The Oregon white oaks thrive where their roots are dry.

In the Carty Unit, the Oregon white oak habitat is found on the basalt bluffs above the Columbia River floodplain where it is dry. The Oregon white oak habitat is a part of the upland woodland habitat.

The Oregon white oak trees grow in closed stands on the basalt ridge, along with open grassland. Most of the trees are mature, and many are greater than 30 inches in diameter.

The Oregon white oak (Quercus garryana) is Washington's only native oak.

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Many species depend on the Oregon white oak habitat.

Understory shrubs include serviceberry, snowberry, and ocean spray. In the spring, brightly colored wildflowers grow in the grasslands.

Species listed as sensitive, threatened, and endangered live in the Oregon white oak habitat.

Many mammals, birds, reptiles, and amphibians roost, nest, and feed in this habitat. Various moths, butterflies, gall wasps, and spiders are found only in the Oregon white oak habitat. Acorns, oak leaves, fungi, and insects provide food. Dead oaks and dead parts of live oaks provide shelter for animals and insects.

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Many factors have contributed to the decline of the Oregon white oak habitat.

Harvesting of oak trees, urban development, forest succession, cattle grazing, and fire suppression have contributed to the decline of the Oregon white oaks.

Natural fires are important to oak forest ecology, because fire initiates oak sprouting and controls the number of trees in oak stands. Managed burning can help restore degraded oak habitat.

Without management or wildfires, Oregon white oaks will be replaced by conifers, mostly Douglas-fir. Douglas-fir grows taller than the Oregon white oaks and shades them out.

Non-native plants introduced through human activity compete with native plant and animal species. The invasion of Himalayan blackberry vines into the white oak woodlands has become a threat on the refuge.

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There are two major efforts we can undertake to better preserve the Oregon white oak habitat on the refuge.

An aggressive program of blackberry vine removal will help regenerate growth of young Oregon white oak trees.

A carefully controlled nursery project for oak seedlings can produce a generation of young trees from the acorns of today's giant Oregon White Oaks.

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Galls are hollow, round shells, attached to oak stems and leaves.

Galls protect the young of an insect, which lays its egg on the oak tree. See if you can find a gall on the ground under an oak tree. Check for the tiny hole where the insect larvae came out of its "shell".