Invasive river plants from Portuguese floodplains: What can species attributes tell us?

Biological traits of aquatic and riparian plants were compared among invasive and non-invasive groups of species from both native and exotic taxa in Portuguese fluvial systems. Twenty-six riparian and aquatic species were selected and their frequency of occurrence and foliar percentage cover was analysed at 401 sampling sites on the main catchments of Central and Southern Portugal. Canonical correspondence analysis and a hierarchical clustering were applied to the species traits data set. No typical invader profile emerged from the analyses. However, some specific attributes were clearly related to the alien and native plant invasiveness, such as vegetative reproduction, fragment viability and life span. The results of the present work could help with the early detection of invasive plant species in Portuguese fluvial corridors.