-occurrence of man-made habitats with fragments of semi-natural habitats. A relatively large percentage of the variation (15.8%) was accounted for by the spatial structure of the data, the environmental factors explained 18.9%, but 65.3% of the floristic variance remained unexplained. The most spatially autocorrelated variables were also the most correlated with regard to species composition. However, the relatively high autocorrelation in the species data and their derivates had comparable or lower effect on species composition than the most autocorrelated environmental factors. The results were compared with those of other European studies, and possible bias due to the different ways of collecting and analysing data, and effect of different scales discussed.
In November 2009, the United Nations declared 2010 to be the International Year of Biodiversity. It has been a celebration of life on earth and of the value of biodiversity for our lives. The world has been invited to take action in 2010 to safeguard biodiversity, i. e., the variety of life on earth. Throughout the year countless initiatives were organized to disseminate information, promote the protection of biodiversity and encourage organizations, institutions, companies and individuals to take direct action to reduce the constant loss of biological diversity worldwide. and Petr Petřík.