g or planting, or by leaving small tracts of pine
surrounded by cleared fire lines to protect them when the slashing
is burned. The size and distance apart of these must be determined
by their situation and exposure to wind, considering both the danger
of windfall and the carrying of seed. Especially in younger growths,
the quantity of merchantable material tied up in this way is not
so great as is sometimes necessary in the case of red fir, where
single seed trees may contain several thousand board feet. On the
other hand, stumpage value may be high. For this reason artificial
replacement may often be more profitable, especially where there
is reasonable safety against recurring fire.

A thing to be borne in mind is that white pine seems to reach a
healthier and better development when mixed with a small proportion
of other species, such as cedar, tamarack, spruce, lodgepole pine
and Douglas fir, so there is no object in trying to produce an
absolutely pure stand. Some authorities think that 60 per cent
of pine, with the rest helping to prune it, is an ideal mixture.

LODGEPOLE PINE (_P. Murrayana_)

Present interest in private reproduction of this species hardly
warrants treating it at length in this publication, although
unquestionably it will eventually occupy a higher place in the
market than at present and its readiness to seize burned land in
many regions will make it a factor whether desired or not. Where
yellow pine will grow, the problem is most likely to be to discourage
lodgepole competition.

In strictly lodgepole territory, however, it may be the only promise
of a new forest. Generally speaking, an even-aged growth should
be induced by clean cutting if the entire crop can be utilized.
Slash burning in such cases is desirable. The chief difficulty
is in providing seed supply, for either individual seed trees or
small groups are almost certain to be blown down. Experiments so
far indicate that heavy strips must be spared, chosen to afford
the least present loss and safeguarded by fire lines.

In some lodgepole stands, especially where only certain sizes are
marketable, the cutting practically amounts to thinning. Here obviously
the effort should be to prevent over-thinning and to remove debris
with the least damage to the remaining stand. Piling and burning
is essential.

SUGAR PINE (_P. Lambertiana_)

This extremely valuable pine, commercially limited to the Oregon and
California mountains, is fas