Figure 44. — Average net increment and commod- 

 ity drain for the 5-year period 1936-40 in board 

 feet, International]/i-inch rule, by species groups 

 and survey units. 



wood-using industries on the piedmont mus? take 

 into account supplies that often contain considerable 

 low-quality material. 



The effect of commodity drain upon species com- 

 position as well as the size and quality of standing 

 timber cannot be ascertained except through inves- 



tigations over a period of years. Observations at 

 present lead to the conclusion that in South Carolina 

 as a whole, large, high-quality trees are being cvit 

 faster than they are replaced by growth, and that 

 the volume of cull trees, particularly hardwoods, is 

 increasing proportionately. 



53 



