VALUE AND USE
SPECIES: Tsuga canadensis | Eastern Hemlock 



WOOD PRODUCTS VALUE : 
Eastern hemlock wood is of low value because of brittleness and abundant
knots [26].  It is used for pulp, light framing, sheathing, roofing,
subflooring, and boxes and crates [20].


IMPORTANCE TO LIVESTOCK AND WILDLIFE : 
Dense stands of eastern hemlock provide excellent wildlife habitat [20].
Cove forests in the southern Appalachian Mountains provide nesting
habitat for many species of birds.  The black-throated blue warbler,
black-throated green warbler, and blackburnian warbler are especially
abundant in virgin eastern hemlock cove forests [25].

Large eastern hemlocks can be climbed by small black bear cubs.  In
northeastern Minnesota, black bear mothers and cubs spent more than 95
percent of the time in April and May within 600 feet (183 m) of either
an eastern hemlock or an eastern white pine (Pinus strobus) larger than
20 inches (51 cm) in d.b.h. [50].

Eastern hemlock has high cavity value for wildlife [12].  Large hollow
trees are commonly used as dens by black bears [49].

The seeds are eaten by birds and mammals [13], and in the winter the
foliage is browsed by white-tailed deer, moose, and snowshoe hares
[2,59].


PALATABILITY : 
In the winter, eastern hemlock browse is moderately preferred by moose
and highly preferred by white-tailed deer [2,10].  In the summer,
white-tailed deer prefer hardwood sprouts and seedlings to eastern
hemlock [44].  The seeds of eastern hemlock are not as preferred by
white-footed mice, red-backed voles, and meadow voles as red pine (Pinus
resinosa) and white pine seeds [1].


NUTRITIONAL VALUE : 
NO-ENTRY


COVER VALUE : 
Eastern hemlock provides cover to ruffed grouse, wild turkey, fishers,
and other wildlife [4,20].  It provides excellent thermal protection and
snowfall interception for moose and white-tailed deer in the winter
[2,17].


VALUE FOR REHABILITATION OF DISTURBED SITES : 
NO-ENTRY


OTHER USES AND VALUES : 
From 1880 to 1930, eastern hemlock was extensively harvested for its
bark which is a source of tannin [64].  

Eastern hemlock is planted as an ornamental [20].


MANAGEMENT CONSIDERATIONS : 
Multiple removal cuttings are the best method for regenerating eastern
hemlock.  Suddenly released seedlings often die, and a series of
removals releases hemlock more slowly [28].  On moist sites, a two-cut
shelterwood system leaving about 50 percent cover may be adequate.  On
drier sites, a three-cut system is appropriate, initially leaving 70 to
80 percent crown cover and 50 percent after the second cut [62].  If too
few residual trees are left, they may die when exposed, and they are
subject to windthrow [28].  Scarification of seedbeds and removal of
competing hardwoods may be necessary [20].  Eastern hemlock regeneration
must be at least sapling size when released if it is to compete
successfully with uncontrolled hardwoods [29].  Single tree selection is
also an effective method to harvest and regenerate eastern hemlock [62].

Effective reproduction may be absent in areas with high deer populations
[3,10].  Regeneration in the Porcupine Mountains in Michigan has
declined over the last several decades because of white-tailed deer
browsing in the winter [17].  In the Allegheny National Forest in
Pennsylvania, the eastern hemlock-northern hardwoods forest type covered
83.4 percent of the land in 1800 and only 15.8 percent in 1986.
Extensive harvesting, fire, and overbrowsing are responsible for the
decline [64].

Numerous insects attack eastern hemlock, but only a few are of economic
importance cause sporadic or local mortality [62].  Mortality
usually occurs following complete defoliation by insects [43,62].

Eastern hemlock seedlings are sensitive to damping-off fungi, root rots,
and stem and needle rusts [20].

Eastern hemlock appears to be resistant to ozone [21].

Related categories for Species: Tsuga canadensis | Eastern Hemlock