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. Origin of sigmoid diameter distributions

    Share via EmailShare on FacebookShare on LinkedInShare on Twitter
    Dislike this pubLike this pub
    Author(s): William B. Leak
    Date: 2002
    Source: Res. Pap. NE-718. Newtown Square, PA: U.S. Department of Agriculture, Forest Service, Northeastern Research Station. 10 p.
    Publication Series: Research Paper (RP)
    Station: Northeastern Research Station
    DOI: https://doi.org/10.2737/NE-RP-718
    PDF: View PDF  (567.82 KB)

    Description

    Diameter distributions--numbers of trees over diameter at breast height (d.b.h.)--were simulated over 20-years using six diameter-growth schedules, six mortality trends, and three initial conditions. The purpose was to determine factors responsible for the short-term development of the arithmetic rotated sigmoid form of diameter distribution characterized by a plateau, near plateau, or bump in the mid-diameter d.b.h. classes. A distinct rotated sigmoid developed when the diameter-growth schedule dropped precipitously in the mid-diameter classes; this might reflect a decadent overstory and thrifty understory. When the initial diameter distribution was distinctly sigmoid, diameter-growth schedules characterized by slow growth in the small-diameter classes tended to maintain sigmoid characteristics. A parabolic growth trend with or without parabolic mortality, also produced moderate rotated sigmoid characteristics. Under most other growth or mortality schedules, the 20-year diameter distribution was J shaped. The results reinforce the concept that diameter distributions tend to maintain or return to the J shape particularly with respect to New England northern hardwoods.

    Publication Notes

    • Check the Northern Research Station web site to request a printed copy of this publication.
    • Our on-line publications are scanned and captured using Adobe Acrobat.
    • During the capture process some typographical errors may occur.
    • Please contact Sharon Hobrla, shobrla@fs.fed.us if you notice any errors which make this publication unusable.
    • 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

    Leak, William B. 2002. Origin of sigmoid diameter distributions. Res. Pap. NE-718. Newtown Square, PA: U.S. Department of Agriculture, Forest Service, Northeastern Research Station. 10 p.

    Cited

    Google Scholar

    Keywords

    diameter at breast height (d.b.h.), sigmoid, diameter distribution, northern hardwoods

    Related Search

    XML: View XML
Show More
Show Fewer
Jump to Top of Page