240 
strata downwards from the highest tree in each plot, according to the procedure 
described earlier. Re-classification of trees in 5 metre strata with reference 
to the highest tree in the 55 hectares was carried out prior to analysis of the 
relationship between canopy strata and stem diameters. The highest trees of 
the plots ranged from 42 to 33 metres. 
On the crown plan 5653 crowns of the 6242 enumerated trees were present. It 
may be safely assumed that the difference is made up by trees belonging to small 
diameter classes. 
DIAMETER DISTRIBUTION 
To ascertain whether the diameter distribution of the 2471 trees located on the 
aerial photographs could be considered as representative for the distribution of 
the 6242 enumerated trees, both distributions were fitted. First of all a beta 
function was applied and good fits were obtained. In both cases, however, better 
fits were offered by a negative exponential. Table 4 gives the regression 
equations and the "t"-values of the regression coefficients. 
Number of 
trees 
N 
Equation 
D = diameter in 
10 cm classes 
Degrees 
of 
freedom 
Residual 
variance 
t 
6242 
log N = 3.997632 - 
9 
0.007887 
25.64813 
2471 
- 0.217650 D 
log N = 3.560935 - 
- 0.20450 D 
9 
0. 003246 
37.66114 
Table 4. 
Regression equations for diameter distributions 
The "t"-values indicate high significance. The regression coefficients display a 
similarity in trend. The residual variance ratio is 2.42976 and is insignificant. 
It may be concluded that the distribution of the trees located on the aerial photo 
graphs is not significantly different from the distribution of the enumerated trees, 
The similarity in distribution may be demonstrated by the relative frequencies in 
table 5.