Oregon White Oak (Quercus garryana)

The Oregon white oak, also known as the Gary oak, is a native oak tree to the Pacific Northwest and a keystone species to the Willamette Valley of Oregon. Their habitat extends from B.C to Southern California, mostly west of the cascades, but there are small shrubby populations and subspecies that grow east of the range as well. They grow between 80-100 feet and can live up to 500 years old. Some of the oldest living trees grow on Sauvie island, just outside of Portland along the Columbia river. Their leaves are deciduous, lobed, dark green, and slightly hairy on the underside. Like most oaks, they form catkin flowers which develop into acorns once they are pollinated. The Oregon white oak is a hub for biodiversity. Ecologically, more than 1000 different and unique species of insects, plants, fungi, and animals are supported by this tree. Standing under an oak tree for an hour you’ll see garter snakes, great horned owls, deer mouse, black tailed deer, gray squirrels, bluebirds, alligator lizards, checker spot butterflies (to name a few) all living together. They grow in early successional, fire-adapted, savannah habitat that’s wet in the winter and dry in the summer. In the Willamette valley, these habitats are/were preserved by the Kalapuya who use prescribed fire to remove understory competition and conifer encroachment for hunting and for gathering traditional foods. Allowing grasslands to flourish encouraged certain traditional plants like camas, chocolate lily, and bracken fern to thrive. As Europeans colonized the area and mandated the end of their burning practices, conifer species, like Douglas fir, began to move in and outcompete these oaks. Due to urbanization, agriculture, and the removal of native Americans from their ancestral lands, only 1% of oak savannah in the Willamette valley remains intact, and much of it is unprotected. The trees pictured above were found on Sauvie island, Oaks Bottom Wildlife Refuge, Cammassia nature preserve and in downtown Portland. If you have time to visit, I really encourage you to experience these trees in person.