What are the Ages of Trees in Your Neighborhood?:
By John F. Dwyer, Research Associate
The Morton Arboretum
Trees are often a distinctive feature of the urban landscape. Large trees are especially prominent, have a particularly significant influence on the urban landscape, and symbolize permanence amid change. We are curious about the age of these venerable giants as an indication of the history they have witnessed. Their ages also offer a clue to their significance by indicating how long we might have to wait for a replacement tree to reach their size.
To get some indication of the age of urban trees, Kerstin Von der Heide, Forester, Village of Downers Grove, Illinois measured tree diameters (4.5 feet above the ground) and counted the number of annual rings on the stumps of 328 trees representing 24 species removed from along village streets. The oldest was a 167-year-old white oak that measured 26.2 inches in diameter. All trees older than 135 years were white oak or burr oak. The largest tree measured was a 52.2 inch American elm 110 years old. Other trees over 40' in diameter were willow, green ash, or honeylocust.