Generalized Comparisons of the Precision Fixed-Radius and Variable-Radius Plots for Basal-Area Estimates

Sampling comparisons of fixed-radius and variable-radius plots for estimation of basal area are presented. Assumptions involving spatial distribution, diameter distribution, and stand density were made to enable generation of artificial forests. All ranges in the assumptions were based on real data encountered in the literature. Sampling was conducted simultaneously with several common plot sizes and basal area factors. Results indicate that a linear model exists relating the logarithm of the coefficient of variation of basal area estimate and the logarithm of the average number of trees sampled per location, provided certain conditions are fixed. Extension of procedures and results to other attributes of interest is discussed. Forest Sci. 17:263-271.