Oak forests are home to thousands of animals and plants. NPS.
Why oaks matter
From most overlooks in the Appalachian Mountains, the green ridges rolling to the horizon are covered in oak. Oak forests support a wide range of life:
- more than 100 animal species depend on acorns as a crucial food;
- more than 500 native butterfly and moth species have caterpillars that eat oak leaves;
- all those insects feed a rich variety of birds.
Why they're in trouble
Their future is uncertain because of mesophication: across the region, forests are losing oaks to shade-tolerant, moisture-loving trees such as maples. The causes:
- decades of fire suppression;
- too many deer;
- rising regional rainfall;
- the loss of keystone animals and plants;
- less flammable leaf litter on the forest floor.
The result: too few oak seedlings and saplings to replace old oaks as they die.
The experiment
Measuring the forest's condition helps choose the right tools. NPS.
New River Gorge National Park and Preserve is testing fire and fences at two mountaintop sites:
| Site | Deer |
|---|---|
| Grandview | many — hunting has been banned in the former state park for nearly a century |
| Backus | far fewer — a long tradition of hunting |
- Baseline: ecologists counted oak and maple seedlings and measured mature trees in permanent plots. Mature oaks ruled the canopy, but maple seedlings far outnumbered oak seedlings on the ground.
- Fences: tall deer exclosures closed off 10-acre sections at each site, compared with neighboring forest left open to deer.
- Fire: in spring 2017 and 2018, wildland fire specialists set controlled burns through some fenced and some unfenced forest. The fires burned the leaf litter without harming mature trees, leaving good ground for acorns to sprout.
- Remeasurement: several years later, the same plots were measured again.
Wildland fire specialists set controlled burns to help oak seedlings. NPS.
What fire did
Fire boosted oak seedlings and cut maple seedlings only at Backus, where deer are moderate. At Grandview, where deer browse heavily stresses the oaks, fire hurt oak seedlings more than maples. The lesson: managers need to know a forest's condition before using prescribed fire.
What fences did
Fences shield seedlings and other sensitive plants from deer. NPS.
- Tree seedlings: four years on, there were six times more seedlings taller than 1 foot inside the fences than outside — the canopy trees of the future, if they grow tall enough to escape deer.
- Wildflowers: deer favorites such as cucumber root (Medeola virginiana), bellwort (Uvularia spp.) and fairybells (Prosartes spp.) were more common inside. These plants matter: Appalachian oak forests hold six forest-floor plant species for every one canopy tree species.
Cucumber root, a deer favorite, flowering inside an exclosure. NPS.
What happens next
The study shows how controlled burns and deer browsing shape tree regeneration and plant diversity. Park managers, forest ecologists and fire specialists keep monitoring the sites and using more controlled burns to grow the next oak forest.
More: the published study and the oak regeneration project on IRMA. Contact: Stephanie Perles, plant ecologist, National Park Service.
Sources
Based on "Protecting Oak Forests in National Parks," New River Gorge National Park and Preserve, National Park Service; a work of the United States government in the public domain.
In these publicationsNew River Gorge National Park & Preserve
Licence: CC0 1.0 (public domain) · Adapted from www.nps.gov
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