Quercus garryana is an oak tree species found most commonly in the Pacific Northwest, with a range stretching from southern California to southwestern British Columbia. It is commonly known as the Garry oak, Oregon white oak or Oregon oak. It is named for Nicholas Garry, deputy governor of the Hudson's Bay Company.

Description

Quercus garryana is typically of medium height, growing slowly to around and occasionally as high as , or in shrub form to tall. The trunks grow to thick, exceptionally . The bark is gray and fissured. It has the characteristic oval profile of other oaks when solitary, but is also known to grow in groves close enough together that crowns may form a canopy. The leaves are deciduous, long and 1–3 in broad, with 3–7 deep lobes on each side, darker green on top and finely haired below. They are attached to the undersides of leaves. One common species responsible for these galls is Cynips maculipennis. Another common predator is the oak twig gall wasp (Bassettia ligni), which causes dead twigs and small branches, especially near the tips of branches. Its effects are cyclic, with successive years producing highly variable amounts of oak twig die-back. Other species create other galls on stems and leaves. Shapes vary from spheres to mushroom-shaped to pencil-shaped.

Individual specimens can grow to around 500 years in age, such as those on Sauvie Island near Portland, Oregon.

The Garry Oak (Quercus garryana), also called Oregon white oak, ranges from British Columbia to California.

The latin scientific name, Quercus garryana, was bestowed by Botanist David Douglas in the early 1800's to honor his friend, Nicholas Garry, an officer in the Hudson Bay Trading Company.

The Garry oak (Quercus garryana) is one of 20 native oak species found on the Pacific Coast of Northern America, but the only native oak found in western Washington or British Columbia.

Taxonomy

Taxonomic history

David Douglas was the first non-native person to record the species. Quercus garryana is named after Nicholas Garry, who was deputy governor of the Hudson's Bay Company from 1822 to 1835 and a supporter of Douglas.

In British Columbia, the Garry oak grows on the Gulf Islands and southeastern Vancouver Island, from west of Victoria along the east side of the island up to the Campbell River area. There are also small populations along the Fraser River on the British Columbia mainland. The Garry oak is the only oak native to British Columbia, and one of only two oaks (along with the bur oak) native to western Canada.

In Washington, the tree grows on the west side of the Cascade Range, particularly in the Puget Sound lowlands, the northeastern Olympic Peninsula, Whidbey Island, the Chehalis river valley, and the San Juan Islands. It also grows in the foothills of the southeastern Cascades and along the Columbia River Gorge.

In Oregon, the tree grows on the west side of the Cascade Range, primarily in the Willamette, Umpqua and Rogue river valleys, and along the Columbia River Gorge, as well as in canyons adjacent to the gorge.

Ecology

It is a drought-tolerant tree. Older specimens are often affected by heart rot. David Douglas recorded that bears consumed them.

In British Columbia, the Garry oak can be infested by three nonnative insects: the jumping gall wasp Neuroterus saltatorius, the oak leaf phylloxeran, and the spongy moth.

Quercus garryana woodlands

Oregon white oak is the only native oak species in British Columbia, Washington, and northern Oregon. In these areas, oak woodlands are seral, or early-successional; they depend on disturbance to avoid being overtaken by Douglas-fir (Pseudotsuga menziesii). The disturbance allowing oak to persist in an area that would otherwise succeed to coniferous forest was primarily fire. Natural wildfires are relatively common in the drier portions of the Pacific Northwest where Oregon white oak is found, but fire suppression has made such events much less common. In addition, tribal histories, soil surveys, and early settlers' records indicate that deliberate burning was widely practiced by the indigenous people of these areas. Fire perpetuated the grasslands that produced food sources such as camas, chocolate lily, bracken fern, and oak; and that provided grazing and easy hunting for deer and elk. Mature Oregon white oaks are fire-resistant, and so would not be severely harmed by grass fires of low intensity. Such fires prevented Douglas-fir and most other conifer seedlings from becoming established, allowing bunch grass prairie and oak woodland to persist. Fire also kept oak woodlands on drier soils free of a shrub understory. Wetter oak woodlands historically had a substantial shrub understory, primarily snowberry.

thumb|right|Gall on Oregon white oak, Sonoma County

Oregon white oak woodlands in British Columbia and Washington are critical habitats for a number of species - plant, animal, and bryophyte - that are rare or extirpated in these areas:

  • Propertius duskywing butterfly Erynnis propertius, sole larval food plant is oak
  • Bucculatrix zophopasta leaf-mining moth, sole larval food plant is oak
  • Lewis's woodpecker Melanerpes lewis
  • Slender-billed nuthatch (subspecies of white-breasted nuthatch) Sitta carolinensis aculeata
  • Sharp tailed snake Contia tenuis
  • Western gray squirrel Sciurus griseus
  • Western tanager Piranga ludoviciana
  • Western wood peewee Contopus sordidulus
  • Western bluebird Sialia mexicana
  • Sessile trillium Trillium parviflorum
  • Banded cord-moss Entosthodon fascicularis
  • Apple moss Bartramia stricta
  • (liverwort) Riccia ciliata
  • Golden Paintbrush Castilleja levisecta

thumb|right|x160px|An Oregon white oak grove

Quercus garryana woodlands create a landscape mosaic of grassland, savanna, woodland, and closed-canopy forest. This mosaic of varied habitats, in turn, allows many more species to live in this area than would be possible in coniferous forest alone. Parks Canada states that Garry oak woodlands support more species of plants than any other terrestrial ecosystem in British Columbia. It grows in a variety of soil types, for instance, rocky outcrops, glacial gravelly outwash, deep grassland soils, and seasonally flooded riparian areas. Remaining Oregon white oak woodlands are threatened by urbanization, conversion to Douglas-fir woodland, and invasion by shrubs, both native and nonnative (Scotch broom Cytisus scoparius, sweetbriar rose Rosa eglanteria, snowberry Symphoricarpos albus, Indian plum Oemleria cerasiformis, poison-oak Toxicodendron diversilobum, English holly Ilex aquifolium, bird cherry Prunus avens). and valley oak (Q. lobata).

Conservation

Oregon white oaks and their ecosystems are the focus of conservation efforts, including communities such as Tacoma, Washington, where an Oak Tree Park has been established; Oak Bay, British Columbia, which is named after the tree; and Corvallis, Oregon, which has protected the oak savannah remnants around Bald Hill. Oak Harbor, Washington, named after the tree and home to Smith Park that contains a dense grove of mature Garry Oak trees, formed the Oak Harbor Garry Oak Society to pursue conservation of the city's namesake tree.

In Southwest Washington, significant acreages of Oregon white oaks are preserved in the Scatter Creek Wildlife Area, in sites such as the Scatter Creek Unit, which contain some of the few remaining areas of south Puget Sound prairie.

In Oak Bay, British Columbia, a fine of up to $10,000 may be issued for each Garry oak tree cut or damaged.

Uses

The mildly sweet (but perhaps unpalatable) acorns are edible, ideally after leaching. The bitterness of the toxic tannic acid would likely prevent anyone from eating enough to become ill. Although it was popularly used around the turn of the 20th century, In Washington, it has been used for aging single malt whiskey since the 2010s. Oregon white oak barrels are said to give the whiskey "burnt sugar notes, marshmallow sweetness, and a light floral character that showcases the best of the Garry oak". When used as firewood, Oregon white oak produces burned.

Notes

Explanatory footnotes

Citations

  • Flora of North America: Quercus garryana
  • Oregon White Oak (Quercus garryana)—Oregon Wood Innovation Center, Oregon State University
  • Plants of British Columbia: Quercus garryana
  • Treatment from the Jepson Manual (1993)—Fagaceae Oak Family—John M. Tucker
  • Province of British Columbia – Ministry of Environment: "Garry Oak Ecosystems"—PDF
  • Province of British Columbia – Ministry of Forests, Lands and Natural Resource Operations: Garry Oak
  • Garry Oak Ecosystems Recovery Team: Information about native plant gardening, propagation, removing invasive plants and events for beginners to professionals.
  • Oak Harbor Garry Oak Society: A nonprofit organization devoted to Garry oak conservation on Whidbey Island whose website includes helpful resources on planting and protecting Garry oaks, and contemporary news and updates on issues facing Garry oaks in the Puget Sound Region of Washington State.