Lichen colonization and associated biodeterioration processes on ancient bricks of the Gonbad-e Qābus tower, UNESCO World Heritage Site, Iran

Lichen colonization on ancient bricks of the Gonbad-e Qābus tower, a UNESCO World Heritage Site in Iran, reveals significant biodeterioration processes. Research shows that lichens thrive more on walls with higher surface moisture, influenced by wind-driven rain and lower solar radiation. Microscopic analysis demonstrates that mycobiont hyphae penetrate bricks to millimetric depths, causing substrate disaggregation. Energy-Dispersive Spectroscopy, X-Ray Diffraction, and Raman analyses further document elemental absorption by hyphae and the formation of calcium oxalate deposits at the interface between lichens and bricks. These findings highlight the strong biodeteriogenic impact of lichens on ceramic materials in (semi-)arid climates, suggesting potential risks to built cultural heritage that warrant further investigation.

Zabihi, M., Sohrabi, M., Nortaghani, A., & Favero-Longo, S. E. (2025). Lichen colonization and associated biodeterioration processes on ancient bricks of the Gonbad-e Qābus tower, UNESCO World Heritage Site, Iran. Scientific Reports, 15(1). https://doi.org/10.1038/s41598-025-20461-4