Restoring Appalachia's Park Forests: Deer, Invasive Plants and Oaks

Forests that can't replace themselves

Appalachian forests matter to ecosystems and communities in and around national parks, giving clean water and air, stable soil, recreation, scenery and habitat. But NPS forest monitoring shows eastern park forests changing fast, without enough young trees to replace canopy trees as they die.

"In a healthy forest, when a big tree falls or dies, seedlings and saplings in the forest understory grow to fill the gap in the canopy," said Kate Miller, NPS quantitative ecologist and lead author of a study finding many NPS forests are one major disturbance from forest loss. "We found most eastern National Park forests lack sufficient seedlings and saplings, so the forest can't maintain itself."

The Resilient Forest Initiative — eastern parks, Inventory and Monitoring scientists, regional biologists and Invasive Plant Management Teams — uses Bipartisan Infrastructure Law funds for integrated forest management. The first targets: too many deer and invasive plants, the leading causes of failed regeneration.

Too many deer

Eleven eastern parks are reducing white-tailed deer, and nearly as many are planning to. "With abundant habitat, the absence of predators like wolves and mountain lions, and land development that has reduced hunting opportunities, deer populations easily grow out of control," said Stephanie Perles, NPS plant ecologist. Overabundant deer strip forests of almost every native plant but mature trees, yet parks with long-term deer management have seen dramatic increases in tree seedlings.

The funding: Flight 93 National Memorial, Friendship Hill National Historic Site and Fort Necessity National Battlefield, in Pennsylvania, will plan and begin deer management, bringing densities to a level where forests can regenerate.

At Fort Necessity National Battlefield, the funds will carry out the park's strategic invasive plant plan. NPS photo.

Invasive plants

Invasive plants rush into canopy gaps and crowd out native seedlings — a growing threat. "We don't have enough resources to manage invasive plants everywhere," Perles said, "so we focus on high-priority areas of the parks where invasive plant management can be successful." An NPS prioritization tool targets the most ecologically and culturally important areas with achievable treatments.

The funding: five western Pennsylvania parks will carry out five-year strategic plans built with that tool. Youth crews, supervised by local certified foresters, will clear invasives in priority areas, aiming to cut them to a maintenance level park staff can hold. More than 25 young people will be trained in the process.

Oak forests

Oak forests cover tens of thousands of hectares of Appalachian ridgetops. More than 100 animal species rely on acorns, and oaks host more than 500 species of butterflies and moths, whose caterpillars feed songbird nestlings. But maples have been replacing oaks because of decades of fire suppression, wetter weather, lost keystone species and less flammable leaf litter. Too few oak seedlings and saplings are coming up to replace old oaks.

NPS fire ecologists track oak seedlings after a prescribed fire at New River Gorge National Park and Preserve. NPS photo.

The funding: at New River Gorge National Park and Preserve, Gauley River National Recreation Area and Bluestone National Scenic River in West Virginia, young maples cast deep shade, and "oak seedlings can't mature into saplings under dense shade," Perles said. Crews will thin small subcanopy maples to let light reach the oaks. The cut trees become snags (standing dead trees) for bats, woodpeckers and squirrels, and coarse woody debris on the ground for fungi, insects and other decomposers.

"Imminent forest loss sounds drastic and permanent, but it's not," Perles said. "We created the Resilient Forest Initiative to facilitate active forest restoration that will ensure park forests can be sustained."

Sources

Based on "NPS Resilient Forest Initiative Restores Forest Ecosystems in Appalachian National Parks," National Park Service; a work of the United States government in the public domain. Funded by the Bipartisan Infrastructure Law – Ecosystem Restoration, signed November 15, 2021.