18 
IMPROVEMENT OF THE CROP—THINNING. 
Having removed all the old growth and secured a young growth, 
there follows its cultivation. This consists first in improving its com- 
position and secondly in promoting its rapid and desirable development. 
Both these objects are attained by proper thinning, repeated from time 
to time. 
The young growth is rarely such as we would like to see. Some 
undesirable kinds are prominent which should be reduced in number; 
here are some stumpy and bushy trees which prevent the development 
of their neighbors and are best removed; there a stump has produced 
more sprouts than it can support and it is wisdom to thin them out, 
cutting especially the inner ones. Here is a kind especially valuable 
that we would protect from being smothered by its less valuable neigh- 
bors. There may also be larger fail places in the natural reproduction, 
and if too large to be covered over in a few years we nay deem it desir- 
able to plant such places with some valuable kind. 
In this way for the first 10 to 15 years, by judicious use of the ax 
mainly, we try to improve the composition of our crop. These trim- 
mings must be made carefully, however, so that the soil which is 
shaded by the crown may not remain exposed for more than 2 or 3 
years; that is to say,in that time the crown cover must close itself 
again. When in this manner the crop has been brought into desirable 
shape, a series of thinnings follows, repeated periodically or going on 
continually, as may be most convenient, the object of which 1s to ad- 
vance the development of the growth, to hasten the formation of valu- 
able wood. In these thinnings a certain number of trees are taken out 
in order to give the remainder an opportunity to develop more quickly 
and with the least hindrance to desirable form and size. 
The philosophy of these thinnings les in the observation that light is 
one of the important factors of life and especially of tree growth. It is 
under the influence of light that foliage develops and that leaves assimi- 
late food; the more foliage and the more light at its disposal a tree has 
the more wood it will form. On the other hand, if we compare trees 
grown in the dense forest with those grown in the open field, we will 
note a difference in habit and shape; while the latter, grown in full 
enjoyment of light, have during the same time attained a greater diame*® 
ter, have in fact made more wood, the latter excel in the length, straight- 
ness, and cylindrical form of their trunks; while the former have de- 
veloped largely into branches, the latter have fewer branches, and alto- 
gether, although having made less wood, have produced a more use- 
ful quality. 
Hence, in order to produce good timber, which is the principal aim 
of forest management, dense growth is necessary, when the light, needed 
for the development of branches, is cut off and a clean shaft the result; 
yet on the other hand, to produce largest amount of material open posi- 
tion is more favorable. 
