LONGLEAF PINE 
13 
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 the 
logging. 
Table 2. — Actual growth in volume of cull longleaf pine trees, left in logging, 
during the 15 years subsequent to the lumbering, on loamy sand in the 
interior coastal plain of central Louisiana 1 
Volume of trees 
Growth in 15 years 
Diameter 
of trees 
(Scribner rule) 
(1902 to 1917) 
(breast- 
height) 
1902 
1902 
1917 
Volume 
Per cent 
(based on 
volume 
in 1902) 
Inches 
Boardfeet 
Boardfeet 
Boardfeet 
Per cent 
7 
10 
80 
70 
700 
8 
20 
95 
75 
375 
9 
32 
114 
82 
256 
10 
45 
134 
89 
198 
11 
62 
157 
95 
153 
12 
83 
186 
103 
124 
13 
110 
223 
113 
103 
14 
142 
264 
122 
86 
15 
185 
315 
130 
70 
16 
235 
371 
13C 
58 
17 
300 
445 
145 
48 
18 
375 
528 
153 
41 
'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 (PL IV). 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- 
ruary, 1917, and afterwards protected. The average yearly growth 
in height of 100 saplings on each of the tracts during a period of 
two seasons before and two after the burnings, furnishes good evi- 
dence of the effect of protection. (See Table 3.) 
