Plant Invasions Across Different Habitat Types at Floristic Survey

On the basis of detailed floristic survey the level of invasion in various EUNIS habitat types identified in NW Poland was assessed. In a data set of 2131 floristic lists the mean number and mean proportion of native species, archaeophytes and neophytes was calculated for each of 25 habitat types. Relationships between this three groups of species were analysed using Pearson correlation. A total of 840 vascular plant species, including 77 archaeophytes and 114 neophytes were recorded. The most invaded habitats were: arable land, fallows and field margins, trampled areas, gardens and parks, lines of trees, anthropogenic tall-forb stands (they contained on average 20-67% alien plants). Most of mean numbers and mean percentage numbers of both alien plants groups in particular habitat types were higher compared to the results obtained from phytosociological databases, therefore the level of invasion assessed on the basis of phytosociological data can be underestimated.