Leaf and root trait variability of alien and native species along Adriatic coastal dunes (Italy)

This study regards the analysis of leaf and root trait variability of the most invasive alien species and some common native species developing along central-southern Adriatic sand dunes in Italy. The results highlight that large leaf area, the reproductive period in late summer, a biennial/annual life cycle and thick, long roots are useful traits for the successful colonisation of the most invasive species Oenothera biennis , Erigeron canadensis and Xanthium orientale subsp. italicum along the mobile coastal dunes. These alien plants grow in spatial niches generated by eutrophication and human pressure, such as waste deposits on the beach and inter-dune gaps, flattened and altered by human trampling. We suggest that exotic species in the study area are currently occupying temporal and spatial niches that are not being exploited by native species and, therefore, they are not competing directly for the same resources.