Negative impact of Opuntia stricta in Italy
The coastal prickly pear Opuntia stricta (Cactaceae) was introduced into the EPPO region, from its native range – North and Central America, between the late 15th and early 16th centuries for various purposes, including fruit consumption, forage for livestock, fencing and ornamental use. It is now widespread in costal and island habitats in Italy, Portugal and Spain. A study was conducted to assess the impact of O. stricta on native biodiversity on Capraia island, a small Mediterranean island in the Tuscan Archipelago (Italy). O. stricta has been present on the island since the 1980s and it now occupies some 70 ha of the islands surface (3.6 %). In total, 12 plots of 4 m2 (6 invaded and 6 control plots) were sampled between May-June 2023. In each plot, 100 cm3 of undisturbed soil were collected using Eijkelkamp cylinders. Ant communities were sampled placing four pitfall traps for each plot, and plant species percentage cover was recorded. The presence of O. stricta had a negative impact on natural plant communities with a decrease in species richness in the invaded areas. However, soil properties were largely unaffected except for total organic carbon, which was reduced in the invaded plots. Soil micro-organisms and ant populations were unaffected by the occurrence of O. stricta.
Sources
Misuri A, Tricarico E, Lazzaro L, Forni S, Siccardi E, Morbidelli A, Landi S, Balzani P, Benesperi R, Viciani D, Becagli C, Mugnai M (2025) Impacts of the invasive alien prickly pear, Opuntia stricta (Haw.) Haw., on natural communities of Mediterranean insular habitats. Journal for Nature Conservation 98, 127110.