(a) Overview of the forest core of the Bosco Niscemi; (b) old dead plant of Quercus ilex (photo from 2012); (c) detail of old trunk of Arbutus unedo; (d), (e) aspects of the Pistacio lentisci-Quercetum ilicis subass viburnetosum tini; (f) Viburnum tinus, a characteristic species of holm oak and Phillyreetum communities (respectively, Pistacio lentisci-Quercetum ilicis subass viburnetosum tini and Viburno tini-Phillyreetum latifoliae ass. nova), represented on the calcarenites, in different ecological contexts.