LONGLEAF PIXE. 35 
or oaks, which shade out a lot of pines and promise less valuable tim- 
ber, these should be cut out much as weeds are eradicated from fields. 
This process, known as " cleaning," may not be necessary more than 
once. The last thinning is followed, at a suitable age and develop- 
ment of the trees, by a clean cutting of the stand. The clean-cutting 
method is recommended for longleaf, because this species grows 
naturally, and probably best, in pure stands or mixed with small 
amounts of other pines. Longleaf, apparently, grows fastest into 
timber when it comes up uniformly over the land and is kept at uni- 
form heights, for it is a species that needs an abundance of light, and 
hence must not be shaded by taller trees. 
The desired number of trees per acre for a given stand is deter- 
mined largely by the quality of the locality or the favorableness of 
the situation, and by the size and age of the trees. It is, after all, 
more a matter of judgment and experience than of rule. (See Table 
1.) In the earlier thinnings, when the stand is about 20 years old, 
sometimes as many as one-fifth to one-third of the trees should be 
removed. These usualty represent, however, less than one-fifth of 
the total timber volume of the stand. 
The final clean cutting of the stand should include provisions for 
early restocking of the land before oaks and other inferior growth 
get a footing. A good w r ay to do this is to leave seed trees. These 
should be the vigorous, full topped, or limb} 7 trees, of less value for 
lumber. In practically all stands they may be found growing alone 
in openings, and hence are well rooted and" wind firm against the 
storms that may follow the cutting. It is well to spot the trees 
with white paint before cutting operations are begun, as is being 
done in some operations in the South. Certain State laws require 
this, as pointed out under "A seed-tree law." It is sometimes 
good practice to cut to a diameter limit, as, for example, down to 12 
inches. In this wa} 7 trees below good merchantable size will be left on 
the ground to aid in reseeding the land and to provide good material 
for cutting 5 to 10 years later. In logging timber, often no profit but 
a positive loss is incurred by trying to handle trees too small in size. 
Good forestry in lumbering operations calls for preserving the young 
and thrifty trees. 
The amount of material secured from the several thinnings re- 
quired in well-stocked stands up to an age of 50 to 70 years might 
easily be equivalent to one-third of the total amount yielded at the 
final cutting of the stand. The value of the timber, of course, would 
depend upon its location with reference to transportation facilities 
and upon the competition from outside markets. Wherever possible 
the trees to be removed in thinnings should first be worked for tur- 
pentine, because at times the gum brings more than would be realized 
