Hardwood Forests

Ecology: Oregon has many species of broadleaved trees (hardwoods), but generally they occur as individuals and in small stands, rather than in expansive forests as they do in the eastern United States. As a result, hardwood forests in Oregon are not uniform, but vary by location, environment and stand history.

Oak-dominated woodlands are the principal hardwood type in Oregon and once spread across the Willamette, Umpqua, and Rogue River valleys. Oregon white oak is the principal species in the north and is joined by California black oak and canyon live oak farther south. Other common species include Pacific madrone and bigleaf maple. Historically these occurred as open woodlands, but with decades of fire suppression, many stands have been invaded by more shade-tolerant conifers like Douglas-fir and incense-cedar. When this happens, the conifers commonly outgrow and shade-out the oaks.

Many of these woodlands have been lost to agriculture and urban development.

River channels and valley bottoms (riparian systems) throughout Oregon are commonly dominated by hardwoods, but the species vary dramatically by location. Oregon ash, red alder, bigleaf maple, and black cottonwood are common throughout much of Oregon. Along the southern coast, Oregon-myrtle and golden chinkapin join the mix.

East of the Cascades, birches, willows, and cottonwoods are common. Oregon ash commonly dominates bottomlands where water stands during the winter, while cottonwoods prefer gravelly stream banks where water drain more effectively. Oregon's riparian forests are getting more attention as their vital contributions to water quality and fish habitat are better understood.

In the cold, dry climate east of the Cascades, picturesque groves of white-barked quaking aspen grow, often in wet meadows. Aspen is a species that produces new trees via root suckers; consequently, each stand may be composed of only a few clones. Wherever it grows, aspen is prized for its brilliant fall color.

Climate: The climates in which hardwood forests occur vary dramatically, from the wet, mild weather of northwestern Oregon to the warmer, drier weather of southwestern Oregon to the highly variable seasonality of eastern Oregon. Different species of hardwoods are adapted to different environmental conditions.

Management: Oregon hardwood management is small in scale, but growing in potential. Red alder is actively managed for wood production and remains an important replacement species in Douglas-fir stands with significant root rot disease. Oregon white oak, Pacific madrone, bigleaf maple, and Oregon ash all have attractive wood and find limited use as flooring and other wood products. Although not a native forest, hybrid poplar plantations are being planted in several parts of the state to help meet the demand for short-fiber pulp; some are also managed for a variety of end uses including veneer and furniture products.

Been to an oak woodland or riparian area recently? Take a virtual tour.

Oak Woodland
Riparian Area

FORESTS HOME Douglas-fir forests western hemlock/Sitka spruce forests urban forests
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