Abstract Point samples with a basal area factor of ten are compared with standard 1/5-acre plots for basal area growth over various time periods. The ongrowth tree is defined as the tree which does not qualify for the point sample on the initial measurement but which both qualifies and is above minimum d.b.h. on the next measurement. Three different computational techniques are considered for this tree. The first considers growth on this tree equal to zero; the second includes growth on the tree since the time it qualified as being in the sample; the third includes the terminal basal area of the ongrowth as part of ingrowth. Use of the first two techniques did not cause significant differences between the plot and point sample estimates of ingrowth; but the technique of incorporating the basal area of the ongrowth tree with the ingrowth estimate resulted in significant differences. Procedures and formulae are given for computing growth estimates from permanent sample points.
Myers et al. (Sun,) studied this question.