The forest at Great Smoky Mountains National Park is sick, infected by invasive bugs and plants. Matt Moore, Kaleb Lique Naitove and Emily Baird of the National Park Service are some of the field medics trying to keep it alive.

“We’re out here trying to save trees,” says Moore, a seasonal forestry tech, as he steps over downed logs and through thick patches of rhododendron on the Tennessee side of Great Smoky Mountains National Park. Moore and his colleagues work on the park’s vegetation management crew, veg crew for short. They carry plastic buckets filled with their “medical supplies” — a bicycle pump, a tangle of tubing and Kool-Aid-blue and candy apple-red pesticides.

The forest they walk through is mesmerizing. The trees glow green in the Tennessee sun. There are a lot of tree species in this forest, but the one they’re looking to treat is an Eastern hemlock, an evergreen conifer that ranges from Canada to northern Mississippi. Hemlocks make up a significant portion of a lot of forests in the eastern U.S., but particularly so in Great Smoky Mountains National Park.

“One out of every five trees in the Smokies is a hemlock currently,” says Jesse Webster, head of the veg crew.

Hemlocks are hugely important to those forests and ecosystems. It is “a foundational species,” Webster says. They’re like lions, wolves or sea otters – keystone species that have an outsized impact on the ecosystem around them. Hemlocks provide a lot of shade, which means “they moderate the highs and lows of air and water temperature,” he says. By moderating those temperatures, they provide good habitat for other plant species and for birds, insects and trout.

To Tame A ‘Wave’ Of Invasive Bugs, Park Service Introduces Predator Beetles

Photos: Mike Belleme for NPR and Nathan Rott/NPR