24 



SHORTLEAF PINE IN VIRGINIA 



increase obtained at the same age by the thinning for lumber. 

 Unless the value of cordwood increases with the diameter of the 

 wood (as it should if the wood is used for heading or stave bolts) 

 no added value per cord is secured by thinnings. 



The yield in standard cords, stem wood with' bark, of thinned 

 and. tfn thin ried stands of shortleaf pine of different ages is shown 

 in Table 5. 



Table 6 shows the approximate number of trees to the acre in 

 crowded stands of different ages, and in thinned stands. The dif- 

 ference between the number of trees in an unthinned stand and 

 in the same stand five years after it has been thinned indicates 

 approximately the number of trees which should be removed from 

 the unthinned stand. In practice, it probably would be best to 

 make two or more thinnings before reducing the number of trees 

 in an old, crowded sfand to the number in a normal, thinned stand. 



TABLE 6. 



Approximate number of trees of shortleaf pine to the acre in crowded and 



thinned stands. 



Maximum Yield of Cordwood. The maximum yield in cords 

 is obtained earlier than the maximum yield in board feet. The 

 best stands more than fifty years old give no heavier yield in cords 

 than younger stands, because they have few trees to the acre, 

 while neglected stands in which disintegregation is taking place 

 show even a decline in the volume. 



