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Wildlife, Animals, and Plants
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Introductory
SPECIES: Pinus aristata | Rocky Mountain Bristlecone Pine
ABBREVIATION :
PINARI
SYNONYMS :
Pinus balfouriana var. aristata (Engelm.) Engelm.
SCS PLANT CODE :
PIAR
COMMON NAMES :
Rocky Mountain bristlecone pine
Colorado bristlecone pine
hickory pine
TAXONOMY :
Bailey designated the western populations of bristlecone pine as Pinus
longaeva D. K. Bailey (Great Basin bristlecone pine) and reserved the
older name of P. aristata Engelm. (Rocky Mountain bristlecone pine) for
the eastern populations. Pinus balfouriana var. aristata (Engelm.)
Engelm. is included in P. longaeva.
Great Basin and Rocky Mountain bristlecone pines differ in several
important characteristics: chemistry, needle structure, and cone
morphology [2]. The Colorado-Green River drainage has separated them
for millions of years, and crosses between the two species are
relatively unsuccessful [5]. Today they are separated by 160 miles (260
km).
LIFE FORM :
Tree
FEDERAL LEGAL STATUS :
No special status
OTHER STATUS :
NO-ENTRY
COMPILED BY AND DATE :
Kathy Ahlenslager November 1986
LAST REVISED BY AND DATE :
Kathy Ahlenslager December 1987
AUTHORSHIP AND CITATION :
Ahlenslager, Kathleen E. 1986. Pinus aristata. In: Remainder of Citation
DISTRIBUTION AND OCCURRENCE
SPECIES: Pinus aristata | Rocky Mountain Bristlecone Pine
GENERAL DISTRIBUTION :
The range of Rocky Mountain bristlecone pine extends from the eastern
slope of the southern Rocky Mountains in the Laramie Range of
southwestern Wyoming southward through the eastern San Juan Mountains of
Colorado to the Sangre de Cristo Mountains east of Sante Fe, New Mexico.
A disjunct population occurs 200 miles (500 km) west in north-central
Arizona in the San Francisco Peaks [1,5,7,9,11,24,32].
ECOSYSTEMS :
FRES20 Douglas-fir
FRES21 Ponderosa pine
FRES23 Fir - spruce
FRES26 Lodgepole pine
STATES :
AZ CO NM WY
ADMINISTRATIVE UNITS :
FLFO
BLM PHYSIOGRAPHIC REGIONS :
11 Southern Rocky Mountains
12 Colorado Plateau
KUCHLER PLANT ASSOCIATIONS :
K021 Southwestern spruce - fir forest
SAF COVER TYPES :
206 Englemann spruce - subalpine fir
209 Bristlecone pine
219 Limber pine
237 Interior ponderosa pine
SRM (RANGELAND) COVER TYPES :
NO-ENTRY
HABITAT TYPES AND PLANT COMMUNITIES :
Stands of Rocky Mountain bristlecone pine are usually pure, even aged,
and open. Trees associated with this species are limber pine (Pinus
flexilis), white fir (Abies concolor), Engelmann spruce (Picea
engelmannii), ponderosa pine (Pinus ponderosa), pinyon pine (P. edulis),
subalpine fir (A. lasiocarpa), aspen (Populus tremuloides), and Rocky
Mountain juniper (Juniperus osteosperma) [11].
The Rocky Mountain bristlecone pine series occurs on cold, dry sites at
high elevations in pure stands or with limber pine. It grades into
Engelmann spruce and subalpine fir at lower elevations. In southern
Colorado and northern New Mexico, Rocky Mountain bristlecone pine and
Engelmann spruce codominate in the Englemann spruce series. This series
occurs on middle and upper slopes over 10,500 feet (3,200 m) and in the
spruce-fir zone where tree growth is limited by drought. In the
Douglas-fir (Pseudotsuga menziesii) series at higher elevations, Rocky
Mountain bristlecone pine dominates or codominates. Publications using
Rocky Mountain bristlecone pine in classification schemes are listed
below.
Forest vegetation of the Gunnison and parts of the Uncompahgre National
Forests: a preliminary habitat type classification. [14]
Major habitat types, community types and plant communities in the Rocky
Mountains [1]
Preliminary classification for the coniferous forest and woodland series
of Arizona and New Mexico. [20]
A preliminary classification of the natural vegetation of Colorado. [3]
A series vegetation classification for Region 3. [26]
VALUE AND USE
SPECIES: Pinus aristata | Rocky Mountain Bristlecone Pine
WOOD PRODUCTS VALUE :
The wood of Rocky Mountain bristlecone pine is moderately soft and is of
low value in construction. It has been used for fuel and mine props
[21,28].
IMPORTANCE TO LIVESTOCK AND WILDLIFE :
The seeds of Rocky Mountain bristlecone pine are edible to some species
of wildlife. Trees often occur in clumps, probably from the caches of
seed eaters, such as Clark's nutcrackers. Small mammals and birds may
benefit from these seed caches. Rocky Mountain bristlecone pine
provides some cover for birds and small mammals.
PALATABILITY :
NO-ENTRY
NUTRITIONAL VALUE :
NO-ENTRY
COVER VALUE :
NO-ENTRY
VALUE FOR REHABILITATION OF DISTURBED SITES :
Rocky Mountain bristlecone pine has little to no value for
rehabilitation due to the extremely slow rate of growth of seedlings and
mature trees. Its growth on gentle to steep slopes is rated as good.
Its potential for erosion control in Colorado is medium [8].
OTHER USES AND VALUES :
With ages ranging to 1,500 years, Rocky Mountain bristlecone pines are
among the oldest living trees. The dense, resinous wood of Rocky
Mountain bristlecone pines contributes to the ability of dead trees to
stand for hundreds of years and fallen wood to persist for thousands.
This wood provides cross-reference for radiocarbon dating [2,6,15].
Living trees, standing snags, and fallen trees provide overlapping
tree-ring chronologies. These ring-width chronologies are used as
paleoclimatic indicators to determine past limits of tree growth.
Variation in ring-widths of trees at upper treeline is an important
indicator of past climatic variations, especially for temperature
fluctuations. Data from these chronologies show that there has been a
net retreat of upper bristlecone pine treeline in the United States over
the last several thousand years [17,19].
The dates of major volcanic eruptions correlate with frost rings of
bristlecones [18]. Rocky Mountain bristlecone pine is of value for its
natural aesthetics and for watershed protection, as well as aiding in
soil-building and stabilization in a harsh environment [12].
MANAGEMENT CONSIDERATIONS :
NO-ENTRY
BOTANICAL AND ECOLOGICAL CHARACTERISTICS
SPECIES: Pinus aristata | Rocky Mountain Bristlecone Pine
GENERAL BOTANICAL CHARACTERISTICS :
Rocky Mountain bristlecone pine is a long-lived, ectomycorrhizal, native
species, which may be nitrogen fixing. Trees attain heights of 15 to 30
feet (5-9 m) with diameters between 12 and 18 inches (31-46 cm).
Needles are retained in excess of 20 years. Trees often have a
contorted and multistemmed appearance. The sparse crowns of twisted or
contorted trees are supported by narrow strips of cambium. The effects
of sand- and ice-blasting by wind are seen in older trees with a double
"pick-a-back" growth form. Here the windward trunk is dead, but a
narrow strip of cambium supports branches on the leeward side of the
tree, the "piggy back" [10,28].
Rocky Mountain bristlecone pine exhibits slow growth rates and dense,
highly resinous wood. Bristlecones are known for their longevity.
Although trees of Rocky Mountain bristlecone pine may reach 1,500 years
in age, some Great Basin bristlecones (Pinus longaeva) have been
estimated to live 5,200 years. Rocky Mountain bristlecone pine and
foxtail (Pinus balfouriana) grow more rapidly than the Great Basin
bristlecone pine because of greater moisture availability. However,
they also are more subject to heart rot and do not reach the longevity
of Great Basin bristlecone [2,13]. Compared with other white pines,
Rocky Mountain bristlecone pine is very resistant to white pine blister
rust.
Rocky Mountain bristlecone, Great Basin bristlecone, and foxtail pine
share the following characteristics [10,24]:
(1) occurrence at the upper limits of tree growth and a reduced rate of
growth
(2) a capacity for long life
(3) continued growth after loss of large areas of tissue from drought,
stress, wind injury, and soil erosion
(4) heavy, dense, resin-impregnated wood with small, closely arranged
water-conducting cells (tracheids) which provide resistance to
moisture and decay
(5) survival in an environment of drought, low temperatures, short
growing seasons, daily temperature extremes, and poor soils
(6) retention of needles for several years, which reduces the need for
moisture and nutrients, as well as carrying a tree over
several years of stress
(7) relative safety from ground fire due to sparse ground cover and
litter scarcity.
RAUNKIAER LIFE FORM :
Phanerophyte
REGENERATION PROCESSES :
The environmental and physiological factors contributing to the
longevity of Rocky Mountain bristlecone pine also work to lower its
regeneration potential. Trees are intolerant of shade, grow slowly, and
are locally scattered in distribution. Reproduction is sparse.
Bristlecones characteristically occur in old to moderately old, open
stands, and form the vegetative climax. However, this species may also
act like a pioneer in recently disturbed areas where under favorable
conditions tree growth is vigorous and fast [5,28]. Recovery from
logging, road construction, and other disturbances, though, is generally
extremely slow, often taking hundreds of years [12].
With 75 percent seed germination within 8 days, researchers concluded
that the seeds of bristlecone pines do not exhibit dormancy. In an
effort to understand the limited occurrence of Rocky Mountain
bristlecone pine, the germinability of seeds was studied in Clear Creek,
Colorado. Rapid germination, scarification mortality, and lack of
seedling cold hardiness were identified as contributing factors working
against Rocky Mountain bristlecone pine reproduction. Seeds had a
germination rate of 80 percent and germinated within 10 days (with or
without light). Infected with fungus, 90 percent of the scarified seeds
died. A gradual decrease in temperature to 14 degrees Fahrenheit (-10
deg C) killed 10- and 180-day-old seedlings [28].
SITE CHARACTERISTICS :
Rocky Mountain bristlecone pine grows in subalpine areas. Stands are
usually pure, even-aged, and open. They are found from 9,200 to 11,800
feet (2,800-3,600 m) in elevation in Colorado and New Mexico, usually on
rocky outcrops of southern or southwestern slopes with limited soil,
intense sunlight, and rapid runoff. In the San Francisco Peaks Research
Natural Area in Arizona, bristlecone pines occur from 10,500 to 11,500
feet (3,200-3,500 m) on south-facing ridges and talus slopes [2,32].
Rocky Mountain bristlecone pines occur most often on igneous and
volcanic substrates. Short growing seasons and little available
moisture characterize their habitat. Trees are intolerant of shading
and occur in areas of sparse ground cover. Precipitation ranges from 16
to 40 inches (400-1,000 mm) [2,31,32].
Above Sante Fe, New Mexico, limber pine dominates on xeric sites between
7,550 to 10,170 feet (2,300 and 3,100 m) but is replaced on the driest
sites by Rocky Mountain bristlecone pine. To the north Rocky Mountain
bristlecone pine increases in importance, and in the area of the Spanish
Peaks of Colorado, it is found from treeline down to ponderosa
pine-Gambel oak (Quercus gambelii) woodlands. North of this area Rocky
Mountain bristlecone pine is replaced by limber pine. At Pikes Peak in
Colorado, it is important on the south slopes from middle to high
elevations; however, on north slopes it is restricted to high-elevation
sites. On Mt. Evans in Colorado, bristlecone and limber pine occur at
high elevations and are partitioned by substrates [2,25,30].
SUCCESSIONAL STATUS :
Rocky Mountain bristlecone pine is a climax species and persists at
treeline for hundreds to thousands of years in the absence of
disturbance and competition. It is highly adapted to its habitat of
very shallow soils, slow primary succession, short growing season, and
avalanches. This tree is intolerant of shading and competition. Below
its lower elevational limits, it is outcompeted and replaced by other
conifers on moist sites. Although its upper limits of growth are
temperature sensitive, its lower growth limits are precipitation
sensitive [2,25,32]. There is no evidence for the expansion or
recession of the range of Rocky Mountain bristlecone pine, so it is
considered a senescent species [27].
SEASONAL DEVELOPMENT :
Bristlecone pines flower from July to August, and cones start ripening
about mid-September. The period of flowering and cone opening is
uniform for Rocky Mountain and Great Basin bristlecone pines and foxtail
pine [5,10]. Phenological data for Rocky Mountain bristlecone pine in
the San Francisco Peaks area of Arizona are as follows:
Plant Activity 1918-23 1969
------------------------------------------------------------------------
Vegetative buds swelling June 1-20 June 1
Vegetative buds elongating or opening June 20-30 June 15
Shoots making rapid growth July 1-30 ----
Male buds appearing July 1-10 ----
Female and male buds mature ---- July 22
Pollen falling July 20-Aug. 20 July 22-27
Cones full grown Sept. 10-20 ----
Seeds mature Sept. 20-Oct. 10 Sept. 24-Oct. 2
Cones opening ---- Sept. 27-Oct. 10
Leaves falling Oct. 1-30 ----
Period of active growth June 20-Sept. 20 ----
FIRE ECOLOGY
SPECIES: Pinus aristata | Rocky Mountain Bristlecone Pine
FIRE ECOLOGY OR ADAPTATIONS :
Rocky Mountain bristlecone pine occurs for the most part in habitats
where fuels to carry fires are essentially nonexistant. In the
subalpine zone where bristlecones are found, low temperatures and a
short growing season keep the production of organic matter low. Burns
with enough intensity to result in crown fires rarely occur in the
grass-dominated understory of bristlecone pine forests. Surface fires
in these areas are infrequent, slow burning, and of low intensity [7].
POSTFIRE REGENERATION STRATEGY :
Tree without adventitious-bud root crown
Initial-offsite colonizer (off-site, initial community)
FIRE EFFECTS
SPECIES: Pinus aristata | Rocky Mountain Bristlecone Pine
IMMEDIATE FIRE EFFECT ON PLANT :
Fire plays a minor role in bristlecone pine habitats due to sparse
ground cover. Although scattered dead and living trees show evidence of
fires, undergrowth is scarce with essentially no sign of past fires. In
these areas undergrowth consists of small shrubs, cushion plants, and
xerophytic bunchgrasses [7].
DISCUSSION AND QUALIFICATION OF FIRE EFFECT :
NO-ENTRY
PLANT RESPONSE TO FIRE :
NO-ENTRY
DISCUSSION AND QUALIFICATION OF PLANT RESPONSE :
NO-ENTRY
FIRE MANAGEMENT CONSIDERATIONS :
NO-ENTRY
REFERENCES
SPECIES: Pinus aristata | Rocky Mountain Bristlecone Pine
REFERENCES :
1. Alexander, Robert R. 1985. Major habitat types, community types and
plant communities in the Rocky Mountains. Gen. Tech. Rep. RM-123. Fort
Collins, CO: U.S. Department of Agriculture, Forest Service, Rocky
Mountain Forest and Range Experiment Station. 105 p. [303]
2. Bailey, D. K. 1970. Phytogeography and taxonomy of Pinus subsection
Balfourianae. Annals of the Missouri Botanical Garden. 57: 210-249.
[375]
3. Baker, William L. 1984. A preliminary classification of the natural
vegetation of Colorado. Great Basin Naturalist. 44(4): 647-676. [380]
4. Bernard, Stephen R.; Brown, Kenneth F. 1977. Distribution of mammals,
reptiles, and amphibians by BLM physiographic regions and A.W. Kuchler's
associations for the eleven western states. Tech. Note 301. Denver, CO:
U.S. Department of the Interior, Bureau of Land Management. 169 p.
[434]
5. Critchfield, William B. 1977. Hybridization of foxtail and bristlecone
pines. Madrono. 24(4): 193-244. [713]
6. Currey, Donald R. 1965. An ancient bristlecone pine stand in eastern
Nevada. Ecology. 46(4): 564-566. [725]
7. DeVelice, Robert L.; Ludwig, John A. 1983. Forest habitat types south of
the Mogollon Rim, Arizona and New Mexico. Final Report. Cooperative
Agreement No. 28-K2-240 between U.S. Department of Agriculture, Forest
Service, Rocky Mountain Forest and Range Experiment Station and New
Mexico State University. Las Cruces, NM: New Mexico State University. 47
p. [780]
8. Dittberner, Phillip L.; Olson, Michael R. 1983. The plant information
network (PIN) data base: Colorado, Montana, North Dakota, Utah, and
Wyoming. FWS/OBS-83/86. Washington, DC: U.S. Department of the Interior,
Fish and Wildlife Service. 786 p. [806]
9. Eyre, F. H., ed. 1980. Forest cover types of the United States and
Canada. Washington, DC: Society of American Foresters. 148 p. [905]
10. Fritts, Harold C. 1969. Bristlecone pine in the White Mountains of
California: growth and ring-width characteristics. Papers of the
Laboratory of Tree-Ring Research. No. 4. Tucson, AZ: The University of
Arizona Press. 44 p. [980]
11. Griffin, James R.; Critchfield, William B. 1972. The distribution of
forest trees in California. Res. Pap. PSW-82. Berkeley, CA: U.S.
Department of Agriculture, Forest Service, Pacific Southwest Forest and
Range Experiment Station. 118 p. [1041]
12. Hess, Karl; Alexander, Robert R. 1986. Forest vegetation of the Arapaho
and Roosevelt National Forests in central Colorado: a habitat type
classification. Res. Pap. RM-266. Fort Collins, CO: U.S. Department of
Agriculture, Forest Service, Rocky Mountain Forest and Range Experiment
Station. 48 p. [1141]
13. Hitch, Charles J. 1982. Dendrochronology and serendipity. American
Scientist. 70(3): 300-305. [1164]
14. Komarkova, Vera; Alexander, Robert R.; Johnston, Barry C. 1988. Forest
vegetation of the Gunnison and parts of the Uncompahgre National
Forests: a preliminary habitat type classification. Gen. Tech. Rep.
RM-163. Fort Collins, CO: U.S. Department of Agriculture, Forest
Service, Rocky Mountain Forest and Range Experiment Station. 65 p.
[5798]
15. Krebs, Paula V. 1973. Dendrochronology of bristlecone pine (Pinus
aristata Engelm.) in Colorado. Arctic and Alpine Research. 5(2):
149-150. [1376]
16. Kuchler, A. W. 1964. Manual to accompany the map of potential vegetation
of the conterminous United States. Special Publication No. 36. New York:
American Geographical Society. 77 p. [1384]
17. LaMarche, Valmore C., Jr. 1974. Paleoclomatic inferences from long
tree-ring records. Science. 183(4129): 1043-1048. [1391]
18. LaMarche, Valmore C., Jr.; Hirschboeck, Katherine K. 1984. Frost rings
in trees as records of major volcanic eruptions. Nature. 307(12):
121-126. [1392]
19. LaMarche, Valmore C., Jr.; Stockton, Charles W. 1974. Chronologies from
temperature-sensitive bristlecone pines at upper treeline in western
United States. Tree-ring Bulletin. 34: 21-45. [1395]
20. Layser, Earle F.; Schubert, Gilbert H. 1979. Preliminary classification
for the coniferous forest and woodland series of Arizona and New Mexico.
Res. Pap. RM-208. Fort Collins, CO: U.S. Department of Agriculture,
Forest Service, Rocky Mountain Forest and Range Experiment Station. 27
p. [1428]
21. Little, Elbert L., Jr. 1975. Rare and local conifers in the United
States. Conservation Research Rep. No. 19. Washington, DC: U.S.
Department of Agriculture, Forest Service. 25 p. [15691]
22. Little, Elbert L., Jr. 1978. Important forest trees of the United
States. Agric. Handb. 519. Washington, DC: U.S. Department of
Agriculture, Forest Service. 70 p. [1463]
23. Lyon, L. Jack; Stickney, Peter F. 1976. Early vegetal succession
following large northern Rocky Mountain wildfires. In: Proceedings, Tall
Timbers fire ecology conference and Intermountain Fire Research Council
fire and land management symposium; 1974 October 8-10; Missoula, MT. No.
14. Tallahassee, FL: Tall Timbers Research Station: 355-373. [1496]
24. Mastroguiseppe, Ronald J. 1972. Geographic variation in foxtail pine,
Pinus balifouriana Grev. & Balf. Humbolt, CA: California State
University, Humboldt. 98 p. M.S. thesis. [1548]
25. Mirov, N. T. 1967. The genus Pinus. New York: Ronald Press. 602 p.
[1663]
26. Moir, W. H. 1983. A series vegetation classification for Region 3. In:
Moir, W. H.; Hendzel, Leonard, tech. coords. Proceedings of the workshop
on Southwestern habitat types; 1983 April 6-8; Albuquerque, NM.
Albuquerque, NM: U.S. Department of Agriculture, Forest Service,
Southwestern Region: 91-95. [1672]
27. Peet, Robert K. 1978. Forest vegetation of the Colorado Front Range:
patterns of species diversity. Vegetatio. 37(2): 65-78. [1866]
28. Preston, Richard J., Jr. 1948. North American trees. Ames, IA: The Iowa
State College Press. 371 p. [1913]
29. Raunkiaer, C. 1934. The life forms of plants and statistical plant
geography. Oxford: Clarendon Press. 632 p. [2843]
30. Reid, William H. 1972. Germination of Pinus aristata Engelm. Great Basin
Naturalist. 32(4): 235-237. [1953]
31. Rominger, James M.; Paulik, Laurie A. 1983. A floristic inventory of the
plant communities of the San Francisco Peaks Research Natural Area. Gen.
Tech. Rep. RM-96. Fort Collins, CO: U.S. Department of Agriculture,
Forest Service, Rocky Mountain Forest and Range Experiment Station. 9 p.
[2023]
32. Schaack, Clark G. 1989. Additions to Arizona flora-range extensions of
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Arizona-Nevada Academy of Science. 23: 35-37. [11414]
Index
Related categories for Species: Pinus aristata
| Rocky Mountain Bristlecone Pine
|
 |
