SILVER, CONSTANCE S. Preservar, Inc., 310 Riverside Dr., New York, NY 10025. - Conservators confront lichens: a summary history of conservation's efforts to understand and control lichen-induced deterioration of cultural property.
By the middle of the nineteenth century, deterioration of cultural
property due to environmental agents was recognized and efforts at
control initiated. Lichen-induced biodeterioration of exterior stone,
such as architectural facades, sculpture, tombstones, and even
stained-glass windows, had been been identified as one such agent.
Conservation's uneasy relationship with lichen has continued; indeed,
it has become increasingly more complex. For example, lichen's
possible role in dating and as an indicator of environmental
conditions militates for its preservation, while its deleterious
effect on cultural materials prompts its eradication. Broader
environmental concerns increasingly move conservators away from
biocides, the standard method of lichen control. This paper will
present an overview of control of lichen on cultural property through
a summary review of historic and current literature. It will also
explain data bases that address this issue. Lastly, a promising new
avenue for control of lichen on cultural property will be described.
Key words: biodeterioration of cultural property, conservation of stone, lichen control, lichen-induced deterioration