An arborist from North Carolina had to climb an eastern hemlock in the Great Smoky Mountains National Park to confirm what had been estimated: The Laurel Branch Leviathan is the heftiest hemlock of its kind.
The Leviathan, with 1,583 cubic feet of wood, edged out an eastern hemlock in Highlands, N.C., for the title even though it is shorter. The Highlands tree, called Cheoah, stands 158.7 feet tall but has a volume of 1,564 cubic feet of wood.
It took a climb to the top of the Leviathan recently to get the accurate measurements needed.
"The only way to really know is to get up there with a measuring tape," said Will Blozan, a professional arborist from Asheville, N.C. He has been working in the park, which is headquartered in Gatlinburg but straddles the North Carolina-Tennessee border, to find and measure the giant eastern hemlocks.
Blozan has reason rushing to complete his tally.
The Smokies park has over 800 acres of old growth hemlocks, but the trees are under attack by the hemlock wooly adelgid. The aphid-like insects, pests from Asia, have devastated stands of hemlocks in Shenandoah National Park in Virginia, the Smokies and other forests in the Southeast.
"We're finding hemlocks that are pushing the boundaries of what we thought were the size limits of the species," Blozan said. "But for many, we're finding them too late."
Blozan and two assistants must climb into the trees to get the height and girth measurements needed.
"This thing is huge," Blozan said as he climbed the trunk of the Laurel Branch Leviathan in the park's Greenbrier section.
In a little less than an hour he had climbed to the top and could see the Cumberland Plateau, more than 100 miles west.
On the way back down, Blozan and his helpers took trunk measurements. At 50 feet high, the girth measured 13.4 feet, at 25 feet high it was 13.6 feet around and at a little less than five feet above the ground the trunk was 18.3 feet in circumference.
"This tree has very little taper," Blozan said. "It maintains its thick trunk."
The Laurel Branch Leviathan also may be the largest evergreen conifer in the eastern U.S., Blozan said. The bald cypress gets bigger but is deciduous.
"We are almost certain that the eastern hemlock surpasses all other native evergreen eastern conifers in sheer mass," Blozan said. "We have not yet measured a single eastern white pine to exceed 1,000 cubic feet, and 1,500 is likely impossible. Even historic records don't support a tree of such size."
The Smokies park also has the tallest eastern hemlock, measured by Blozan and his crew at 173.1 feet. It is in the park's Cataloochee section amid a tall trio Blozan calls the "Holy Grail Hemlocks."
"The old threshold for tall hemlocks was 160 feet," Blozan said. "Now we've documented 52 trees that are taller than that."
Park officials said Blozan's work helps identify areas that become high priorities for treatment to kill the hemlock wooly adelgid.
The Laurel Branch Leviathan appeared to be free of the adelgid, but park workers poured an insecticide around the base of the three which should protect it from infestation for three more years.