Bryophyte and lichen epiphytic communities were studied in the Mediterranean-montane area of M. Artu in Sardinia (ltaly) by mean of relevés carried out in different oak forest types, with the aim of pointing out differences due to anthropogenic activities. Altogether, 15 bryophyte species and 74 lichen species were found. Relevés were classified using cluster analysis. In well-preserved forests, communities dominated by bryophytes and close to the climax associations Antitrichietum californicae and Leptodontietum smithii are present. together with elements of the Lobarion pulmonariae. Lichen communities of the Xanthorion parietinae (Physcietum adscendentis, Parmelietum acetabulae and Ramalinetum fastigiatae) are dominant in the most disturbed conditions, rarely accompanied by clements of the Leucodontietum sciuoides. In closed coppice and young woodland a community dominated by Neckera complanata, Metzgeria furcata, Frullania dilatata, Phlyctis argena and Physconia venusta is present. probably close to the Antitrichietum curtipendulae. In mature forests of Q. pubescens and open coppices of Q. ilex, a similar community is also present, though richer inlichen species, and with Frullania dilatata as the only dominant livewort. Widespread temperate species are most frequent in disturbed conditions, while suboceanic species are more common in well-preserved and closed woodland. Mat- and tail-forms of the bryophytes are dominant in well-preserved forest. together with crustose lichens. Broad- and narrow-Iobed lichens are dominant in the most disturbed conditions. This is the first study on epiphytic cryptogamic communities of the island. Key words: Epiphyte, Bryophyte, Lichen, Ecology, Sardinia, Italy.