The scene in a tiny pocket park outside Plaza Mariachi here on Nolensville Pike last Wednesday was like a tableau from a Norman Rockwell painting, 21st-century style. Surrounded by signs advertising the Hispanic Family Foundation, Dubai Jewelry, the Dominican Barber Shop and restaurants offering Peruvian, Chinese, Mediterranean and Indian food — as well as a Game Stop franchise and H&R Block — was a small sign that read, “Today: Free trees.”
The arrow on the sign pointed to a pop-up canopy where the Nashville Tree Foundation was hosting its fourth tree giveaway of October. A family standing under the canopy was posing for a photo with the sapling they had just adopted. Carolyn Sorenson, executive director of the foundation, was taking the picture: “Say ‘trees’!” she said.
The tree giveaway at Plaza Mariachi happened to fall on the very day that Nashville’s mayor, David Briley, announced a campaign to restore and enlarge the city’s tree canopy. The effort, called “Root Nashville,” will be overseen by the city and the Cumberland River Compact, an environmental nonprofit, and funded through a combination of public, corporate, foundation and private dollars. Together with several municipal departments and other nonprofit organizations, the initiative aims to plant 500,000 trees in Davidson County by 2050.
Many of these newly planted saplings will replace very large, very old trees that have been lost to Nashville’s meteoric growth — a population increase of more than 45 percent since 2000. As the city has grown, the city’s trees have fallen: deliberately felled by developers to make room for new construction or unintentionally killed as a side effect of nearby building. Just since 2008, the tree canopy in the urban core has dropped from 28 percent to 24 percent, a loss of roughly 9,000 trees a year.
The Nashville Tree Foundation’s giveaway program — which continues through Friday — is just one of the nonprofit organization’s outreach efforts, each focused on planting trees in the poorer parts of town, which tend to have the least green space. “We’re all working toward the same goal of 500,000 trees, and we want an equitable distribution of free trees in the county,” said Ms. Sorenson. “We usually plant in areas where there’s an intersection of low canopy and low income. We’re trying to make a large impact over a short period of time.”
I learned about the tree giveaway the same way I learn about most other initiatives sponsored by nonprofits with a limited advertising budget: through social media. That’s the same way — and on the same day — I heard Erica Ciccarone’s story of the developer who cut down three ancient black walnut trees on the property line they share. What’s going up next to Ms. Ciccarone’s small house in the Wedgewood-Houston part of Nashville is a four-story duplex, and she wasn’t surprised when the builder took out the old tree closest to the monstrous new structure under construction. But there was no reason at all to take down the trees in the back of the lot.
As it happens, Ms. Ciccarone lives in an area where the tree canopy is well below its target density, but for her the loss of the black walnuts was personal. “They weren’t majestic,” she wrote in an email. “Their leaves were small and scraggly. But they provided shade for us and the chickens, housed songbirds, and they blocked the sight line from the alley into our yard and back porch.”
Her reaction is typical: When trees die, people invariably mourn. And when trees are planted, people become demonstrably happier. Rhitu Chatterjee of National Public Radio recently reported on a randomized study designed to discover the effect of urban green space on mental health. The study found that cleaning up vacant lots and planting grass and trees was associated with a significant improvement in the mental health of nearby residents: According to the report, “feelings of depression and worthlessness were significantly decreased.”
An earlier experiment by Eugenia South, one of that study’s authors, had found that merely walking past a newly planted lot in an urban neighborhood lowered the participants’ heart rates. Smaller unrelated studies have found lower blood-pressure readings and lower cortisol levels among participants who spent time in nature.
From an urban-planning perspective, trees do something of the same thing for densely occupied parts of the planet. They remove carbon, including greenhouse gas emissions, from the air. They cool the surrounding area, offsetting the heat impact of asphalt and combustion engines. They absorb and filter stormwater. They lower energy costs for nearby buildings. It’s no wonder that so many people in Nashville are worried about their trees.
When I left Plaza Mariachi last week, Ms. Sorenson was taking a photo of another family and the oak tree they had just selected for their yard. The father was holding the heavy tree, which was taller than his little girl’s head. Dressed in “Where’s Waldo?” stripes, she was lifting her hands toward it anyway, reaching high, wanting to help.
Margaret Renkl is a contributing opinion writer who covers flora, fauna, politics and culture in the American South.