58 BULLETIN 1496, U. S. DEPARTMENT OF AGRICULTURE - 
SWAMP FORESTS 
Because swamp forests as a rule contain a large proportion of 
trees that are unmerchantable even for pulpwood, present-day 
logging does not amount to real clear cutting. Yet the small unmer- 
‘chantable trees left on the ground are usually spindling, easily over- 
thrown by the wind, and generally a total loss. Such cutting results 
in great waste, especially in pure stands of black spruce. Neverthe- 
less, even such cutting, unless it is followed by very bad fires, does 
not prevent the logged-off land from coming back to more or less 
the same species. Since the swamp forests, especially in undrained 
swamps, are of slow growth and the stands are light, under crude 
ae ey other method of cutting may be economically justifiable. 
(Pl. 7, B. 
CUTTING IN BLACK SPRUCE 
Cutting in spruce forests may be partial or clear, depending 
upon the condition of the stand and the natural reproduction in it. 
Where the stand is dense and is made up of trees of different sizes, 
the removal of not more than 50 per cent, or preferably less, of the 
merchantable timber may be desirable. The denser the cover that is 
left after cutting, the fewer are the chances for wind throw. Where 
the stand, however, is made up of merchantable trees of more or less 
the same size and the ground is stocked with fair reproduction, the 
removal of all merchantable trees is justified both economically and 
silviculturally. 
Black spruce is very susceptible to attacks by bud worm, and large 
areas have been denuded in recent years by that insect. Although 
the bud-worm epidemic has now subsided, there is no assurance that 
it will not occur again. Therefore, leaving mature black-spruce 
forests uncut is assuming the risk of losing the merchantable stand 
left on the ground. Evidence points to the fact that the recent out- 
breaks of the bud-worm infestation have resulted from the increased 
proportion of balsam fir in certain localities resulting from clear 
cutting black spruce. Selective cutting should tend to decrease 
the proportion of balsam fir and thus possibly reduce the danger of 
another bud-worm outbreak. 
CLEAR CUTTING IN STRIPS 
A method of cutting that results in good reproduction, offers many 
conveniences in logging and utilization, and avoids the necessity of 
marking the timber, is cutting clean in strips from 150 to 200 feet 
in width, leaving alternate strips from 150 to 200 feet untouched. 
The timber in such clean cuttings is thrown to the center of the 
strip, and the tops are left in windrows, while the sides of the 
strips are left clear for skidding. The abundance of seed from 
trees on both sides of the strips provides one of the essentials for 
natural reproduction of the spruce and commends the method. The 
alternate strips of forest left uncut are removed when the young 
growth on the cut-over strips reaches the seeding stage and is capable 
of reseeding the adjoining cut-over strips, 
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