Distribution pattern of the invasive alien plant Bunias orientalis in Rów Podtatrzański trench, North of the Tatra Mts, Poland

Abstract

Bunias orientalis is an alien species that has spread greatly in recent decades in Central Europe. This coloniser is particularly well (pre)adapted to anthropogenic disturbances and human-mediated dispersal, allowing it to spread mainly along roads and railways. Here, its distribution and population structure is investigated for the sub-montane region located in the northern foothills of the Tatra Mts. Based on 70 phytosociological samples of invading vegetation, the relationships between B. orientalis cover and species diversity, together with the composition of vegetation, were analysed using regression analysis. Comparison of the current distribution of B. orientalis within the investigated area with published records indicates that the expansion rate of this alien species is not particularly high, despite its increased frequency in anthropogenic habitats and meadows. Meadows invaded by this species revealed that increased B. orientalis cover was accompanied by a significant reduction in the values of the Inverse Simpson diversity index and Pielou's measure of evenness. Reduced diversity was caused by considerable decrease in cover by species of the Molinio-Arrhenatheretea class. However, for anthropogenic habitats, no statistically significant relationships were found to occur between the abundance of B. orientalis, species diversity and vegetation composition. © 2013 Institute of Botany, Slovak Academy of Sciences.