Impacts of Carpobrotus acinaciformis and C. edulis on Giglio Island, Central Italy
Carpobrotus acinaciformis and C. edulis (Aizoaceae: both EPPO List of Invasive Alien Plants) are succulent plants which are native to South Africa. Both species can invade coastlines, in particular cliffs and dune systems. Due to the inaccessible nature of invaded habitats, these species are difficult to control. Both species have a number of negative impacts including modifying the nutrient dynamics, and outcompeting and reducing the fitness of native plant species. The current study was conducted on the Island of Giglio, the second largest island in the Tuscan Archipelago (Italy). The impact of Carpobrotus species was evaluated along rocky coastal cliffs. The study was established to include three different habitats, all with conservation status at the EU level (1) vegetated sea cliffs of the Mediterranean coasts with endemic Limonium spp., (2) Halo-nitrophilous scrubs, and (3) low formation of Euphorbia close to cliffs. In total 44 permanent plots were sampled where each plot was comprised of an invaded area and a control area. Each plot was georeferenced, and vegetation sampling was carried out during May–June in 2020 and 2021. In each plot, the cover of Carpobrotus species was estimated, as well as the cover of native species. In all habitats, Carpobrotus species had significant impacts on the diversity of native plant species. In addition, the invaded sites had a lower abundance of native plant species compared to the uninvaded controls. The invasion of Carpobrotus species has a negative impact on the conservation value of the invaded habitat.
Sources
Mugnai M, Benesperi R, Viciani D, Ferretti G, Giunti M, Giannini F, Lazzaro L (2022) Impacts of the Invasive alien Carpobrotus spp. on coastal habitats on a Mediterranean Island (Giglio Island, Central Italy). Plants 11, 2802. https://doi.org/10.3390/plants11202802