Eugene South Ridgeline Habitat Study

Upland Prairies and Rock Outcrops

Prairies are open areas dominated by grasses and wildflowers, and naturally do not contain shrubs or trees. Upland prairies were formerly common on the margins of the Willamette Valley, and on well-drained soils in other parts of the valley. More than 98% of the native upland prairies in the Willamette Valley have been converted to human uses or have been overgrown by non-prairie plant species. These prairies are among the rarest of habitat types in North America.

Like the prairies themselves, plant and animal species that live in prairie habitats are also threatened. The Fender’s blue butterfly, and its host plant, the Kincaid’s lupine, are both upland prairie species that are listed species under the federal Endangered Species Act (ESA).Like oak habitats in the Willamette Valley, upland prairies were created and in many cases maintained by periodic fires, many of which were set by Native Americans to enhance natural food sources. When these fires were suppressed with the coming of Euro-American settlers, nonfire- resistant plants were able to grow in these areas, and shade out the native prairie plants that were adapted to the fires.

Rock outcrops are unique habitats where exposed rocks provide small areas of habitat unlike any other, usually with shallow or minimal soil, and often with exposure to harsh wind and sun. These areas are inhabited by plants and animals that are adapted to these conditions, and often cannot live in any other type of habitat. In many cases, these hilltop or mountaintop features provide habitats for species that lived more widely during colder eras, and are now limited to these small hilltop habitats. Like oak habitats and prairies, these areas are susceptible to overgrowth by fast growing tree species that can shade out unique plants when fire or other natural processes are prevented. Human foot traffic is also problematic in these areas, as humans are attracted to the views these areas afford.

- Main Habitats & Wildlife Page -
- Upland Prairies & Rock Outcrops - Oak Woodlands & Oak Savannah -
- Willamette Valley Ponderosa Pine - Pileated Woodpecker & Norther Red-legged Frog -
- Habitat for Wildlife - Habitat for Rare Plants -

For more information on the South Ridgleline Habitat Study, please contact City of Eugene, Planning and Development Department
Neil Björklund, Project Manager Senior Planner, Natural Resources Specialist (541) 682-5507 Email	Jason Dedrick Associate Planner, Natural Resources Specialist (541) 682-5451 Email