Study looks at best spots to plant trees in Nashville

By Jenny Upchurch
Nashville, TN (September 4, 2010)- Nashville is greener than many other cities, boasting more tree canopy than Atlanta, Washington or Seattle. But Davidson County’s first-ever tree assessment, including its most urban areas, shows where more trees could be added, including a possibility that trees could shade almost two-thirds of downtown.

It would take a lot of trees – 197,213 – to add 1 percent more canopy countywide. To guide the greening effort, volunteers who plant trees along neighborhood streets will have to get Metro approval of what and where they plan to plant. “We need the right tree in the right place,” said Veronica Frazier, head of Metro Beautification & Environment, which led the study.
A $40,000 state grant paid for the canopy study, which used aerial imagery to plot where trees cover the ground. It is the first for a Tennessee city, state officials say, calling it “a really big step.” Protecting and increasing tree canopy pays off by improving air quality, helping filter storm water and reducing air-conditioning costs. The trees downtown, about 2,000, provide an annual benefit calculated at $71,857, based on a calculator from the U.S. Forest Service. And it would cost almost $2.5 million to replace them.
The tree canopy covers 47 percent of Davidson County; even its urban areas have 44 percent coverage. Almost 19 percent of downtown has a tree canopy. Nashville’s percentages are similar to those of Chattanooga and Charlotte, N.C., according to studies this year by American Forests, a trade group formerly known as the U.S. Forestry Council.
Chattanooga has tree canopy on 51.4 percent of its space, including 13.2 in its central business district. Charlotte has 46 percent, and 50 percent in Mecklenburg County. A tree canopy is possible in 35 percent more of Davidson County, according to the report, but some of that is really off limits to trees, said Justin Graham, an employee of AMEC Earth and Environmental, a private company that did the assessment.
For example, cropland cannot be covered in trees, so rural areas such as Joelton and Bellevue have less possible growth than suburban residential areas such as Madison and Elm Hill/Woodbine. Parking lots offer significant opportunities to add tree canopy without losing spaces. That is achieved by planting trees in the surrounding and interior grassy area that can shade the pavement, he said.
Nashville’s code already requires that trees be planted or preserved in the construction of parking areas with more than five spaces. The tree canopy could expand dramatically downtown. Almost a fifth of the urban core has tree cover now, and that space could expand to 70 percent. Nashville Electric Service underwrote a downtown tree census at the same time as the tree canopy study. Each tree was identified by species and place and graded for condition. That will help identify where trees can be added, and it can help pinpoint which trees need pest control or fertilizing, said Glenn Springer of NES.
Nashville’s next step is to create a master plan for downtown, says Randall Lantz, head of horticulture for Metro Parks. That may come with the ongoing Open Space Plan, which a task force is preparing for Mayor Karl Dean. It may also evolve from the new permit process for volunteer tree planting efforts. Thousands of trees are planted each year. For example, Cumberland River Compact last fall began an effort to distribute 5,000 trees for volunteers to plant over the next five years.
Beginning in September, groups will need to provide a plan that describes the species of trees and where they will be planted, if the planting site is in the right of way. Metro will approve it or ask for revisions. The group must agree to maintain the trees for two years. Efforts can backfire, Frazier explained, such as planting a tree that drops fruit over on-street parking or one whose limbs block stop signs and traffic signals. Carol Norton, an East Nashville resident long active in landscaping its streetscapes, says the Metro review won’t be a problem if groups get a timely response from Metro.
Related Resource:
The Tennessean- Study looks at best spots to plant trees in Nashville