Oak Savanna

Oak savannas, woodlands and woodlands with mixed oaks and conifers are found throughout the interior valleys of western Oregon. A signature feature of the Willamette Valley’s rural landscapes, Oregon white oak woodlands and savannas provide a home for one of the richest assemblages of wildlife in the west, almost 200 species ranging from birds and butterflies to small mammals and big game.

• Forty-seven breeding bird species are highly associated with oak woodlands, including acorn wood pecker, white-breasted nuthatch, chipping sparrow, and ash-throated flycatcher.
• Large oak trees with expansive canopies, generally grown in more open settings, typically have the highest habitat values with large dead branches and cavities that provide wildlife with opportunities for nesting, resting, and rearing of their young.

Present status: In the Willamette Valley, Oregon white oak woodlands and savannas have been disappearing at an alarming rate. The two most significant factors contributing to loss and alteration of oak woodlands have been clearing for development or agriculture, and invasion by conifers and dense exotic shrubs from fire suppression and grazing. More than half of the remaining oak woodlands in the Willamette Valley are now dominated by Douglas fir, and without active management, will eventually become conifer forests. An estimated 98 percent of these savanna and oak habitats are in private ownership, and less than one percent receive any formal protection. Several key sites have been protected by joint venture partners in recent years, and habitat restoration work is under way on a handful of public and private properties in the Willamette Valley.

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