Saving a Keystone Species: Hemlock Restoration on the Grandfather RD

Introduction of the invasive Hemlock Woolly Adelgid (HWA) to the Eastern US has wreaked havoc on the native hemlock species, leading to range-wide declines and total loss of hemlocks in many areas in the Southern Appalachians. In late October, the Grandfather Restoration Project collaborative group got together for a fieldtrip to explore potential for expanded work on hemlocks. This includes both treatments of Hemlock Woolly Adelgid (HWA), which have been taking place on the district for close to a decade, and hemlock restoration, which is a new concept both for the Grandfather Ranger District, and throughout the range of Eastern and Carolina hemlock.

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Collaborative members discuss hemlock restoration along the Kitsuma trail

Joining us on this trip were 3 of the leading experts in hemlock research in the Southern Appalachians.

Chelcy Miniat, Research Project Leader from Coweeta Hydrological Laboratory, presented on the hydrological impacts of hemlock loss. Hemlocks provide an important role in riparian forests, regulating stream flow and shading streams from winter sun. As hemlocks die, they are generally replaced by rhododendron, and to a lesser extent water-loving hardwood species. This replacement has been found to lead to higher stream flows in the winter, and lower flows in the summer. Chelcy and her team also tested the effectiveness of the manufacturer recommended treatment dosages for imidacloprid, the main pesticide used to treat HWA on helmocks. Her research determined that the recommendations under-treated large trees, a finding that our silviculturalists can use in their management of HWA.

Bud Mayfield, Research Entomologist at the Southern Research Station in Asheville, spoke about current research on predator beetles that feed on HWA. These predator beetles provided a non-chemical treatment option, and are an important part of an integrated pest management approach to HWA treatments. The predator beetles Bud studies, a species called Laricobius nigrinus, are native to the Pacific Northwest. Compared to other potential predator beetles, they have a higher tolerance for cold Southern Appalachian winters. While predator beetles alone cannot keep up with the adelgid infestations alone, Bud’s research found that combining chemical HWA treatments with predator beetles allowed treatments to be effective longer, reducing the amount of pesticides used.

Robert Jetton, Research Professor at NC State University and Hemlock Project Leader at CAMCORE presented on species conservation efforts. CAMCORE, a non-profit tree conservation organization, has been collecting seeds from Carolina and Eastern hemlock populations in the Southern Appalachians for over a decade. With seeds in cold storage from hemlock populations across the Grandfather Ranger District, CAMCORE provides a seed bank repository for the Forest Service to be used in replanting the species. In addition to seed conservation, Robert is starting work with the US Fisheries and Wildlife Service to map all existing Carolina hemlock populations in order to more fully understand the distribution of the species and its conservation needs.

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Treated Carolina Hemlocks along the Kitsuma trail

The collaborative also discussed current and future hemlock work on the Grandfather. Currently, we are treating Eastern hemlock trees that remain alive on the district, and are working to expand Carolina hemlock treatments with the help of CFLR funding. When treating mature hemlocks, young trees within a 10 meter radius of the treated mature tree also benefit from the effects of the pesticide treatment. However, beyond the ambient effect of treatments on regrowth nearby, there is little chance for young hemlocks to reach the over story, as HWA infests both young and old trees. Thus, planting of hemlocks was discussed as an option to supplement this new generation of hemlocks.

Eastern Hemlocks are considered a keystone species in stream-side areas, where they provide habitat for a variety of wildlife species. Unfortunately, there are no substitute evergreen tree species that grow in the streamside zones that Eastern hemlock occupies in the Southern Appalachians. So, even though there are no existing resistant varieties of Eastern hemlock, planting native Eastern hemlocks back into areas that we are currently treating, and committing to a long-term treatment plan for those hemlocks, is a viable option to ensure the persistence of the species and its role in the ecosystem. The members of the Grandfather Restoration Project are just starting to look at options for hemlock restoration plantings, and will be forming a sub-committee to discuss desired conditions and methods for restoration with minimal vegetation disturbance. We are excited to be working with the research community to take the first steps toward restoring this important keystone species on the Grandfather Ranger District!

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Japanese weed a growing problem at Wilson Creek

The Grandfather Restoration Project has been highlighted in the news once again! A story detailing the invasive species work being done at Wilson Creek was featured on the front page of the Sunday edition of the Lenior, NC Newspaper, The Lenior News Topic.

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“In the 1920s, Bill Crump ordered a packet of seeds from a Sears Roebuck catalog to help him stave erosion after a flood washed through his woodworking mill in Cary’s Flat, near the headwaters of Wilson Creek.

In the 70 years since then, the plant that grew from those seeds, Japanese knotweed, has multiplied exponentially, migrated down the creek and taken up residence along uninhabited stream banks.

Today, what was supposed to be a fix has become a big problem for the ecology in the Wilson Creek area.”

The story brings attention to the Japanese knotweed overtaking the Wilson Creek Corridor, and highlights both the work of the NC Wildlife Resource Commission and the US Forest Service.

Read the full article on the newspaper’s website here: Japanese Weed a Growing Problem at Wilson Creek

Japanese Knotweed: Wilson Creek’s Most Unwanted Invasive Species

The Wilson Creek Wild and Scenic River corridor in Caldwell County is a priority area for non-native invasive species treatments under the Grandfather Restoration Project. One of the most prevalent and destructive invasive species along the river is Japanese knotweed (Reynoutria japonica), which takes over riparian areas, competing with native vegetation and reducing the quality of trout habitat in the waters of Wilson Creek. First planted on private property in the early 1900’s for erosion control, the Japanese Knotweed can now be found throughout the Wilson Creek area.

Volunteers work to remove Japanese Knotweed from riparian areas along Wilson Creek

Volunteers work to remove Japanese Knotweed from riparian areas along Wilson Creek

Wilson Creek has mixed ownership, with Forest Service lands in the headwaters and downstream. Treating Japanese knotweed only on Forest Service property would not accomplish the objectives of the Grandfather Restoration Project, as plants would continue to wash downstream from private property. In order to fully eradicate Japanese knotweed from the river corridor, it is critical that individual property owners work with the Forest Service to properly treat infestations on their portion of the river.

In order to educate both private property owners and the visiting public about Japanese knotweed, the Grandfather Restoration Project has posted flyers throughout the area that highlight the species as Wilson Creek’s Most Unwanted Invasive Species. Already, several property owners, including the Wilson Creek Visitors Center run by the non-profit organization “Friends of Wilson Creek”, have expressed interest in controlling the species on their riverfront properties. With the help of these private landowners, as well as the North Carolina Wildlife Resources Commission, the Grandfather Restoration Project hopes to eradicate Japanese knotweed from the area by 2017.