150 PROCEEDINGS OF THE SOCIETY OF AMERICAN FORESTERS 



Pprin.l nf nniHiiP- Distance between each Average amount per 



venr cutting series- cent total stand to 



* chains. be cut each year. 



25 

 20 

 16| 

 12J 

 10 

 5 



3i 

 2J 



This may be shown diagrammatically as follows : Assuming as unit of 

 area a square section (640 acres), with an average stand of 5,000 feet, 

 board measure, per acre, a total of 3,200,000 feet for the whole section. 



In its application this method pres-upposes a careful division of the 

 cutting area into types and the notation of the areas of burns, blanks, 

 previous cuttings, young growth, and the like. The average stand per 

 acre must also be determined for each type. All these data and more 

 are already required in the timber estimate and forest description of the 

 Forest Service and in the reconnaissance estimates, maps, and descrip- 

 tions as well. 



In this method area and volume check each other e. g., knowing the 

 volume to be cut each year the requisite area can be worked over, and 

 conversely. The method facilitates and systematizes supervision and 

 administration. The marking of the trees in the selection cutting, the 

 supervision of the logging, and the inspection of the resultant regenera- 

 tion are made simple in so definitely bounded an area. 



The final result will be a segregation of the age classes, each in their 

 proportional area, with even-aged stands instead of the all-aged, or at 

 best several-storied forest, which results from the usual shelterwood and 

 selection cuttings. Thus the method leads over to a regulation of yield 

 by area according to age classes, which has come to be considered the 

 "ultima ratio" of systematic forest management. 



As to the increased menace i. e., that fire may destroy the entire re- 

 production without leaving any seed trees present to restock the area 

 it may be repeated that the increased yield will allow of more extensive 

 methods of fire protection, and that in general the practice of forestry 

 presupposes efficient fire protection, especially of young growth. 



The practical application of this method in America depends on the 

 accessibility of all parts of the tract to be logged, which means a well- 

 developed system of roads or other method of transportation. It will 

 meet with the best success on good fresh soil and with coniferous species. 

 In regenerating hardwoods such elaborate protection from storm and 

 drought is seldom necessary. 



