LONGLEAF PINE 
11 
Table 1 shows, for different ages, the average height and diameter 
of longleaf pine trees growing in well-stocked, even-aged stands, on 
three different grades of land or situations. These figures, it is be- 
lieved, are approximately representative of the rate of growth in 
stands of good density over the range of longleaf pine. They are 
based upon the measurement of selected portions of 78 longleaf pine 
stands whose locations range from South Carolina to Texas. 
Table 1. — Average growth of trees in height and diameter, and number of 
trees per acre in well-stocked, even-aged longleaf pine stands on various 
qualities of land 
Height 
Diameter i (breast-high) 
Approxi- 
Age 
of 
mate 
number 
stand 
Better 
Medium 
Poorer 
Better 
Medium 
Poorer 
of trees 
land 
land 
land 
land 
land 
land 
per acre 2 
Years 
Feet 
Feet 
Feet 
Inches 
Inches 
Inches 
15 
39 
24 
10 
5.3 
3.6 
1.9 
550 
20 
50 
34 
19 
7.0 
5.0 
3.1 
450 
25 
58 
42 
27 
8.1 
6.0 
4.0 
393 
30 
63 
48 
33 
9.0 
6.9 
4.8 
355 
35 
68 
54 
39 
9.7 
7.6 
5.5 
328 
40 
72 
58 
43 
10.4 
8.3 
6.2 
308 
45 
75 
60 
46 
10.9 
8.8 
6.7 
293 
50 
78 
64 
49 
11.4 
9.3 
7.2 
280 
55 
80 
66 
52 
11.8 
9.6 
7.5 
270 
60 
82 
68 
54 
12.1 
10.0 
7.8 
264 
65 
83 
69 
56 
12.4 
10.2 
8.0 
258 
70 
84 
70 
57 
12.7 
10.4 
8.2 
254 
* Diameters measured at breastheight, or A\i feet above the ground. 
2 The number of trees per acre varies considerably with age, but for any given age averages approximately 
the same on the better and poorer classes of land. Not only can the better lands support more trees of a 
given size, but the trees are much larger in size at any specified age than on unfavorable situations. 
On good lands, or good situations, it will be seen, for example, 
than at 20 years longleaf pine reaches heights averaging about 50 
feet; on medium, land, about 34 feet; and on poor land, about 19 
feet. The medium class of land, for instance, would include the 
loamy sands of the middle and upper coastal plains, and the last 
class the poorer parts of the flatwoods and the very deep, dry sands. 
The corresponding diameters, depending upon the situation, range 
from 7 inches down to a little over 3 inches. During the next 10 
years, the trees increase yearly in height at the rate of about 1.4 
feet (16.8 inches) and in diameter nearly 2 inches. The average 
diameter, as shown, usually represents: an actual range of 4 to 6 
inches, or 2 to 3 inches greater and 2 to 3 inches less. Likewise, 
the average height would probably represent a range of 5 feet at 
20 years and as much as 10 feet at 50 years. The average diameter 
at breastheight, for example, of trees in a 25-year-old stand on a 
medium grade of soil is shown to be about 6 inches, and the trees 
in that particular stand probably ranged in diameter mostly from 
about 8 inches down to 4 inches. Table 1 shows that longleaf trees 
growing in well-stock stands on medium situations (land), have 
an average yearly height growth of about 17 inches at 25 years, 12 
inches at 35, 6 inches at 50, and 4 inches at 60 years; and an increase 
in diameter at the rate of about 1 inch in 5 years at 25 years, in 7 
years at 35, in 12 years at 50, and in 16 years at the age of 60 (fig. 3). 
There should be no misapprehension regarding the time necessary 
to grow a crop of pines to a size that is merchantable for timber or 
