Garden Tips: Trees beneficial to humans, environment
I hope you celebrated Mother’s Day with some pretty flowers or plants. They can help moms live longer. Recent research from Harvard University shows that higher levels of green vegetation are associated with decreased mortality in women.
Harvard researchers also found that women living in the study areas with the highest levels of greenery had a 12 percent lower mortality rate. The lead researcher attributes this lower mortality rate to less air pollution, greater physical activity, more social interaction, better mental health and decreased depression. This is proof that green spaces, including parks, street trees and even turf, are important to our health and well being.
Too stressed to think about it? Trees and green spaces can help. A university study in Scotland measured cortisol levels (the principal human stress hormone) in men and women over the span of a day. Individuals experiencing everyday life stresses had lower cortisol levels if they were surrounded by green spaces.
If you find these benefits too vague, consider that trees and green spaces provide economic value to communities. A 1990 study in Sacramento revealed that residents whose homes had shade trees planted on the west and south sides saved an average of $25.16 on power bills throughout the summer. While not impressive on an individual basis, the savings were significant considering the number of homes in Sacramento.
A study in Portland found that street trees added an average of $8,870 to a home’s sale price, as well as raising the value of nearby houses. Those conducting the study extrapolated these numbers to include the entire city, and found that Portland street trees have a capital value of $1.1 billion and provide an annual benefit of $45 million. Considering the increased property tax revenues because of homes with street trees, the trees bring in $15.3 million each year. This is greater than the estimated $4.6 million in annual maintenance costs of the trees. This has Portland seeing green, and as a result, they have focused efforts on planting many more street trees.
Need more convincing? Consider that studies show paved streets shaded by trees last longer and require less maintenance over time, saving potentially up to 60 percent of repaving costs over 30 years. Other documented benefits of trees and green spaces have shown that they improve air quality by trapping pollutants and particulates, decrease asthma and other respiratory problems, increase physical activity levels, improve mental well being, lower stress levels, provide protection from UV radiation, reduce noise pollution, calm drivers and slow traffic.
And there is more. Trees store carbon, reduce the heat island effect in cities, reduce violence and crime, and increase a sense of community.
Kudos to Kennewick, Pasco and Richland for their dedication to improving our communities with trees and green spaces. Each city has been recognized as a Tree City USA by the Arbor Day Foundation. The award acknowledges these cities for addressing the core standards of urban forestry management, which are maintaining a tree board or department, having a community tree ordinance, celebrating Arbor Day and spending at least $2 per capita on urban forestry. All three cities celebrated Arbor Day last month and worked with volunteers to plant trees in our city parks and along our streets.
If you find this as exciting as I do, a free seminar called Quality Trees, Quality Cities is planned from 8:30 a.m. to 1 p.m. June 1 at the Richland Community Center at Howard Amon Park. Attendance is limited to 30 people. The Washington State Department of Natural Resources Urban & Community Forestry Program is presenting the talk about managing our community trees. For more information, go to bit.ly/tree_seminar.
Marianne C. Ophardt is a horticulturist for Washington State University Benton County Extension.
This story was originally published May 15, 2016 at 3:21 PM with the headline "Garden Tips: Trees beneficial to humans, environment."