40 WORKING PLAN, FOREST LANDS IN SOUTH CAROLINA. 
The total merchantable volume for the same diameter does not vary 
ereatly for the different pines. Loblolly has a slightly greater volume 
at a given diameter than any of the other pines, and Longleaf Pine has 
generally the least. 
As explained on page 20, the volumes given for merchantable heart- 
wood and sapwood are not the actual volumes of heartwood and sap- 
wood, but the volumes which the logs scale under the specifications for 
heartwood and sapwood logs. Consequently the curves in the dia- 
grams showing the development in volume of sapwood and heartwood 
do not progress evenly. The curve for sapwood falls abruptly when 
the tree has reached a diameter such that the butt log has 8 inches of 
heart diameter at the small end and the tree no longer scales as all sap- 
wood; similarly the curve for- heartwood rises abruptly when all the 
logs begin to scale as heartwood. 
The measurements upon which the tables and curves for Pond Pine 
are based were necessarily made upon such trees as were being cut by 
the lumbermen. As only the best trees were logged, the tables and 
diagrams represent a development considerably above the average of 
the species. 
The following table and diagram (9) show the height in feet of Long- 
leaf, Cuban, and Loblolly Pine for successive 10-year periods from 
10 to 240 years: 
TABLE 15.—Height on a basis of age. 









Age. Longleaf! Cuban Loblolly | Age. Longleaf) Cuban | Loblolly 
Pine. Pine. Pine. | Fine. .|. > Pine: Pine. 
Years. EGE || Cele Feet. | Years. | Feet. | Feet. Feet. 
joer lone 6 14 19 |] © 180) “a2 100 108 
20 | 19 29 44 | 140 | 84 101 108 
30 | 30 44 65 | 150 | 86 102 109 
40 | 40 57 79 | 160 | 87 103 109 
50 | 48 67 <l2he S86 | 170 | 89 103 110 
60 | 55 75 95 | 180 90 104 110 
70 60 81 99 | 190 | 91 104 111 
80 | 65 86 102 |} 200 (| 92 105 111 
90 | 70 90 | 104 | 210 | 93 105 111 
100 | 73 93 105 | 220 94 105 112 
110 | 77 96 106 | 230 95 106 112 
120 | 79 98 107 | 240 | 96 106 112 






The rate of height growth of Longleaf Pine shows wide variation. 
Under unfavorable conditions the seedling stage is prolonged, the 
young trees requiring as much as eight or ten years to reach a height of 
1 foot. On plowed land and on good soil the growth is rapid from the 
start. Fire greatly retards the growth. Under average conditions 
the maximum height growth of the tree is between the tenth and 
twentieth years—15 to 16 inches annually. By the fiftieth year it has 
fallen to 95 inches; by the hundredth year, to 34 inches. The mean 




