by Julie Dodd
The eastern hemlock is one of the most common trees in the Great Smoky Mountains National Park. Called the “redwood of the east,” eastern hemlocks can grow to more than 150 feet, with trunks measuring six feet in diameter. Some of the hemlocks in the park are more than 500 years old.
Take a hike on many trails in the Smokies – especially hikes at lower elevations in the Cosby and Elkmont areas — and you’ll be hiking through hemlocks.
Not only do the hemlocks provide much of what you see in terms of forest canopy but they help keep the area cooler, regulating temperatures that support Brook Trout and some bird and animal species.
Hemlock woolly adelgid
So the attack of the hemlock woolly adelgid (HWA) in the Great Smoky Mountains National Park is a serious issue.
The hemlock woolly adelgid is a non-native species that has infected hemlocks in the Shenandoah National Park since the late 1980s and the Blue Ridge Parkway for about 10 years. As many as 80 percent of the hemlocks in those areas have succumbed to the infestation.
I talked with Holly Scott, Friends of the Smokies marketing director, about the Friends of the Smokies’ leadership in trying to save the hemlocks.
GSMNP and FOTS collaboration
Friends of the Smokies and the GSMNP have been working together since 2003 to fight the HWA and save hemlocks in the Smokies. GSMNP Supervisory Forester Kris Johnson attended the Friends of the Smokies board meeting in 2003 to explain how crucial the Friends of the Smokies’ support was to helping save the hemlocks, and the board voted to provide that support.
The GSMNP and the Friends have created the most ambitious program in the Southeast aimed at protecting the hemlocks. To date, Friends of the Smokies have invested $1.3 million in the project.
Friends of the Smokies has funded on-going treatment over the last 11 years. More than 220,000 individual trees in more than 10,000 acres and trails have been treated. Park Ranger Jesse Webster, who coordinates the GSMNP program to control the hemlock woolly adelgid, has hand-treated many of those trees himself.
Treating hemlocks with insecticidal soap or horticultural oils
Friends of the Smokies purchased a sprayer truck that can target large numbers of trees. The trees are treated with an insecticidal soap or horticultural oils. The Friends also funds the purchase of the chemicals for the spray.
The solution is applied from mounted spray units on the truck, which can reach up to 80 feet into the canopy. A total of 104 areas — including campgrounds, picnic grounds and parking lots at trailheads — have been treated.
In areas off the road or when the trees are too tall for spraying, the soil is drenched or the solution is injected directly into the trunk.
Using predator beetles
Another strategy to fight the hemlock woolly adelgid is the use of predator beetles. The Friends of the Smokies provided $150,000 in startup funding to help create the Lindsay Young Beneficial Insects Laboratory at the University of Tennessee to research the predator beetles.
The first research initiative confirmed that the predator beetles only ate hemlock woolly adelgid and not any other vegetation. Once that was confirmed, the predator beetles were reared in the lab.
A misconception that some people have is thinking that the predator beetles are the imposter ladybugs (or Asian Lady Beetles). The predator beetles are a different insect and are smaller than the head of a pin. To date, GSMNP has released more than a half million of the predator beetles. Results from the monitoring are encouraging.
[You can see the predator beetles being placed on the hemlocks in a NPS video narrated by Jesse Webster.]
The Friends of the Smokies appreciates the funding for the save the hemlock program provided by those who contributed to the effort. Special thanks to major funding from the Aslan Foundation and from Fred and Alice Stanback and Brad and Shelli Stanback.
Fighting the hemlock woolly adelgid is an ongoing effort. Hemlocks must be treated every six months, and predator beetles continue to be released in targeted areas. Those efforts are showing results in a process that is very systematic, with mapping equipment and record keeping of individual trees.
The Friends has a goal of raising $20,000 this year to continue to the efforts to save the hemlocks. You can support the program. Visit the Friends of the Smokies — and choose the “Save the Hemlocks” donation item from that page.
Friends of Great Smoky Mountains National Park, a 501 (c)(3) not-for-profit organization has been helping to preserve and protect Great Smoky Mountains National Park by raising funds and awareness and recruiting volunteers for needed projects.
Over the last 21 years, support from Friends of the Smokies members, sponsors, donors, and Tennessee and North Carolina specialty license plate owners has totaled more than $44 million. To see this year’s list of Park Support Projects visit our website at FriendsOfTheSmokies.org