Oak Loss is Driven by New Urban Development in Urban Areas and Logging in Rural Areas

The Oak Prairie Work Group, established in 2012, mapped Oregon white oak (Quercus garryana) distribution from 2014-2018 within the northwest Oregon-southwest Washington Intertwine boundary and identified 110 of the largest, most important remaining oak habitat patches called “Oak Cores.” In 2024 I assessed the status of the Oak Cores using recent aerial photographs in Google Earth Pro. Twenty-two percent of Oak Cores appeared intact since we mapped oak. Nearly half (45%) exhibited some loss of less than 5%. Twenty-five percent showed moderate loss of 5-25%, 6% showed heavy loss of 25-50% and three Oak Cores in newly developing urban areas are currently being developed and would no longer qualify as Oak Cores under our original criteria. Inside the Urban Growth Boundary, new development including roads and buildings caused the highest losses. In rural areas, logging caused the highest losses, with large lot residential development, small patch tree cutting and agricultural encroachment also contributing. Getting ahead of new urban area planning, educating residents about the importance and resilience of our native oak species, and working with the timber industry to retain climate-friendly oak trees when logging could help slow these losses.