Research suggests Pacific Nortwest forests might not be as heathy as they look

By Eric Mortenson, The Oregonian

Pacific Northwest forests may look healthy, but their ability to sequester carbon, filter water and shelter wildlife may be declining, according to researchers at Oregon State University and the University of Washington.

In articles published in the Proceedings of the National Academy of Sciences, researchers said forests may be losing ecological, economic or cultural values beneath a "veneer" of health.

Traditional forest management practices such as timber production, clear-cutting and replanting "tend to produce young forests with uniform structures and low diversity," according to OSU summary of the research.

The researchers centered on problems in mountain ash forests of Australia, but note the same issues occur in Pacific Northwest forests, an OSU news release said.

"If you just look at a forest, it may look about the same as it used to," the news release quoted K. Norman Johnson, a professor of forest ecosystems and society at OSU. "But we're losing them without really knowing it."

The researchers particularly question logging in old-growth forests and salvage logging after fires or storms. They called for more attention to natural processes and restoration of the broad range of forest structures needed to maintain the original ecosystem. They said policies and management practices should be reassessed.

Johnson said the dry forests of Eastern Oregon are an example. In the past, frequent small fires cleared undergrowth but allowed large trees to survive. They're now crowded and prone to catastrophic fire -- after which they regrow and repeat the pattern. Allowing burned forests to recover naturally would allow growth of diverse understories and more complex forest structures, according to the news release.