Biodeterioration of Stone Surfaces Lichens and Biofilms as Weathering Agents of Rocks and Cultural Heritage

This is a timely volume in view of the considerable interest currently shown in the preservation of our cultural heritage and the extensive and growing literature on the subject. Unfortunately, the latter is to be found in a wide variety of published sources, some aimed at a very specific readership. The present volume draws together a spectrum of biodeterioration work from across the world to provide an overview of the materials examined and the methodologies employed to elucidate the nature of the problems, as well as an extensive and current bibliographical resource on lichen biodeterioration. Generally, we do not think of rock surfaces as particularly conducive to the growth and development of living things. Occasionally, we may encounter grasses or forbs or even more rarely a small shrub or stunted tree growing from a crack in a large boulder or rock wall; but for most people, rock is perceived as dry, sterile, impenetrable, and generally uninviting. However, to the experienced eye rock surfaces are often teeming with life – lichens, bryophytes, a host of small invertebrate animals, as well as a vast array of microscopic organisms including bacteria, cyanobacteria, algae and non-lichenized fungi. The longevity and structural stability of most rocks superficially suggest that rock surface inhabitants are benign; however, slowly and steadily all rock dwelling organisms contribute to the relentless decomposition of rock surfaces – augmented by the natural physical forces associated with changing seasons, weather patterns, and in some localized settings the caustic effects of air pollution. Rock dwelling communities vary in complexity and composition depending on the specific structural and chemical features of the rock. Even human manipulated or manufactured stone supports to some degree a living community – and herein are found the real issues and concerns related to biodeterioration of rock substrata. In a natural setting biodecomposition of rock is accepted as normal and even desirable – integral to the process of soil development; however, in the human environment biodeterioration of monuments, buildings, artwork, statues and gravestones is counted as a serious problem. Even in natural settings, culturally significant prehistoric and historic rock art is subject to the same processes of biodeterioration. In this volume the editors have compiled current papers from leading experts dealing with various issues related to biodeterioration of rock substrata. Topics range from biodeterioration effects on prehistoric rock art as well as culturally significant, historic rock structures. This is the first treatment of the subject of biodeterioration that includes a careful consideration of the role of related disciplines including geology, archaeology, crystallography, cultural conservation and resource management. This combination of disciplines makes this book valuable not only as a solid scientific treatise but equally important as a serious resource for evaluating both impact processes and preservation options related to biodeterioration of culturally significant rock substrata.