Ponderosa Pine Forests

Ecology: Ponderosa pine forests are widely distributed in eastern Oregon, ranging in elevation from 2500 to 6000 feet. Ponderosa pine occurs in pure stands or may be mixed with lodgepole pine, grand fir, Douglas-fir, western larch, western white pine, incense-cedar, white fir, and quaking aspen. Volcanic pumice soils often support pure stands of ponderosa pine. Ponderosa pine is also an important component of the mixed-conifer forests of southwestern Oregon, but does not form pure stands there. The Willamette Valley of western Oregon also supports a native population of ponderosa pines.

Climate: Ponderosa pine forests are the second driest forests in Oregon; they thrive in climates with short, dry summers and cold, snowy winters. The range of these forests is closely tied to soil moisture.

Management: Fire has shaped these forests. Historically, frequent ground fires, both human-caused and natural, maintained open, park-like conditions. Fire suppression during the past 100 years has left many stands over-crowded with more shade-tolerant trees. These forests are now very susceptible to insects and fire. They can be returned to more natural and healthy conditions with a combination of thinning and fire. Removing the entire overstory can lead to extreme soil temperatures and poor regeneration, making it difficult for ponderosa pine to regenerate naturally. As a result, uneven-aged forestry is often practiced, typically with single-tree selection as the harvest technique. Ponderosa pine is prized for lumber and may other uses; its color and beauty attracts movie makers and recreationists alike for its photogenic forest scenes.

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Siskiyou mixed conifer forests coast redwood forests hardwood forests ponderosa pine forests
lodgepole pine forests subalpine forests western larch forests western juniper forests