The Environmental Journal of Southern Appalachia
Friday, 20 August 2021 12:37

Scott Schlarbaum speaks for the trees and the future of Tennessee forests

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IMG 8094Tennessee Tree Improvement Program director Scott Schlarbaum stands among a collection of grafted and cloned native trees at the program’s grafting facility off Alcoa Highway. Thomas Fraser/Hellbender Press

2-minute video on hemlock genetic diversity conservation added to this article on September 2, 2021

UT Tree Improvement Program prepares for its greatest grafting season yet

“What you have here is the future of Tennessee forests,” said Scott Schlarbaum, a professor and director of the University of Tennessee Tree Improvement Program.

You can tell from a chuckle he thinks his statement might sound hyperbolic and a bit dramatic, but it’s really not.

He gestured across an unassuming but important UT facility just off Alcoa Highway tucked within the East Tennessee AgResearch and Education Center that will be the main base for a historic tree-grafting effort that will commence this winter. 

The goal: Create trees with high-quality genetic traits ranging from wildlife and habitat qualities to timber value.

Heavy traffic hissed down the nearby highway as it passed by the modest understock yard, greenhouse, raised beds and small house containing offices used as the main grafting facility for the UT Tree Improvement Program (TIP). At least 50,000 vehicles pass by the site every day but most drivers and passengers are oblivious to the existence of this small but important outpost of forest conservation skirted by a Knox County greenway.

The Tree Improvement Program was first established in 1959. It survives as a notable exception to the cost-cutting of such projects in other states at both university and government levels.

“These days we tend to look only at the short term. UT did not.”

Beginning in January, Schlarbaum, director of the program since 1983, will oversee grafting efforts on some 3,600 trees. Last year, during which TIP efforts were disrupted by the Covid-19 pandemic, about 2,000 trees were grafted.

“We are gearing up for our biggest grafting year ever. That’s a huge deal,” Schlarbaum said.

The collection of seedlings in the understock yard awaiting grafting outside the greenhouse were transplanted from the East Tennessee State Nursery operated by the state forestry division in Delano on the Hiwassee River. The trees will be grafted with scion wood from regional trees with proven genetically superior fruit, timber and other characteristics. To close the circle, as the trees eventually flourish in orchards across the state, the seed will be available for sale to land owners or managers at the state nursery.

The program focuses mainly on hardwoods, representing oak, cherry, butternut, maple, hickory and other species ultimately destined for state and private orchards or other sites in west, middle and east Tennessee. 

That includes some species that will be part of a new orchard on Jack Daniels property near Lynchburg in Middle Tennessee. The University of Tennessee entered into an agreement with Jack Daniels distillery in 1998 to ensure the world-renowned distillery never runs out of the sugar maple and white oak crucial to its charcoal-mellowing process.

Among the understock is progeny from old historical trees, such as the massive white oak near the Native American burial mound on the UT agriculture campus, as well as the so-called Adair oak. That massive white oak, named after pioneering East Tennessean John Adair, grows in a graveyard in Fountain City. 

Some of the trees are being improved and propagated as stopgaps against the potential loss of individual species to global warming and climate change.

Overcup oak native to Middle Tennessee, which is uniquely adapted to wet habitats, is an example. It has poor timber value, but is valuable from an ecological standpoint.

“With climate change, those pockets are going to go away if there’s a drying trend.” TIP is establishing an overcup oak stand at the Jack Daniels orchard.

The bottomland plain at the Jack Daniels property also lends itself to butternut and bald cypress, both of which will likely be further stressed by regional warming trends. The butternut stands could also eventually provide some clues to resistance against a canker that has threatened the species over the last few decades.

Another short-term plan is to further establish a West Tennessee swamp white oak orchard in hopes of restoring the vanishingly rare tree to its former range.

In addition to improving and protecting native tree species for a variety of contemporary uses and reasons, TIP ensures a genetic bank of sorts exists well into the future. It’s a hedge against climate change or other threats such as exotic insects or similar invasive attacks.

Hemlock, for instance, is under an enduring threat from the hemlock woolly adelgid, an invasive insect native to China. Clones of hemlocks representing multiple East Tennessee counties are being raised at the South Knoxville facility for eventual distribution to Tennessee Valley Authority land.

IMG 8114 2These hemlock seedlings cloned by the UT Tree Improvement Program will be moved to TVA land to be preserved as a genetic reservoir should the trees be eradicated by hemlock woolly adelgid. Thomas Fraser/Hellbender Press

The viability of hemlock in the region is questionable, as evidenced by the skeletons of ancient dead hemlocks in formerly old-growth forests such as Albright Grove in Great Smoky Mountains National Park.

Thanks to the efforts of TIP there will be healthy, young hemlocks ready to replace those lost giants over time should the adelgid be vanquished.

Trees that provide ample food for wildlife are also a big goal of TIP’s enhancement efforts. 

Black cherry and wild pecan, which (relative to commercially cultivated pecan varieties) produce smaller nuts that “slide right down a turkey’s throat,” are also set for grafting next year.

The 2022 grafting effort will be labor intensive. It involves seeking out scion wood and the actual grafting, tagging and care of the trees. 

While TIP efforts are funded by a variety of sources, and enjoy the leverage of overall UT resources, Schlarbaum operates lean and mean and has grown accustomed to make do to deliver his goals.

“We run like the Marine Corps: Improvise, adapt and overcome,” he joked.

Seed and grafted trees need to be refrigerated, and when he first arrived at UT, he sought out cast-off refrigerators from the UT housing department for that purpose. Thirty-eight years later, two are still in operation.

The program is costly by a thousand cuts: TIP currently has $40,000 invested in plant containers alone (and shipping costs are a killer). Most of the program’s work — which has a “hard cash” annual budget of about $150,000 — is funded by recurring grants from independent sources, such Brown-Forman (which owns Jack Daniels) and the Shackleford Foundation. Operational and other support is also provided by TVA, the state division of forestry, and the Biology Service Facility at UT.

“We have a tremendous support network,” Schlarbaum said. “It’s not just me.”

Still, he said somewhat wistfully as birds chattered in a willow tree near the greenhouse: “I wish we could double or triple the output of this program,” he said.

He wants the program to cultivate more woody shrubs and bushes such as beauty bush that provide food and habitat for wildlife. They could then be procured, as well as traditional hardwood timber species, by landowners from the state nursery. 

A lot of forest remains, he notes, but much of that is either unproductive secondary forest or has been high-graded, meaning the largest, most mature trees have been removed.

More aggressive human intervention in the management of our remaining healthy woodlands is inevitable, Schlarbaum said, though he admits he’s fighting something of a holding action from his small outpost near the Tennessee River. 

“There’s no doubt our forest land will be decreased,” especially as people chase a tendency to live near water in prime forest. “The forest land base is shrinking because of urban sprawl,” and other development, he said, and notes additional threats to forest health from invasive species, exotic pests, and climate and habitat changes.

“If we want to maintain our wood quality and diversity of forest products, we are going to have to go to (increased) domestication.”

“When you look at history, more people mean more pressure on natural resources,” and the state of Tennessee needs a forest-protection plan and politicians and leaders with a long view to see beyond their terms in office or careers, he said.

He also wonders, just a few years from retirement, what will become of his life’s work when he’s gone, and who will carry it on. 

The traffic continued to roll by earth movers on an ever-widening Alcoa Highway and an airplane choked off the sound of birdsong as Schlarbaum returned to tend to the future of our forests.

 

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Last modified on Tuesday, 07 September 2021 15:02
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