Carolina Curious: Why are large trees falling down along streets in Winston-Salem?

Every October, flecks of red, gold, and orange flicker in autumn sunlight in the leafy canopies above the streets of Winston-Salem. Recently though, a listener noticed breaks in certain canopies. She asked Carolina Curious: 

“Why have so many large trees fallen over this year in Winston-Salem, especially near Robinhood Road and Reynolda Road?”

WFDD’s April Laissle took a walk with a tree expert to find the answer.

The root of the problem

For Ron Stanley, “What’s your favorite tree?” is a tough question with a two-part answer.

“Oh, mercy,” he says. “Would have to say for a species, native tree, it's eastern hemlock. And my favorite individual is probably the ancient cypress tree that I got to give a hug.”

Stanley has dedicated his life to trees, first as a forest ranger and then as an arborist and landscaper. As we walk along the Reynolda Gardens trail to Reynolda Road, his love for them comes through in the words he uses to describe the ones we pass. They’re beings, he says. And they can be wounded.

“They bleed,” he says. “I've seen it.”

When we finally make it out to the roadside, he identifies the ones towering above immediately: maples. He says the species is notorious for its inability to heal properly after limbs are cut off — a particularly unlucky trait given their location.

“There's a power line going on the backside of this whole row of maples. And they have pruned every limb off outside to keep them away from the lines, which I understand,” he says. “But as a result, you can see they're all leaning hard toward the road, which could create a hazardous situation for the drivers or pedestrians.”

Ironically, too much maintenance can put these trees at a huge disadvantage. And the ones positioned across the street along the manicured grounds of Graylyn Estate clearly get a lot of attention. 

“The grass goes right up to the base of the tree. Trees self mulch, that's how they feed themselves, they drop their leaves, they decay and they take them back up. It's a beautiful cycle,” he says. “These guys don't get the opportunity because the landscape crews come in and blow all the leaves away.”

He spots another issue below us.

“We're walking along, there's a foot trail here. The soil is severely compacted. And there’s mitigation techniques that can help with that," he says. "But in a high traffic area, it usually eventually leads to crown decline, because the roots are being killed.”

All of this may mean one thing:

“They don't stand much of a long-term chance,” he says.

Obstacles to survival

Trees on Robinhood Road may face similar issues, and these problems aren’t unique to Winston-Salem.

Dr. Robert Scheller, a professor of landscape ecology with North Carolina State University, says trees in general are facing more obstacles to survival. Extreme weather events brought about by climate change make it harder for forests to thrive — and trees in urban environments are particularly vulnerable. 

“They stand much more in isolation. And when you get a burst of downwind from either a hurricane or a thunderstorm, they're really catching the full force of that wind,” he says. “Whereas, say, a very similar tree was living in a dense forest. That collection of trees reduces the wind load on any one of the trees.”

Globalization also plays a big role, Scheller says. Increased trade means more diseases and insects are being introduced into forests that don’t have the right immunities in place. Severe weather conditions can compound the problem. 

“So when trees are stressed, let's say by drought, they have less resources available to produce defensive compounds, or sap, which will help prevent insects and diseases from attacking the tree,” he says. “And so if they have less energy to produce that they become just much more vulnerable to insects and diseases.”

The eastern hemlock, Ron Stanley’s favorite tree species, has been nearly wiped out in North Carolina by the hemlock woolly adelgid, a non-native insect first found in the state in 1995. Stanley worries about which species could be next. 

“It seems to be a steady, downward slope. It's discouraging,” Stanley says. “But I do what I can to work with the trees that have a chance and try to educate people and encourage people to treasure them and take care of them.”

That includes advising residents to mulch around the trees in their yards and to avoid over-pruning them. And Stanley says it’s possible to give trees too much love by getting too close to their bases — that could compact the soil, making it harder for roots to thrive.