It’s difficult to convince people to commit time, money, and energy to an abstract concept. Show people an image or some thoughtful calculations, however, and suddenly it is easier to motivate them in your favor. Such is often the case with planting trees in our cities and parks. Environmentalists, designers, arborists, and others have known for decades that trees offer myriad benefits that quite literally pay off for homeowners and cities but communicating this to the public, city leaders, and neighborhood committees can be difficult. People see the price of planting and maintaining trees and often balk at the cost. As a result, some scientists have set out to put a price on nature, measuring the monetary benefits of forests, soil, and clean air.
A dollar amount can be placed on things like carbon sequestration, air quality, shade, noise reduction, and stormwater absorption. The U.S. Forest Service has developed i-Tree, specialized software to help evaluate a tree’s worth. With this tool, the Forest Service was able to determine the approximate value of California’s 9.1 million street trees and found their value to be over $1 billion. The breakdown is as follows:
- $10 million in carbon storage
- $18 million in air pollutant removal
- $41.5 million in stormwater absorption
- $101 million in energy savings
- $839 million in boosted property values
The Forest Service went further, determining that for every $1 spent on planting and maintaining street trees, the average return is $5.82 in benefits. Plus, trees don’t have office hours – they are hard at work 24 hours a day, 365 days a year! This kind of information is important when promoting urban tree plantings. Whether we like it or not, money drives decision making, and placing a dollar amount on benefits can help individuals who may not be big on trees see their value from a different perspective.
Some U.S. Cities have begun tracking the value of their urban canopy for this very reason. The Parks and Recreation Department of Tampa, Florida approaches their trees as “the living equivalent of roads and bridges.” They understand the intrinsic value of trees in their city but have found it easier to secure funding for planting and maintenance when they can show they city’s existing trees as having a positive financial contribution. Working with the University of Florida’s Institute of Food and Agricultural Sciences and the Forest Service, they completed a 2017 study that estimated nearly $35 million in annual savings thanks to trees. Public health, stormwater management, energy savings, erosion prevention, and other services were all taken into consideration when calculating the price tag. Expanding on this concept, the University of South Florida has begun tracking the benefits of individual trees, so they can pinpoint a single specimen and estimate its annual payoff. This type of research and mapping helps the city understand where to focus their resources. Just as crumbling roads or high traffic areas are likely to get prioritized for resurfacing, key trees may get pruned or watered more often.
Tree health plays an important role in a tree’s ability to “turn a profit.” For example, an urban tree that lives only 13 years will not exist long enough to “pay” for the cost of its installation and maintenance. A tree living 50+ years, however, will more than pay for itself, netting over $25,000 in benefits throughout its lifespan. Investing in trees early on in their lives truly pays off in the long run. Constantly replacing trees is costly and frustrating but planting a tree and caring for it so it lives a long and productive life guarantees decades of benefits.
It is important to realize that when trying to monetize our urban trees, we will never be able to fully compute all the hidden, intricately connected impacts trees have on our lives. It seems that if we could, their value would only increase. Trees pay us back every day, benefiting our environment, health, and pocketbooks.
- McPherson, E.G. 2001. Sacramento’s Parking Lot Shading Ordinance: Environmental and Economic Costs of Compliance. Landscape and Urban Planning 57. (Economic Benefits).
Photo courtesy of Claude Cormier + Associates