Large Trees a Must for Combatting Intense Heat

Recent studies—and the brutal heat dome we just faced in June 2021—affirm why Trees for Life Oregon is asking City leaders to start addressing heat-island effect by getting all City bureaus on board when it comes to preserving large-species trees and space for them. Climate crisis isn’t the future—it’s now.

“Trees are stationary superheroes,” according to a recent New York Times article. They are, “quite simply, the most effective strategy, technology, we have to guard against heat in cities,” says Brian Stone Jr., professor of environmental planning at the Georgia Institute of Technology.

A study based on ground-level temperature measurements in Madison, Wisconsin, found that adequate tree cover can reduce summer daytime temperatures by up to 10 degrees. Carly Ziter, co-author of that study, says that findings call for different city bureaus as well as homeowners to be on the same page when making decisions about tree planting, and that tree planting should happen where people live and are active, not just in parks.

These studies and others lend substance to Trees for Life Oregon’s argument for planting large-species trees. Trees that grow 50 feet or taller and live more than 75 years provide much more canopy than small-species trees do.

 “The trees we plant now or the areas we pave now are going to be determining the temperatures of our cities in the next century,” says Ziter.

Portland leaders—please take note.

American elms (Ulmus americana) line a street in the Ladds Addition neighborhood.