88 LOBLOLLY OR NORTH CAROLINA PI.M-. 



In Cubic Feet and Cords. 



Table 35 gives the yield in cubic feet of all trees 3 inches and over in 

 diameter in fully stocked unthinned stands of loblolly pine on different 

 quality sites at different nges. This embraces only the volume of stem 

 wood without bark to a diameter of 3 inches (see foot note to Table 33). 

 The average annual increment for the entire period and for five year 

 periods is given. The basal area, showing in square feet the sum of the 

 cross sections of all trees inside the bark at breast height, is also given. 

 The basal area of stands on very dry soils often declines after 30 years ; 

 and if the basal area is measured outside the bark it declines in all 

 stands after they are 40 or 50 years old except those on the best sites.* 

 Table 36 gives the yield of stem wood of trees 6 inches and over without 

 bark. Table 37 gives the yield in cubic feet and cords of all merchantable 

 trees 6 inches and over in diameter without stump, bark and top. 



While the basal area af the wood only inside of bark increases in stands up to 100 years of age and 

 more, the baral area measured outside of the bark soon begins to decline. This is due to the propor- 

 tional greater thickness of the bark in small trees than in large ones. 



