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): William R. Harms
    Date: 1983
    Source: Proceedings of the Second Biennial Southern Silvicultural Research Conference
    Publication Series: Scientific Journal (JRNL)
    Station: Southern Research Station
    PDF: Download Publication  (274.0 KB)

    Description

    A flexible sigmoid function of the form S = 1/[1 + (H/Hc)0], where S is survival expressed as the ratio of number of living trees (N) to the number of trees at stand  establishment (Ni), H is mean stand height, Hc is mean height at S = 0.5, and 0 is an exponent defining the shape of the curve, was fit to a set of loblolly pine survival data cover­ing a range of densities from 1000 to 16,000 trees per acre. The equation provided an adequate fit to the data vith r2 values from 0.76 to 0.98. The estimated parameters Hc and 0 were found to be correlated to initial density. Both can be predicted satisfactorily with regressions of the form
    Hc = b0Ni b1, and 0 = b0 + bi/Ni.

    Publication Notes

    • You may send email to pubrequest@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

    Harms, Williams R. 1983. An empirical function for predicting survival over a wide range of densities. Charleston, SC. In: Proceedings of the Second Biennial Southern Silvicultural Research Conference; 1982 November 4-5; Atlanta, GA: p.334-337.

    Related Search


    XML: View XML
Show More
Show Fewer
Jump to Top of Page
https://www.fs.usda.gov/treesearch/pubs/59709