this growth, cutting should be confined to the 
mature and overmature stands, and should not 
exceed 22.7 million board feet on the average 
(table 25, Appendix). Current drain is apparently 
about 31.2 million board feet per year (table 27, 
Appendix). 
If partial cutting in old-growth stands—i. e., 
removal of old trees while leaving young thrifty 
trees to grow—will prove practicable, annual 
growth on saw-timber areas can doubtless be 
stimulated during the next two decades and the 
allowable cut increased accordingly. In other 
words, it is not out of the question that current 
levels of industrial utilization be maintained, if 
fire and other losses are minimized and cutting 
practices that will stimulate growth on saw-timber 
areas are generally applied. 
Hemlock 
More than one-fourth of the total sawlog volume 
in the Upper Peninsula is eastern hemlock. ‘The 
bulk of this volume (98 percent) is in saw-timber 
stands and mostly in trees 14 inches or larger in 
diameter. It is associated commonly with maple, 
birch, elm, and other hardwoods. 
Hemlock is a tree of the climax forest and does 
not appear commonly in the second growth. It 
does not reproduce well on cut-over lands and when 
left in selectively logged stands it usually succumbs 
to windthrow, sunscald, or insect damage. De- 
pending upon market conditions, it seems logical 
in stands made up mainly of hemlock either to cut 
the species clean or leave the stand intact until the 
market improves. In the meantime, experiments 
with various types of partial cutting adapted to 
hemlock should be tried. 
On account of difficulties in management and 
the relatively low value of this species, the allowable 
cut has been set fairly high—168 million board feet. 
This is more than three times the current incre- 
ment and is somewhat greater than current drain. 
Northern Hardwoods 
About 3% percent of maple, birch, basswood, and 
beech in saw-timber stands is being liquidated 
each year in clear-cutting operations. ‘This means 
that, if continued at present rates, the commercial 
hardwood forests will be gone in 25 to 30 years. 
More probably, production will decline at an 
18 
earlier date as certain individual operators cut 
out their holdings. There is always the possibility, 
however, that some change in markets or other 
economic factors may cause owners of large 
reserved tracts to throw them on the market, and 
a number of new mills may be constructed, thus 
shortening the period of liquidation. 
If the old-growth hardwoods and the small 
tracts of merchantable second growth are clear- 
cut, forest industries will have to rely upon yields 
from the present cordwood and restocking areas. 
Unless definite efforts are made to conserve the 
growing stock on these areas now, it is not likely 
that the annual yields will greatly exceed the 
current increment, which is 46 million board feet 
per year (table 24, Appendix). 
Under a plan of selective logging with thorough 
protection of immature stands, an annual yield of 
278 million board feet of the four commercial hard- 
wood species could be obtained on virtually a 
permanent basis. The yield during the second 
20-year period might be slightly lower but could 
be increased to an even higher level in later periods. 
If the forests are put under sustained-yield 
management, 1t would be necessary, in addition to 
adjusting the method of cutting, to reduce the 
actual volume of drain on maple, birch, beech, and 
basswood by about 123 million board feet. Reduc- 
tions can be made in a number of places; in the 30 
million feet going into distillation wood, in the 33 
million feet of fire and other losses, in the 10 million 
feet of logging and milling waste, and in the saw 
timber used for fuel wood, posts, etc. But no 
doubt some downward adjustments in mill pro- 
duction will be necessary. This can probably 
better be accomplished by early closing of some 
of the old and obsolescent mills already nearing 
the end of their operating life than by attempting 
a proportionate reduction for all mills. 
Pulping Species 
The normal drain on spruce and balsam fir is 
3.3 times the recommended drain. The disparity 
is still greater in the case of jack pine. Even 
tamarack is overcut more than 100 percent. ‘This 
unfavorable condition is aggravated by the fact 
that practically all of the mature cordwood and 
saw timber of these species has already been cut. 
Present operations are chiefly taking out immature 
