Could Raleigh, proudly known as the City of Oaks, end up having much less tree cover, like Baltimore?
Though it’s not likely that Raleigh will have to rethink its New Year’s Eve drop of the giant acorn any time soon, planners and policy makers need to take steps to prevent the City of Oaks from looking like the home of “The Wire.”
That’s the bottom line of an NC State study published in the journal Ecosystems by NC State University researchers Kevin Bigsby, Melissa McHale and George Hess.
“In the Southeast, it’s easy to take tree cover for granted,” says McHale, an assistant professor of forestry and environmental sciences. “To keep the benefits of urban forests, we need to consider the reasons why we will or will not have our trees in the future.”
At a leafy 55 percent, Raleigh’s tree cover overshadows Baltimore’s 24 percent. But the gap could be closing because of trends in urban morphology—factors related to development patterns, housing density and land parcel size.
NC State researchers found that the size of land parcels was closely related to the amount of tree cover. That’s a concern for Raleigh residents, given that land is being divided into Baltimore-sized parcels for development, McHale says.
Another factor that’s related to tree cover is the amount of pervious area, ground that’s free of pavement, concrete or compacted soil that limits permeability. The age of houses was also related to tree cover.
Although both Raleigh and Baltimore are in the same climate zone, their histories are vastly different. Much of the development in Baltimore took place before World War II, a time of smaller houses and fewer cars. Raleigh, one of the nation’s fastest-growing cities, experienced a 47 percent population boom from 2000 to 2012.
With that kind of explosive growth, Raleigh will have to prioritize and plan to keep its trees, McHale says. “Otherwise, development will eat up the land and tree cover. Not only do we have to plan in advance to preserve forest cover, we also need to implement creative strategies for planting and maintaining tree canopy cover in our neighborhoods.”
Along with their beauty, trees provide shade, cooling, water filtration and carbon-scrubbing in urban areas.
“Raleigh is a city in the forest,” McHale says. “Very few cities can be described that way. It’s part of what makes this one of the nicest places to live.”