Life on and in Stone – an Endless Story?

Concern with rock decay started early in the history of the mankind. However, the last two centuries yielded a large wealth of information on the manifold aspects of rock decay and rock protection related to the physical cultural heritage. The most important branches of scientific endeavour in this field were air pollution related studies and the increasing awareness of biodeterioration. In this overview the evolution of trends and techniques in the study of rock biology is described. The main lines of the presentation are the changes in search for the most detrimental organisms and the causes for their deteriorating activity. An attempt is made to quantify the influence of organisms within the general frame of rock decay mechanisms. Another focus of the contribution is on protective biofilms or products of biofilms. Within this context the role of lichen, algae, cyanobacteria and fungi in the formation of rock films usually described as patina is elaborated. A brief summary is given on modern molecular techniques of analysis and novel combined or multi-technical approaches to eliminate or avoid detrimental growth on and in rock.