VALUE AND USE
SPECIES: Vaccinium myrtillus | Dwarf Bilberry 



WOOD PRODUCTS VALUE : 
NO-ENTRY


IMPORTANCE TO LIVESTOCK AND WILDLIFE : 
Browse:  A variety of small mammals consume the twigs, leaves, and bark
of dwarf bilberry [57,71].  Throughout most of Scandinavia, dwarf
bilberry is the primary winter food of the gray-sided vole
(Clethrionomys rufocanus) [57].  Browse appears to be of negligible
value to large ungulates.

Fruit:  Berries of dwarf bilberry are eaten by many birds and mammals
[56] including the ring-necked pheasant, hares, grouse, partridges,
ptarmigans, and bears [35,74,81].  In Finland, these berries make up a
high percentage of brown bear diets during August.  Coniferous forests
with a dwarf bilberry understory provide essential brown bear habitat
during late summer in parts of Scandinavia [74].  Dwarf bilberry was
presumably of similar importance to grizzly bears in North America prior
to their extirpation from the central and southern Rocky Mountains.
Vaccinium berries are readily eaten by the band-tailed pigeon, wild
turkey, gray catbird, ruffed, spruce, blue, and sharp-tailed grouse,
tanagers, bluebirds, thrushes, quails, and towhees [63,92,94].  The
white-footed mouse, gray fox, red fox, raccoon, pika, deer mouse, and
numerous species of chipmunks, ground squirrels, tree squirrels, and
skunks also feed on Vaccinium fruit [54,63,94].


PALATABILITY : 
Dwarf bilberry browse is described as "worthless" for cattle but on
occasion is of fair palatability to domestic sheep [22].  Palatability
to big game species appears slight.  Fruit of dwarf bilberry is highly
palatable to a wide variety of birds and mammals.  Overall palatability
of dwarf bilberry has been rated as follows [26]:

                      CO     UT     WY

Cattle               poor   poor   ----
Sheep                fair   fair   ----
Horses               poor   poor   ----
Pronghorn            ----   poor   poor
Elk                  ----   good   fair
Mule deer            ----   good   good
White-tailed deer    ----   ----   good
Small mammals        good   good   good
Small nongame birds  good   good   good
Upland game birds    ----   good   good
Waterfowl            ----   poor   poor


NUTRITIONAL VALUE : 
Browse:  Blueberry (Vaccinium spp.) foliage is relatively high in
carotene, manganese, and energy content [20,39,93].  Nutrient value of
dwarf bilberry browse varies according to weather conditions, site
characteristics such as soil type and elevation, plant part, and timber
treatment [18,57,86,100].  Nitrogen content depends in large part on
available soil nutrients, with total leaf nitrogen typically increasing
with elevation [57,100].  Selected nutrient value of dwarf bilberry
browse by timber treatment is as follows [18,86]:

                       subalpine forest - central Colorado -
                                  (percent)          

                                3 yrs                 5 yrs
                       uncut    clearcut         uncut       clearcut

crude protein          9.3        11.2            11.0         12.6
moisture              57.3        60.3            60.2         60.4
in vitro digest.      28.0        29.2            31.1         38.3

                        northwestern Montana -
                         (micrograms per g)

                  Ca    Cu   Fe    K    Mg    Mn    N    Na    P    Zn
clearcut - burn
         stem    6105   7.4   66  3895  1259 1059  6718  134  1232  53
         leaves  8950   9.7  113  9480  3061 1410 19040  160  2296  25
control - unburned
         stem    5100    --   92  2880   752 1200  9100  119   943  39
         leaves  8540  12.1  153  7460  1808 2770 25470 1721  1937  21

Fruit:  Vaccinium berries are sweet and contain high concentrations of
both mono- and di-saccharides [88].  Berries are rich in vitamin C and
energy content but low in fats [45,77].


COVER VALUE : 
Dwarf bilberry provides some cover for small birds and mammals.  The
diverse canopy layers associated with subalpine fir/dwarf bilberry
forests of the Southwest reportedly serve as good habitat for deer, elk,
and many species of birds [32].  Cover value of dwarf bilberry has been
rated as follows [26]:

                          UT     WY

Pronghorn                poor   poor
Elk                      poor   poor
Mule deer                poor   poor
Small mammals            good   good   
Small nongame birds      fair   good
Upland game birds        fair   fair


VALUE FOR REHABILITATION OF DISTURBED SITES : 
The extensive rhizome network of dwarf bilberry can aid in preventing
soil erosion once plants become established [93].  Species within the
genus Vaccinium can be propagated from hardwood stem cuttings or from
seed [17].  Root cuttings of dwarf bilberry can be successfully
transplanted onto disturbed sites and mature plants can be transplanted
during the spring [9,33].  Vegetative propagation of dwarf bilberry has
been examined in detail [92].  Vaccinium seedlings grown in the
greenhouse can be transplanted onto favorable sites 6 to 7 weeks after
emergence.  Seed collection and storage techniques have been well
documented [17].


OTHER USES AND VALUES : 
Fruit of dwarf bilberry is juicy, edible, and has a "nutlike flavor"
[50].  Berries are eaten fresh or gathered for use in jams and jellies
[31,92].  Fruit may be used in pie filling [92]; however, collecting
enough of the small berries can be difficult [50].  Leaves of dwarf
bilberry have been used to make tea [50].  Both fruit and leaves are
reported to have some medicinal value [56].  Vaccinium berries were
traditionally an important food source for many native peoples.  Fruit
of the dwarf bilberry was traditionally used by the Kootenai, Carriers,
and Shuswap in North America, and by many indigenous peoples throughout
northern Europe and Siberia [92].

Dwarf bilberry may have potential value for breeding commercial
fruit-producing strains [60], particularly those suited to upland
mineral soil [53].  Dwarf bilberry may also be useful in developing
cold-hardy cultivars for northern plantings [21].  It is tolerant of
cold winter temperatures, and some strains may be hardy to -70 degrees F
(-57 degrees C) [21].


MANAGEMENT CONSIDERATIONS : 
Berry production:  Berry production in dwarf bilberry fluctuates
annually with weather conditions [31,56].  Spring frosts and summer
droughts can greatly decrease yields [31].  Production is typically good
in favorable, moist years, but during bad years no fruit is produced
over extensive areas [50].  Generally, fruit production is poor when
winter snow cover is less than 8 inches (20 cm) deep.  Buds are
vulnerable to damage by cold winter temperatures.  In some areas, flower
bud development may be greatly reduced when January temperatures have
reached -26 to -29 degrees F (-32 to -34 degrees C) [75].

The age of plant, canopy cover, stand age, and other site
characteristics can also influence berry production [56].  In some
areas, berry production may peak at stand ages of 20 to 70 years [20].
However, Kuchko [56] reports that in Finland, dwarf bilberry can bear
fruit for "some time after clearcutting," suggesting optimal fruit
production occurs during somewhat earlier seral stages.  Very young
shoots often allocate more resources to vegetative growth than to fruit
production [71].  As branches age, growth often declines [71].

Livestock:  Livestock trampling can compact the soil and reduce rhizome
sprouting and vegetative expansion of dwarf bilberry clones [7].  Stems
tend to be shorter where livestock numbers are high [95].

Chemical control:  Bilberries (Vaccinium spp.) exhibit variable
susceptibility to herbicides such as 2,4-D, 2,4,5-T, glyphosate,
karbutilate, and picloram [12,104].

Timber harvest:  Most species of Vaccinium are susceptible to
postlogging treatments which include heavy scarification [64].  This
appears to be true of dwarf bilberry as well.  However, other types of
timber treatments may produce increases in cover.  In central Colorado,
dwarf bilberry increased at all levels of tree thinning but declined
immediately after clearcutting [19].  Combined cover of dwarf bilberry
and grouse whortleberry was as follows after various types of timber
harvest [18,19]:

                                    percent cover
                 before logging     years after logging
                                    1     2     3     4     5

control          32.4             34.0  36.4  31.0  30.7  35.7
clearcutting     17.2             12.6  18.3  18.8  14.7  22.4

                                    percent cover
basal area      before thinning     years after thinning
(ft sq/acre)                        1     2     3     4      5

control         15.9              15.5  16.9   17.9  16.5   17.0
120             18.8              11.5  17.5   21.4  23.1   26.2
 80             12.6               5.3   7.4   10.6  10.5   16.7
 40             14.4               3.3   5.9    7.9   9.6   10.5 


Damage:  Large clones may be broken up by frost, fire, or burrowing
mammals [38].  In the absence of a protective layer of snow, plants are
vulnerable to cold winter temperatures and may be killed by exposure to
temperatures of 3 degrees F (-19.5 degrees C) [38].

Silviculture:  Dwarf bilberry frequently serves as a nurse crop for
Douglas-fir seedlings [78].

Wildlife considerations:  Vaccinium berries are an extremely important
food source for bears.  In many areas, bear-human conflicts are most
likely to occur during years of berry (Vaccinium spp.) crop failure
[64,83].  Both black and grizzly bears typically exploit areas with
dense concentrations of berries.  The value of Vaccinium shrubfields as
grizzly bear habitat can be increased by permanent or at least seasonal
road closures, by coordinating timber harvest dates to have minimal
impact on habitat use patterns, and by considering the cumulative
effects of habitat modification across a broad area.  In general, site
preparation should include minimizing soil compaction, using cooler
broadcast burns rather than hot burns, or by eliminating site
preparation entirely wherever possible.  Grizzly use is favored where
hiding cover is retained by treating small, irregular patches instead of
large contiguous areas, and by leaving stringers of timber within larger
cuts [102].

Related categories for Species: Vaccinium myrtillus | Dwarf Bilberry