138 



LOBLOLLY OR NORTH CAROLINA PINE. 



TABLE 70. VALUE OF FULLY STOCKED STANDS OF LOBLOLLY PINE, AS SCALED BY DOYLE-SCBIBNEB 

 RULE, AT DIFFERENT AGES ON DIFFERENT QUALITY SITES AND UNDER DIFFERENT COSTS OF 

 OPERATION; AND THE PER CENT OF INTEREST ON AN INITIAL INVESTMENT OF $5 AN ACRE 

 REPRESENTED BY THIS VALUE. 



Quality I 



Quality II 



Quality III 



with different costs of operation. The less favorable the quality site, the 

 later is the age at which the maximum interest rate is attained. Like- 

 wise, as the cost of operating increases and stumpage value decreases, the 

 period at which the stand attains its maximum interest rate is post- 

 poned and the rate of interest yielded is lower. 



On Quality I site with operating costs of $11 per 1,000 feet, the maxi- 

 mum rate, 9 per cent, is obtained on the soil value of $5 an acre when 

 the stand is 30 years old ; with costs of $13 per 1,000 feet, a maximum 

 rate of 8 per cent is obtained when the stand is 40 years old ; with costs 

 of $15 per 1,000 feet, the maximum rate is 6 per cent and is attained 

 when the stand is 50 years old. 



On Quality II site the maximum interest rate on the soil value of $5 



