Alien and invasive plant species in plant communities of floodplain forests of the Małopolska Upland

During the field studies on the floodplain forests of the Małopolska Upland carried out in 2009–2013, the author tried to determine which species of alien and invasive plants could be a threat to the stability of these vegetation communities. Efforts were also made to answer the question, which floodplain forests are particularly vulnerable to the penetration of alien species and in which layers of the forest plant community are the best conditions for the development of the individual alien plant species. During the research, a total number of 344 reléves were made, of which 90 recorded the presence of alien species. The most common were: Impatiens parviflora, Acer negundo and Padus serotina. The highest percentage of reléves involving alien species was found in the riverside floodplain forests of Salicetum albo-fragilis and Populetum albae.