GENERAL 



245 



"To obtain the coefficient of fertility of any stand in a selection (fir) forest, normally 

 stocked (that is to say, complete and carrying trees of all ages properly spaced), divide 

 the figure 40 by the average number of rings in the last centimeter of growth." 



This rule is explained by the following table : 



Another innovation in working plan description is the wide use of 

 graphics which allow a comparison between the forest at different 

 stages of its development and with average or normal conditions. An 

 example of the latest forest description follows (see also p. 532): 



