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 vegetation relevés stored electronically in the Czech National Phytosociological Database are reviewed. The database was established in 1996, with the central database located in the Department of Botany, Masaryk University, Brno (www.sci.muni.cz/botany/database.htm). On 15 November 2002 this central database contained 54,310 relevés from the Czech Republic, collected by 332 authors between 1922–2002. Ca. 54% of the relevés were taken from published papers or monographs, 21% from theses and the rest from various unpublished reports and field-books. These relevés include 1,259,008 records of individual plant species. Territorial coverage of the country by the reléves is irregular as the areas with attractive natural or semi-natural vegetation are more intensively sampled, with gaps in coverage of less attractive or poorly accessible areas. Most relevés are of broad-leaved deciduous forests (Querco-Fagetea), meadows (Molinio-Arrhenatheretea), dry grasslands (Festuco-Brometea), and marsh grasslands (Phragmito-Magnocaricetea). The quality of the data is discussed, such as researcher bias, preferential selection of sampling sites, spatial autocorrelation and missing values for some data elements.
A syntaxonomical revision of dry grasslands of the alliances Bromo pannonici-Festucion pallentis, Festucion valesiacae and Koelerio-Phleion phleoidis (class Festuco-Brometea) in the natural biogeographical region of the Western Carpathians and northern Pannonian Basin is presented. A geographically stratified data set of 2686 relevés from the south-eastern Czech Republic, northeastern Austria, Slovakia and northern Hungary was divided into 25 clusters using a modified TWINSPAN algorithm. The proposed classification simplifies and unifies the previous syntaxonomical systems, which differ in these four countries. Main environmental gradients responsible for variation in species composition of theses grasslands were revealed by detrended correspondence analysis and interpreted using indicator values. The major pattern of variation reflects soil nutrient availability and moisture, which are negatively correlated with soil reaction.
The pattern of natural vegetation on non-calcareous soils in two deep river valleys of the Bohemian Massif (Vltava and Dyje rivers, Czech Republic) was analyzed in order to determine the main topographic and soil variables affecting the composition of the vegetation. Vegetation data together with topographic and soil variables were collected along transects down the slope from the upper edge to the bottom of the valley. The distribution of vegetation types within the valleys was described using cluster analysis and non-metric multidimensional scaling (NMDS). Effects of topographic and soil variables were compared using a set of canonical correspondence analyses (CCAs) with explanatory variable selection based on the Akaike information criterion (AIC). In order to describe the non-linear interaction between the two topographic variables, elevation and aspect, a new method (moving window CCA) was introduced. This method assessed the explanatory power of aspect at various elevations above the valley bottom. Results show that main vegetation coenoclines are correlated with two complex environmental gradients: the moisture-nutrient-soil reaction and light-temperature-continentality gradients. Soil variables are slightly better predictors of vegetation composition than topographic variables. Altogether, these variables explain 18.8–21.6% of the total inertia. Although soil development depends on topography, the variation jointly explained by both groups of variables is only 3.9–5.2%, indicating that each of these two groups of variables influences vegetation pattern in a different way. Variables selected by the most parsimonious model for the Vltava valley are aspect, soil pH, soil type fluvisol and soil depth. For the Dyje valley the same variables as in Vltava valley were selected except for soil depth, which was replaced by soil type cambisol. Aspect has a strong effect on vegetation on the middle slopes but not on the lower slopes of the valleys. The results of all analyses are similar between the two valleys, suggesting that similar patterns may also occur in other deep river valleys of mid-altitudes of the Bohemian Massif.
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.
Biologické invaze mohou mít závažné důsledky pro biodiverzitu invadovaných území, mohou působit ekonomické škody i negativně ovlivňovat lidské zdraví. Proto se jejich výzkum v posledních dvaceti letech prudce rozvíjí. První díl seriálu, ve kterém budou představeny nové poznatky z výzkumu invazibility (invasibility) ekosystémů nepůvodními rostlinami, se zabývá rozdíly v invadovanosti (level of invasion) velkých území. Obecně lze shrnout, že ostrovy jsou invadovány více než pevnina, Nový svět více než Starý svět, temperátní a boreální zóna více než tropy a nížiny více než horské oblasti. and Biological invasions can have huge consequences for the biodiversity of invaded areas. They can cause economic damage and have a negative effect on human health. This is why research into them has been highly developed over the last 20 years. The first of this series of articles aiming to present new knowledge from research on the invasibility of ecosystems by alien plants deals with differences in the level of invasion of large areas. On the whole it can be said that islands are invaded more than continents, the New World more than the Old World, temperate and boreal zones more than tropics and lowlands more than mountains.
Výsledky studií z území s různými přírodními podmínkami, různou skladbou flóry a různou historií vlivu člověka na přírodu dávají tušit, že invazibilita rostlinných společenstev není jevem náhodným, ale je do značné míry řízena obecnými zákonitostmi. Obecná teorie invazibility však může mít velký význam jak pro ekologickou teorii, tak pro praxi. Taková teorie umožní předvídat, kde a za jakých okolností vznikne největší riziko invazí, což by ve spojení s efektivním ochranářským managementem mohlo vést k jejich účinnému předcházení nebo omezování. and Results of study carried out in areas with varying natural conditions and varying floral composition, as well as on the history of man’s influence on nature show that the invasive potential of plant communities is not an accidental phenomenon but that it follows general rules. A general theory on invasibility may be of great importance both for ecological theory and practice. Such theory enables us to foresee where and under which conditions the highest invasion risk occurs, and this can be used in combination with effective conservation management to prevent or reduce risk.
Znalosti o invadovanosti různých společenstev nebo biotopů byly až donedávna spíše kusé a nepodložené reprezentativními daty, která by srovnávala větší počet společenstev. Teprve koncem 90. let 20. století se objevil vhodný zdroj dat pro hodnocení invadovanosti rostlinných společenstev, a to velké databáze fytocenologických snímků vytvářené v některých zemích, zejména v Evropě. Článek přináší mj. odpověď na otázky, která společenstva jsou nejvíce a nejméně invadována a jaké jsou rozdíly v invadovanosti společenstev archeofyty a neofyty. and Knowledge on the level of invasion in different communities and biotopes has been very scarce until recently and not supported by representative data comparing a higher number of communities. As late as at the end of the 1990s, an important source of data allowing for the evaluation of plant communities’ level of invasion was discovered, namely great databases of phytosociological relevés collected in some countries, especially in Europe. The article answers to such questions as which communities are invaded at the highest and which at the lowest level and which differences exist in invasion level by archeophytes and neophytes.
Where today means yesterday: Southern Siberian Ice Age refugium. Recent evidence suggests that the closest modern analogues of the Pleistocene full-glacial ecosystems of Central Europe are not found in Northern Eurasia, but in Central Asia, namely in the Altai and Sayan Mountains of southern Siiberia. This area is a refugium for many species of plants, mammals and snails which were abundant in full-glacial Central Europe but went extinct in this region in the Holocene. Peculiar co-occurrence of tundra, steppe, forest and desert species encountered in modern ecosystems of these mountain ranges is also typical of the European Pleistocene fossil record, but does not exist in today´s Europe.