Urban Forestry: What’s That About?
BY EMILY ORR
What if I told you a means exists to simultaneously boost a city’s economy, increase public safety, and provide substantial health and environmental benefits? Would you believe me? What if I told you that this means is as simple and cheap as planting a tree? Planting trees, or “urban tree projects,” has gained attention in cities across the nation. The projects themselves range from the strategic place-ment of trees 10-15 feet apart along city sidewalks, to the installation of trees on Silva cells to serve as green infrastructure. Regardless, both actions, and the many variations of them, constitute the next big move for local governments working with non-profits and sustainability groups to dramatically improve their cities.
Trees are the lungs of a city. This is true on a microscopic level when plant cells engage in photosynthesis and macroscopically due to the cumulative effect of each tree’s photosynthetic activity. Because the carbon dioxide consumed by trees is stored throughout its cells as other carbon compounds, one acre of trees is able to absorb the amount of carbon dioxide released from a car traveling 26,000 miles each year. Therefore, in a way, trees are natural filter systems to reduce levels of carbon dioxide, a major greenhouse gas, from the atmosphere. This carbon dioxide reduction, plus the lower temperatures of concrete due to tree shade, decreases the average temperature of a city, combating the “heat island effect” caused by urban areas. Additionally, a tree’s leaves trap and hold particulate matter, small pollutants that damage lungs and trigger asthma attacks, until it is washed away by rainfall into storm drainage facilities. Thus, trees provide cities with significant environmental and health benefits. And I’m just getting started.
From an economic perspective, urban forestry considerably aids nearby businesses and residents. A 2006 Michigan urban design study shows that streets with treescaping attract more businesses, tourists, and consumers than do tree-free areas. In fact, businesses on these streets show a 12 percent increase in income while benefiting from a 10-15 percent increase of property value. Furthermore, buildings can easily reduce air conditioning and heating costs due to the shade and insulation that trees provide. Even the city itself benefits from this shading. The same article discusses how tree coverage of large asphalt and concrete areas leads to a reduction in the cracking of concrete from sun exposure, resulting in 40-60 percent increases of pavement lifespan.
Moreover, treescaping dramatically increases public safety in cities. A University of Illinois study of Chicago socio-cultural benefits indicated that trees could cut crime by as much as 7 percent. Generally speaking, the presence of trees encourages citizens to walk more, which develops a greater sense of community and causes people to have greater concern for their property and neighborhoods. The aesthetic and natural aspect of trees is also known to relax and improve the psychological health of an individual. This effect accordingly translates to public road safety. Trees that border streets have proven to reduce drivers’ speeds and run-off-road crashes by providing a reference point of speed and direction to drivers. This barrier of trees between sidewalk and street also serves to protect pedestrians, creating a safer community.
I could go on, rattling off a litany of benefits – how urban forestry reduces need for storm water management systems, stabilizes watersheds, reduces soil erosion, etc. – without even taking into account the aesthetic and natural value the trees provide. But for any local government, it all boils down to the following conclusion: a single street tree, with installation costs ranging from $250-600, returns more than $90,000 of direct benefits to a city. These numbers have not gone unnoticed. In addition to hundreds of state and local efforts to plant more urban trees, the national US Forest Services has initiated the Urban and Community Forestry (UCF) to “provide technical, financial, research, and education services to local government.”
Yet in our own community, St. Louis has only implemented two urban tree programs. Firstly, the County Parks Urban Tree Program, introduced in 2005, asks for sponsorships of trees to promote urban forestry in the community. Between the Urban Tree Program and its predecessor, the Memorial Tree Program, the department has planted over 4,000 trees in St. Louis County. However, St. Louis’s other program, the Green Tree Academy, has lacked funding to hold any of its educational programs since 2011. Thus, though St. Louis has begun to explore the potential benefits of planting trees, the city is still largely behind the national trend. Hopefully, as other local governments and non-profits across the country endorse this sustainable and beneficial undertaking, St. Louis will similarly take full advantage of treescaping’s potential to improve the city’s health, economy, environment, and future.