44 WORKING PLAN, FOREST LANDS IN SOUTH CAROLINA, 
The following table and diagram (11) show the merchantable volume 
in board feet by the Two-thirds Rule of Longleaf, Cuban, and Lob- 
lolly Pine for successive ten-year periods from 40 to 250 years: 
TABLE 17.—Total merchantable volume on a basis of age. 







mee. | Mopelent | Cuban” Tovey abe ee ee 
Years. | Board Jjeet. | Board feet. | Board feet. Years. | Board feet. | Board feet. | Board feet. 
40 | ge ae a ae as eats 110 | 150 220 410 740 
Dek Were heresy WOR ne ce 200 | 160 245 450 790 
60) Wises eceeece: 59 275 || 170 270 490 * 840 
FO wer enese gt 100 345 | 180 300 925 890. 
80 50 140 400 | 190 325 565 945 
90 | 75 180 455 || 200 355 605 1, 000 
100 100 220 500° | - 210 390 650 1, 060 
110 | 125 260 550 | 220 420 690 1, 115 
PA) 145 295 595 | 230 455 739 1,170 
130 170 335 645 || 240 485 | 775 1, 225 
140 | 195 375 | 690 250, 520 820 | 1, 280 






CYPRESS AND THE SWAMP HARDWOODS. 
Cypress must have a large and constant supply of soil moisture. 
Surface water is not essential, but the tree will not develop on situa- | 
tions where the subsoil dries out. On Cypress ponds, shallow swamps, 
and situations where the soil is subject to drying out it is small and 
unsound, and in all the high parts of the swamps gives way entirely 
to the swamp hardwoods. 
The Cypress seeds frequently and abundantly. It is tolerant, and 
young growth is fairly common in favorable situations. Seedlings 
are seldom found. It grows to large dimensions on these lands. The 
largest trees now standing are between 4 and 5 feet in diameter, but 
there are stumps which measure 8 or 9 feet in diameter. It is very 
apt to be unsound; even logs sound at both ends often turn out to be 
more or less rotten when sawed. 
The Sweet Gum is the largest and most abundant of the swamp 
hardwoods. It occurs throughout the swamps. Small trees are often 
found on moist flats which approach a swampy condition. It reaches 
its best development on soil which is always moist, standing close to 
Cypress in its power to withstand excessive moisture. The size of the 
trees falls off greatly as the edges of the swamp are approached and 
true swamp conditions fail. The Sweet Gum endures a consider- 
able amount of shade, and is one of the commonest trees in the young 
growth. 
The Black Gum is distributed in much the same manner as the 
Sweet Gum, but is much less common. It is tolerant of shade. 
Much of the lumber is unsound. 


