VOLUME GROWTH. 



61 



Scotch pine. 

 Oak. 

 Ash. 

 Birch. 

 On the whole, conifers produce much larger volumes than 

 broad-leaved species. The accompanying diagram (p. 60) 

 will illustrate this. 



The increment laid on by an individual tree does not 



>pruce. 

 Silver Fir. 

 Uif.-h and 

 Scotch Pine. 



iO CO 70 80 

 AGE, IN' YEARS. 



100 110 120 



Fig. 4.— Diagram illustrating the Numher of Trees per Acre at Various Ages, and on 

 "" Localities of the First Quality, of Spruce, Silver Fir, Beech, and Scotch Pine. 



by itself govern the increment produced per acre, because 

 the latter is represented by the increment per tree multiplied 

 by the number of trees per acre. For instance, if an acre of 

 ground can hold 100 mature silver firs, each of which has a 

 volume of 100 cubic feet, the total volume per acre will be 



