66 



Studies in Forestry 



[CHAP. III. 



it is advisable to allot to timber crops grown in high forest ; 

 but so much depends in each case on the concrete conditions 

 as to climate, soil, and situation, that the figures must be 

 regarded as rough generalizations only : 



From these approximate data it will be at once apparent 

 that when mixed crops are formed of several genera, these may 

 attain their technical and financial maturity at different ages ; 

 hence it is the duty of the forester to utilize those which mature 

 soonest, by extracting them at the time of their highest 

 economic value. This is done not only with a view to obtain- 

 ing the maximum monetary returns, but also for the purpose 

 of protecting, to the greatest possible extent, the productive 

 capacity of the soil. For the realization of both of these 

 objects abundant opportunities are given during the process 

 of tending the timber-crops throughout all stages of their 

 development, to the consideration of which matter one of 

 the succeeding chapters will be devoted (see Chap. IX). 



