Negative impacts of Acacia saligna in Italy
Acacia saligna (Fabaceae: EPPO List of Invasive Alien Plants) is native to Australia and has been recorded as an invasive species in a number of regions including the EPPO region (e.g. Cyprus, Portugal, Israel, Italy (including Sardinia)), South Africa and South America. The ecological impacts of A. saligna on the vegetation composition and structure of two coastal dunes habitats (woody habitats coastal dunes with Juniperus spp. and dunes with sclerophyllous vegetation) was assessed along 50 km of the Adriatic coast in Southern Italy (Molise and North Puglia Regions). The vegetation was sampled in 20 paired plots per habitat where a paired plot consisted of invaded (A. saligna cover > 70%) and non-invaded vegetation. The results showed that the invaded dunes with sclerophyllous vegetation had a decline in species richness and cover of native species, and an increase in cover of ruderal species. A. saligna can form a thick litter layer with allelopathic substances that inhibit the germination and establishment of other plants. It can also directly outcompete native species and hinders the growth of evergreen Mediterranean shrubs. The invaded dunes with Juniperus species maintained the species composition but had variations in vegetation structure. A. saligna can transform the structure by forming a dense tree layer that can lead to the decrease of the shrub layer. Over time, this can lead to habitat transformation. It is essential to ensure a platform for monitoring of invasive alien plants in vulnerable habitats and to identify preventive measures and effective strategies for its control and eradication.
Sources
Tozzi FP, Carranza ML, Frate L, Stanisci A (2021) The impact of Acacia saligna on the composition and structure of the Mediterranean maquis. Biodiversity, https://doi.org/10.1080/14888386.2021.1936640