Explanation and risk assessment of alien woody plants invasion in Central Europe by historical and ecological factors

Conclusions The studies presented focus on the historical and ecological traits corresponding with the successful invasion process of alien woody plants in Central Europe. In regard to invasion biology, woody plant species are among the most problematic plant life forms and constitute a high proportion of the World's worst invasive species. The irreversible changes in ecosystems often caused by invasion of these species constitute one good reason for study. The second is the large amount of data available, especially on human influence and activity (such as the intensity of planting, residence time). The reason for studying alien woody species is also reflected in their ambivalence: on the one hand, the group is represented by the most serious invasive species, while on the other hand, there is still strong pressure to plant these species for timber, food and ornamental purposes. The native woody flora of the Czech Republic contains about 280 species. The exact number of alien woody species in not known. Based on different approaches and datasets, it has been estimated to be in the order of 4,300 species. Exact data is available for a representative sample of frequently-planted alien woody species that contains 1,691 species. An estimated 128 alien species have escaped from cultivation, of which about 17..