Growing the future, acorn by acorn

Restoring native oak woodlands in the eastern Cascade foothills

(see photos of the restoration site below)

November 2007:  A pilot project to restore an oak woodland, home to white-breasted nuthatches and western bluebirds, is taking root in the Swauk Valley in Kittitas County.

The Oregon white oak, or Garry oak, can live for 400 years and is one of the most drought-tolerant trees in Washington. Its acorns are prized food, a rich source of energy for western gray squirrels and other native wildlife. Tree cavities provide nesting places for Lewis’ woodpecker, flammulated owls, and migratory birds. It’s the only native oak in Washington, and the Swauk Valley is the northernmost outpost for the tree on the east side of the Cascade Mountains. Over the years, oak woodlands have been cleared for pasture and other human uses, but important stands remain.

Owners of the Swauk Valley Ranch have donated conservation easements on more than 1,000 acres of land surrounding Swauk Creek, and are also participating in restoration activities on areas of their ranch that are not included in the easements. That’s where this pilot project to restore five acres of oak woodlands is taking place.

Conservancy biologist Jim Evans has been working with Ranch caretaker Eric Morris to remove invasive weeds from this five-acre section and to seed it with native grasses. In the spring, volunteers will plant 1,000 seedlings grown from locally collected acorns. University of Washington graduate student Laura Blume will monitor survival of the newly planted oaks in their first year. Blume will also gather data to characterize the existing, remnant stands of oak on and around the site so that future projects in the area can be designed to replicate the characteristics of natural oak stands as closely as possible.

It will take awhile to show results, he said. In the first year or two, most of the Oregon white oak’s growth goes into its roots, not into parts you can see above ground. “In three years, we should know if the project is viable, if we’ve set the target area on a trajectory for success. It’ll be 10 years before we’ll really start seeing the beginnings of a real woodland.”

They’re aiming not for a forest, but for big, large-crowned oaks that are not crowded or limited by lack of light. Those are the trees that produce lots of acorns and create the valuable habitat for wildlife.

The goal of this pilot project is to provide a better understanding of restoration targets and techniques for east side oaks than we have now. “We’re interested in testing techniques that have been used successfully in the Puget Trough to see how they work in the drier East Cascades foothills,” Evans said.

The lessons from this project can be used in the future for restoration of oak woodlands elsewhere along Swauk Creek and in other oak habitats such as Yakima County’s Tieton River Canyon to the south.