Biocrusts on Great Wall of China

Recent research as of December 2023 has revealed that biocrusts, composed of moss, lichen, and cyanobacteria, play a crucial role in protecting the Great Wall of China from erosion. These biocrusts cover a significant portion of the wall, especially in sections built with rammed earth, a material prone to erosion. Contrary to previous assumptions that natural vegetation might accelerate weathering, these biocrusts have been found to strengthen the wall, increase soil stability, and reduce the effects of environmental factors such as wind, rain, and temperature fluctuations. This discovery highlights the potential of biocrusts as a promising and innovative strategy for heritage conservation, offering multiple protective functions in a nature-based, eco-friendly manner. This research could change the way heritage sites globally approach the preservation of ancient structures, particularly those with significant earthen components.