254 REAL AND NORMAL FOREST. 



a suitable manner, followed by efficient regeneration and 

 tending of the growing woods. More especially as regards the 

 regulation of cuttings, care must be taken that all woods which 

 have a poor increment are cut over at an early date, and 

 replaced by vigorous young woods. Next, a proper proportion 

 and distribution of age classes must be aimed at, so that each 

 wood can be cut over when ripe, without endangering thereby 

 other adjoining woods. Only in this way is it possible to 

 avoid loss of increment in the future, due to the premature 

 cutting over of vigorous woods, or to the retarded cutting over 

 of incompletely stocked or diseased woods. 



The establishment of a normal proportion amongst the 

 several age classes (or normal series of age gradations) fully 

 insures a regular sustained yield, provided the increment is 

 not interfered with. With these two conditions in the normal 

 state, the third, or growing stock, must also be normal. The 

 latter in its numerical aspect is valuable as a means to judge 

 the capacity of a forest to yield a fixed return for a certain 

 period of time ; but it seems a procedure of doubtful ex- 

 pediency to begin by establishing the numerically normal 

 state of the growing stock, because it can be reached while the 

 forest is in other respects highly abnormal. 



A forest consisting of a normal series of age gradations, and 

 worked according to the system of a sustained annual yield, is, 

 after all, nothing else but a number of age gradations, each of 

 which is worked under the system of intermittent yields ; by 

 adding together the intermittent yields of the several age 

 gradations, the sustained annual yield of the whole series is 

 obtained. It stands, therefore, to reason that the best method 

 of regulating the management of a forest is that which con- 

 siders first the special lequirements of each wood, and then 

 adds up the cuttings which have been determined on during 

 this process. In this way a healthy treatment can be insured 

 to every part of the forest, leading to a healthy treatment of 

 the whole. How this can be accomplished will be shown in 

 Part IV. of this volume. 



