42 WORKING PLAN, FOREST LANDS IN ALABAMA. 
besides, will yield better and more valuable grades. Thus, looking at 
the problem of what the forest will produce both in quantity and 
quality, the conclusions point strongly to 18 inches as the superior 
cutting limit. 
SELECTION OF TREES TO BE CUT. 
The diameter recommended should be taken as a general guide, sub- 
ject to frequent modifications when forest conditions render it advisable. 
For example, it is obvious that cutting to an 18-inch diameter will 
leave more trees standing than would cutting to a 15-inch diameter, 
and consequently the number of cases where the limit must be raised 
in order to secure a sufficient basis for a second crop will be rare. On 
the other hand, there are cases where it will frequently be advisable 
to cut trees under 18 inches in diameter to improve the silvical con- 
dition of the forest. Modifications of the diameter limit recommended, 
unless they are made by a trained forester, will be dangerous. It is 
of the first importance not only that these modifications be made, but 
that they be made skillfully: To this end the supervision of the mark- 
ings by aman of sufficient training to put their policy into good effect 
is essential. 
Where the forest is pure longleaf pine, as on Block II and on the 
larger part of Blocks V and VI, the selection of trees for cutting 
should be governed by the density of the stand and the distribution of 
the diameter classes of the longleaf pine alone. Where all diameter 
classes, both above and below the cutting limit, are well represented 
and are evenly distributed, the 18-inch diameter limit should be closely 
followed. 
Where the trees run so small that those 18 inches arid over in diam- 
eter are scarce or entirely lacking, and where the stand is so dense 
that the trees are crowding each other and consequently losing in rate 
of growth, it will be wise to lower the diameter limit and to take out 
some of the dominant trees which are suppressing their neighbors, thus 
opening up the stand and increasing the rate of growth of the remain- 
ing trees. Where, on the other hand, the stand is open, consisting 
of only a few large trees per acre, and there are few or no trees under 
18 inches in diameter, it will be a good plan to select a few sound and 
healthily growing trees over 18 inches in diameter, and to leave them 
to form part of the second crop. 
In Blocks III and IV and in certain small portions of the other 
blocks, where the loblolly or shortleaf pines, especially of the smaller 
diameters, form an important part of the mixture, they, as well as the 
longleaf, should be considered in preparing for the second crop. 
Although their timber is less valuable than that of the longleaf, they 
orow at a more rapid rate and produce a larger yield per acre than 
the longleaf. Therefore, where the basis for a second crop of long- 
