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    Letter to the Editor

    by ArchitectureWeek

    The Tree Growth Game

    Thanks for your article "The Corruption of Wood," reviewing some of the forestry myths that prevail out here "behind the timber curtain."

    Another manipulation of forestry facts drives some misleading numbers often cited to present over-harvesting as sustainable. I call it the tree growth game. This will be part of cooking the numbers to support a return to "regen harvesting" (also known as clearcutting) by the BLM in the O&C checkerboard forest lands of Oregon.

    Here's how the tree growth game works:

    Most BLM "sustained yield" models are based on maintaining tree growth, not age classes, diameters, or stand structures. In an average Oregon growing site, well-stocked 20 to 30 year old Douglas-fir grows about three times as fast in cubic feet per acre as well stocked mature (80 to 90 year old) Doug-fir stands. This implies that in growth-balanced sustained yield, three acres of mature DF timber can be cut and balanced against an acre of advanced reproduction.

    The younger stands typically have 5 to 8 times the stems per acre of the older stands. Thus, the shop-worn industry disclaimer, "We replace six trees for every one we take", has a twisted truth if all you're doing to "sustain yield" is balancing cubic feet of biological growth.

    The biological cubic foot growth dynamic explains how pushing the BLM back into regen harvesting would allow a far larger harvest of mature timber, based on their computer-twinked sustained growth models. It also explains why BLM can only thin for so long, especially in older stands... not only does "heavy thinning" (partial harvesting) deplete older stands, it also messes-up the BLM's growth model, and reduces their future anticipated yield.

    None of the pilot units I've seen so far are focused on serious old growth. Some, however, will clearcut mature native stands like the Myrtle Creek pilot. There's no real reason to log what scant native stands remain in Myrtle Creek's fragile headwaters, since the surrounding area is crammed with oceans of early seral habitat, including "complex" by default units (unpoisoned). What's really lacking are stands like the intact unit of mature native forest pictured in the Myrtle Creek pilot.

    Roy Keene
    Public Interest Forester
    Lane County, Oregon

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    July 29, 2012, Lane County, Oregon: A recent industrial clearcut in the O&C checkerboard lands of western Oregon, runs indiscriminately over steep slopes and headwaters streams. Logging on the private industrial timberland shown here is regulated by the Oregon Forest Practices Act, which still dates back to the 1970s.

    The standing forest on the left in this photo, and in the middle distance, is on public land sections managed by the BLM. Another clearcut, on the next industrial forest land section, is visible on the skyline. Even at such a distance, the light streaks of a significant slope failure are clearly visible.
    Photo: Kevin Matthews/ArtificeImages

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