FOREST MANAGEMENT OF LOBLOLLY PINE. 
39 
Table 26. — Diameter growth due to thinning and proportion of trees cut and dying on 
thinned and unthinned plots. Growth in diameter on thinned and unthinned plots. 
Thinned plot. 
Unthinned plot. 
Tree classes. 1 
Total 
num- 
ber of 
trees. 2 
Average 
diameter 
breasthigh. 
Total 
num- 
ber of 
trees. 2 
Average 
diameter 
breasthigh. 
1906 
1910 
1906 
1910 
Dominant 
195 
160 
68 
49 
3 
4.6 
3.6 
3.0 
3.0 
3.0 
5.8 
4.2 
3.3 
3.2 
3.6 
234 
201 
77 
60 
50 
4.6 
3.5 
3.0 
3.0 
3.4 
5.5 
Codominant 
4.0 
3.3 
3.1 
4.0 
Total 
474 
622 
1 Under dominant and codominant are included all trees which go to form the upper or main crown 
cover: (1) Dominant— trees with well-formed crowns, receiving light on all sides; (2) codominant— trees 
with uneven crowns and crowded on the sides. The intermediate and suppressed classes include over- 
topped trees below the upper crown cover: (a) Intermediate— receiving some direct sunlight on tips of 
crowns; (b) suppressed — with tips of crowns shaded. 
2 Total number of trees alive in 1910. The average diameter given for 1906 is onlv for trees still alive in 
1910. 
Beforethe thinning in 1906 the thinned plot had 679 living trees 
and the unthinned plot 691 trees, as shown in the following classi- 
fication, showing proportion of trees cut and dying: 
Thinned plot. 
Unthinned plot. 
Tree classes. 
Alive 
1910. 
Cut in 
1906. 
Died 
since 
1906. 
Total. 
Alive 
1910. 
Cut in 
1906. 
Died 
since 
1906. 
Total. 
195 
160 
68 
49 
2 
13 
62 
33 
8 
32 
2 
8 
18 
25 
4 
210 
230 
119 
82 
38 
234 
201 
77 
60 
50 
3 
21 
26 
17 
237 
222 
103 
77 
52 
Total 
474 
148 
57 
679 
622 
69 
691 
The beneficial result of thinning is very evident from the foregoing 
tables, both in the more rapid growth of the trees left in the thinned 
stand, and in the possible returns from the 148 trees cut in the 1906 
thinning. 
As a rule, thinnings in young stands 25 years or less in age should 
be heavy, that is, removing (1) all dead, dying, and unhealthy trees 
of all classes; (2) most suppressed and intermediate trees; (3) many 
codominant; (4) and some poorly formed dominant. In older stands 
as a rule only moderate thinnings should be made, removing only 
intermediate and suppressed trees, in addition to the dead, dying, 
and unhealthy of all classes. 
In all thinnings two points should be aimed at: (1) To secure an 
even distribution of the most desirable trees with a suitable amount 
of growing space for each; (2) to preserve sufficient density of stand 
