Adequacy of bases 



The amount of cull associated with cull indicators did not 

 vary appreciably between the various study locations. Since a wide 

 geographical range was sanpled, there should be no appreciable 

 variations at other locations which were not sampled. For this 

 reason, the number of areas upon which the cull factors are based 

 is undoubtedly adequate to give true values for the cull indicator 

 factors wherever they may be applied in Southeast Alaska. 



The niimber of study trees at each area is adequate for a 

 reliable sample of cull conditions at these locations. To be 

 reliable throughout Southeast Alaska, however, flat factors probably 

 should be based on a larger number of study areas so that a more 

 intensive range of cull conditions could be included. 



It is suggested that, whenever possible, cruisers use the 

 indicator factors in preference to the flat factors. This suggestion 

 is especially applicable when a high degree of accuracy is required 

 on small areas, 



COMPUTATION PROCEDURE 



Tree classification 



>Jhen data for the cull factors were compiled, each study tree 

 was first classified in one of the following three categories: 



1. No cull indicators present, 



2. Cull indicators on only the lower bole (first 32-foot 

 log), or on only the upper bole (above the first 32-foot log). 



3. Cull indicators on both the lower and the upper bole. 



At first the trees with indicators only on the lower bole were 

 separated from those mth indicators only on the upper bole, ^'hen 

 the cull factors ^^rere computed for these two groups, we found no sig- 

 nificant difference whether indicators occurred on the upper bole or 

 on the lower bole. However, when they occurred on both the upper and 

 the lower bole, the cull was greater. 



Stump heights 



The stiomp height used in the computations was 1,5 feet (meas- 

 ured from the ground at the highest or uphill side) for trees up to 

 20,9 inches d.b.h. For all trees 21 inches d.b.h. or greater, the 

 stump height was equal to the d.b.h. to the nearest foot; that is, 

 trees 21 to 30 inches d.b.h. were allowed a 2-foot stump; trees 30.1 

 to 1;2 inches, a 3-foot stumpj and so on. 



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