ATENA: dATabase of ornamEntal non-NAtive trees of seven Italian cities

Ornamental non-native trees play a key role in urban landscapes, enhancing the aesthetic appeal and providing many ecosystem services. This paper aims to present the database ATENA (dATabase of ornamEntal non-NAtive trees of seven Italian cities), which includes taxonomic information, ecological traits, and indicators of non-native ornamental trees of public spaces in seven representative Italian cities (Milan, Turin, Asti, Pavia, Rome, Campobasso and Palermo). The checklist includes a total of 317 plant taxa, with most originating from temperate Asia, North America, and tropical Asia. Zoochory is the primary mode of dispersal, followed by anemochory. When looking at the distribution of ornamental non-native trees across seven different cities, it is notable that the majority of these species are found in only one city. Furthermore, more than half of the species with unique occurrences are from Palermo. In the analysed Italian cities, we observed that the majority of the species used as ornamental trees are alien (54.8%), of which 8.2% are invasive taxa, while 45.2% are only cultivated. This raises concerns about the risks associated with planting non-native species that are invasive or potentially invasive, despite the well-documented negative impacts these species can have on native biodiversity. The ATENA database is a crucial resource for urban afforestation and the planning and design of green spaces, as it allows highlighting and avoiding species that are listed as invasive alien plant species. ATENA db is an open-access database designed for continuous updates, allowing for the inclusion of new traits and species from other Italian cities.