156 Forestry Quarterly 



The normal forest is a model rather than a measure. It de- 

 veloped as a necessary part in the plan to work to in forest 

 regulation. 



As soon as the forest was required to furnish timber every 

 year and of a certain (obtainable) size and quality it became 

 evident that old and yotmg and middle-aged stands must all be 

 properly represented on the property. This led to the model or 

 normal forest with as many age classes as there are years in the 

 rotation, each age class occupying equal area. In this plan or 

 model the stands are generally assumed even-aged and fully 

 stocked. This is almost a necessity, to do otherwise would make 

 this extremely useful model into a perfectly useless "muddle." 

 Nevertheless it is at this point that more or less confusion comes 

 to the mind of the beginner. 



The normal forest may be, for instance: Spruce; Site II; method, 

 clear cut and plant; rotation 100 years; yield table as per Schwap- 

 pach, all stands fully stocked. This forest can be represented 

 by 100 acres, with conditions, in the fall of the year, as follows: 



One acre, planted in the spring and hence one year's growth, 

 1 acre, 1 year old; 1 acre, 2 years old; 1 acre, 3 years old; etc., up 

 to 1 acre, 100 years old. 



Here we have a combination of two quite distinct things: — a 

 mathematical arrangement of age classes based on a yearly cut 

 and a rotation agreed upon; and a silvicultural condition of each 

 stand in keeping a certain accepted standard as to site, species, 

 method and age. 



This normal forest, like the normal yield table, serves to judge 

 the actual forest. But it compares or judges it in two distinct 

 ways, namely: as to age classes, and as to the conditions of each 

 stand. Ordinarily this last condition is simply assumed, hardly 

 mentioned and therefore easily lost sight of. 



The actual forest then, when compared to the normal forest, 

 may and usually does, fail in these two distinct directions: 



1. Its age classes are not all represented, or at least not properly 

 or regularly represented (equal or equivalent areas) . 



2. The stands of the actual forest are, for the most part, not 

 in a normal condition as to growth, size and volume of timber. 



The examination required is one of survey and maps as to the 

 areas in each age class and also a study of each stand as to volume 

 and condition. 



