Czechoslovak Documentation Centre

Abstract This study focuses on the frequency of reproductive modes and the role of reproductive mode variation in diversification of the genus Sorbus s.l. and evolutionary success of individual taxa. Our sampling covers all four ploidies known in Sorbus and includes stabilized taxa and recently formed biotypes. We infer reproductive modes of 3660 seeds using the flow cytometric seed screen method; we also calculated ploidy of contributing pollen. Sorbus shows high variability in reproduction pathways (sexuality, apomixis, formation of BIII hybrids, haploid parthenogenesis). Diploids are sexual, whereas polyploids show predominantly pseudogamous apomixis. In half of the polyploids studied, several reproductive modes were present and even intra-individual variation was detected. Diploids, tetraploids and pentaploids are pollinated by conspecific pollen, whereas triploids are largely, but not fully, dependent on the pollen of other species. In pseudogamous seeds, fertilization of the central cell by both sperms is a dominant pathway of endosperm origin. Flow cytometry of pollen did not detect unreduced pollen at any ploidy. The principal mechanisms of diversification in Sorbus are residual sexuality in apomicts, production of triploid taxa from diploid–tetraploid crosses and production of BIII hybrids. Evolutionary success of Sorbus taxa is largely dependent on the breeding system and is determined by self-(in)compatibility and the interplay between stabilizing apomixis and variation-generating sexuality.

This dataset contains records from 67 vegetation plots that we sampled at all the sites with preserved halophytic vegetation in southern Moravia (Czech Republic) and nearby Lower Austria on 9-13 August 2020. At each site, we sampled at least one vegetation plot in a relatively homogeneous area of each visually distinct type of halophytic vegetation found. All the plots were of standard size of 10 m². Most of them were squares of 3.16 m x 3.16 m, but if a square area contained non-homogeneous vegetation, we used a rectangular plot of 10 m² instead. We measured geographic coordinates of all the four corners of each plot using a GPS (Topcon HiPer SR with Getac PS336 Data Collector) with a positioning accuracy of ~5 cm. In each plot, we recorded all the species of vascular plants and bryophytes and estimated their cover using the nine-grade Braun-Blanquet scale (Westhoff & van der Maarel 1978). We also collected a soil sample from a depth of 2-10 cm in 3-4 places within each plot. We mixed these samples for each plot and measured the pH and electrical conductivity of the mixed sample in a suspension with distilled water (soil:water ratio ~ 2:5) using the Hach HQ40D multimeter (Hach, Loveland, CO, US). The data on species composition, plot location, soil pH and conductivity and other variables are provided in two formats: TXT file with columns separated by tabs - file Plot-data-halophytes-southern-Moravia-Lower-Austria-2020.txt Turboveg 2 database (see https://www.synbiosys.alterra.nl/turboveg/) - file TurbovegDbBackup_Plot-data-halophytes-southern-Moravia-Lower-Austria-2020.zip; to use this dataset in Turboveg, the database dictionary (TurbovegDdBackup_Default dictionary.zip) and species list (TurbovegSlBackup_Czechia_slovakia_2015.zip) have to be installed. These data are also stored in the Czech National Phytosociological Database (Chytrý & Rafajová 2003; https://botzool.cz/vegsci/phytosociologicalDb). In addition, photographs of each plot are provided as JPG files (Photos-of-plots-halophytes-southern-Moravia-Lower-Austria-2020.zip). The name of each of these files starts with the plot code (e.g. HAK12) which refers to the code indicated in the FIELD_NR field of the vegetation-plot database.

The intensively farmed fishponds of the Třeboň Basin in South Bohemia, Czech Republic host a substantial number Great Crested Grebe (Podiceps cristatus) pairs that nest later than the expected spring season and instead in summer, which may be associated with fishpond farming. A two-factor nested ANOVA of Great Crested Grebe egg and clutch characteristics showed no differences between spring (May-June) and summer (July - August) seasonal clutches. High egg total volume in spring nests was significantly related to both decreasing distance between nests and decreasing number of nests on the fishpond. The increase of total egg volume in summer nests was significantly related to the distance to the edge of littoral vegetation. There is no substantial difference between spring and summer egg characteristics, but total egg volume in spring nests is dependent on other characteristics that those in summer nests.

The events that became known as the‘Prague Spring’ of 1968 are better understood in fact as part of a more complex chain of crisis situations, making up three dimensions of a broader crisis of Czec...

Vertigo moulinsiana (Dupuy, 1849) was found in 2003–2005 in Northern Bohemia (Czech Republic) at 11 sites. All these sites are situated on floodplains of smaller streams in a sandstone area. The known occurrence of this endangered relict in the Czech Republic is concentrated in three areas – a large area of Bohemian Cretaceous Basin, a floodplain near villages Břežany and Božice (Dyje River Basin) in Southern Moravia and small, isolated, treeless fens in the White Carpathians (Bílé Karpaty Mts.). The principal habitats where V. moulinsiana lives in the Czech Republic are sedge marshes, Typha swamps, reed swamps (with Carex spp.), alder carrs (also with Carex spp.) and tufa-forming spring fens.

This dataset contains records from 67 vegetation plots that we sampled at all the sites with preserved halophytic vegetation in southern Moravia (Czech Republic) and nearby Lower Austria on 9-13 August 2020. At each site, we sampled at least one vegetation plot in a relatively homogeneous area of each visually distinct type of halophytic vegetation found. All the plots were of standard size of 10 m². Most of them were squares of 3.16 m x 3.16 m, but if a square area contained non-homogeneous vegetation, we used a rectangular plot of 10 m² instead. We measured geographic coordinates of all the four corners of each plot using a GPS (Topcon HiPer SR with Getac PS336 Data Collector) with a positioning accuracy of ~5 cm. In each plot, we recorded all the species of vascular plants and bryophytes and estimated their cover using the nine-grade Braun-Blanquet scale (Westhoff & van der Maarel 1978). We also collected a soil sample from a depth of 2-10 cm in 3-4 places within each plot. We mixed these samples for each plot and measured the pH and electrical conductivity of the mixed sample in a suspension with distilled water (soil:water ratio ~ 2:5) using the Hach HQ40D multimeter (Hach, Loveland, CO, US). The data on species composition, plot location, soil pH and conductivity and other variables are provided in two formats: TXT file with columns separated by tabs - file Plot-data-halophytes-southern-Moravia-Lower-Austria-2020.txt Turboveg 2 database (see https://www.synbiosys.alterra.nl/turboveg/) - file TurbovegDbBackup_Plot-data-halophytes-southern-Moravia-Lower-Austria-2020.zip; to use this dataset in Turboveg, the database dictionary (TurbovegDdBackup_Default dictionary.zip) and species list (TurbovegSlBackup_Czechia_slovakia_2015.zip) have to be installed. These data are also stored in the Czech National Phytosociological Database (Chytrý & Rafajová 2003; https://botzool.cz/vegsci/phytosociologicalDb). In addition, photographs of each plot are provided as JPG files (Photos-of-plots-halophytes-southern-Moravia-Lower-Austria-2020.zip). The name of each of these files starts with the plot code (e.g. HAK12) which refers to the code indicated in the FIELD_NR field of the vegetation-plot database.

Menetus dilatatus (Gould, 1841) has been found in July 2005 in the Lipno Reservoir (Bohemian Forest = Šumava Mts., Southern Bohemia, Czech Republic) at 12 particular sites. This locality is about 80 km south of the nearest known locality of Menetus dilatatus and more than 160 km south of the Elbe Lowland where Menetus dilatatus occurs in many sites including the Elbe River. The altitude of the Lipno Reservoir reaches 725 m a.s.l. and is the highest known altitude of Menetus dilatatus in the Czech Republic.

Populations of the freshwater snail Gyraulus rossmaessleri (Auerswald, 1852) (Gastropoda, Planorbidae) were found at 4 sites in the Meandry Smědé Nature Reserve (Northern Bohemia, Czech Republic). In Bohemia this species has not been found for last 25 years and the nearest localities with its known occurrence in the past are situated about 100 km to the south-west.