Oak Woodland and Savanna

Since they are so slow growing, restoration focuses on protecting existing trees. They are particularly vulnerable to competition from faster-growing Douglas-fir. Historically indigenous people used low-intensity fire to prevent conifers from establishing in oak woodlands. Without this regular disturbance, Douglas-fir easily outgrows Garry oak and shades it out, slowly killing it by removing sunlight.

Ecostudies is restoring oak savanna and woodlands by:

• Removing Douglas-fir and other encroaching conifers
• Planting Garry oak saplings
• Returning regular fire to the landscape
• Restoring native understory species

Slender-billed white-breasted nuthatch (Sitta carolinensis aculeata) need large, mature Garry oaks for foraging and making nesting cavities. Where there are a limited number of large trees, we install nest boxes to support breeding. We also remove encroaching conifers to promote the growth of larger oaks that sustain more insects the nuthatches feed on.  Read more about our nuthatch monitoring efforts.

Western gray squirrels (Sciurus griseus) are endangered in Washington. While they eat a variety of foods including Douglas-fir and pine seeds, Garry oak acorns are critical for winter storage. We plant Garry oak and other native mast-producing shrubs to expand habitats and increase food supply for this species. By limiting competition from other trees, we also support larger oaks capable of producing more acorns.

Oregon vesper sparrows (Pooecetes gramineus affinis) are endangered in Washington. They have complex habitat requirements, needing patchy bare ground for foraging, some structured vegetation for nesting, and shrubs and trees for cover and perching. We are using fire to remove invasive shrubs such as Scotch broom from Garry oak and prairie habitat to foster the heterogenous landscape this species requires.  Read more about our work with Oregon vesper sparrows.