Reality check: shedding new light on the restoration needs of mixed-conifer forests, based on science.

Published online
23 Dec 2014
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Spies, T. & Merschel, A.
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USA & Oregon & Pacific Northwest States of USA


Until recently, scientific understanding of the history and ecology of the Pacific Northwest's mixed-conifer forests east of the Cascade Range was minimal. As a result, forest managers have had limited ability to restore the health of publicly owned forests that show signs of acute stress caused by insects, disease, grazing, logging, and wildfire. A recent study co-authored by a Pacific Northwest Research Station research forester revealed that the traditionally used term "mixed-conifer forest" is too broad for ecological management. The study fills a knowledge gap by providing evidence about how the pattern and timing of land-use effects in mixed-conifer forests vary with regard to topography, elevation, and climate. It specifies four major types of mixed-conifer forests in central Oregon and provides an ecological foundation for restoring each type. The study reveals that all mixed-conifer types are considerably denser than they were prior to the onset of fire exclusion in the late 1800s and suggests that the effects of fire suppression on composition and structure are most evident in the types found in warm, moist environments. It provides evidence that selective harvesting in the 20th century halved the density of large, fire-resistant pines in older forests. Findings are helping stakeholder groups come together on a shared vision for restoring mixed-conifer forests in central Oregon.

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