Page 17 - Tree Line - North Carolina Forestry Association - Fourth Quarter 2021

(Fig. 3) Producing hemlock clones from cuttings stuck in rooting media. The chamber with cover closed (below) and open (below, right) has an automated mist irrigation system and thermostatically controlled exhaust fan (not visible).
is no practical way to perpetually apply insecticides
to an entire forest, but individual trees and stands
can be temporarily protected chemically via a
number of various soil- or trunk-based application methods. Since there are no known parasites of HWA, biological control research has focused on predators and pathogens. Several predators from Asia and western North America, where HWA is considered native, have been successfully established.
The goal of the Hemlock Restoration Initiative (HRI), sponsored by the North Carolina Department of Agriculture & Consumer Services and the USDA Forest Service Forest Health Protection, is to restore both species of hemlocks to their native habitats throughout the state and to mitigate damage caused by HWA. Since its establishment, HRI has set
up hemlock conservation areas where HWA are controlled through an integrated pest management approach that uses both predators and insecticides. This approach has increased the number of trees treated on public lands through partnering with state agencies, educated landowners on how to treat and manage hemlocks, and advanced the development of other control strategies such as HWA-resistant trees and silviculture efforts.
Hemlock restoration in areas devastated by HWA requires HWA-resistant hemlocks found in nature
or genetically bred. The early work on searching
for natural resistance was done by scientists at the University of Rhode Island. After a region-wide search, they found a small stand of eastern hemlocks where many trees appeared healthy despite growing in a forest devastated by HWA for over 30 years.
Left: (Fig. 4) Successful rooted cutting.
Above: (Fig. 5) Volunteers from the Hemlock Restoration Initiative working at the facilities of the Forest Restoration Alliance.
ncforestry.org / FOURTH QUARTER 2021 15
BEN SMITH
BEN SMITH
BEN SMITH