Mechanism and Control of Black Spot Deterioration on Lacquered Architectural Components of Dajue Temple

Dajue Temple, a representative ancient architectural heritage in North China, houses numerous lacquered wooden components of exceptional historical and artistic value. Prolonged environmental exposure causes severe dark discoloration and black spotting on lacquer surfaces, threatening their structural integrity. This first investigation into the damage identifies the spots as microbial in origin, with Cladosporium spp. as the primary agent driving deterioration and possessing wood-degrading capabilities. Antifungal tests show that thymol, clove essential oil, and nano-silver gel are all effective inhibitors. We proposed targeted, relic-friendly microbial control strategies tailored for ancient lacquered wooden components. These findings provided scientific guidance for the sustainable conservation and restoration of lacquered architectural elements in historic temples and comparable cultural heritage sites. In future work, environmental monitoring and the biocides' compatibility should be involved, which will help to clarify microbe-environment interactions, enable early warning of biodeterioration risks and explore the wood-friendly biocides.