V. ROTATION 



In planning a forest business it becomes necessary to decide 

 upon a rotation. To do this is one of the most important tasks of 

 forest regulation and requires a most careful consideration of all 

 conditions and factors concerned. Among these the most impor- 

 tant are the market, site, species and treatment. 



The market sets its requirements as to species, size and quality 

 which must be raised, and it is useless to discuss rotations which fail 

 to raise timber of the required size. Site, species, and treatment, 

 particularly practice of planting and thinning decide the length of 

 time in which the desired size and quality of timber can be raised. 

 Being largely a weighing of conditions and factors, the setting of 

 the rotation is primarily a problem in statics and perhaps the most 

 important task of statics in forestry. 



In so far as the conditions and results require expression in 

 dollars and cents, the basis for the study of a proper rotation is sup- 

 plied by forest valuation. In any ordinary forest business the aim 

 is to keep the forest and land in best possible condition and at the 

 same time make the largest income. 



Assuming the silvicultural conditions cared for, the best rota- 

 tion is the one furnishing the best income for the longest time. 



There are two distinct ways of judging this income: 



1. We may demand the largest net income per acre of estab- 

 lished forest; 



2. We may wish to secure the largest per cent on the money 

 invested in the forest or the largest net rental on the soil, the max- 

 imum Se. 



These two viewpoints have for many years divided the foresters 

 of central Europe into two schools, the division still exists and prom- 

 ises to continue for a long time. 



a. Rotation for largest net income per acre of forest. 



The assumption here is that we start with a forest and not 

 merely bare land ; that this forest is more or less regulated and able 

 to produce a yearly income. All of these conditions actually apply 

 to the majority of forest properties of central Europe. 



The following case illustrates the calculation : 



Area of forest, 16,000 acres; rotation, 80 years; age classes 

 fairly regular. From this forest we can select an 80 acres sample 



