In a city recurrently named to the Tree City USA list, and in a city with more than 23,000 trees, which are valued at more than a total $130 million, it comes as no surprise that the person managing the city's natural beauty is passionate to the point of near obsession.

"I'll never retire," said Aaron Campbell, the city of Aiken's grounds supervisor and horticulturist. "Long after the city is gone – or whatever happens – I'll do this until the day I die, in some form, some aspect."

"This is what I enjoy doing," he continued. "If it wasn't a job it would definitely be my hobby."

Campbell is charged with maintaining all of the city's 200-plus parkways, its trees, its flowers and its plants. That includes making sure things are in good health, removing dead trees, and planting new ones in their place.

It can sometimes be a heavy lift, especially in a city with "very high expectations" and when factoring in the fight against Mother Nature, he said.

But it's highly rewarding.

"I do feel like I am very lucky that I get to do for a living what I am passionate about, in that I get to work in a city that is as unique as Aiken," said Campbell, who described himself as most comfortable in "Carhartts, boots and a T-shirt."

A 2018 inventory of all the city's trees – on parkways, city-owned parcels and rights of way – found the city's most valuable tree to be worth more than $70,000. It's located at Hopelands Gardens, where Campbell got his start years ago.

Eight of the top 10 most valuable trees in the city are live oaks, according to the inventory count. However, none of the top 10 trees are located on Aiken's iconic South Boundary Avenue.

"We have the largest diversity of oaks anywhere in the country," Campbell said. "Our arboretum trail is citywide. We have a great budget for our annual flowers, so we're able to have lots of color throughout the entire city."

The city's designated arboretum trail has existed for years. The trail, highlighting some of Aiken's emerald beauties, meanders down Colleton Avenue, right near downtown. It's even interactive via a cellphone. More information about it is available online and via the city.

Aiken Mayor Rick Osbon has previously described the city's trees as landmarks.

"I certainly couldn't imagine our city without them," the mayor said at the time.

Campbell doesn't exactly recall what spurred him to enter horticulture.

"It just kind of naturally happened," he said. Whether that was a pun or not is unclear. "Even when I go home I'll read arborist magazines, and I'll read design magazines and gardening magazines. So even in my spare time I still enjoy learning and reading."

Campbell, who has worked with the city for about three years now, graduated from Clemson University in 2002 with a degree in horticulture. He's an International Society of Arboriculture arborist and is TRAQ certified.

Membership in the International Society of Arboriculture requires training and knowledge in all aspects of arboriculture; to even be eligible for the exam, one needs at least three years of full-time arboriculture working experience or a degree in arboriculture, horticulture, landscape architecture, or forestry. The recognition also comes with a code of ethics that must be adhered to.

TRAQ certification – shorthand for Tree Risk Assessment Qualified – has a lengthy list of prerequisites, as well.

And that's just the beginning.

Campbell at one point worked on research regarding military training and its affect on plants and animals. He has also owned a landscaping and design company in Charleston.

He's a Master Gardener and tries his best to attend local related events. He also works closely with Trees S.C., a nonprofit founded in 1991 that works to foster forest care by way of advocacy and education.

"I have invested a lot of time," said Campbell, who was born in Nashville, Tennessee. "I'm 42 years old, and it's taken me a long time to acquire these."

Mayor Osbon said Campbell has an "amazing skill set."

"We are fortunate to have someone of his ability and character as part of our team," Osbon said. A September 2018 Trees S.C. article portrayed Campbell as the "main 'tree guy' for the city."

Aiken City Manager Stuart Bedenbaugh had similar things to say, applauding Campbell for continuing the city's "strong legacy" of manicured foliage.

Every day is different for Campbell, who replaced Tom Rapp after his retirement. There are special projects that need to be handled, there's heat to battle against, and there's always something that can be spruced up.

His 40-hour work week is roughly split between the office and the outdoors. Being outside, he commented, is a perk unlike anything else.

"My favorite part is being able to work outdoors ... and being able to work with the diversity of the plants and the trees that we have throughout the city," Campbell said.

Being outside and doing hands-on work – "Yes, I still like to get out there and actually physically do the work," Campbell said – is something he described as therapeutic. And that is something that translates to the general public.

It only takes a quick Google search to see publications and online forums hailing the myriad benefits of outdoor work.

Studies and research suggest moods shift positively when outdoors. There's even a hypothesis drawing an innate connection between humans and the surrounding natural world: biophilia.

"You know, it really takes away a lot of the troubles in the world, it can ease your mind," Campbell said of not working behind a desk. "It's fun. ... I planted those trees over there, and when you come back years later you can see them growing."

Campbell is a member of Aiken's First Baptist Church and is on the grounds committee there. The group maintains the church's landscape.

He's the father of two boys, 6 and 2, who he often takes on hikes and on nature walks. He said his proudest moments were their births.

The accomplished horticulturist has enjoyed his time in Aiken. Beyond the city taking its landscape "very seriously," Campbell said there's something so lovable about a small city with "a lot to offer."

"You can do just about anything here," he said.

Colin Demarest covers the Savannah River Site, the U.S. Department of Energy, the National Nuclear Security Administration and government in general. Follow him on Twitter: @demarest_colin