Flora vascolare del Sulcis (Sardegna Sud-Occidentale, Italia)

Abstract

The vascular flora of Sulcis (South-West Sardinia) has been studied. 1479 taxa have been found. 1235 were species, 210 subspecies, 24 varieties and 10 hybrids, belonging to 584 genera and 130 families. The Dicotyledones with 91families, 429 genera and 1084 taxonomic units were dominant over the other systematic groups. The most represented families are: Fabaceae (153 taxonomic units), Poaceae (151), Asteraceae (146), Apiaceae (59), Caryophyllaceae (56) and Brassicaceae (53). The most represented genera are: Trifolium (28), Ranunculus (22), Vicia (20), Juncus and Allium (19), Medicago and Carex (17), Silene and Ophrys (16), Euphorbia (15). The floristic richness indices have been determined and compared with those of other studied areas of Sulcis. An analysis of the biological spectrum showed the therophytes at 41.3% confirming the full Mediterranean character of the area, and the phanerophytes at 8.0%, showing a high level of forest area. A comparison with the biological spectra of other floras shows similar values, except for a higher value for the therophytes and hydrophytes (3%). The chorological spectrum shows the dominance of Mediterranean elements (74.2%), particularly Steno-Mediterranean (30.5%) and Euro-Mediterranean (22.5%). The western- Mediterranean (11%), Atlantic-Mediterranean (6.4%) and the southern- Mediterranean (4.5%) components are important in identifying the biogeographic barycentre of the studied area. The contingent of endemics (138 taxonomic units) was 12.6% of the Mediterranean component which shows the dominance of Sardinian-Corsican (31.1%) and Sardinian (30.5%) elements, that together make up 61.6% of the total. This flora consists of 93 species, 32 subspecies, 10 varieties and 3 hybrids; belonging to 88 genera and 37 families. The most represented families are: Asteraceae (18), Orchidaceae (12), Fabaceae (11) and the Scrophulariaceae (10). The most represented genera are: Ophrys (10), Limonium (8) and Genista (7).

The analysis of biological and chorological data highlighted the environmental peculiarities of Sulcis, shown by the local evolution of a rich floristic contingent. Eighteen exclusive endemics, together with a unique blend of geolithologic, geomorphologic, paleogeographic, bioclimatic and vegetation features, allow the attribution of the rank of biogeographic sector to the Sulcis- Iglesiente territory. The southern part, with seven exclusive endemics, Anchusa formosa, Genista bocchierii, G. insularis subsp. insularis, Limonium carisae, L. malfatanicum, L. tigulianum, Silene martinolii, can be seen as the Sulcis subsector.  A contribution regarding the phytotoponymy of the Sulcis area is presented here. 394 vegetal place names have been counted in a census, referring to 89 taxonomic units (8.8% of the Sulcis flora). Most of these are written in Campidanese dialect and the refer to entities frequently found in the territory. The most recurrent species are: Olea europaea s.l. (25), Arbutus unedo (18), Cistus sp. pl. (18), Myrtus communis subsp. communis (17), Quercus suber (16) and Juniperus oxycedrus subsp. oxycedrus (9). The most represented species are shrubs (37.6%) and trees (35.9%) spontaneous and cultivated, most of them calcifuge. Only in the far western areas is it possible to find calcicole taxa linked to sedimentary substrata of a carbonated nature. From research carried out it appears that in the IGM plans, in scale 1:25.000, the greater number of phytotoponymy are in Capoterra (68), Narcao (52), and the Santadi and Carbonia areas both with 39. For the emblematic tree, 42 plants (only 16 discovered in the past) have been counted and studied. The most represented species are: Taxus baccata (7), Ceratonia siliqua (4), Eucalyptus camaldulensis (4), Juniperus oxycedrus subsp. oxycedrus (4) and Quercus ilex (4).