Skip Ribbon Commands Skip to main content
Help (new window)
University of Balamand > News > Archive > The Weather in Centuries

The Weather in Centuries

Want to know what the weather was like in Ehden 200 years ago, or in Bsharri 600 years ago? The dean of the Faculty of Sciences, Jihad Attieh, can tell you.

He knows.

He can tell you more, too. For example, he can tell you in what years in those six centuries were there forest fires, or an insect infestation, or when air pollution became significant and started to affect the vegetation.

Prof. Attieh has been involved in a dendroclimatology research project spanning the eastern Mediterranean and involving researchers from a number of universities. In a recent issue of the celebrated journal The Holocene, Prof. Attieh and nine collaborators published the first results of their work in a paper entitled “Spatial Patterns of Eastern Mediterranean Climate Influence on Tree Growth.” The paper is available online.

Dendroclimatology, explains Prof. Attieh, is the study of climatic shifts by examining tree trunk rings. The process of examining ring patterns and dating them is known as dendrochronology. Correlating these two disciplines allows researchers to establish the climatic conditions under which a tree developed during each year of its existence.

The eastern Mediterranean dendroclimatology research has been ongoing since 2010 and is being led by the Tree Ring Research Laboratory at the University of Arizona under the direction of Professor Ramzi Touchan. It involves researchers from universities in Lebanon, Cyprus, Greece, Turkey and Syria.

In Lebanon, Prof. Attieh and his team sampled 30 cedar trees from each of the following regions: Kamouaa, Wadi El Blat, Jurd al Njas, Ehden Reserve, Hadath, Bsharri, Tannourine, Kfoor El Arbeh, Arz Jaj and Maaser el Shouf. The sampling is done using an instrument known as an increment borer. It bores into the tree with a cylinder half a centimeter in diameter, removing small segments of each ring.

“We can obtain extremely precise information about the age of the tree, and by studying the patterns of the rings width one can correlate that to the weather and build a chronology in which one maps the climate pattern.”

The oldest tree Prof. Attieh was able to identify in Lebanon is 637 years old, in Bsharri. He points out that there are parts of the world where trees are much older, particularly in areas where trees were not being used for lumber.

“In the White Mountains, in the U.S., there are pine trees that are 5,000 years old.” However, says Prof. Attieh, only a few types of trees maintain their core as they grow older, among them the cedar, pine and juniper trees. While other trees may, too, be very old, their cores crumble as they grow older.

The still ongoing research, explains Prof. Attieh, is based on the hypothesis that the weather follows a pattern and that if we can know the weather in the past we can probably explain the weather patterns we are experiencing today, or might experience in the future. ​​​
facebook twitter LinkedIn



Social Media
University of Balamand,
Balamand Al Kurah,

Tel:  +961-6-930250
Fax: +961-6-930278