SHORTLEAF PINE: IMPORTANCE AND MANAGEMENT. 
37 
TABLE 19.—Trees per acre in unthinned and thinned stands of various ages. 
Trees per acre. 
Trees per acre. 
Better situations. | Poorer situations. Better situations. | Poorer situations. 
Age. Age. 
Un- After Un- After Un- After Un- After 
thinned} thin- |thinned| thin- thinned] thin- |thinned| thin- 
stands. | ning. | stands.| ning. stands.| ning. | stands.| ning. 
Years Number.| Number. | Number. | Number Years. Number. | Number. | Number.| Number. 
A) ereiaie die sails 1, 400 990 2,120 1, 460 (0 re aaa 225 195 260 230 
BO eer nceteiets 680 525 990 820 SORES hee 200 175 200 190 
oT) Reta seta 480 380 680 540 OOS. oe ease 185 165 185 180 
DU cet ee: 340 280 460 SSO} ||P 1OOB ae eee 175 160 180 iki) 
GOP ses oki 270 230 340 290 
1 Represents about an average number based on measurements in 128 well-stocked stands in various 
portions of the range. 
TREES TO BE REMOVED. 
For convenience in thinning, trees may be divided into four groups 
of “dominant,” “ codominant,” ‘“ intermediate,” and “suppressed.” 
These groups are termed “ crown classes,” and represent the relative 
importance of the trees in the composition of the stand. The domi- 
nant and codominant trees compose the bulk of the stand, forming 
the general level of the forest canopy. They receive full light from 
overhead, and the dominant ones some from the sides also. The co- 
dominant trees are somewhat crowded on the sides. The intermedi- 
ate trees have smaller crowns and are generally below the main 
level of the stand, where they receive only a small amount of light 
from above. They clearly belong to the class of trees which is be- 
ing gradually crowded out. The suppressed trees are the smaller 
sickly ones completely below the general forest canopy. 
Athough there are certain more or less essential rules for thinning 
average shortleaf pine stands, they will not fit all cases, and the removal 
of the trees is largely a matter of individual judgment. In general, 
thinnings should be made primarily for the better development of 
the dominant and codominant classes. This is accomplished through 
the removal of the more crowded intermediate and suppressed trees 
on the lower side and the exceptionally large, overshading or “ wolf” 
trees on the upper side. In the crowded groups it is often necessary 
to remove as many as one-half, or occasionally two-thirds, of the 
intermediate trees, together with a few trees of the codominant class. 
Figure 3 represents an overstocked 30-year-old shortleaf stand and 
several subsequent thinnings. In ordinary early thinnings the num- 
ber of trees removed is about one-third of the total stand. The sup- 
pressed trees are making exceedingly small growth and exert no ap- 
preciable influence upon the stand. Their removal, however, is 
beneficial in decreasing the fire menace. Large openings should al- 
a 
