WESTERN WHITE PINE AND LARCH-FIR FORESTS St 
The percentage of merchantabie stand to be left will vary widely 
according to conditions, but will usually be between 10 and 30 per 
cent. 
Groups of trees between 12 and 16 inches in diameter should be 
thinned. This is a phase of the marking calling for skill and judg- 
ment in selecting the best and most promising trees to leave and 
maintaining proper spacing for the best growth. Larch should be 
given preference over Douglas fir, and particular attention should be 
given to removal of badly fire-scarred or diseased trees. 
Yellow pine in mixture should be encouraged. Trees of the “ bull 
pine” type and thrifty mature trees capable of putting on good 
growth should usually be left. : 
It is desirable to encourage white pine where it occurs on the 
moister situations. Occasional scattering white pine trees should 
nearly always be left for seed trees unless distinctly overmature. 
White fir, balsam, and lodgepole pine should not be encouraged 
and should be cut to the lowest merchantable limit. 
Even-aged mature stands with no reproduction present are some- 
times encountered. ‘To obtain reproduction after cutting, a stand of 
this class should be cut clean except for three to six seed trees to the 
acre. Seed trees, preferably of larch, should be thrifty, full-crowned 
trees of the dominant or codominant class, selected for their seed- 
bearing qualities and probable windfirmness. 
PRACTICABILITY OF TIMBER GROWING IN THE LARCH-FIR TYPE 
From the standpoint of value of product and rate of growth the 
larch-fir type does not offer as high returns as do some of the other 
forest types. The value of larch and fir lumber is comparatively 
low and may always remain considerably under such species as white 
pine and yellow pine. The rate of growth is considerably less than 
in the white pine type or the coast fir region. 
On the other hand, the larch-fir has some advantages which other 
types do not possess. The general uneven-aged character of much of 
the larch-fir timber makes it possible to leave standing enough timber 
to serve as the basis for a second cut in 20 to 40 years. It is not neces- 
sary to wait for a full rotation to get returns. Furthermore, the 
cost of leaving the stand in productive condition after logging is 
comparatively small, and the cost of fire protection in the larch-fir 
region in Montana is very considerably less than in the white pine 
region in Idaho. 
Conditions will vary according to the character of stands, but 
whenever a thrifty stand of 10 to 14 inch timber is left after logging, 
as is often the case, it would appear to be a promising speculation 
to hold the area for a second cut, which may be expected in 20 to 40 
years. 
