12 
BULLETIN 1061, U. S. DEPARTMENT OF AGRICULTURE. 
two seasons before and two after the burnings, furnishes good evi- 
dence of the effect of protection. (See Table 3.) 
Because of the stimulus of increased light and soil 
moisture, a tree measuring 10.4 inches in diameter 
at the time of logging grew during the next 18 years 
to a diameter of 18.2 inches, an average of nearly 1 
inch in 2 years. The merchantable length increased 
from 48 to 56 feet; the merchantable volume from 
100 to 326 board feet, an average yearly increase of 
13 per cent and a total increase of 226 per cent. 
The butt log, which at the time of logging would 
have furnished a 4 by 4 stick, now yielded a 10 by 10 
timber. The value of the standing tree at $1 per 
thousand was 10 cents when it was left in logging, 
and in 1920 at $8 per thousand it was $2.60. The 
value of the lumber product of the tree increased 
from $1.70 to $14.75. 
Table 3. — Growth in height of longleaf trees from 4 to 12 feet in height, on 
lands burned yearly and on protected lands. {Berkeley County, S. C.) 
Year. 
Yearly growth in height. 
On land 
burned 
over 
yearly. 
On pro- Growth on 
tected 1 burned 
or 'Tough" land 
land ; on basis of 
(except that on 
burned in unburned 
February). land. 
1915 
Inches. 
11.8 
12.9 
15.0 
12.3 
Inches. 
19.6 
22.1 
10.2 
18.1 
Per cent. 
60 
58 
147 
68 
1916 
19171 
1918 
Total 2 
52.0 
70. 3 74 
1 
1 Fire in February. 
2 Four years. 
3 Average. 
Thus the two-year average growth of longleaf pine for 1915 and 
1916, on the land regularly burned over, was 12.4 inches as com- 
pared with 20.3 inches on the unburned land, or a growth on the 
burned land of only 61 per cent of normal. 
Following the accidental fire on the protected land, the growth 
the following season averaged only 10.2 inches, or about one-half 
the usual amount under protection; and the following or second 
