97 
THINNING. FOREST CONDITIONS. 
take out every alternate tiee and maintain the even spacing. It is the weak and 
defective units that must go; the strong and well formed that must remain. The 
result will be to give an ample percentage of the good trees a fair chance in the 
competition for root nutrition and light. Close planting thus ensures for the 
forester proper control of his plantations, and enables him to maximize the future 
crop while meantime making some profit out of the thinnings. Spacing of six feet 
each way gives 1,210 trees per acre; and it may be laid down as a general principle 
that at the start every acre of planted ground must carry at least 1,000 trees. But 
methods must adapt themselves to circumstances. If it is probable in any given 
case that thinning will be neglected, it may be well to make the original spacing 
8 feet or even 10 feet each way and take the risk of rather strong side branches. 
The foregoing remarks refer to cases where the seedlings are raised in the 
nursery and separately planted out. Where the seed is sown in situ the problem 
is somewhat different. If it is sown broadcast nature may have to be allowed to 
do the thinning by suppressing the weaker plants, as she does in a natural forest. 
If the seed is sown in lines and there is a good take, it is certain that the plants 
will be crowded along the lines. To compensate for this it may be well to place 
the lines 12ft apart. Thinning can then be done at any time after the saplings 
are large enough for use. 
Eucalypts, if cut down while still vigorous, very persistently sprout again 
from the stump. This is troublesome when our object in cutting is merely to thin 
the plantation. Later when we make clear fellings in blocks, it will be a great 
advantage. Each stump will throw up several coppice shoots, the rate of growth 
will be very rapid, and the resultant crop of poles very heavy. Thinning will again 
be needed, and will consist in removing one or more of the poles from each stump. 
Where it is intended that eucalypts shall sprout again they should always be cut 
down close to the ground, each stump being left with a clean sloping surface. 
FOREST CONDITIONS. 
The necessity for forcing growth upward and suppressing side branches 
condemns all planting of timber trees in single rows or in very narrow belts. The 
single row is the extreme form of excessive spacing. It gives the trees 
unrestrained growth on two sides and encourages heavy branching low down. In 
a belt or block of trees the outside units can branch freely in one direction. If 
the belt is narrow, the percentage of heavily branched units will be large. In any 
very narrow belt it will be much too large. The only way to produce a sufficient 
percentage of tall, clean trees suitable for the sawmill is to plant in wide belts or 
compact blocks. The minimum width permissible for any plantation where timber 
production is concerned appears to be about one chain. That is too narrow for 
best results; but on smaller farms it may sometimes be as much as circumstances 
will allow. A model plantation of an acre on a small farm would be two chains 
wide by five chains in length. Even if the main purpose of the planting is shelter 
for stock, the single row or very narrow belt stands condemned, foi the i eason 
that the wind drives through between the stems of the trees and causes unpleasant 
and dangerous draughts. 
