Comparative Analysis of the Alien Vascular Flora of Sardinia and Corsica

Abstract

This article provides a comparison of the vascular alien flora of Sardinia (Italy) and that of Corsica (France), both territories belonging to the Western Mediterranean biogeographic subregion. The study has recorded 598 (90 doubtful) alien taxa in Sardinia (18% of the total flora) while 553 (87 doubtful) in Corsica (17%); six are new report to Sardinia and 27 to Corsica. A total of 234 taxa are common to both islands. Neophytes are 344 taxa (68% of the total) in Sardinia and 399 taxa (73%) in Corsica. The invasive component includes 64 taxa in Sardinia (13% of the alien flora) and 99 taxa (21%) in Corsica, 33 of them common to both territories. The total 740 alien taxa of Sardinia and Corsica are included in 93 families; being Fabaceae the richest. The comparison of the biological spectrum reveals that phanerophytes (202 taxa, 40%) are the most represented in Sardinia and therophytes (149 taxa, 32%) in Corsica. A study of the geographical origin shows supremacy of the American element in Sardinia (170 taxa, 34%) and in Corsica (136 taxa, 29%). The majority of taxa arrived as a result of intentional human introductions, mainly for ornamental use (247 taxa, 49% in Sardinia; 208 taxa, 45% in Corsica). Seminatural, agricultural and synanthropic are the most occupied habitats. These data show the need for joint action to stem the increasingly worrying phenomenon of the alien flora in order to reduce the negative effects on natural habitats and native flora.

The specific vulnerability of plant biodiversity and vegetation on Mediterranean islands in the face of global change

“…The impacts depend on both the identity of the invasive plant and of the invaded island, suggesting that impact of invaders is context-specific (Traveset et al 2008). The most invaded large islands are Corsica and Sardinia with a percentage of alien plants slightly higher than 17% (466 and 508 alien taxa, respectively, according to Puddu et al 2016), but the percentage of invasive plants is almost twice as high in Corsica (21.2%) as in Sardinia (12.6%). The other major islands are characterized by a lower number of alien taxa comprised between 6.7 and 9.5% (Table 2).…”

Notulae to the Italian alien vascular flora: 6

“…After a few years, Brundu et al (2003) and Camarda et al (2004) indicated it as naturalized in the island. Later, several authors confirmed the same status (e.g., Podda et al 2011, Camarda et al 2016, Puddu et al 2016 (Galasso et al 2018a). This species has been found in an area previously subjected to weeding of the road margins.…”

“…Its presence in these regions could date back to several years ago; additionally its distribution may be much broader than reported, given the possible confusion with C. hirsuta (see Šlenker et al 2018 This species is endemic to the Atlas Mountains, in Morocco and Algeria, but it has been used in reforestations and as an ornamental tree in many countries (Farjon 2017). In Sardegna it was reported as cultivated by Pavari and De Philippis (1941), and recently indicated as a casual alien species (Bacchetta et al 2009, Puddu et al 2016, Galasso et al 2018a). Actually, the species is naturalized in those places where it was abundantly introduced since the 1930s, such as the State Forests of Bono, Bultei, Ane-la, and Monte Limbara (Pavari and De Philippis 1941) A young individual has grown within a flowerbed of a public garden, among shrubs of Westringia fruticosa (Willd.)…”

“…It was reported from various localities of southern Sardegna by Bocchieri et al (1982) and Bocchieri (1984), and then confirmed by Arrigoni (2010). Later, Puddu et al (2016) indicated it as a casual alien in Sardegna, while Camarda et al (2016) reported it as naturalized. It is widespread in Gallura, Logudoro, Ogliastra, Sulcis-Iglesiente, Sarrabus-Gerrei and Campidano, from sea level to 1,050 m a.s.l., along roadsides and in fallow land, ruderal places, and gardens, mainly on sandy granitic soils.…”

Why did Acanthus mollis, native to West Mediterranean, become a so relevant artistic and symbolic element arising from ancient Greece

“…Two subspecies are known: A. mollis L. subsp. mollis distributed in Italy (Pignatti 1982(Pignatti , 2018, but in the northernmost regions and Sardinia it is considered an alien species (Ballelli & Pedrotti 2009;Puddu & al. 2016); south France and Corse, and A. mollis subsp.…”