Floristic and vegetational features of Monte Marganai (SW Sardinia)

A floristic and vegetational study of Monte Marganai (SW Sardinia) is presented. Monte Marganai is a limestone massif located between the Cixerri plain to the south and Monte Linas to the north. The fi eld and bibliographic investigation allowed 686 taxa to be assessed, 648 of which were observed, belonging to 395 genera, 93 families and 38 orders. Considering only the observed taxa, the most represented subclass is Magnoliidae (625 taxa), and within it the Eudicotyledones is the most represented systematic group with 23 orders, 64 families and 479 species and subspecies. The most represented orders are Asterales (78 taxa), Poales (76), Fabales (68), Lamiales, and Asparagales (58). Asteraceae, with 74 species, is the most represented family, followed by Fabaceae (66) and Poaceae (56). The most numerous genera are Galium (12), Trifolium and Euphorbia (11), Medicago and Ophrys (10). From the viewpoint of biological strategies, therophytes prevail (38.1%), which is typical for the Mediterranean region. Other forms present in the area are the hemicryptophytes (29.0%) and the geophytes (14.8%). The chorological spectrum of the fl ora of the study area shows a prevalence of Mediterranean distributions. Among the strictly Mediterranean species (54.3%), those with a circum-Mediterranean range are prevalent (31.0%), followed by endemic species (11.3%), and by W-Mediterranean species (7.8%). Taxa more widespread but with a distribution centred on the Mediterranean basin amount to 25.1%. Among the endemics (73 species altogether) the most numerous families are the Asteraceae (12) and the Orchidaceae (7). From a biogeographical viewpoint the Sardo- Corsican endemics (27) are most abundant, followed by those from the Italo-Tyrrhenian super-province (17) and from the Sardinian sub-province (14). Besides these, 1 taxon (Genista valsecchiae) is endemic of the Sulcis Iglesiente sector, and 3 ( Genista sulcitana, Linum muelleri and Sesleria insularis subsp. morisiana) are exclusive of the Iglesiente sub-sector. The analysis of rarity showed that the most common category (158 taxa) is that of the widespread generalist species with sometimes an extensive and/or dominant population (WBL), while the least frequent category (1 taxon) is that of generalist species with a limited distribution and with sometimes dominant populations (NBL). Protected species or those deemed worthy of protection are 51, of which 31 are included in the Habitats Directive 92/43/EEC and in the Bern and Washington convent ions, while 23 species are included in the IUCN Regional Red Lists. Vegetation analyses were mainly focused on the forest community and allowed the physiognomic and structural description of the forests, shrublands, maquis, and the edaphoxerophilous, climatophilous and edaphohygrophilous serial phases. In addition, the psammophilous, rupicolous and synanthropic vegetations were analysed, with particular reference to the vegetation of post-mining sites. These analyses allowed the characterization of 6 vegetation series and 1 riparian geosigmetum. Finally, a syntaxonomic scheme of the forest vegetation is proposed, from which 3 classes, 4 orders, 6 alliances, 3 sub-alliances, 7 associations, and 7 sub-associations turned out to be present in the Marganai area.