24 



YELLOW POPLAR ix TENNESSEE. 



As in the case of individual trees, the growth of trees in such stands 

 varies widely with the quality of the soil. Table 8 gives the yield per 

 acre under different conditions of growth of pure unthinnecl stands of 

 yellow poplar at different ages, in board feet from all trees 10 inches and 

 over in diameter breast-high, outside of bark, and the cord wood suitable 

 for pulp in small trees and tops. Stands which have been thinned and 

 otherwise cared for should give larger yields than shown. 



TABLE 8. Column "a" includes the saw timber from trees 10 inches and 

 over; column "b" , the cordwdpd in trees 5 to 9 inches which are too 

 small to be cut into saw timber; column "c", the cordwood in the 

 tops of trees in column "a" ; column "d", the sum of columns "V 

 and "c" ; column "c", the cordwood in column "a" converted into 

 cordwood plus columns "b" and (( c". 



30 



40 

 50 

 GO 



Poor condition of growth 



1,800 10.5 1.0 11.5 



7,920 12.0 1.8 13.8 



13,680 12.2 2.3 14.5 



18,630 11.5 3.0 14.8 



17 

 23 



28 



Graded volume tables. With the increase in the diameter of the tree 

 there is also an increase in the width of the boards which can be sawed 

 from the logs ; a decrease in the amount of sapwood on the boards, and 

 in the proportion of knots to the total width of boards and even in the 

 actual number of knots. Yellow poplar lumber increases in value as the 

 boards become wider, as the proportion of heartwood increases and as 



