THE RED SPRUCE. 
51 
species and will expose mineral soil most opportunely for aspen 
seed to catch and take possession of the ground, followed by 
spruce in subsequent seed years. 
This method should prove satisfac- 
tory, particularly where spruce saw 
timber is desired. The early growth 
of the main stand under the cover 
crop would prevent the development 
of stout branches to such a height at 
least that one or more clear logs to 
each bole could be produced. The 
cover crop would reach merchantable 
size by about the fortieth or fiftieth 
year and could be harvested. (See 
Fig. 2b.) The main crop could be 
thinned at the same time to secure 
satisfactory distribution of the trees 
to be left. With the removal of the 
cover crop all spruce would be stimu- 
lated and rapid development follow. 
At the time of clean cutting the 
second area, in from the sixtieth to 
seventieth year, it would be profit- 
able to thin the stand again on the 
first area. (Fig. 2c.) The final thin- 
ning of the first area would take 
place between the one hundredth 
and one hundred and twentieth year 
when the removal of the cover crop 
and first thinning of the second area 
was made, thus at least three thin- 
nings of the spruce would be pos- 
sible with little or no additional 
expense. The cost of bringing the 
cut of spruce to maturity would be 
somewhat more under this length- 
ened rotation than under a shorter 
rotation, but this would be offset 
to a considerable extent by the in- 
termediate revenues from the har- 
vesting of the cover crop and the 
thinnings and by the better quality 
of timber yielded. The method 
could obviously only be employed 
where there was an available market for the products yielded by 
the cover crop, namely, aspen pulp and excelsior stock, and maple 
