Douglas-fir Forests

Ecology: Douglas-fir forests are the most extensive in Oregon; they're also the most important for timber production. Although Douglas-fir is the dominant forest tree west of the crest of the Cascades, it's also an important component of eastside forests. West of the Cascades, Douglas-fir often forms vast, nearly pure stands, a result of both natural conditions and human management. Common associates include western hemlock (the climax species for much of this region), western redcedar, noble fir, bigleaf maple, and red alder (the most common early successional species for most of this region).

East of the Cascades, common associates include incense-cedar, sugar pine, western white pine, ponderosa pine, grand fir, white fir, and western larch, depending on moisture and stand history. Understories vary from dense to sparse depending on the availability of moisture, but are generally rich in shrubs and herbs. Douglas-fir is a long-lived, early- to mid-successional species. This means that it can colonize recently disturbed sites, but continue to dominate them for hundreds of years.

Climate: Douglas-fir forests grow under a wide variety of conditions. The climate of westside Douglas-fir forests ranges from wet and mild in the north to drier and warmer in the south. Eastside Douglas-fir forests are drier than those of southwestern Oregon and have more extreme temperature fluctuations, both daily and seasonally.

Management: Prior to human management, Douglas-fir forests originated following large disturbances such as fire, landslides, and windstorms, resulting in a combination of even- and uneven-aged stands. Douglas-fir trees become commercially valuable around the age of 30 years. Over most of the west side, timber management practices such as clearcutting and shelterwood harvests followed by planting and thinning result in even-aged forests. Rotation lengths range from 30 years to hundreds of years, depending on management objectives. In drier areas like southwestern and eastern Oregon, management practices commonly include individual tree and small group selection harvests, resulting in uneven-aged stands.

FORESTS HOME Douglas-fir forests western hemlock/Sitka spruce forests urban forests
Siskiyou mixed conifer forests coast redwood forests hardwood forests ponderosa pine forests
lodgepole pine forests subalpine forests western larch forests western juniper forests