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Abstrakty/Abstracts

Zprávy České botanické společnosti 47/1, 2012


Abstrakty/Abstracts

Roleček J., Čech L. & Danihelka J.
Strošek polopásý (Lappula semicincta) v České republice
Lappula semicincta in the Czech Republic

Abstract
Lappula semicincta (Boraginaceae), a critically threatened species of the Czech flora, has been reported to occur in the Czech Republic in just a small area in south-western Moravia. The last record dates from 1980. During a field survey and a search in four regional herbaria, we recorded two extant populations of the species and found specimens from another three sites where the species had been collected in the past. All the sites are located in south-western Moravia between the Oslava River valley south-west of Brno city in the north and the Dyje River valley near the border with Austria in the south. The species inhabits warm and dry non-forest habitats in or near deep river valleys with base-rich skeletal soils. Semi-natural dry grasslands often prevail at these sites; however, L. semicincta usually occurs in disturbed places, often influenced by past or recent human activities.

Duchoslav M. & Krahulec F.
Rozšíření druhů rodu česnek (Allium) v České republice. V. Druhy sekce Allium (A. sphaerocephalon, A. vineale)
Distribution of Allium species in the Czech Republic. V. Species of sect. Allium (A. sphaerocephalon, A. vineale)

Abstract
The distribution and habitat conditions of two taxa of the genus Allium sect. Allium (Allium sphaerocephalon, A. vineale) were studied on the territory of the Czech Republic. Allium sphaerocephalon is a rare species which inhabits two types of habitat: thermophilous, perennial vegetation of rock outcrops (Alysso-Festucion pallentis alliance) and continental steppe vegetation (Festucion valesiacae alliance), in the warmest and driest areas of both Bohemia (northern part of Central Bohemia and North Bohemia) and Moravia (South Moravia) at lower altitudes (150-550 m a.s.l.) with most localities found below 400 m a.s.l. The species is included in the Red List of vascular plants of the Czech Republic. In contrast, Allium vineale is a common species occurring from the lowlands up to montane belt (128-850 m a.s.l.) with most localities found between 200 and 500 m a.s.l. The species inhabits a wide spectrum of habitats ranging from arable fields and vineyards (mostly in the past, presently seldom), field margins and road embankments (common), through mesic pastures (Cynosurion alliance) and meadows (Arrhenatherion alliance), disturbed broad-leaved dry grasslands (Bromion and Cirsio-Brachypodion alliances), and grassland vegetation on sandy soils, to scrub and rarely also mesic forests (Carpinion alliance) and floodplain forests (Alnion incanae alliance).

Hadinec J. & Lustyk P.
Additamenta ad floram Reipublicae Bohemicae. X.
Additions to the flora of the Czech Republic. X.

Abstract
This tenth part of floristic contributions includes newly published data of criticaly endangered species and data unpublished so far. Data of taxa newly discovered in the Czech Republic (Dryopteris cambrensis, Hieracium visianii, Orobanche kochii, Potamogeton × cooperi, P. × nitens, P. × olivaceus, P. × sparganiifolius, P. × undulatus, Rubus sorbicus, Scilla bifolia subsp. buekkensis and subsp. spetana) and data of alien species found in the Czech Republic for the first time (Galium murale, Hypericum annulatum, Pimpinella peregrina and Trachyspermum ammi) are summarised. Finds of Scilla bifolia subsp. rara, a subspecies described from the Czech Republic as new to science, are also listed below. Furthermore, critically endangered species (according to the Black and Red List of Vascular Plants of the Czech Republic) are reported from new sites (e.g. Aira caryophyllea, Ajuga pyramidalis, Arnoseris minima, Asplenium adulterinum, Botrychium matricariifolium, Bromus arvensis, B. secalinus subsp. secalinus, Campanula cervicaria, Conioselinum tataricum, Conringia orientalis, Diphasiastrum tristachyum, Draba nemorosa, Epipactis microphylla, E. neglecta, Erysimum repandum, Festuca amethystina, Filago vulgaris, Gentianella amarella subsp. amarella, G. obtusifolia subsp. sturmiana, G. praecox subsp. bohemica, Geranium divaricatum, Hackelia deflexa, Hierochloë odorata, Juncus sphaerocarpus, Misopates orontium, Montia fontana, Najas minor, Orchis ustulata subsp. ustulata, Orobanche arenaria, O. picridis, O. purpurea subsp. purpurea, Polycnemum arvense, Pyrola chlorantha, P. media, Scrophularia vernalis, Senecio erucifolius, Thesium arvense, T. dollineri, Thymus pulegioides subsp. carniolicus, Tofieldia calyculata, Torilis arvensis, Trapa natans, Viola elatior, Xanthium strumarium). Finally, rare and threatened species are mentioned from areas where they had not been recorded yet.

Zelený D.
Poznámky k používání průměrných Ellenbergových indikačních hodnot při analýze vegetačních dat
Notes to the use of mean Ellenberg indicator values in vegetation analyses

Abstract
Ellenberg indicator values (EIVs) represent valuable expert information on ecological behaviour of vascular plant species in the western and central parts of Europe. The mean of EIVs for species in vegetation relevés and floristic inventories are considered to be a good proxy of habitat characteristics and a relevant surrogate for environmental factors, especially when the latter are not available. However, as mean EIVs are derived from data on species composition, caution must be exercised when using them in analyses with other variables derived from the same data set. Such analyses include e.g. correlation of mean EIVs with ordination axes in unconstrained ordination, analysis of variance of mean EIVs between vegetation types, and correlation of mean EIVs and species richness. As a consequence, such analyses tend to return biased and more optimistic results, especially if their significance was verified using traditional tests, and their interpretation may therefore be inappropriate. In this study, examples using real vegetation data are given and a possible remedy is proposed. Due to the biased results, mean EIVs are not recommended to use in the above-mentioned analyses unless appropriate modified permutation tests are applied.