FOREST SURVEY METHOD 



A. The forest resource statistics in this report are based on a field 

 survey made during 1947 - 1949. Briefly the method used in making 

 this survey was as follows: 



1. The forest area was determined by an area sampling system 

 which involved measuring and classifying systematically 

 distributed sample segments. 



2. The timber volume was determined by measuring the trees 

 found on randomly selected one-fifth acre plots located 

 within the sample segments. 



B. The basic data from which the area and volume were determined con- 

 sisted of the following field samples: 





: Area 



: Volume 



Class 



: Number of: Area per ; 

 : sample : sample segment: 

 : segments : (acres) : 



Number of : 



• 



plots 



• 

 • 



Area per 

 sample plot 



( acres ) 



I 



522 2,560 



1,496 



' 1/5 



II & III 



106 640 



146 



1/5 



C. Distribution of the area sample segments and volume plots was con- 

 trolled by the following method. 



1. The entire area was divided on 1-inch-to-the-mile base maps in- 

 to three primary classes: 



Class I Areas predominantly forest for which aerial 

 photographs were available. 



Class II Areas predominantly nonforest for which aer- 

 ial photographs were available at moderate 

 cost . 



Class III Areas predominantly nonforest for which aer- 

 ial photographs cost more than $2 per print, 

 or for which there were no aerial photographs. 



2. Each of the three primary classes was further subdivided into 

 units in the following manner: Beginning with a random selec- 

 tion, Land Office section corners were marked on a base map at 

 4-mile intervals for areas in Class I, 7-mile intervals for 



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