Ancient cedar forests preserve genetic diversity lost in over-harvested Lebanese populations. Genomic studies show Turkish cedars have 40% more heterozygosity, making them important for Mediterranean reforestation programs.
A Genetic Vault in the Mountains
The Cedar of Lebanon, Cedrus libani, is a tree with a long history. Its durable, aromatic wood was a prized commodity in the ancient world, used to construct Solomon's Temple, Egyptian ships, and Phoenician palaces. This demand, continuing for millennia, led to the near-total destruction of the magnificent cedar forests that once covered Mount Lebanon. Today, the Lebanese populations of this famous tree are small and fragmented, covering only about 2,300 hectares.
The species, however, did not end there. Across the Mediterranean in the Taurus Mountains of southern Turkey, vast, continuous forests of Cedrus libani survived, protected by the rugged and inaccessible terrain. These Turkish forests now cover an area of 482,391 hectares, comprising more than half of the species' entire global distribution. This vast area is a large genetic reservoir, preserving the diversity that was lost in the heavily exploited Lebanese stands. Genetic studies confirm that the Turkish and Lebanese populations are two distinct groups that originated from different glacial refugia, making the Turkish trees a separate and robust branch of the species' lineage.
The 40% Advantage
The reason for the Turkish cedars' importance lies in their superior genetic diversity. Heterozygosity, a measure of the variety of gene versions within a population, is a direct indicator of genetic health and adaptability. Genomic analysis shows that the Turkish cedar populations possess 40% greater heterozygosity than their Lebanese counterparts. The Lebanese populations show signs of severe genetic drift due to low gene flow between the small, isolated forest fragments. In contrast, the extensive Turkish forests have maintained robust gene flow, preventing the genetic bottlenecks that often plague remnant populations.
This genetic diversity gives the Turkish cedars a greater capacity to adapt to environmental pressures like climate change, drought, and disease. The species is noted for its ability to tolerate extreme winter cold, with temperatures on the Taurus Mountains dropping as low as -35°C, and also endure prolonged summer droughts. This resilience makes Turkish cedars the primary source of seeds for reforestation and afforestation projects throughout the Mediterranean. In Turkey alone, over 50 million young cedars are planted annually. Provenance trials demonstrate that saplings from Turkish genetic stock have the best performance in terms of both survival and growth, ensuring that future cedar forests are as resilient as their mountain-dwelling ancestors.
💡Fun Facts
The oldest known Cedar of Lebanon in the world, named "Ambar Katran," is located in Turkey's Antalya province and is approximately 2,346 years old.
The aromatic oil in cedar wood is a natural insect repellent, which is one reason ancient civilizations used it for sacred and high-status constructions they intended to last.
*Cedrus libani* in the Taurus Mountains typically grows at altitudes between 800 and 2,100 meters (2,600 to 6,900 feet).
The first recorded conservation effort for any tree species was for *Cedrus libani*. In 118 AD, the Roman Emperor Hadrian created an imperial forest and marked the boundaries with inscribed stones to protect the remaining cedars.
The forests are natural areas, accessible 24/7. Daytime visiting is recommended for safety.
Admission
Free
Accessibility
Access to remote cedar stands often requires a high-clearance vehicle and involves driving on unpaved forestry roads. Hiking is necessary to reach many of the oldest trees.