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Editor's Picks

Quercus sp. Ardnamurchan Peninsula
Is Q. robur invading Q. petraea populations or is it the...
Steve Potter | Apr 17, 2025
Acorn of Quercus carduchorum
A rare species from the Zagros forests in Iran
Website Editor | Apr 17, 2025
Compton Oak in 2023
The landmark oak was found as a naturally occurring hybrid
Ricklin Brown | Apr 05, 2025

Plant Focus

The Ecology and Conservation of Quercus garryana Plant Communities in the Willamette Valley

The story of Oregon white oak (Quercus garryana var. garryana) is a story of people who are connected with nature, both benefiting and benefiting from these ecosystems. Below are links to articles and other materials that discuss Q. garryana plant communities in the Willamette Valley and the challenges they face.

Quercus garryana Marion Co., Oregon
Quercus garryana in a privately owned restoration site in Marion County, Oregon © Ed Alverson

The conifer forests of northwestern North America are renowned, but the prairies, savannas, and woodlands characterized by Oregon white oak are equally important for the diversity of plants, vertebrates, and pollinators that they support. Particularly in the lowlands located between the coastal mountains and Cascade range, oaks and associated ecosystems are located in areas with relative warm and dry climate, but also with a long history of landscape management by Native Americans. Read more

Plant Talk Images
Article published in Plant Talk, April 2005
Pre settlement Q. kelloggii Lane County, Oregon
A pre-settlement Quercus kelloggii, Lane County, Oregon, at the northern limit of its range © Ed Alverson

Descriptions from early explorers and government land survey records document the character and extent of the oak-prairie landscape in the mid-19th century when a wave of white settlement began to overtake the land. In the Willamette Valley alone there were 500,000 acres of savanna, 600,000 acres of oak or oak-conifer woodland, and 1 million acres of prairie. These habitats have since been diminished to a small percentage of their original footprint, with 90% to 98% of the original acreage lost to development, agriculture, plantation forestry, and fire exclusion. Read more

Historical vegetation of Williamette Valley
"Historical Vegetation of the Willamette Valley, Oregon,
circa 1850", article by John Christy and Ed Alverson, Northwest Science, Vol. 85, No. 2, 2011

 

The video above is an introduction to the story of oak and prairie conservation in the Willamette Valley. But the same story has played out throughout the range of Oregon white oak in the Pacific Northwest. A collaboration led by Pacific Birds and the Cascadia Prairie-Oak Partnership has developed a business plan titled “Prairies, Oaks, and People” that identifies conservation needs and costs for ecosystem restoration and recovery of endangered species. Read more

Oak Plan cover

 

are rose checkermallow, Sidalcea virgata (Malvaceae).
Quercus garryana woodland with rose checkermallow (Sidalcea asprella subsp. virgata) © Ed Alverson