How Urban Trees Save Lives

It’s no surprise that street trees benefit public health, but a new study shows a “direct statistical connection” between street trees and reduced mortality rates. Robert Steuteville explains the research in an article for Congress for the New Urbanism.

To be sure, association is correlation, and correlation is not causation. And yet the study controlled for such factors as race, education, income, age, and year of planting in the analysis of tree plantings and people in Portland, Oregon, census tracts. Importantly, researchers were able to control for demographic causes for the health benefits, which strengthens the case for street trees being a critical factor.

Important findings include that “Tree plantings were significantly associated with reductions in non-accidental and cardiovascular mortality,” with bigger, older trees having a stronger connection than younger ones. 

The study focused on street trees rather than trees in private gardens, which are easier to monitor, are “a uniquely visible type of tree that, a priori, we would expect to have a broader neighborhood-level impact on health,” and can be planted through public initiatives.