The study of three archaeological sites of southern Spain showed that
mortar is a building material easily colonized by a diversity of calci
colous and rather nitrophilous lichens. The interface between lichen a
nd mortar showed an intense chemical activity of the hyphae producing
extensive alteration on the surface. The nature and amount of the mort
ar components greatly influenced the colonizing species and the patter
ns of alteration. (C) 1997 Elsevier Science Ltd. All rights reserved.