Evanstonians may see bright green tags hanging from trees around town this week. These are part of an Arbor Day campaign by Evanston TreeKeepers and the Evanston Ecology Center to draw attention to some of the extraordinary benefits trees provide.

The tags, provided by the Morton Arboretum, list just four of the countless benefits of urban trees. Sometimes called ecosystem services, these are assigned dollar values based on extensive data collection and analysis.

Here is an example: An American elm that is 20 inches in diameter, or about 48 years old, and located downtown, intercepts 2,764 gallons of stormwater, saves 146 Kilowatt hours of electricity for cooling, raises property values, and removes 682 pounds of carbon from the atmosphere. Those benefits are valued at $211 annually, and if the tree lives for 10 more years, they rise to $257. (www.treebenefits.com/calculator)

Most street trees do not live that long. But taking care of trees – by watering them, mulching them properly, and keeping dogs, mowers, and bicycles from damaging their bark – can help them live longer and continue helping the environment. 

With atmospheric carbon on the rise, more hot summers and extreme storms ahead, trees are needed trees now, more than ever.

Evanston TreeKeepers organize workdays throughout the year in collaboration with the City of Evanston Department of Forestry and sponsor other programs and events to help citizens learn about the value of trees and how to care for them. Anyone wishing to joint the mailing list should contact evanstontreekeepers@gmail.com.