﻿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 



bre&sthigh. 



Total 

 num- 

 ber of 

 trees. 2 



Average 



diameter 



breasthigh. 





1906 



1910 



1906 



1910 





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 





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; (ft) suppressed — with tips of crowns shaded. 



2 Total number of trees alive in 1910. The average diameter given for 1906 is only for trees still alive in 

 1910. 



Before the 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 



2 



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 



