Eugene-Springfield news: the impact of wind & salt on trees

By Whitey Lueck

“Many people are aware of the apparent effect of strong winds on trees that grow along the coast and on exposed ridges in the  high mountains. The trunks of trees in these locations that sometimes experience severe weather may be strongly slanted or bent, and the crowns or canopies of  the trees are often very asymmetrical.

“But few people realize that, even where  relatively gentle weather prevails most of the time, such as here in the upper Willamette Valley, wind can cause significant crown deformation in both native and cultivated trees.

“Interestingly, trees at the coast and in the mountains are not deformed due to the wind, per se. At the coast, for example, the strongest winds occur in the wintertime as storms arrive—generally from the southwest—from the Pacific Ocean.

“But tree canopies there are deformed as if a wind from the northwest were acting on them! How can that be? Well, what causes the deformation of coastal tree canopies is not the wind itself, but the salt that is carried on the wind—which kills the tissues, buds and needles on the windward side of the tree.

“During the winter, storms off the ocean are accompanied by rain, which washes any salt off. But during the summer, the strong, north/northwest winds that blow almost daily along Oregon’s coast deposit on the northwest sides of trees salt that does not wash off, resulting in the southeast side of the tree (out of reach of the salt) growing more luxuriantly than the northwest side and thus over time creating the lopsided canopy. …”

—Read the rest of Whitey Lueck’s story, The Wind in the Trees,” and other tree news in the current Friends of Trees Eugene newsletter.