Oregon white oak

As many of you know from reading this blog, I have been staying in the Pacific Northwest, far from the heat and flames of my home in So Cal. I can’t say I miss the triple digit temperatures and fire, but silly as it may sound, I do miss weeding in the nature park in South Pasadena. Last weekend, however, I learned about an ecological project here on Orcas Island to restore an Oregon white oak ecosystem. Not only is the project interesting, it reassures me that there are plenty of weeds for me to attack during future visits to this beautiful place.

Oregon white oak ecosystem

Oregon white oak, Quercus garryana, is Washington’s only native oak. Its latitudinal range, though, extends more than 15° from British Columbia in Canada (~50° N) all the way down to Southern California (~34° N in Kern and northern LA Counties). Though the species is not at risk, Oregon white oak ecosystems are limited and shrinking. This is due to land development and fire suppression. In addition, ecological disruption has resulted in excessive competition from invasive species, including an overpopulation of deer. The following video describes the value of this special ecosystem and the threats it faces.

Oak restoration

The San Juan County Land Bank is working to to restore an Oregon white oak ecosystem in Turtleback Mountain Preserve. Volunteers have been removing conifers and competing nonnative weeds in an area that has older – and declining – Oregon white oaks. It appears, though, that heavy grazing due to an overpopulation of deer on the island presents a major threat to the next generation of oaks (and many other plants). Hence, after removing vegetation that shades out the mature oak trees, volunteers have been busy locating and protecting oak seedlings that appear wherever the acorns from the old oaks take root. It is hoped that the next generation of oaks will have a chance now that they are neither shaded out, nor nibbled to the ground.

As I heard the project described, I wondered why the native conifers had to be removed. I learned that for hundreds (maybe thousands) of years Native Americans regularly burned Oregon white oak, and other oak, ecosystems. Without burning, the white oak savannas would have converted to coniferous forests, and so the native peoples managed the oak ecosystems that sustained them.

The following photo gallery includes pictures from our walk with David Jordan, Dendrochronologist from Trinity Western University. David discussed his studies of tree rings and why Oregon white oak ecosystems are so special.

Old Oregon white oak

David Jordan describing what we can tell from tree “cookie”

Jordan showing tree core

Conifer and Ore. white oak grow together.

Oregon white oak sapling protected from deer grazing.

Girdling trees to make room for garry oak ecosystem.

Ailing Oregon white oak

Sprout from base of ailing Ore white oak.

I truly enjoyed the event. It was fun to learn about another interesting plant community, and I met some new “plant people” who I hope to work with in the future. A good day all around!