Oregon white oak woodlands are in drastic decline — they represent only 15% of their historic range. The trees are magnificent and support a multitude of wildlife such as the acorn woodpecker, the slender-billed nuthatch and the Western gray squirrel, as well as hundreds of species of insects, including pollinators, which provide food for birds and wildlife. Even isolated mature, or “granny” oak trees in farm fields are important oases for birds (a documented 47 species) and other wildlife, providing food, shelter and nesting sites. They are habitat magnets and also an important part of our cultural heritage. On Sauvie Island, where historical data shows they were important, the District has counted 1,400 remaining oak trees. They are the foundation for a continuous wildlife corridor, to which new oaks can be added. Learn more about oaks and wildlife.
Oregon oak and associated habitats, such as oak savanna and prairie, are part of a diminishing ecosystem that was actively managed by Native Americans in our region for thousands of years. Native Americans harvested the acorns and the camas bulbs, seeds and berries found in adjacent open areas. These open ecosystems are even more endangered than oak woodlands, representing less than 2% of their previous range. Collectively, they are one of the most endangered ecosystems in North America, yet one of the most productive. There are more than 700 associated plant species. Some of the causes of habitat decline include a lack of active management and disturbance from fire and flooding, encroachment of invasive species, and outright land conversion. Harm to individual oak trees can result from tillage, compaction, paving, equipment damage, over-pruning, fertilization and competition.
Do you have native oak on your property? Here’s a primer on Native Oaks in Your Landscape.
Protecting our native white oak may involve removing some trees, particularly encroaching Douglas fir, that are preventing the oak from thriving. Thinning a wooded area will help the trees that you want to grow and provide firewood or larger logs for either your own use or to sell to a sawmill. The District can help you walk through your project, including getting the proper permits and possibly hiring a professional forester or logger to oversee and accomplish the work. We also encourage woodland owners to leave some downed logs and piles of woody debris on their property for wildlife habitat. An important part of maintaining the oak woodland may also involve removing invasive plant species, such as English ivy, spurge laurel, Armenian blackberry, or Scot’s broom, and planting native shrubs or grasses. Restoring or enhancing savanna and prairie also includes controlling invasive plants and seeding and maintaining native grasses and wildflowers.
For lots of information about conserving native white oak, see the new publication, Conserving Oregon White Oak in Urban and Suburban Landscapes.
Two wonderful videos are available from the Yamhill Watershed Stewardship Fund that give an overview of native oak in Oregon:
Oregon’s Oak: A Vanishing Legacy
Oregon’s Oak: Caretakers in Time
Click here for a fact sheet on caring for native white oak on your farmland.
And click here for a brochure on Pacific Northwest Oak Communities.
For more information on oak habitat restoration, contact Senior Conservationist Kammy Kern-Korot; kammy@wmswcd.org, or 503.238.4775, ext. 108.
For help distinguishing between native Oregon white oak and its non-native look-alike:
For more information on creating prairie or meadow habitat on a small scale, visit our Meadowscaping page.
