by Betty Harris
A new study found that an additional ten trees on a given block corresponded to a one-per-cent increase in how healthy nearby residents felt.
“To get an equivalent increase with money, you’d have to give each household in that neighborhood ten thousand dollars—or make people seven years younger,” says University of Chicago psychology professor Marc Berman.
“The emerald ash borer, which has killed a hundred million trees across North America in recent years, offers a grim natural experiment. A county-by-county analysis of health records by the U.S. Forest Service, between 1990 and 2007, found that deaths related to cardiovascular and respiratory illnesses rose in places where trees succumbed to the pest, contributing to more than twenty thousand additional deaths during the study period. The Toronto data shows a similar link between tree cover and cardio-metabolic conditions such as heart disease, stroke, and diabetes. For the people suffering from these conditions, an extra eleven trees per block corresponds to an income boost of twenty thousand dollars, or being almost one and a half years younger.” –Alex Hutchison, Runners World columnist, author of Which Comes First, Cardio or Weights: Fitness Myths, Training Truths, and Other Surprising Discoveries from the Science of Exercise
Perhaps more interesting is that the greatest benefit appears to be where trees are planted in front yards and along sidewalks rather than back yards. Think about those rare times when you drive along a road or street and there are trees on both sides that shade the road. On Littleton Blvd between Bemis and Windermere the street is lined with mostly mature trees and it feels good to go that direction. Which just brings to mind the claustrophobic feeling some of us get where buildings are built right up to the sidewalk. Consider the different “feel” of walking on most downtown Denver streets compared to the feel of walking down the 16th street mall.
“Something deep within us responds to the three-dimensional geometry of nature, and that is where arguments of economic equivalence, however well intentioned, fall short. If someone offers you ten thousand dollars or ten trees, take the trees.” –Hutchison
The human brain which controls behavior (bad thoughts perhaps creates bad behavior?) responds positively to areas that have a higher proportion of green mass over that of gray mass (building, sidewalks, streets). Open spaces with grass to play and lay on and trees to create shade help humans relax. No amount of hard surfaces provides relaxation. Green spaces is one of the reasons that people want to move here. People want to come here because of our green spaces because it feels safer and calmer than the hardscape of Denver and other cities. Demand for houses in this area is strong and thus prices for houses are still strong.
When I moved out to Colorado in 1983 a friend who was living here was complaining big time about there being so few trees and was trying to push her husband to move away from here. Since 1983 many trees that were planted then and since have filled and softened the spaces between all that hard scape and my friend is happy and still here.
The soothing effects of trees on our psyches is perceived as a desirable character in a city. Maybe we should consider that developer’s desire to make more money by building right up to the sidewalk is detrimental to the citizenry as well as the desirability of a city as a place to live and work. It may also decrease the value of our properties as greater spans of concrete and steel and brick and mortar destroy the desirable character of a city of any size and create more agitated and unhealthy populations.
Besides trees help us breathe better along with all their other desirable qualities. Next edition we’ll talk about breathing more.