Invasive plants in three of the largest cities in Italy
In urban areas, invasive alien plants can have a number of impacts, including impacts on biodiversity and ecosystem services, impacts on urban infrastructure and in some cases human health impacts for example from allergenic pollen. Alien plants were surveyed in three Italian cities: Milan (Lombardia), Rome (Lazio) and Turin (Piemonte). Of the 28 alien plants surveyed (Table 1), Ailanthus altissima, Sorghum halepense, Phytolacca americana and Robinia pseudoacacia were the most dominant recorded species across the three cities. Invasive alien plants showed differences in distribution across urban areas where more species were identified in abandoned sites within the city, agricultural areas, and areas where there are water bodies and green areas. Focusing management in these priority areas can also act to protect urban islands of biodiversity and increase citizen wellbeing.
Table 1. Alien plants surveyed in Italian cities
Taxa | Family | EPPO Status |
Acer negundo | Sapindaceae | |
Ailanthus altissima | Simaroubaceae | List of invasive alien plants |
Ambrosia artemisiifolia | Asteraceae | List of invasive alien plants |
Amorpha fruticosa | Fabaceae | List of invasive alien plants |
Artemisia annua | Asteraceae | |
Broussonetia papyrifera | Moraceae | List of invasive alien plants |
Buddleja davidii | Scrophulariaceae | List of invasive alien plants |
Helianthus tuberosus | Asteraceae | |
Humulus scandens | Cannabaceae | A2 List |
Ligustrum lucidum | Oleaceae | |
Ligustrum sinense | Oleaceae | |
Lonicera japonica | Caprifoliaceae | Observation List |
Parthenocissus inserta | Vitaceae | |
Parthenocissus quinquefolia | Vitaceae | |
Paulownia tomentosa | Paulowniaceae | Alert List |
Phytolacca americana | Phytolaccaceae | |
Prunus laurocerasus | Rosaceae | |
Quercus rubra | Fagaceae | |
Reynoutria japonica | Polygonaceae | List of invasive alien plants |
Robinia pseudoacacia | Fagaceae | |
Senecio inaequidens | Asteraceae | List of invasive alien plants |
Sicyos angulatus | Cucurbitaceae | List of invasive alien plants |
Solidago canadensis | Asteraceae | List of invasive alien plants |
Solidago gigantea | Asteraceae | List of invasive alien plants |
Spiraea japonica | Rosaceae | Observation List |
Sorghum halepense | Poaceae | |
Trachycarpus fortunei | Arecaceae | |
Ulmus pumila | Ulmaceae |
Sources
Montagnani C, Sebesta N, Vegini E, Daniele G, Barni E, Celesti-Grapow L, Emili F, Larcher F, Gentili R, Citterio S (2026) Invasive alien plants and the city: distribution patterns in response to urban elements and urbanization in three of the largest cities in Italy. Urban Ecosystems 29,14, https://doi.org/10.1007/s11252-025-01876-3