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Wildlife, Animals, and Plants
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VALUE AND USE
SPECIES: Pinus albicaulis | Whitebark Pine
WOOD PRODUCTS VALUE :
Whitebark pine is slow growing and after about 250 years reaches small
to moderately large sizes, depending on the site. The bole is generally
short and often of poor form for timber. In general, there is little
interest in whitebark pine for commercial timber, although it is
harvested in some localities in small amounts for lumber, posts, poles,
and firewood. Yields of merchantable timber are very low, about 10 to
20 feet per acre per year (0.7-1.4 m/ha/yr) in high-elevation stands
where it forms a short tree with large branches [3,8,14,19,25,40,48].
Higher yields of up to 40 feet per acre per year (48 m/ha/yr) have been
reported in better subalpine forest sites.
The best sites for treeline growth of whitebark pine in Montana are in
subalpine fir and sedge (Luzula hitchcockii) habitat types, Menziesia
(Menziesia ferruginea) phase. On such sites, whitebark reaches 70 to
100 feet (21-30 m) tall and 20 to 30 inches (50-70 cm) in d.b.h. at 250
to 300 years of age. When growing in association with whitebark pine,
Engelmann spruce grows larger and is the primary objective of management
[3].
Where whitebark pine is a component of better sites in spruce-fir
forests in Canada and the Rocky Mountains of the western United States,
whitebark pine produces good-quality timber with lumber properties
similar to western white pine. However, whitebark pine is graded lower
because of its darker appearance [3,14].
In some mountain valleys of southwestern Alberta between 5,000 and 6,000
feet (1,520-1,830 m), whitebark pine trees grow larger than associated
lodgepole pine and are harvested. The wood density of whitebark pine is
similar to local Douglas-fir (Pseudotsuga menziesii, but heavier than
hybrid spruce, subalpine fir, and lodgepole pine [12,15].
IMPORTANCE TO LIVESTOCK AND WILDLIFE :
Compared with other temperate coniferous forests, whitebark pine forests
are highly productive in terms of forage. Whitebark pine seeds are
present in early spring (from caches) and late fall when other wildlife
foods are scarce or low in digestibility. Seeds are wingless, large,
and high in calories. Although seed crops vary annually, they are an
important food source for numerous birds, rodents, and bears. Cones are
indehiscent and retain mature seeds. Thus, they can be harvested
efficiently [30,47].
The distribution of whitebark pine is strongly influenced by the
dispersal and establishment of seeds by Clark's nutcrackers. The
interaction between the two species is a result of coevolution and is
mutualistic. Clark's nutcrackers have evolved a sublingual throat pouch
in which to carry seeds to sites where they cache them about 2.5 inches
(1 cm) below the soil surface in groups of one to five. Birds harvest
and cache seeds in the late summer and fall for use during the following
winter and spring. Additional birds which feed on whitebark pine seeds
include William's sapsucker, white-headed woodpecker, mountain
chichadee, white-breasted nuthatch, Cassin's finch, red crossbill, pine
grosbeak, and blue grouse [20,33,44,45,46].
Bears in the Yellowstone area regularly eat pine seeds in the spring
(March to June) and fall (September and October). Most whitebark pine
seed eaten by grizzly and black bears are from red squirrel cone caches.
Rodents, such as red squirrels, Douglas' squirrels, ground squirrels,
and chipmunks, store large quantities of intact cones in middens at the
base of trees or underground in caches. Although deer mice cannot gnaw
the cones, they eat and cache loose seeds [26,46].
Whitebark pine survives where tree growth is limited and provides hiding
and thermal cover for wildlife. Cavity-nesting birds use tree trunks
and snags. Mule deer, elk, and predatory animals also use whitebark
habitat [40,45].
PALATABILITY :
The foliage of whitebark pine is not browsed to any extent by animals.
Blue grouse do eat the buds and needles of it in the winter [Arno pers.
comm. 1987]. The degree of use shown by livestock and wildlife species
for whitebark pine in Montana and Wyoming is rated as follows [13]:
MT WY
Cattle Poor Poor
Sheep Poor Poor
Horses Poor Poor
Pronghonr ---- Poor
Elk Poor Fair
Mule deer Poor Fair
White-tailed deer ---- Fair
Small mammals Fair Good
Small nongame birds Good Good
Upland game birds Good Good
Waterfowl ---- Poor
NUTRITIONAL VALUE :
Whitebark pine is rated poor in energy value and poor in protein value
[13].
COVER VALUE :
The degree to which whitebark pine provides environmental protection
during one or more seasons for wildlife species in Montana and Wyoming
is rated as follows [13]:
MT WY
Pronghorn ---- Poor
Elk Good Fair
Mule deer Good Fair
White-tailed deer ---- Poor
Small mammals Good Fair
Small nongame birds Good Good
Upland game birds Good Fair
Waterfowl ---- Poor
VALUE FOR REHABILITATION OF DISTURBED SITES :
Growth of whitebark pine in Montana, North Dakota, and Wyoming is
reported to be good on gentle to steep slopes. Its potential for
erosion control is low to medium. Short-term revegetation potential is
rated low; long-term potential is medium [13].
Whitebark pine has limited use in the rehabilitation of disturbed sites.
Vegetation recovery is slow in the exposed, dry, rocky sites where it is
found, and soil erosion can prevent complete restoration. Its survival
at high elevations indicates that it has potential for use in land
reclamation projects. Its slow growth and low seed germination are
handicaps in its use in reclamation [14,41,43].
OTHER USES AND VALUES :
Besides providing cover and food for numerous animals and birds, the
principal use of whitebark pine sites is watershed protection. In
western Montana whitebark pine habitats are the major sources of
streamflow. On steep terrain, trees help to stabilize snow, soil, and
rocks [3,14,19,23,30,40,43].
Seeds and inner tree bark of whitebark pine were included in the diets
of some Indians [20,28]. The species is also used to a limited extent
as an ornamental [28]. Although the open character of whitebark pine
sites appeals to many recreationists, the sites are often fragile and
degrade rapidly even with relatively low levels of recreation use [18].
MANAGEMENT CONSIDERATIONS :
Watershed protection and enhancement are of primary management
importance in whitebark pine areas. In addition, the slow rate of
vegetation recovery requires dispersed and low-impact recreation if the
aesthetic appeal of whitebark pine forests is to be maintained
[8,14,40].
Whitebark pine is replaced by more shade-tolerant species on many sites.
This can result from fire suppression, as well as damage by mountain
pine beetle and white pine blister rust. Unless these stands are
rejuvenated, seed crops of this pine species will diminish.
Rejuvenation may be accomplished by prescribed burning, seed plantings,
and propagation of rust-resistant trees. The recovery of grizzly bears
and their use of pine seeds is also a consideration for the management
of whitepark pine sites [3,14].
Damaging agents: Whitebark pine is very susceptible to white pine
blister rust (Cronartium ribicola). Large areas of whitebark pine in
northern Idaho and northwestern Montana have died from blister rust
[Arno pers. comm. 1987]. Infection occurs where adequate moisture
permits infestation of currants and gooseberries (Ribes spp.), alternate
hosts for the rust. White pine blister rust kills the upper
(cone-bearing) branches of large trees and sometimes entire trees.
Blister rust has a severe impact on saplings, thus often preventing
whitebark pine replacement [Arno pers. comm. 1987]. Several other
diseases also infect trees, generally with minor consequences [3,14,19].
Whitebark pine trees are also killed by the mountain pine beetle
(Dendroctonus ponderosae), often after being weakened by rust. The
inner bark of larger trees supports the growth of larvae which girdle
the trees. Numerous other pests infect whitebark pines, including dwarf
mistletoes (Arceuthobium spp.) and saprophytes [3,44].
Related categories for Species: Pinus albicaulis
| Whitebark Pine
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