28 BULLETIN 308, U. S. DEPARTMENT OF AGRICULTURE. 



must necessarily be made for such stands. The influence of stand 

 density upon yield in saw timber and cordwood is discussed on pages 

 35 and 36, respectively. 



Yields from fully stocked, pure shortleaf stands have been meas- 

 ured in representative regions in the Piedmont uplands of North 

 Carolina, Virginia, and central western Arkansas. In addition, a 

 few yields have been obtained in Georgia, South Carolina, and New 

 Jersey, and are interesting for comparison. 



The yield table for the Piedmont region of North Carolina (Table 

 14) is based upon the measurement of yields of 80 well-stocked 

 stands of various ages up to 80 years. It gives the yields in terms 

 of board feet saw timber, scaled both by the Doyle and the Scribner 

 rules, also cubic feet, for three different qualities of site; also the 

 number of trees per acre, and average height and diameter of the 

 trees. For logs up to 24 inches in diameter the Scribner rule gives 

 higher values, which represent more nearly the actual mill cut than 

 does the Doyle rule. The latter rule is therefore advantageous to 

 the purchaser of standing timber or logs, while it is equally dis- 

 advantageous to the seller. For example, at the age of 50 years, 

 on Quality II site, a fully stocked shortleaf pine stand, scaled to 

 include all logs 6 inches and over at the top end, yields an average 

 of 17,000 board feet by the Scribner rule, but only 9,500 feet if scaled 

 by the Doyle rule. The average size of the trees is 57 feet in height 

 by 9.4 inches in diameter, and the stand contains an average of 355 

 trees per acre, having a total cross section or basal area of 179 square 

 feet at breastheight. The cubic volume, including bark, is 4,360 

 cubic feet. Table 15 shows that at the age of 50 years, the stand 

 was increasing annually at the rate of 525 board feet per acre, or 106 

 cubic feet in total stem volume, the average yearly increase during 

 the whole life of the stand (column headed "Mean annual incre- 

 ment") was somewhat less, as might be expected — 340 board feet 

 (Scribner), 190 feet (Doyle), or 87 cubic feet per acre. 



A similar yield table (Table 16) for fully stocked pure stands of 

 shortleaf in its region of best development west of the Mississippi 

 Eiver is based upon the measurement of 38 sample plots in central 

 western Arkansas. The stands had been protected against frequent 

 fires, and the portions measured were completely stocked, so that the 

 table may be considered as representing fairly well the yields to be 

 expected from protected and managed stands. The number of plots 

 used as a basis for both Tables 16 and 17 is obviously too few, so 

 the tables are tentative, and have been included for the purpose of 

 indicating the character of second-growth stands in Arkansas, with 

 the view of later comparison and revision when additional measure- 

 ments are available. 



