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The spread of species far from their native range is an important component of global changes. Investigating the ability of alien plants to invade different habitats is one of the most important approaches in the analysis of biological invasion mechanisms. The study was based on floristic research carried out in 1998–2002 in the north-western part of Poland. The habitats sampled were classified according to the EUNIS classification. A dataset of 2638 naturalized neophyte records was compiled based on a total of 2132 floristic lists. Species entries were supplemented with data on taxonomic position (family), origin, frequency, life form and number of habitats a particular species colonises. Ordination analyses showed the level of disturbance in individual habitats to be important in species-habitats relationships. Some of the species (e.g. Chamomilla suaveolens, Galinsoga parviflora, Veronica persica) occurred mainly in man-made, heavily disturbed habitats, while others (e.g. Impatiens parviflora, Padus serotina, Quercus rubra) were present primarily in natural habitats, less affected by humans. The species with the broadest habitat ranges identified included, i.a. Conyza canadensis, Impatiens parviflora, Epilobium ciliatum, and Oxalis fontana. Most of them, however, had different “core” habitats. Some species, e.g. Juncus tenuis, Elodea canadensis, Veronica persica were associated with one or a few habitats. The ability of species to invade numerous habitat types did not depend on their invasive status. The most successful aliens are those which spread dynamically along forest paths as well as those penetrating forest communities. The phytocoenotic role of each naturalized neophyte in plant communities requires a detailed study. Each individual habitat supports well-established alien species whose traits fit its characteristics and the disturbance intensity. Analysis of alien species traits, local distribution, habitat preferences and range makes it possible to reliably assess potentially successful invaders.
The paper presents a brief review of published so far and recently recorded unpublished bryological data concerning the distribution in Poland of two neophytic (sensu Meusel 1943) mosses: Campylopus introflexus (Hedw.) Brid. and Orthodontium lineare Schwaegr.to estimate their current influence on native bryoflora. The data clearly indicate the constant spreading of these species towards the east, however, there is no direct evidence that they have been limiting the occurrence of native moss species. They are acidophilous species, so the acidification of the environment probably promotes their expansion. Maps of the most current distribution of Campylopus introflexus and Orthodontium lineare in Poland (in a system of ATMOS-grid squares) are provided, as well as a description of the first locality in Poland of another European bryo-neophyte species Leptophascum leptophyllum Mull. Hal.
A new stand, formed by some fifty individuals of Ambrosia artemisiifolia L., an invasive plant of alien origin, was discovered at the Katowice railway station (southern Poland), in 2011. Two years later, the stand (increased to more than 160 individuals in the meantime) was re-visited, phytosociological survey was made, and four soil cores (5 cm deep and 80 cm² surface area, each) were taken for seed bank studies. The phytosociological sampling revealed 28 co-occurring vascular species, most of them representing hemicryptophyte and geophyte life forms. According to Ellenberg's values, the species pool indicated sunny (L7 and L8 species dominating) and semi-dry (mainly F4 species) habitat for the common ragweed population, whereas Zarzycki's soil granulometric data reflected coarse-grained soil. Albedo of the soil was lower than that of the vegetation thus sparsely vegetated sites were considered as heat accumulating microhabitats that might support establishment of the thermophilic A. artemisiifolia. During soil seed bank analysis a high number of naturally opened fruits (dehiscent achenes) were found (718.75 per m²) most probably indicating frequent germination in previous years. Greenhouse germination tests proved successful germination of 125 individuals per m², which was considered enough to maintain the A. artemisiifolia stand at the station. The results call attention to a newly discovered, established population with increasing demography of A. artemisiifolia, a highly allergenic introduced weed of Poland.
Black cherry, Prunus serotina (Ehrh) is one of the invasive plant species that, for its ability to negatively affect local plant communities, may deserve particular attention and control measures. The authors present species composition of Coleoptera found on P.serotina in two habitats in SW part of Poland. It is the first record of this kind from Poland.
The study is focused on evaluating changes in the presence of alien species in ruderal vegetation. Two datasets comprising phytosociological relevés of ruderal communities during two time periods within the Bratislava City (in southwestern Slovakia) were analyzed. The old dataset consisted of 387 relevés recorded in the years 1975–1982, and the more recent dataset consisted of 308 relevés from the years 2011–2014. The relevés from both time periods were assigned to phytosociological classes via the same procedure – numerical classification (hierarchical clustering) using HIERCLUS software. The average values of the percentage number and percentage cover of the archaeophytes and neophytes as groups in the earlier and more recent relevés of each class were compared by the main effects ANOVA analysis in the STATISTICA 7.0 software. The proportion of each taxon of archaeophytes and neophytes in both datasets was also calculated. The invasive status, origin, and life forms of alien species in both datasets were compared. In total, both datasets comprised 120 archaeophytes and 71 neophytes. The old dataset contained more archeaophytes than the more recent dataset. On the contrary, the more recent dataset contained more neophytes than the old dataset. In the years 2011–2014, more invasive neophytes were recorded than in the past. The results revealed a statistically significant decrease in the average percentage number of archaeophytes in the classes Stellarietea mediae, Artemisietea vulgaris, and Galio-Urticetea, and a decrease in the average percentage cover of archaeophytes in the class Artemisietea vulgaris, compared to the past. On the contrary, a statistically significant increase in the average percentage number and cover of neophytes in the classes Artemisietea vulgaris and Galio-Urticetea was recorded. Some rare species of archaeophytes were only recorded 30 years ago (e.g., Kickxia elatine, Silene gallica). Furthermore, several species of neophytes (including some invasive taxa, e.g., Fallopia japonica, Helianthus tuberosus, Juncus tenuis) occur only currently in the ruderal vegetation of Bratislava.
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