trees with a diameter of less than 25 cm were included. The results of photo and 
field counts are given in table 1. 
No. 
Pan 
Colour 
I. R. Colour 
Field 
1 
113 
113 
114 
111 
2 
117 
115 
118 
115 
3 
110 
112 
112 
111 
4 
108 
109 
110 
107 
5 
116 
117 
116 
114 
6 
114 
117 
119 
115 
7 
121 
124 
126 
123 
8 
112 
111 
112 
109 
9 
119 
117 
121 
117 
10 
111 
113 
114 
110 
11 
114 
115 
117 
115 
12 
103 
101 
105 
102 
Total 
1358 
1364 
1384 
1349 
Table 1. 
Crown counts on plots of one hectare 
All photo counts were conspicuously larger than the field counts. Apparently not 
all trees judged to be suppressed on the ground were invisible on the photos. 
After a two-way analysis of variance, DUNCAN’s multiple range test was applied 
to find the significant differences between counts. The results are given in 
table 2. 
Difference 
Significance 
I. R. Colour - Field 
+ 
I. R. Colour - Pan 
+ 
I.R. Colour - Colour 
+ 
Colour - Field 
+ 
Colour - Pan 
- 
Pan - Field 
- 
Table 2. 
Significant differences between crown counts