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Invasions by alien plants in the Czech Republic : a quantitative assessment across habitats / Milan Chytrý in Preslia, 77 (2005) 

Public Citation [article]  inPreslia > 77 (2005) . - 339-354 Titre : Invasions by alien plants in the Czech Republic : a quantitative assessment across habitats Type de document : Électronique Auteurs : Milan Chytrý (1967-) ; Petr Pyšek ; Lubomír Tichý ; Ilona Knollova ; Jiří Danihelka (1968-) Année de publication : 2005 Article en page(s) : 339-354 Langues : Anglais (eng) Catégories : [CBNPMP-Thématique] Plantes subspontanées, naturalisées, envahissantes Résumé : 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. 100–102 m2. Permalink : https://biblio.cbnpmp.fr/index.php?lvl=notice_display&id=142460 Chytrý, Milan (1967-), Pyšek, Petr, Tichý, Lubomír, Knollova, Ilona, Danihelka, Jiří (1968-) 2005 Invasions by alien plants in the Czech Republic : a quantitative assessment across habitats. Preslia, 77: 339-354.

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Maps of the level of invasion of the Czech Republic by alien plants / Milan Chytrý in Preslia, 81 (2009) 

Public Citation [article]  inPreslia > 81 (2009) . - 187-207 Titre : Maps of the level of invasion of the Czech Republic by alien plants Type de document : Électronique Auteurs : Milan Chytrý (1967-) ; Jan Wild ; Petr Pyšek ; Lubomír Tichý ; Jiří Danihelka (1968-) ; Ilona Knollova Année de publication : 2009 Article en page(s) : 187-207 Langues : Anglais (eng) Catégories : [CBNPMP-Thématique] Plantes subspontanées, naturalisées, envahissantes [CBNPMP-Géographique] République Tchèque Mots-clés : Picea abies (L.) Karsten  Pinus sylvestris L. Résumé : 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. Permalink : https://biblio.cbnpmp.fr/index.php?lvl=notice_display&id=142446 Chytrý, Milan (1967-), Wild, Jan, Pyšek, Petr, Tichý, Lubomír, Danihelka, Jiří (1968-), Knollova, Ilona 2009 Maps of the level of invasion of the Czech Republic by alien plants. Preslia, 81: 187-207.

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Consultable Article (2009) URL