Thursday, November 13, 2008

Fires, not logging, now bigger threat to old growth

The Bulletin (Bend, Oregon): Threats to old-growth trees in the region’s federal forests have changed over the decade and a half since the Northwest Forest Plan went into effect in 1994. While logging of the big, old trees has dropped dramatically since the plan, wildfires are now consuming more acres of the valuable habitat.

That switch, reinforced by numbers from a new study by U.S. Forest Service scientists and others, means forest managers need to take action across the landscape to reduce the risk of catastrophic wildfires, according to the authors.

…Before the plan, he said, the area of large trees lost to wildfire was a small fraction of that lost to logging on federal lands. But in the decade after the plan went into effect, that flipped and wildfires caused 2.2 times as many acres of big, old trees to be lost than chain saws did.

Many scientists link the jump in fires to climate change, he said, with fires in the late 1990s and early 2000s coming as the result of a series of dry, warm years. Or it could be an episode of big fires like the state saw in earlier parts of the century, unrelated to climate change, he said.

… Logging projects in the past have actually helped make the current forests more prone to fire, he said, with crews leaving slash piles of tree limbs on the forest floor, soils damaged and dense seedlings taking the place of older, fire-resistant trees. “The forests are very different than what they once were, and it’s excessive logging that got us there,” he said….

Northwest crown fire experiment, Wikimedia Commons, via Bunk S: World on Fire. PLoS Biol 2/2/2004: e54. http://dx.doi.org/10.1371/journal.pbio.0020054. This image was published in a Public Library of Science journal. Their website states that the content of all PLoS journals is published under the Creative Commons Attribution 2.5 license.

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