These living things have quietly preserved the Great Wall of China for ages and we weren't even aware

For millennia, the Great Wall has stood as an enduring symbol of China's dynastic prowess, showcasing both ingenuity and authority.

The remarkable preservation of this colossal structure is no accident. Conservation and restoration efforts have tirelessly worked to ensure that future generations can marvel at this archaeological wonder.

A recent collaborative study by researchers from China, the US, and Spain delves into the contentious debate within the conservation community regarding the impact of biocrusts on historical monuments, according to Science Alert.

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What are biocrusts?

Biocrusts, composed of lichen, bacteria, fungi, moss, and small plants, grow on mineral surfaces, potentially posing risks to the structural integrity of historical sites.

Debates arise over whether these living organisms contribute to weathering, jeopardising the monuments, or act as a protective shield, increasing the longevity of historical structures.

The research team conducted an extensive survey of approximately 600 kilometres of the Great Wall, focusing on segments in drier climates to understand the specific conditions under which biocrusts may impact archaeological sites.

Contrary to the perception of a single wall, the Great Wall is a complex series of fortifications, towers, and battlements built over centuries to define China's northern border.

Examining the construction materials, from clay-rich soil to sand and pebble layers, reveals the adaptability of the Great Wall to different environmental challenges, including those in arid regions like the Gobi Desert.

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Many older sections of the wall, particularly those constructed with rammed earth, display signs of biocrusts. The study explores whether these living coatings contribute to the preservation or deterioration of the ancient structure.

While the presence of lichen and moss may alter the expected visual appeal of the Great Wall, the researchers grapple with finding a balance between protective vegetation and aesthetic considerations.

In the face of climate change threats, the study suggests that future generations may welcome a "patina of green" as a trade-off for preserving one of the world's biggest architectural treasures.

(With inputs from agencies)