What's So Special About Oregon White Oaks? It’s now estimated that more than 99 percent of pre-settlement prairies and savannas in Oregon have been converted to urban areas, farms, and other developments. In addition to urban development, yet another challenge to this native tree is the spread of invasive plant species. Diversity of bird species is often higher in oak forests than in adjacent conifer forests. Oregon white oaks provide favorable habitat to a number of importa