Logging debris matters: better soil, fewer invasive plants

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New research from the U.S. Forest Service’s Pacific Northwest Research Station and authors Timoth B. Harrington and John Kirkland:

Abstract: The logging debris that remains after timber harvest traditionally has been seen as a nuisance. It can make subsequent tree planting more difficult and become fuel for wildfire. It is commonly piled, burned, or taken off site. Logging debris, however, contains significant amounts of carbon and nitrogen—elements critical to soil productivity. Its physical presence in the regenerating forest creates microclimates that influence a broad range of soil and plant processes. Researchers Tim Harrington of the Pacific Northwest Research Station; Robert Slesak, a soil scientist with the Minnesota Forest Resources Council; and Stephen Schoenholtz, a professor of forest hydrology and soils at Virginia Tech, conducted a five-year study at two sites in Washington and Oregon to see how retaining logging debris affected the soil and other growing conditions at each locale. They found that keeping logging debris in place improved soil fertility, especially in areas with coarse-textured, nutrient-poor soils. Soil nitrogen and other nutrients important to tree growth increased, and soil water availability increased due to the debris’ mulching effect. The debris cooled the soil, which slowed the breakdown and release of soil carbon into the atmosphere. It also helped prevent invasive species such as Scotch broom and trailing blackberry from dominating the sites. Forest managers are using this information to help maximize the land’s productivity while reducing their costs associated with debris disposal.

The entire study can be downloaded here.

2 thoughts on “Logging debris matters: better soil, fewer invasive plants”

  1. Actually the link above is to an article in “Science Findings” . Here’s the purpose of that publication.

    To communicate our most significant findings to people who make and influence decisions about land management, we select up to 12 projects each year to highlight in a monthly publication.

    This series, Science Findings, is available in PDF (To view and print PDF documents, you need the free Adobe Systems Inc. Acrobat Reader). We’ve recently added epub and mobi formats (You will need an ereader device or app to view these). Most issues also are available in hardcopy, although a few of the earlier ones are out of stock. If you would like copies, just contact us at [email protected]

    Here’s a link to all the other issues of Science Findings. Readers might find other topics of interest there.

    But as to this one, I plucked this photo from page 4 of the article.

    What was interesting to me looking at it was that this was where the debris was left. Not being familiar with West Side of the Cascades logging practices, I found it hard to imagine how you could remove that debris…given the size. Do they have giant rakes?

    Also I remember Jerry Franklin talking about the importance of leaving material for nutrients back in the 80’s when I worked on the Ochoco. The challenge, as I recall in that field trip discussion, was to leave enough for nutrients but not so much that fires would burn very hot close to the soil. I remember back in the day that the west side was well funded in research compared to the drier east side (at the time they were producing more boards and value) but west side lessons, as in the case of the Franklin field trip, were not so easily applied to the east side. Now that the national forests are all about biodiversity, I wonder whether the amount spent studying each side of Washington and Oregon has equalized?

    Reply

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