Lichen diversity on dolmen and menhir in the Megalithic complex of Sa Coveccada (Mores, Sardinia)

Abstract

This work describes the lichen diversity found on the megalithic Dolmen of Sa Coveccada (Mores, Sardinia) until 2010. After that year, a restoration with chemical removal of lichen crusts took place, which destroyed a great part of the lichen communities. These were studied again after removal and lichen communities occurring on rock outcrops in the surroundings of the Dolmen and on a contiguous menhir were investigated as well for comparison. Before the restoration, 33 species had been recorded on the Dolmen, most being crustose, followed by foliose and fruticose forms. Among these, eight species are regarded as rare in Sardinia and five rare at lower elevations. Most of the recorded species are typical for eutrophic substrates and for meso- to xerophytic conditions. Studies on lichen diversity on archaeological monuments in Sardinia are limited. This is the first report on the lichens of a Sardinian dolmen. This paper questions whether the lichen diversity of such monuments should be preserved as lichens have been an important part of the monument ecosystem and of the landscape for many centuries. This work also aims to improve collaboration among lichen and monument experts, in order to avoid hasty restoration decisions.

Keywords:

• biodiversity
• dolmen
• Italy
• lichens
• monument
• Sardinia

Acknowledgements

Authors gratefully acknowledge Prof. Giacomo Oggiano for the information on the geology of dolmen, menhir and natural outcrops in the area.