70 ELEMENTARY FORESTRY. 
branches before felling. This is practiced to some extent where 
forests are very valuable. 
The Small Dead Twigs on such trees as spruce, and also 
the shrubbery which may surround them, are often a very val- 
uable protection against sun-scald. This also protects from 
drying winds, which would otherwise, perhaps, sweep through 
the forests and do them injury. Forest trees seldom do best 
where they are subject to a strong draft of wind around the 
trunks. While, under some conditions, it may be desirable to 
remove the dead branches from trees, yet even if it is decided 
to do this in the interior of the forest, it is generally best to 
leave the borders without such pruning in order to protect it 
from drafts. 
Forest Weed is a term used to signify any growth that 
may occur in forests which crowds the other growth, and so pre- 
vents it from developing to the best advantage. It may apply 
to raspberry bushes, hazel brush, poplars and other similar 
materials which often come in our forests in the early growth 
of the plantation; or even to large inferior trees which are in 
the way of the proper development of the better species. Buta 
tree may at one period of its growth be of much value in a for- 
est in producing shade and acting as a nurse tree, while later on 
in its growth, after its usefulness has been completed, it may be 
regarded as a weed. 
Thinning is the most important part of the forester’s art in 
securing good timber and in reseeding the land. The ideal con- 
dition in the life of timber trees is to secure a natural crop of 
seedlings so crowded when young as to increase very rapidly in 
height and produce slender trunks free from side branches. 
When this crowding has gone far enough the less valuable and 
weaker trees should be removed to give the better trees suf- 
ficient room for their crowns to develop. These remaining trees 
in the course of a few years will again crowd one another too 
severely, and this process of removing poorer trees must then 
be repeated. ‘Then when the final stand of trees is approaching 
maturity, thinning should be commenced to let in light and air 
to produce the conditions under which seedlings develop to best 
advantage. 
Heavy thinning should be practiced only after very careful 
