A phytosociological analysis of the Brachypodium rupestre (Host) Roem. & Schult. communities of Sicily.

A phytosociological study on the Brachypodium rupestre grasslands in Sicily is presented. These grasslands form discontinuous secondary stands dynamically linked to the deciduous oak woods, which are widespread within the upper-colline, submontane and lower montane belts (800-1400 m) of the Tyrrhenian side of the northern Sicily and in the Sicani mountains. In the study area B. rupestre grasslands were mainly found in colluvial plains or drainage lines where relatively deep and mesic soils occur. In this paper 42 phytosociological relevés were performed and statistically analysed. Two new associations were described and classified in the alliance Polygalo mediterraneae-Bromion erecti (Brometalia erecti, Festuco- Brometea): Lolio pluriflori-Brachypodietum rupestris and Tanaceto siculi-Brachypodietum rupestris. The Lolio pluriflori-Brachypodietum is typical of the limestone substrates of Nebrodi, Madonie and Sicani mountains and of the mounts surrounding Palermo and Trapani. Two subassociations (typicum and violetosum ucrianae) and an impoverished variant rich in therophytes have also been identified. The Tanaceto siculi-Brachypodietum is restricted to the metamorphic substrates of the Peloritani mountains on the north-eastern side of the island. Finally the association Polygalo mediterraneae-Brachypodietum rupestris, which was only provisionally described in 2014 for the Lucanian Apennines (Peninsular Italy), has been validated here.