302 PRACTICAL ARBORICULTURE 
NO SPONTANEOUS COMBUSTION IN A FOREST. 
A woolen mill, with oil-saturated rags, may at times cause spontaneous 
combustion, but there never was an instance of such in a forest. The burning end 
of a match, cigar or cigarette often causes destructive fires. Fire guards properly 
arranged will check the advance of a fire, but they must be closely watched 
during the summer and autumn, as dry leaves accumulate, and an ample space 
be kept clear of inflammable debris. 
The usual method of lumbering is first to cut and remove all good trees of 
sufficient size to make boards. Trees of inferior size are next made into ties, the 
remainder being cut into cord wood. 
In proximity to pulp mills, suitable trees are converted into paper. To 
facilitate logging operations, teamsters and loggers are permitted to cut away 
much if not all young growth. In this manner the entire forest is quickly 
destroyed. 
If this should be rich agricultural land it may bring a good price after the 
timber has been sold; otherwise it may be without material value. Now, this 
property having been converted into cash, some other investment must be sought 
in order that the money may continue its earning capacity. 
The land has ceased to produce an income. Has it paid the owner for his 
time, trouble and use of the capital? 
Rather would it not have been better if only a portion of the timber were 
removed, leaving the younger trees for a future cutting? If the crop be a large 
one, a twenty years’ rotation would make it a source of perpetual productiveness. 
There are many tracts of forest land which were cut over twenty years ago, and 
which are now ready for a second or even third harvest. 
Under proper conditions trees continue to grow, adding to their bulk each 
year, until they are ripe or have become mature. Then they decrease in value 
annually until they have ceased to exist and become a part of the soil from which 
they are produced. 
To cut a tree in its prime, while in healthy, growing condition, is waste, and 
to destroy younger trees which have required from ten to a score of years to 
develop thus far is a useless sacrifice. 
On the other hand, to permit trees to pass their day of greatest usefulness 
and enter upon a decline is equally unwise. Just when to cut trees requires 
judgment and careful observation. 
Often one mature tree, if left, will prevent the development of many small 
growths near by. Thrifty trees of greater value should always be preserved, 
removing those of lesser worth where they interfere with the development of more 
valuable young timber. 
A proper stand of trees on the ground should be maintained. When too 
thickly growing, all are stunted, as they can not maintain a vigorous enistence. 
On the other hand, land unoccupied is a source of loss which must detract from 
the value of the whole. Therefore every space should be growing some tree: if 
they do not exist naturally or have been cut away, other trees should be planted 
in these vacancies. 
It has been the constant practice of many farmers who own wood lots of 
