Hemlock Guardians: Volunteers, public agencies work to save the Eastern Hemlock
A creative partnership is reducing the scourge of invasive species in the Laurel Highlands. On Tuesday, June 25, the group worked to protect eastern hemlock trees, Pennsylvania无毛视频檚 official state tree and a critical component of the region无毛视频檚 forests.
The Southern Laurel Highlands Plant and Pest Management Partnership (SLHPPMP) is a collaboration of conservation organizations and public land agency professionals. Partners include the Fayette County Conservation District, Dept. of Conservation and Natural Resources Bureau of State Parks, Pennsylvania Game Commission, National Park Service, Western Pennsylvania Conservancy, and Chestnut Ridge Chapter of Trout Unlimited.
The SLHPPMP partners assist one another in managing invasive species on public lands such as state parks, national parks (Fort Necessity and Friendship Hill), state forests, and state game lands. Invasive targets for the group have included Japanese knotweed, garlic mustard, stiltgrass, and others. Interested volunteers assist on work projects in the field. The partnership informally adopted the name 无毛视频淗emlock Guardians无毛视频� for its hemlock conservation initiative.
Hemlock is an evergreen conifer that grows along stream corridors in the Laurel Highlands. It is an important tree because nearly two dozen species of birds, some rare or declining, nest in the cover of its dense boughs. Hemlocks also provide shade to trout streams, keeping the water cool enough to support trout. In addition, hemlocks protect streams from erosion by anchoring the streambank with their roots.
无毛视频淓astern hemlocks are the very heart of the Laurel Highlands landscape,无毛视频� said Heather Fowler, watershed coordinator with the Fayette County Conservation District. 无毛视频淭hey help to create the aquatic environment for cold-water fisheries and support communities of native wildlife. Hemlocks are essential to the dramatic beauty of our tree lined streams and are a foundation of our unique Laurel Highlands ecosystem.无毛视频�
But hemlock throughout the eastern United States is under serious threat from an invasive insect pest无毛视频揾emlock woolly adelgid, often referred to as HWA.
HWA is a tiny aphid-like insect native to Asia. Sometime in the early 20th century, Asian hemlock trees were imported into the southeastern United States for landscape plantings. These imports were infested with HWA, and the pest has been spreading northward and westward toward Pennsylvania and the Laurel Highlands. Hemlocks have already suffered devastating mortality in the southern Appalachian Mountains and in eastern and central Pennsylvania.
HWA insects probe hemlock needles with their sharp mouthparts and suck out the fluid. Heavily infested trees turn gray and pallid and die within a few years.
Cold temperatures suppress HWA spread, but recent mild winters have enabled the HWA invasion to accelerate and strengthen. Laurel Highlands hemlocks have suffered noticeable decline and some loss, but the region has not yet experienced heavy hemlock mortality.
无毛视频淭he loss of hemlocks would irrevocably change the Laurel Highlands landscape,无毛视频� Fowler said. 无毛视频淚f the trees are lost, resulting gaps will allow sunlight to penetrate, where the gaps would quickly fill with invasive plant species which do not provide ecological benefit.无毛视频�
You can recognize HWA infestation on hemlocks by checking the underside of branches. If you see woolly white tufts, about the size of an upper-case 无毛视频淥无毛视频� on this page, packed along the small twigs and under the needles, you have seen evidence of HWA.
Several strategies are used to combat HWA. There is increasing optimism for the use of biological controls including the release of approved predatory beetles and silverflies that feed on HWA.
Another option is chemical pesticides. Both methods are expensive, and pesticide treatment is labor-intensive, often requiring teams to hike into remote areas carrying equipment and supplies.
Volunteers from EQT Corporation in Canonsburg and the Chestnut Ridge Chapter of Trout Unlimited supplied the labor to treat hemlock trees along a portion of Dunbar Creek on State Game Land No. 51 near Dunbar. Game Commission land management personnel, who are licensed pesticide applicators, trained and accompanied the teams of volunteers as required by law.
Twenty volunteers broke into four 5-member teams. One member measured a hemlock tree无毛视频檚 diameter with a special tape, while another counted out the appropriate number of pesticide pellets for insertion into the soil around the tree无毛视频檚 base. Some EQT and Trout Unlimited volunteers used battery-powered drills to auger holes in the soil, while others inserted and covered the pellets.
The teams protected approximately 200 hemlock trees along both sides of a mile-long span of Dunbar Creek within State Game Land 51. Plans call for treatment of more hemlock stands farther upstream in the Dunbar Creek drainage. The method provides protection to treated trees for five to seven years, allowing those trees to shed seeds for the future.
无毛视频淚 knew this is an important thing to do, especially considering the hemlock is our state tree. But it really hit me when we came across a big 无毛视频榩arent无毛视频� tree that was almost dead from the HWA attack, too far gone to treat,无毛视频� said Dennis Croft, vice-president of Chestnut Ridge Chapter of Trout Unlimited. 无毛视频淲e then realized the progeny from that tree were all around its base. Dozens of hemlock seedlings that we were able to treat with small amounts of pesticide. There is hope.无毛视频�
无毛视频淰olunteer efforts like the Southern Laurel Highlands Plant & Pest Management Partnership无毛视频檚 Hemlock Guardians program are crucial for hemlock survival here, allowing limited resources to be shared across the landscape,无毛视频� Fowler said. 无毛视频淲e are very thankful for all our volunteers and partners.无毛视频�
Work of the Southern Laurel Highlands Plant and Pest Management Partnership, and its Hemlock Guardians project is funded through the Native Plant Sale held in Ohiopyle State Park every May. Every plant purchase there supports the native ecology of the Laurel Highlands.
Ben Moyer is a member of the Pennsylvania Outdoor Writers Association and the Outdoor Writers Association of America.