News Excerpt:

A recent collaborative study by Chinese, American, and Spanish experts explores the contentious discussion among the conservation community about the influence of biocrusts on the Great Wall of China.

About Biocrusts:

• Biocrusts, which are made up of lichen, bacteria, fungi, moss, and small plants, grow on mineral surfaces and may endanger the structural integrity of ancient structures.
• There is uncertainty about whether biocrusts contribute to weathering and endanger the structural integrity of historical structures.

Key highlights of the research:

• The research team surveyed nearly 600 kilometers of the Great Wall, focusing on stretches in drier climates to better understand the exact conditions under which biocrusts may harm archaeological sites.
• As per the study, 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, which range from clay-rich soil to sand and pebble layers, illustrates the Great Wall's flexibility to many environmental problems, particularly those found in desert locations such as the Gobi Desert.
• In the face of climate change threats, the study implies that future generations may be willing to accept a "patina of green" as a trade-off for conserving the Great Wall of China.

About the Great Wall of China:

• The Great Wall of China is an ancient series of walls and fortifications located in northern China, totaling more than 13,000 miles in length. 
• Emperor Qin Shi Huang originally conceived the Great Wall in the third century B.C. as a means of preventing incursions from barbarian nomads. 
• The best-known and best-preserved section of the Great Wall was built in the 14th through 17th centuries A.D., during the Ming dynasty. 
• Though the Great Wall never effectively prevented invaders from entering China, it became a powerful symbol of Chinese civilization’s enduring strength.
• The Great Wall was designated a UNESCO World Heritage site in 1987.
• The Great Wall has three major components: passes, signal towers (beacons), and walls.
• Passes were major strongholds along the wall, usually located at such key positions as intersections with trade routes.
• Signal towers (beacons) were used to send military communications
• Walls were made of tamped earth sandwiched between wooden boards, adobe bricks, a brick and stone mixture, rocks, or pilings and planks.
• The Great Wall has long been incorporated into Chinese mythology and popular symbolism, and in the 20th century, it came to be regarded as a national symbol.