Abstract:
The purpose of this study was to examine the geometry of enclosed
circles in order to predict the probable effects of increment
boring methods used in determining basal area growth. Of specific
concern was the comparison of areas derived from sets of borings
taken from opposite sides of the tree contrasted with sets taken at
right angles to each other. A simple function for bias using opposite
borings is given. Four borings in each of 107 sample trees were
combined in several ways, and the differences between areas produced
by these combinations were statistically tested. The differences
between areas computed using opposite sets of borings were
significantly smaller than those using sets at right angles at the .01
level, and the variance of those differences was also significantly
smaller at the .01 level.
