Carpobrotus edulis

In the 50's Carpobrotus edulis as been introducted in order to avoid the overthrow of rocks in the leasure areas of the island, it as been planted in two islands, Berlenga and Farilho Grande and has successfully established. Presently Carpobrotus edulis as spread out over the cliffs and hillsides mainly in those with south exposition. Spontaneous occurences of this specie have been observed in three other islands of the arquipelago. Carpobrotus edulis establishes a monospecific cover that obstructs the occurrence of the autochthone vegetation. The Flora of this protected area consists of around a hundred species mainly annuals and few perennials, three species are endemics from the arquipelago. (Tauleigne Gomes et al., 1999)

The high genetic diversities for C. edulis and C. acinaciformis may contribute to the continued invasion of both plant taxa, since it provides a wide range of genetic variation on which natural selection can act in new environments...Among the consequences of such introgressive hybridisation between invasive taxa is the propagation of advantageous genotypes/evolutionary novelties (Ellstrand and Schierenbeck, 2000). This possibility is especially worrying in light of the fact that C. edulis, rather than C. acinaciformis, has proven to be a very successful and aggressive invader in the Mediterranean Basin (Lambinon, 1995; Me´dail, 1998; Suehs et al, 2001). Within the introgressive events occurring on Bagaud island, the possibility exists that advantageous genes are being passed from a taxon that is problematic on a large scale (C. edulis) to one which is traditionally not considered invasive due to its rarity, but exhibits aggressive clonality (C. acinaciformis).In fact, C. acinaciformis maximises seed production when crossed with C. edulis, thus reinforcing introgression of C. edulis genes to the C. acinaciformis genome (Suehs et al, in press). This could thus create new genotypic combinations with a high invasion potential.Hybridisation may contribute to the successful invasion of C. edulis and C. acinaciformis in the Mediterranean Basin. (Suehs et al., 2004)

Carpobrotus edulis hybridises with the endemic Disphyma australe in New Zealand, forming highly sterile triploids (Chinnock, 1972). Carpobrotus edulis hybridises with the native or naturalised C. chilensis in virtually all areas of sympatry in California. Intermediate plants have been shown to be more similar to C. edulis than C. chilensis, and have been shown to have fewer native plants growing in association with them than C. chilensis (Albert et al., 1997). Hybrid individuals can show higher clonal growth than parental types in some habitats (Vila and D’Antonio 1998).

Carpobrotus edulis also lowers Ca and Na content and increases salinity and phosphorus concentration. Those soil modifications have strong negative effects in the early stages of Malcolmia littorea (L.) R.Br. populations, decreasing total germination and survival (Novoa et al. 2013). The litter of the invasive C. edulis, which remains on the soil surface for several years, releases allelopathic substances that suppress the native plant germination process and root growth (Novoa et al. 2012) depending on plant species and density (Novoa and González 2014). (Campoy et al., 2018)

Carpobrotus edulis (Aizoaceae) is native from South Africa. This perennial succulent was introduced in Portugal for dune stabilisation and erosion control. The fleshy fruits of C. edulis are edible and the native fauna may constitute a strong dispersion mean. Once stabilised this plant shows a high vegetative reproduction rate and growth is not affected by herbivory or competition. This exotic species was greatly dispersed throughout Portuguese sand dunes, affecting the natural succession and ecological processes by changing species composition. (Campelo et al., 1999)

Invasion by the introduced and invasive succulent Carpobrotus (Aizoaceae) constitutes one of the most severe threats to numerous terrestrial plant communities in coastal and island habitats of the Mediterranean Basin. Two South African taxa, C. edulis and C. aff. acinacijormis, have been introduced in Mediterranean France during the middle of the XIXth century. They have invaded the backdunes, coastal rocky slopes and cliffs, and even coastal scrubs, mainly in siliceous continental parts of Provence and on the island of Corsica. These alien taxa may induce severe local extinctions of native plants with a high patrimonial value (endemic, rare andlor protected plant species). (Suehs et al., 1999).