Witham Hill Natural Area

Witham Hill Natural Area is a city park located on the Western edge of Corvallis in the Oak Creek subbasin of the Marys River watershed. Corvallis Parks and Rec completed a management plan for the natural area in 2022 where they evaluated past and present site conditions as well as their goals for future management of the park. Historically the natural area was mostly Oak Savanna with some wet and upland prairie habitats. As historic disturbance patterns ceased in the area and invasives were introduced the forest canopy has closed and invasive plants have crowded out natives.

Invasive trees in the area include bird cherry, English hawthorn, English holly, English laurel, and feral apple trees. These trees are crowding out native undergrowth and suppressing recruitment of young native trees that should growing to cycle in and replace the aging overstory. Some of the mature invasives trees are also directly competing with the Oaks for space and sunlight.

The Marys River Watershed Council is partnering with Corvallis Parks and Recreation to achieve desirable plant communities in the park. Currently we are participating in thinning the invasive trees to clear the canopy and allow for increased growth of natives. Spaces left after the invasive trees are removed allow the recruitment of young oaks and stop old growth oaks in the area from having to compete for resources and canopy space.

In the future forest planners will be able to make management and thinning decisions that encourage diverse and healthy populations of plants in the park that support healthy native ecosystems. The Watershed Council has worked with the City of Corvallis and other partners to remove invasive trees on 5.5 acres of the park, removal of fire fuels to reduce fire risk, tree ivy and scotch broom removal where necessary in the park.