Skip to Main Content
U.S. Forest Service
Caring for the land and serving people

United States Department of Agriculture

Home > Search > Publication Information

  1. Share via EmailShare on FacebookShare on LinkedInShare on Twitter
    Dislike this pubLike this pub
    Author(s): Warren D. DevineConstance A. Harrington
    Date: 2013
    Source: Forest Ecology and Management. 291: 87-95
    Publication Series: Scientific Journal (JRNL)
    Station: Pacific Northwest Research Station
    PDF: View PDF  (824.14 KB)

    Description

    In the Willamette Valley-Puget Trough-Georgia Basin ecoregion of the North American Pacific Northwest, there has been widespread encroachment of Douglas-fir (Pseudotsuga menziesii) upon Oregon white oak (Quercus garryana) savanna and woodland stands that were historically maintained by frequent anthropogenic fire. Restoration of these stands requires removal of the Douglas-fir overstory, although there is little information on how oak trees that have been suppressed for decades respond to release. Our objective was to evaluate the 10-year response of oak trees to three release treatments from overtopping Douglas-fir in a study replicated at four western Washington sites. Treatments were: full release (removal of all Douglas-fir within a radius equal to the oak's height), half release (removal of Douglas-fir within a half-height radius), and thin only (stand-level commercial thinning of the Douglas-fir overstory; oaks not targeted for release). Periodic diameter growth of oak trees in the full-release treatment was significantly greater (by as much as 243%) than that in the other treatments and increased with time since treatment. Oak height and crown area growth rates were not influenced by treatment, but larger pre-treatment crown size was associated with greater post-treatment diameter growth and acorn production. Full release increased acorn production compared to thin only in years when region-wide production was moderate to high (5 of 9 years): half release increased production relative to thin only in 2 of 9 years, but to a lesser degree. Height growth of residual Douglas-fir trees was greater than that of oak trees in all treatments. The increasing post-treatment growth rate of the fully released oak trees and their increased acorn production indicate the capacity of long-suppressed Oregon white oak to rapidly recover following complete removal of a conifer overstory. The oak trees showed no negative effects following the dramatic change in environment associated with this treatment. Thus, a single-entry, complete release from overtopping conifers was effective in restoring overstory structure and composition, which is an initial step in restoration of invaded oak woodland or savanna.

    Publication Notes

    • You may send email to pnw_pnwpubs@fs.fed.us to request a hard copy of this publication.
    • (Please specify exactly which publication you are requesting and your mailing address.)
    • We recommend that you also print this page and attach it to the printout of the article, to retain the full citation information.
    • This article was written and prepared by U.S. Government employees on official time, and is therefore in the public domain.

    Citation

    Devine, Warren D.; Harrington, Constance A. 2013. Restoration release of overtopped Oregon white oak increases 10-year growth and acorn production. Forest Ecology and Management. 291: 87-95.

    Keywords

    Oregon white oak, Quercus garryana, restoration, release, acorn production, suppression

    Related Search


    XML: View XML
Show More
Show Fewer
Jump to Top of Page
https://www.fs.usda.gov/treesearch/pubs/43712