723 JOURNAL OF FORESTRY 



1. Determine the approximate diameter limits to which black jack 

 and yellow pine would be cut, in conformity with the volume per unit 

 of area to be retained. 



2. Tally by diameter classes all trees which are retained and cut, 

 but which do not fall within the prescribed limits. Since the number 

 of trees which would fall outside of the diameter limits should be 

 relatively few, no very large amount of extra work should be involved. 



3. Compute the volumes of trees retained and cut outside of diame- 

 ter limits and add the balance (volumes of trees cut minus volumes 

 of those retained, or vice versa), to the estimated volume to be re- 

 tained.^ If more than the desired amount to be retained results, a 

 re-mark corresponding to the necessary reduction can be made. 



POSSIBILITY OF APPLYING METHOD" 



Obviously, the method described cannot be applied unless the com- 

 position of a stand is known. To measure a whole stand previous to 

 cutting would be the most feasible plan, but it is probably not eco- ■ 

 nomically warranted. The selection and measurement of trees on 

 typical sample plots should, however, furnish the desired data. This 

 ought to apply especially in stands of uniform density.^ 



* While no data are available to prove the assumption, it seems probable that 

 the balance resulting from cutting and retaining trees outside of the prescribed 

 diameter limits, will be small. 



"Even in the irregular stands of western yellow pine this seems to apply. 

 Comparison of composition of stands on sample plots with that of more exten- 

 sive areas shows them to be quite similar. This does not imply, however, that 

 the volumes per unit of area are the same. Neither is this to be expected, owing 

 to the large and irregular extent of unstocked area. If the composition (dis- 

 tribution of diameter classes) is the same on sample plots as on more extensive 

 areas, the essential data for the application of the described method is obtain- 

 able, because we are concerned with management on a volume rather than on an 

 area basis. 



