34 
BULLETIN 244, U. S. DEPARTMENT OF AGRICULTURE. 
in basal area at breast height was 75.4 per cent, the largest 311 per 
cent, and the average for 7 representative trees was 171.4 per cent 
over their former rates of growth. The trees ranged from 45 to 101 
years old at the time of the logging, but most of them were between 
60 and 70 years. Since height growth was mainly complete at this 
age, it is perfectly safe to say that the volume increment of the trees 
took place at approximately the same or possibly at a somewhat 
greater rate, because of the greater increase in the size of the upper 
part of the stem at this age. 
Table 13. — Comparative groivth of shortleafin Jive-year periods before and after logging. l 
Age at 
time of 
logging. 
Increase in basal area (breast height). 
Five-year periods prior to logging. 
Five- 
year 
period 
after 
logging. 
1908-1912. 
Rate of 
increase 
Tree No. 
1883-1887 
1888-1892 
1893-1897 
1898-1902 
1903-1907 
since 
logging 
over pre- 
vious 
five-year 
periods. 
1 
45 
57 
65 
65 
69 
69 
101 
Sq. in. 
4.2 
2.0 
4.6 
1.7 
4.5 
3.2 
5.8 
Sq. in. 
4.9 
6.2 
7.2 
3.6 
9.5 
10.1 
6.0 
Sq. in. 
5.6 
13.0 
7.8 
3.9 
10.5 
8.2 
6.3 
Sq. in. 
6.5 
8.1 
5.6 
6.3 
8.6 
11.8 
6.5 
Sq. in. 
8.2 
6.8 
8.8 
6.9 
6.0 
12.8 
6.8 
Sq. in. 
14.4 
12.4 
15.8 
24.0 
16.1 
52.7 
18.0 
Per cent. 
75.4 
2 
83.0 
3 
80.3 
4 
247.9 
5 
166.6 
6 
311.2 
7 
165.9 
Average 
67 
3.7 
6.8 
7.9 
7.6 
8.0 
21.9 
171.4 
1 Typical shortleaf stand cut 5 years ago to an approximate diameter limit of 14 inches in average quality 
site in western Arkansas. 
CAUSES OF INJURY. 
FIRE. 
The damage to forest growth caused by fire far exceeds the com- 
bined effect of all other injurious agencies. At the same time, this 
cause of injury is the most susceptible to control of man. The annual 
burning of the forest floor, extensively practiced in the past through- 
out the shortleaf region, has been done with little realization of the 
damage to the forest. Shortleaf which has passed the earlier stages 
suffers much permanent inj ury from fire. Abundant seeding, low resin 
content of the wood, and early rapid height growth, in addition to 
sprouting, afford shortleaf perhaps the best chance of any of the im- 
portant southern pines to survive under adverse conditions caused by 
fire, but in spite of these favorable characteristics much loss and injury 
occur. 
Completely stocked stands of shortleaf over 20 years in age are 
rarely found in tracts of considerable size, except in old fields and in 
other situations where fire has been practically excluded. As a rule, 
the stand is irregular in density, with many small openings, for which 
