Willamette Valley Upland Prairie and Savanna

This grassland ecological system is known only to the Puget Trough and Willamette Valley area. These are rare, dry, upland prairies and savannas found in the valleys and foothills of western Washington and Oregon. They are dominated by native bunchgrasses and diverse wildflowers, often with a few open and scattered trees of Oregon white oak, Douglas-fir or Ponderosa pine. In Washington and British Columbia, prairies can be found on glacial outwash areas, while in Oregon they are on deep soils and were maintained by Native American burning. Without regular burning, more and more trees come in and shade out the prairie sun-loving wildflowers. Much of these prairies have been converted to agriculture or developed for housing.For more information, see NatureServe Explorer.

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