[Research progress on the bioweathering and controlling of stone cultural relics]

The bioweathering of stone cultural relics is a ubiquitous problem. Weathering prevention is an escalating challenge under the increasing global climate and environmental changes. Here, the mechanisms of lichen-microorganism mediated weathering of stone materials and their relationships with climatic and environmental factors were reviewed. The biological protection of lichens and the evaluation of the efficacy of biocides in lichen-control were discussed. The potential research directions in this field were proposed. Research on lichen-rock interfaces suggested that biological weathe-ring could be mainly attributed to physical and chemical weathering which represented by mycelium penetration and calcium oxalate formation. Bioweathering of outdoor stone cultural relics is closely related with the whole ecosystem encompassing factors, such as stone matrix, surrounding environment, and climate factors. Lichens have both biological weathering and protection effects on stone heritage. For the restoration of bioweathered stone cultural relics, environmental conditions for pre-servation of stone cultural relics should be improved step by step. The related industry regulations and national standards for evaluating biological weathering and control efficiency should be established to promote the efficient development of scientific protection.