Achillea asplenifolia Vent. is one of three central European diploid species (together with A. setacea Waldst. et Kit. and A. roseoalba Ehrend.) of the A. millefolium group. Its taxonomic and phytogeographic account from the central European perspective is given mainly on the basis of herbarium and field studies. The synonymy of A. asplenifolia includes A. millefolium var. crustata Rochel and A. scabra Host; both names are typified here. No variation deserving taxonomic recognition was observed. From the taxonomic point of view, A. asplenifolia is a clearly delimited species. It grows in the Czech Republic, Slovakia, Austria, Hungary, Croatia, Serbia, and Romania. From the phytogeographic point of view, it can be classified as a Pannonian geoelement with overlaps to Transylvania and to the marginal parts of the eastern Mediterranean. Within the Czech Republic, its distribution range includes only the warmest and driest part of southern Moravia, with the northernmost site situated near the town of Vyškov. In southern Moravia, A. asplenifolia was confined to extrazonal habitats, mainly to islands of halophilous vegetation such as moist saline meadows (formerly used as pastures) and lowland fens rich in mineral nutrients, but most of the sites were destroyed. Out of six or seven localities preserved up to present, only two host vital populations.
A complete list of all alien taxa ever recorded in the flora of the Czech Republic is presented as an update of the original checklist published in 2002. New data accumulated in the last decade are incorporated and the listing and status of some taxa are reassessed based on improved knowledge. Alien flora of the Czech Republic consists of 1454 taxa listed with information on their taxonomic position, life history, geographic origin (or mode of origin, distinguishing anecophyte and hybrid), invasive status (casual; naturalized but not invasive; invasive), residence time status (archaeophyte vs neophyte), mode of introduction into the country (accidental, deliberate), and date of the first record. Additional information on species performance that was not part of the previous catalogue, i.e. on the width of species’ habitat niches, their dominance in invaded communities, and impact, is provided. The Czech alien flora consists of 350 (24.1%) archaeophytes and 1104 (75.9%) neophytes. The increase in the total number of taxa compared to the previous catalogue (1378) is due to addition of 151 taxa and removal of 75 (39 archaeophytes and 36 neophytes), important part of the latter being the reclassification of 41 taxa as native, mostly based on archaeobotanical evidence. The additions represent taxa newly recorded since 2002 and reported in the national literature; taxa resulting from investigation of sources omitted while preparing the previous catalogue; redetermination of previously reported taxa; reassessment of some taxa traditionally considered native for which the evidence suggests the opposite; and inclusion of intraspecific taxa previously not recognized in the flora. There are 44 taxa on the list that are reported in the present study for the first time as aliens introduced to the Czech Republic or escaped from cultivation: Abies concolor, A. grandis, A. nordmanniana, Avena sterilis subsp. ludoviciana, A. ×vilis, Berberis julianae, B. thunbergii, Bidens ferulifolius, Buddleja alternifolia, Buglossoides incrassata subsp. splitgerberi, Buxus sempervirens, Corispermum declinatum, Cotoneaster dielsianus, C. divaricatus, Euphorbia myrsinites, Gleditsia triacanthos, Helleborus orientalis, Hieracium heldreichii, Koelreuteria paniculata, Lonicera periclymenum, Lotus ornithopodioides, Malus baccata, M. pumila, Miscanthus sacchariflorus, Morus alba, Muscari armeniacum, Paeonia lactiflora, Pennisetum alopecuroides, Pinguicula crystallina subsp. hirtiflora, P. grandiflora subsp. rosea, Podophyllum hexandrum, Pyracantha coccinea, Rhodotypos scandens, Rumex patientia × R. tianschanicus ‘Uteuša’, Salix cordata, Sarracenia purpurea, Sasa palmata ‘Nebulosa’, Scolymus maculatus, Spiraea japonica, Tagetes tenuifolia, Thuja occidentalis, Trifolium badium, Vaccinium corymbosum and Viburnum rhytidophyllum. All added and deleted taxa are commented on. Of the total number of taxa, 985 are classified as casuals, 408 as naturalized but not invasive, and 61 as invasive. The reduction in the number of invasive taxa compared to the previous catalogue is due to a more conservative approach adopted here; only taxa that currently spread are considered invasive. Casual taxa are strongly overrepresented among neophytes compared to archaeophytes (76.7% vs 39.4%), while naturalized but non-invasive taxa follow the reversed pattern (18.8% vs 57.4). However, these two groups do not significantly differ in the proportion of invasive taxa. Of introduced neophytes, 250 taxa (22.6%) are considered vanished, i.e. no longer present in the flora, while 23.3% became naturalized, and 4.5% invasive. In addition to the traditional classification based on introduction–naturalization–invasion continuum, taxa were classified into 18 population groups based on their long-term trends in metapopulation dynamics in the country, current state of their populations, and link to the propagule pressure from cultivation. Mapping these population groups onto the unified framework for biological invasions introduced by Blackburn et al. in 2011 made it possible to quantify invasion failures, and boom-and-busts, in the Czech alien flora. Depending on inclusion criteria (whether or not extinct/vanished taxa and hybrids are considered), alien taxa ever recorded in the Czech Republic contribute 29.7–33.1% to the total country’s plant diversity; taking into account only naturalized taxa, a permanent element of the country’s flora, the figure is 14.4–17.5%. Analysis of the dates of the first record, known for 771 neophytes, indicates that alien taxa in the flora have been increasing at a steady pace without any distinct deceleration trend; by extrapolating this data to all 1104 neophytes recorded it is predicted that the projected number would reach 1264 in 2050. Deliberate introduction was involved in 747 cases (51.4%), the remaining 48.6% of taxa are assumed to have arrived by unintentional pathways. Archaeophytes are more abundant in landscapes, occupy on average a wider range of habitat types than neophytes, but reach a lower cover in plant communities. The alien flora is further analysed with respect to representation of genera and families, origin and life history. and Nevejdou se dvě poslední jména autorů
The frequently used subspecific name Eleocharis palustris subsp. vulgaris Walters (1949) is a later homonym of E. palustris var. vulgaris Čelak. (1867), so a replacement name, E. palustris subsp. waltersii, is proposed here. Eleocharis palustris var. vulgaris Čelak. is neotypified here with a modern specimen with 2n = 38, making it a taxonomic synonym of E. palustris subsp. waltersii or E. vulgaris “(Walters) Á. Löve et D. Löve”.
Occurrence of alien plant species in all the major habitats in the Czech Republicwas analysed using a data set of 20,468 vegetation plots, classified into 32 habitats according to the EUNIS classification. The plots contain on average 9.0% archaeophytes and 2.3% neophytes; for neophytes, this proportion is much smaller than 26.8% reported for the total flora of the country. Most neophytes are found in a few habitats: only 5.6% of them were recorded in more than ten habitats. By contrast, archaeophytes, and especially native species, tend to occur in a broader range of habitats. Highest numbers of aliens were found on arable land, in annual synantropic vegetation, trampled habitats and anthropogenic tall-forb stands. These habitats contain on average 22–56% archaeophytes and 4.4–9.6% neophytes. Neophytes are also common in artificial broadleaved forestry plantations; they also tend to make up a high percentage of the cover in wet tall-forb stands, but are represented by fewer species there. Entirely or nearly free of aliens are plots located in raised bogs, alpine grasslands, alpine and subalpine scrub and natural coniferous woodlands. Correlations between the number of archaeophytes or neophytes and the number of native species, calculated with habitat mean values, were non-significant, but there was a positive correlation between the numbers of archaeophytes and neophytes. The ratio of archaeophytes to neophytes was high in semi-natural dry and mesic grasslands and low in disturbed habitats with woody vegetation, such as artificial broadleaved forestry plantations, forest clearings and riverine willow stands. When individual plots were compared separately within habitats, the relationships between the number of archaeophytes, neophytes and native species were mostly positive. This result does not support the hypothesis that species-rich communities are less invasible, at least at the scale of vegetation plots, i.e. 10 0–10 2 m2.
Letnění, v minulosti tradiční součást obhospodařování rybníků, se v současné době v českém rybníkářství již prakticky nevyužívá. Intenzifikace produkce ryb vede ovšem ke snižování biodiverzity rybničních ekosystémů. V roce 2007 bylo proto uskutečněno částečné letnění rybníka Nesyt v národní přírodní rezervaci Lednické rybníky. Cílem bylo vytvořit optimální podmínky pro vzácnou a často kriticky ohroženou květenu obnaženého rybničního dna a některé druhy vodního ptactva, např. celoevropsky ustupující bahňáky. and Summer drainage, a traditional fishpond management method in the past, is now hardly used in the Czech Republic. Moreover, fish production intensification has resulted in biodiversity decline and loss in many fishpond ecosystems. In 2007, the Nesyt fishpond in the Lednice Fishponds National Nature Reserve (South Moravia) was partially drained. This measure is intended to establish optimal conditions for rare and often endangered flora in the exposed fishpond bottom and some bird species declining in Europe, e.g. waders.
A series of maps showing the level of invasion of the Czech Republic by alien plants was developed based on a quantitative assessment of the level of invasion of 35 terrestrial habitat types at different altitudes. The levels of invasion were quantified for 18,798 vegetation plots, using two measures: proportion of the species that are aliens and total cover of alien species. Separate assessments were made for archaeophytes and neophytes. Within each habitat, the level of invasion was related to altitude using generalized linear models. The level of invasion, depending on the measure used, decreased with altitude in 16 out of 20 habitats for archaeophytes and 18 out of 23 for neophytes. In two habitats, one measure of the level of invasion increased with altitude for archaeophytes. The values of the level of invasion predicted by generalized linear models for particular combinations of habitats and altitudes were projected onto a land-cover map and digital elevation map of the country. Four maps showing the level of invasion were produced, based on the proportion of the species that are archaeophytes or neophytes, and cover of archaeophytes and neophytes. The maps show that both archaeophytes and neophytes are most common in lowland agricultural and urban areas, whereas they are sparsely represented in mountainous areas. At middle altitudes, agricultural areas are more invaded than forested areas. Outside agricultural and urban areas, high levels of invasion are found especially in lowland sandy areas and river corridors.
V roce 2007 se podařilo rozluštit téměř dvousetletou záhadu moravské floristiky, totiž otázku přirozeného výskytu hvězdnice sivé (Aster canus) na jižní Moravě. Až donedávna existoval o výskytu tohoto význačného slanomilného druhu jediný literární údaj ze samých začátků moravské floristiky. Pátrání ve staré literatuře však ukázalo, že existují i další zprávy. Tento článek rekapituluje výsledky pátrání v historické literatuře a herbářích a zasazuje je do souvislostí historie výzkumu a destrukce flóry jihomoravských slanisk. and As late as 2007 an almost 200-year-old mystery of the natural distribution of Aster canus in South Moravia was solved. Until recently only one set of literary data existed on the distribution of this rare halophytic species. However, the study of ancient literature revealed the existence of further information on this species. The results of this study of literature and herbaria are summarized and coupled with research into the history of South Moravian salt marsh flora and its destruction.