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): Michael S. Williams; Ken A. Cormier
    Date: 1996
    Source: Southern Journal of Applied Forestry. 20(2): 103-109.
    Publication Series: Miscellaneous Publication
    PDF: View PDF  (133.83 KB)


    Due to economic and political pressures placed on timber production, information from timber inventories needs to be broken down into information on particular value groups, which are groupings based on individual tree characteristics. Thus estimates of totals and variances need to be computed for individual value groups, all value groups combined, and any collection of value groups. A method for reporting these estimates using a variance-covariance matrix is given. This is followed by two examples of the estimation of totals and variances for value groups applied to a population comprising two strata. Poisson (3P) and sample-tree sampling are used in the first and second strata, respectively. These examples are included to highlight important estimation considerations. A worked example based on an artificial population is also given. The population for the worked example is divided into two strata, with three value groups in each stratum. 3P and sample-tree sampling are used in the first and second strata.

    Publication Notes

    • You may send email to 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.


    Williams, Michael S.; Cormier, Ken A. 1996. Composite estimation for forest inventories using multiple value groups and strata. Southern Journal of Applied Forestry. 20(2): 103-109.


    forest inventory, multiple value groups and strata, Poisson (3P), sample-tree sampling

    Related Search

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