Quantitative Analysis by the Point-Centered Quarter Method

Abstract

This document is an introduction to the use of the point-centered quarter method. It briefly outlines its history, its methodology, and some of the practical issues (and modifications) that inevitably arise with its use in the field. Additionally this paper shows how data collected using point-centered quarter method sampling may be used to determine importance values of different species of trees and describes and derives several methods of estimating plant density and corresponding confidence intervals. New to this revision is an appendix of R functions to carry out these calculations.Comment: 56 pages, 12 figures, 16 tables. Corrected typos. Expanded Appendix B on Angle-Order Methods. Added Appendix D containing R functions to carry out all calculations. Added references. Original version: 34 pages, 6 figures, 16 table