VALUE AND USE
SPECIES: Picea mariana | Black Spruce 



WOOD PRODUCTS VALUE : 
The principal commercial value of black spruce is pulpwood.  It is the
most important pulpwood species in Canada, and is commercially important
in the Lake States.  It is also used occasionally for lumber and a
variety of other specialty items.  The wood is relatively light-weight
but strong [65].


IMPORTANCE TO LIVESTOCK AND WILDLIFE : 
Browse:  Livestock and wild ungulates rarely eat black spruce.  Moose
occasionally browse saplings, but white-tailed deer eat it only under
starvation conditions [27].  Spruce grouse feed entirely on spruce
needles during winter.  In Alaska, spruce grouse subsist on a diet of
spruce needles from early November through March [21].  Black spruce is
a major food of snowshoe hares, especially in winter.  One study found
that consumption of black spruce by hares in interior Alaska varied
seasonally as follows [69]:

                Dec-March   April    May    June-Sept   Oct-Nov
                     (percent composition in diet)

needles           38.5      27.6     12.4     12.3       26.0

bark and twigs    17.0      10.0      2.7      1.9        7.8

Seed:  Numerous seed-eating birds and small mammals feed on black spruce
seed.  Red squirrels consume seed from harvested cones [42].  Mice,
voles, shrews, and chipmunks consume seeds off the ground.  Chickadees,
nuthatches, crossbills, grosbeaks, and the pine siskin extract seeds
from open spruce cones and eat seeds off the ground [31,38].


PALATABILITY : 
The palatability of black spruce to big game and livestock is low to
nil.


NUTRITIONAL VALUE : 
Data from a nutritional study of black spruce needles collected in the
winter on the Kenai Peninsula of Alaska are presented below [21]:

            (percent chemical composition and caloric content)
                            range           mean   

protein                   4.4 - 6.5          5.7
fat                       5.5 - 7.1          6.2
crude fiber              21.7 - 23.5        22.47
ash                       1.9 - 2.8          2.33

Kilogram calories/100 g   502 - 517        508.9

In this study black spruce had a higher fat and caloric content than
white spruce, but a lower ash content.

Black spruce seeds are not as nutritious as white spruce seeds.  In
Alaska, black spruce seeds averaged 6,053 cal/g, about 9 percent less
than white spruce seeds [11].  


COVER VALUE : 
Black spruce provides good cover for moose.  It often grows in dense
stands and on moist substrates, conditions which provide cool bedding
areas for moose [3].  Black spruce also provides good cover for spruce
grouse [37].  In the Lake States, spruce grouse are dependent upon black
spruce stands for much of their habitat needs.  The ruby-crowned
kinglet, magnolia warbler, Cape May warbler, and ovenbird commonly nest
in black spruce [38].


VALUE FOR REHABILITATION OF DISTURBED SITES : 
Black spruce is recommended for revegetating disturbed sites in boreal
regions.  It may be useful for revegetating seismic lines, borrow pits,
abandoned roads, and construction and well sites [10].  In southeastern
Canada, Maine, and Minnesota, black spruce naturally invades
well-drained raised surfaces in abandoned mined peatlands [23].  It can
be established on disturbed sites by direct seeding or by transplanting
nursery-grown seedlings.

Special procedures have been developed for removing black spruce seed
from the semi-serotinous cones [55].  Seeds retain their viability for
several years when stored in sealed containers in a cool, dry
environment [55].  Seeds require no stratification prior to sowing.
They should be sown soon after snowmelt [10].  On peatland sites,
seedling establishment is best when surface organic layers are exposed
by burning or machine scarification.  On upland sites, exposing mineral
soils before sowing is essential [38].

On well-drained soils 8- to 12-inch-tall (20-43 cm) bareroot transplants
show good growth and survival when planted directly into organic layers
[4].  Thus, site preparation which removes organic layers should not be
undertaken when transplanting black spruce on uplands.  Transplant
survival and growth are generally better following summer than spring
outplanting [4].  In northeastern Alberta, overwinter survival of
container-grown and transplanted black spruce seedlings was satisfactory
on amended oil sand tailings [24].

Black spruce can be readily propagated by root cuttings [4].


OTHER USES AND VALUES : 
Black spruce is still harvested for Christmas trees, but recently the
amount harvested from natural stands has declined [65].  In the past,
specialty items made from black spruce included healing salves from the
gum, antiscorbutic and diuretic beverages from twigs and needles, and
rope from the roots [55].


MANAGEMENT CONSIDERATIONS : 
Timber harvest:  Clearcutting in strips or patches is generally
considered to be the best silvicultural system for managing black spruce
[38,65].  Most sites are broadcast burned and seeded naturally from
nearby uncut stands [6].  Direct seeding has been used on large
clearcuts in Minnesota.  On these cuts, seeding rates were 4 ounces (112
grams) per acre (approx. 100,000 seeds) to achieve 60 percent stocking,
but 2 to 3 ounces (56-84 grams) were adequate on well-prepared sites
[37].  On brushy sites, aerial spraying herbicides has been used to
release black spruce [38].

Pests and diseases:  Eastern dwarf mistletoe (Arceuthobium pusillum) is
the most serious disease of black spruce in the Lake States and eastern
Canada.  It is less frequent in the West, and completely absent in
northwestern Canada and Alaska.  Infection results in reduced vigor,
witches brooms, deformed trees, and death.  Control is possible through
silvicultural management [27,65].  Black spruce is susceptible to
numerous needle rusts and fungi which result in defoliation and reduced
vigor.  These diseases usually remain at low levels but may become
epidemic [65].  Wind breakage is caused by butt and heart rots which are
common in 70- to 100-year-old stands on upland sites and 100- to
130-year-old stands on organic sites [27,37].  The spruce budworm
defoliates black spruce; however, black spruce is less susceptible than
white spruce, red spruce, or balsam fir (Abies balsamea).  Black spruce
trees most likely to be attacked are those growing with balsam fir and
white spruce [27].  Numerous other insects attack black spruce but only
occasionally cause serious damage [27,65].

Flooding:  Black spruce is susceptible to damage from flooding and
disruptions in normal groundwater movements.  Trees have been killed
over large areas where newly constructed roads impede water movements
and where beavers dam drainage ditches or small streams [27].

Related categories for Species: Picea mariana | Black Spruce