14 THE PRINCIPLES OF HANDLING WOODLANDS 



those areas which are to be held permanently for forest 

 use should be managed in such a way that the production 

 by yearly growth will not be progressively reduced, but 

 will at least be maintained. If by failure to provide for 

 replacement, or through destructive fires, the productive- 

 ness of the forest is constantly decreasing, there will ulti- 

 mately be little or no forest at all; and that is exactly what 

 is happening in many places under the present methods. 

 If, on the other hand, there is a provision for new growth 

 and a conservative handling of growing timber, so that 

 the growth equals that which produced the present stand, 

 the forest's productiveness is not decreasing, even if it 

 does not approximate what might be secured by a larger 

 outlay of money. 



This measure of production is a very easy matter to 

 determine if it is based on the mean annual growth of .the 

 forest. If, for example, the first forest is 200 years old 

 and yields 10,000 board feet to the acre, the annual 

 growth is 50 board feet. In this case, if the forest is 

 handled so that the mean annual growth of the next 

 crop will be 50 feet, it falls within what may be called 

 the dividing line between forestry, or a system of main- 

 taining forest production, and exploitation, in which 

 there would be a constant lowering of the yield. It may 

 be said, however, that on account of the small yield of 

 the virgin forest compared with what might be produced 

 under forestry, such a return is exceedingly low. Any 

 system that does not produce at least 100 feet per acre 

 per annum is decidedly poor forestry. But between this 



