Climate change threat to Lebanon's emblematic cedar trees
Sturdy cedar trees (Cedrus libani) perched high in the mountains stand for many Lebanese as symbols of their land's survival. But some environmentalists worry that the trees face a new threat from climate change and its associated impacts.
Cedars once covered vast swathes of southern Turkey, Syria and Lebanon, but their timber and resin has long been in demand. Valued by Phoenician shipwrights, Egyptian builders and many others, the forests shrank over the millennia.
In areas of Lebanon, the cedar's natural range is
now 1,200 to 1,800 metres (4,000 to 5,900 feet)
above sea level. A warmer climate would
mean cedars could only prosper higher up.
Now cedars cover only 2,000 hectares (5,000 acres) in Lebanon, clinging on in just a dozen high-altitude areas.
Almost all of these are protected. The cedars in Barouk Cedar Nature Reserve are thriving and regenerate naturally. Their larger, older cousins in a walled grove near Bsherri in the north are more famous, but only a few remain. Some are thought to exceed 2,000 years old.
Yet "The biggest challenge now for the cedars of Lebanon is climate change," says Nizar Hani, scientific co-ordinator of the Barouk Reserve in the Shouf mountains, which contains a quarter of Lebanon's cedar forests.
Cedars are comfortable at a certain altitude and like moist, well-drained soil with a certain level of humidity. "These are aspects that climate change could very much impact, especially in this region," says Rania Masri of Notre Dame University in Beiruit. "There could well be a decrease in humidity, a decrease in rainfall."
There could also be an increaed threat from pests and diseases. A decade ago insects devastated cedars at Tannourin in northern Lebanon. Researchers linked the infestation of Cephalcia tannourinensis, a wood wasp, to changes in temperature and soil moisture.
The flag of Lebanon
Lebanon's cedar, which adorns the national flag, grows into its distinctive wedge shape only after it has reached a height of seven or eight metres (23-26 feet).
"Then the head dies. This is a natural condition, not a disease, because the underground water reservoir can only feed the tree to that height," explained Hani. "This is the difference between the Cedrus libani in Lebanon and in other places. If you plant a Cedrus libani in a place with more water and more snow, you cannot see this shape, the flag shape."