Differences in germination and seedling establishment of alien and native

nation and seedling establishment of alien and native Impatiens species. – Preslia 81: 357–375. Comparative studies of closely related species may provide useful insights into the effect of species traits on invasion success since some of the biases associated with multispecies studies, such as phylo-genetic effects, are considerably reduced by virtue of the experimental design. In this study seed and seedling traits of three congeneric alien species in Europe, differing in their region of origin, invasion status and history (Impatiens glandulifera, I. parviflora, I. capensis), were compared with the native I. noli-tangere in laboratory and common garden experiments. Seeds of I. glandulifera required the shortest period of stratification, germinated well both under laboratory and experimental garden con-ditions and the seedlings produced more biomass than those of the other species. Seeds of I. parviflora required a longer period of stratification, had the highest percentage germination but seedling emer-gence in the experimental garden was poorer than in I. glandulifera. Neither of these two species inva-sive in the Czech Republic formed soil seed banks. The native I. noli-tangere had the lowest percentage germination and formed a short-term persistent seed bank. Impatiens capensis germinated well in the laboratory, had the highest seedling emergence in the garden and its seed remained viable in the soil for three years. This indicates that in terms of germination and emergence, this species i