LONGLEAF PINE. 
11 
Another example may be cited. On a tract logged "clean" in 
1903, about eight trees per acre were left as culls. They were spike- 
topped, crooked, and suppressed in growth, and averaged about 8 
inches in diameter breast high. Within 2 years these trees had started 
a rapid growth and for the next 12 years increased at the rate of 1 
inch in every 4 years. The average diameter in 1917 was 12 inches. 
At the time the trees were left they contained 226 board feet per 
acre and in 1917 a total of 803 board feet per acre, or three and one- 
half times their former volume — a gain of 250 per cent in less than 
15 years. At $5 per thousand feet, 800 board feet would bring $4, a 
sum sufficient to cover, for the entire period of 15 years, the cost of 
fire protection at 10 cents per year, reckoned at 5 per cent compound 
interest, and give a return of 5 per cent compounded on an assessed 
land value of $2 per acre. Table 2 shows the growth which actually 
took place on the cull trees during a period of 15 years following 
logging. 
Table 2. — Actual growth in volume of cull longleaf pine trees, left in logging, 
during the 15 years subsequent to lumbering; on loamy sand in the interior 
coastal plain of central Louisiana* 
Diameter 
of trees 
(breast 
height) 
1902. 
Volume of trees 
(Scribner rule). 
Growth in 15 years 
(1902 to 191'7). 
1902 
1917 
Volume. 
Per cent 
(based on 
volume 
in 1902). 
Inches. 
7 
8 
9 
10 
11 
12 
13 
14 
15 
16 
17 
18 
Board feet. 
10 
20 
32 
45 
62 
83 
110 
142 
185 
235 
300 
375 
Board feet. 
80 
95 
104 
134 
157 
186 
223 
264 
315 
371 
445 
528 
Board feet. 
70 
75 
82 
89 
95 
103 
113 
122 
130 
136 
145 
153 
Per cent 
700 
375 
256 
197 
153 
124 
103 
86 
70 
58 
48 
41 
1 Measurements by W. W. Ashe, U. S. Forest Service. 
GROWTH UNDER FIRE PROTECTION. 
Under repeated burning, growth is continually set back and 
finally most of the saplings are killed. This has, for many years, 
been occurring over practically the entire South (PI. VI). The 
yearly height growth of longleaf-pine saplings from 4 to 12 feet in 
height (mostly 6 to 8 feet) was ascertained simultaneously on a 
tract burned over yearly, and on an adjacent tract which, after 
having been protected for five years, was accidentally burned in Feb- 
ruar}', 1917, and afterwards protected. The average yearly growth 
in height of 100 saplings, on each of the tracts during a period of 
