Index of Species Information
SPECIES: Larix lyallii
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| Subalpine larch in Headlight Basin, WA. Wikimedia Commons image by J. Brew. |
Introductory
SPECIES: Larix lyallii
AUTHORSHIP AND CITATION:
Habeck, R. J. 1991. Larix lyallii. In: Fire Effects Information System, [Online].
U.S. Department of Agriculture, Forest Service, Rocky Mountain Research Station,
Fire Sciences Laboratory (Producer). Available:
https://www.fs.usda.gov/database/feis/plants/tree/larlya/all.html [].
Revisions:
On 2 March 2018, the common name of this species was changed in FEIS
from: alpine larch
to: subalpine larch. Images were also added.
ABBREVIATION:
LARLYA
SYNONYMS:
NO-ENTRY
NRCS PLANT CODE:
LALY
COMMON NAMES:
subalpine larch
alpine larch
lyall larch
lyall's larch
tamarack
timberline larch
woolly larch
TAXONOMY:
The scientific name of subalpine larch is Larix lyallii Parl [20].
There are no recognized subspecies, varieties, or forms of subalpine
larch. Hybridization with western larch (Larix occidentalis)
results in a genetically different tree [2,6,7]. Although these hybrids
occupy a similar geographic area, they inhabit different altitudinal
zones, separated from each other by 500 to 1,000 feet (150-300 m) [2].
Differentiation between subalpine larch and hybrids can be determined by
analyzing the foliar terpenes and volatiles [7,15].
LIFE FORM:
Tree
FEDERAL LEGAL STATUS:
No special status
OTHER STATUS:
NO-ENTRY
DISTRIBUTION AND OCCURRENCE
SPECIES: Larix lyallii
GENERAL DISTRIBUTION:
Subalpine larch occupies two mountain systems: the northern Rockies and
northern Cascades [3,16]. It can be found on high mountains in southern
British Columbia and Alberta, north-central Washington, north-central
and east-central Idaho, and western Montana [1,13,23]. Subalpine larch
exhibits a highly discontinuous distribution, which is believed to be a
remnant of a continuous range existing at a time when cooler, more
extensive timberline habitat existed [1,3]. Typical subalpine larch stands
are often isolated pockets of open, parklike groves, less than 0.05 acre
(0.2 ha) [3].
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| Distribution of subalpine larch. 1971 USDA, Forest Service map digitized by Thompson and others [29]. |
ECOSYSTEMS:
FRES23 Fir - spruce
FRES25 Larch
STATES:
ID MT WA AB BC
BLM PHYSIOGRAPHIC REGIONS:
2 Cascade Mountains
8 Northern Rocky Mountains
KUCHLER PLANT ASSOCIATIONS:
K004 Fir - hemlock forest
K015 Western spruce - fir forest
SAF COVER TYPES:
205 Mountain hemlock
206 Engelmann spruce - subalpine fir
208 Whitebark pine
212 Western larch
SRM (RANGELAND) COVER TYPES:
NO-ENTRY
HABITAT TYPES AND PLANT COMMUNITIES:
Subalpine larch is a dominant species occupying the timberline habitat type
within the subalpine fir (Abies lasiocarpa) series [23]. Principal
associates include whitebark pine (Pinus albicaulis), subalpine fir, and
Engelmann spruce (Picea engelmannii) [3]. Major undergrowth species
include mountain-heather (Phyllodoce empetriformis), smooth woodrush
(Luzula hitchcockii), and grouse whortleberry (Vaccinium scoparium)
[3,9,23]. See successional status for more information.
Publications listing subalpine larch as an indicator or dominant species in
habitat types (hts), community types (cts), or vegetation types (vts)
are listed below:
Area Classification Authority
MT forest hts Pfister & others 1977
n ID general veg. cts Cooper & others 1991
s AB general veg. vts Holland & others 1982
MANAGEMENT CONSIDERATIONS
SPECIES: Larix lyallii
WOOD PRODUCTS VALUE:
Subalpine larch wood has no potential commercial value [2,7]. No site
index or yield data have been developed for subalpine larch stands. Annual
yield capability has been estimated to be only 10 to 20 cubic feet per
acre (0.7-1.4 m3/ha) on sites having better than average productivity
[23]. Defect is very high, and no commercial timber harvesting has been
reported, or is likely [2].
IMPORTANCE TO LIVESTOCK AND WILDLIFE:
Many timberline bird and mammal species are associated with subalpine larch
communities. Mountain goat, bighorn sheep, hoary marmot, pika, mule
deer, elk, black and grizzly bear, red squirrel, and snowshoe hare
are among the mammals that feed in subalpine larch stands. Blue grouse
feed heavily on the needles. Two studies suggest that subalpine larch
foliage may be one of the most important summer foods for blue grouse
[3].
PALATABILITY:
Big mammals do not heavily browse subalpine larch branches, twigs, or
foliage. The primary consumers of needles are upland game birds such as
the blue grouse.
NUTRITIONAL VALUE:
NO-ENTRY
COVER VALUE:
Subalpine larch provides concealment and thermal cover in an otherwise open
habitat. Woodpeckers and other cavity nesters utilize the hollowed-out
portions of larger trees. Larger mammals may utilize subalpine larch
stands as windbreaks or burrows [3]. Grizzly bears often den in subalpine
larch stands in Banff National Park [2].
VALUE FOR REHABILITATION OF DISTURBED SITES:
Subalpine larch contributes to watershed protection by stabilizing snow
loads on steep northern slopes, and thus reducing the threat of
avalanches. Subalpine larch is considered useful for high-elevation
reclamation projects [2].
OTHER USES AND VALUES:
Subalpine larch communities are valued as wildlife habitat, and for outdoor
recreation and esthetics [2]. Photographers and hikers appreciate the
changing colors of subalpine larch, which is a translucent bright green in
summer, and lemon yellow and gold in fall. Dendrochronologists have
found subalpine larch to be an excellent indicator of climatic variability
[8].
OTHER MANAGEMENT CONSIDERATIONS:
Subalpine larch is generally not placed under active management. Disease
or insects cause little damage to this tree. Occasionally, damage may
occur by an unidentified fly larvae (Diptera), which destroyed a heavy
seed crop in north-central Washington [3]. It is suspected that the
larch case bearer (Coleophora laricella) will eventually spread from
lower western larch stands to subalpine larch stands [3]. Brown heart rot
caused by Quinine fungus (Fomes officinales) is often found in subalpine
larch, but not often enough to be considered prevalent. Needle blight
(Sarcotrochila alpina) and cast fungi (Hypodermella laricis) severely
infected many stands of subalpine larch in British Columbia. The most
common fungus infecting subalpine larch is an unidentified canker, similar
to the European larch canker (Dasyscypha willkommii). This fungus
creates noticeable swellings in young and mature twigs. These fungi
weaken but usually do not kill the tree [3].
BOTANICAL AND ECOLOGICAL CHARACTERISTICS
SPECIES: Larix lyallii
GENERAL BOTANICAL CHARACTERISTICS:
Subalpine larch is an intolerant, native, deciduous, coniferous tree
[2,13]. Dominant subalpine larch usually live 400 to 500 years, but many
trees reach 700 years, and the oldest individuals may live up to 1,000
years [1]. Subalpine larch generally has one erect bole, with a braided
stem. It rarely grows as krummholz because its leaves are deciduous and
its buds are woody and protected [2,18]. Young subalpine larch have very
flexible boles, which allow them to occupy snowslide and snow creep
sites [3]. As a high-elevation species, it averages 40 to 50 feet
(12-15 m) in height and 12 to 24 inches (30-60 cm) in d.b.h. on
north-facing slopes. The largest recorded subalpine larch, found in the
Cascade range of Washington, is 95 feet (29 m) tall and 79 inches (201
cm) d.b.h.
Subalpine larch produces a coating of white tomentum on its growing shoots.
This 'wool' remains present for at least 1 year and is believed to
decrease water loss from these shoots by increasing the boundary layer
[25]. The leaves are grouped into clusters of 30 to 40 rigid needles,
borne on short, light bluish-green spurs, 1 to 2 inches (2-4 cm) long.
The bark is thin (generally less than 1 inch), initially smooth,
becoming more deeply furrowed with age. Cones are reddish-yellow to
purple-green and 1 to 2 inches (3-5 cm) long. The bracts are much
longer than the cone scales [22]. Subalpine larch trees are generally
deeply rooted on poor soils. They are well anchored by a large taproot
and long, continuous lateral roots [3].
RAUNKIAER LIFE FORM:
Phanerophyte
REGENERATION PROCESSES:
Flowering and fruiting: Subalpine larch can begin producing cones when
they are 100 years old, but generally do not produce seed in quantity
until they reach 200 years of age [3]. Subalpine larch are monoecious.
Pollen is wind-dispersed from the male strobili in June, and by
September, small purplish cones 1.5 to 2.0 inches (4-5 cm) long emerge.
Low cone production can be attributed to late season frost damage.
Other factors limiting fertilization, pollination, and seed maturation
are unknown [2].
Seed production and dissemination: Large seed crops are infrequent,
occurring only 1 year out of 10 in Montana. Seeds are winged and are
usually wind-disseminated in September. Snowslides have been known to
transport seeds to lower elevations [7]. Cleaned seed number between
105,000 and 163,000 per pound (231-359 500/kg). Seed destruction by
fungi and larvae are discussed under management considerations.
Seedling establishment: Studies have shown that without seed
scarification, germination rates are poor. Dry winds and high
temperatures on southern slopes probably contribute to poor germination
[3]. Soaking seeds for 24 hours in 3 percent hydrogen peroxide solution
can improve seed germination [3,26]. Subalpine larch seedlings generally
have five cotyledons, although four or six may appear. They are narrow,
pointed, and 0.4 to 0.6 inch (1.0-1.5 cm) long. Germination is epigeal.
Successful germination takes place mostly on moist mineral soil surfaces
on northern aspects. Richards [25], however, found that height and
diameter growth for young subalpine larch was 1.5 times greater on southern
exposures than on northern. Seeds of subalpine larch germinate in July,
soon after snowmelt; they require full light and low temperatures for
germination [2].
For the first 20 to 25 years, growth is typically very slow. This
strategy allows for extensive establishment of the root system and
decreases the probably of top-kill from windthrow or heavy snowpack [2].
Subalpine larch apparently become deeply rooted; thus, soil moisture near
the surface seems to have no influence on their growth [3]. Seedlings
16 to 25 years old and only 8 to 16 inches (20-40 cm) tall had taproots
penetrating 16 to 24 inches (20-40 cm) and laterals 8 to 24 inches
(20-60 cm) beneath the surface [25]. Subalpine larch seedlings and
saplings up to 3 or 4 feet (1.00-1.25 m) tall exhibit evergreen basal
limbs. This foliage lasts for two summers and helps establish subalpine
larch on severe sites [3].
Hybridization is known to occur between subalpine larch and western larch
[17]. Areas most likely to support hybrid populations are those that
have experienced natural disturbances, such as snow or rock slides. The
creation of such microsites may allow these species to intermingle
because of their varying successional adaptabilities [17].
Vegetative reproduction: Subalpine larch does not reproduce from sprouts.
Layering has been known to occur only in a few severely stunted trees or
krummholz [3].
SITE CHARACTERISTICS:
Climate: Subalpine larch is most commonly found in very cold, moist, high
altitude sites. Altitudinal limits are approximately 5,800 to 9,900
feet (1,770-3,010 m) [3,16]. The mean temperatures are below freezing
for 6 months [2]. Mean annual precipitation on most subalpine larch sites
is between 32 and 75 inches (800 and 1,900 mm), occurring principally in
the form of snow and sleet. Periods of drought do occur in late summer
but have minor effects on tree vigor. Violent winds are very common,
often reaching hurricane velocity of 73 miles per hour (117 km/h).
Soils: Subalpine larch commonly grows on slopes covered with granite or
quartzite talus, not previously occupied by vascular plants. This tree
will also establish itself in cracks between big boulders [2]. Soil
development on subalpine larch sites is extremely poor due to low
temperatures and short growing seasons, which retard microbial and
chemical activity [2,3]. The rocky shallow soils are generally very
gravelly loams, ranging in pH from 3.9 to 5.7 [24]. General
classification of subalpine larch soils are in fragmental, and loamy
skeletal families within the order Entisols (cryorthents) [27].
SUCCESSIONAL STATUS:
Subalpine larch is an intolerant seral species that will decrease when
shaded by more shade-tolerant conifers [11]. This long-lived dominant
often forms pure stands 500 to 1,000 feet (150-300 m) above the
elevational limits of other conifers. Subalpine larch is generally
classified as an associate species within the whitebark pine, Engelmann
spruce, subalpine fir, and mountain hemlock (Tsuga mertensiana) habitat
types. In higher elevation sites, subalpine larch is classified under the
subalpine larch/subalpine fir hts; while in lower elevation sites, it is
categorized more broadly into the subalpine fir/smooth woodrush hts
[2,23].
Subalpine larch can be thought of as a pioneer species, establishing itself
on rocky surfaces. It also proliferates after fire, avalanche, or other
site disturbances. On some occasions, subalpine larch will regenerate on
burned areas within the subalpine fir zone, 330 to 490 feet (100-150 m)
below its usual elevational limits [2]. This regenerative trend is more
dominant on northern exposures and at high elevations [3]. At the
highest timberline elevations, subalpine larch fills a vacant niche
representing the potential climax. Its ability to grow at higher
elevations than other conifers relates to its superior resistance to
winter desiccation [2].
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| Yellow fall cover of subalpine larch in Glacier Peak Wilderness, WA. Green trees are whitebark pine. Wikimedia Commons image by Marshmallow. |
SEASONAL DEVELOPMENT:
The growing season for subalpine larch lasts approximately 90 days. Bud
development is triggered by rising mean air temperature to about 39
degrees Fahrenheit (4 deg C) and can be normally expected to begin the
end of May. Shoot growth occurs mostly in July and progresses rapidly.
The height growth of a small subalpine larch will average approximately 0.6
inch (1.5 cm) a year during the first 25 years. Leaf fall and dormancy
are controlled by photoperiod. Late summer drought, however, has been
shown to induce early yellowing [3]. Subalpine larch far outlives its
associated conifer species and usually dies as a result of being
windblown after pronounced heart rot. If lower limbs remain on the
stump, the tree can remain alive for many more decades [3].
FIRE ECOLOGY
SPECIES: Larix lyallii
FIRE ECOLOGY OR ADAPTATIONS:
Subalpine larch is a thin-barked species easily damaged by fire [3,11,19].
It does not usually suffer from fire effects because the tree tends to
occupy remote, rocky, cold sites where fire does not spread well [3,19].
Fire appears to have an important influence on the establishment of
subalpine larch by creating mineral soil seedbeds [5].
FIRE REGIMES:
Find fire regime information for the plant communities in which this
species may occur by entering the species name in the FEIS home page under
"Find Fire Regimes".
POSTFIRE REGENERATION STRATEGY:
off-site colonizer; seed carried by wind; postfire years 1 and 2
FIRE EFFECTS
SPECIES: Larix lyallii
IMMEDIATE FIRE EFFECT ON PLANT:
On the occasion fire does reach subalpine larch stands, the tree will not
do favorably under those of high intensity. Pure stands of subalpine
larch, particularly if krummholz, have a high surface area that becomes
extremely flammable. Low-intensity fires, however, may be beneficial to
open stands by consuming ground debris, or by reducing insects and
disease [2,5].
DISCUSSION AND QUALIFICATION OF FIRE EFFECT:
NO-ENTRY
PLANT RESPONSE TO FIRE:
Being highly susceptible to fire, subalpine larch's only defense seems to be
isolation on high rocky sites, and long life spans which result in thick
bark, self-pruning, and heavy seed crops. Seedling establishment is
very successful on scarified sites because seedlings are able to anchor
quickly and mature in barren conditions, while out-living competitors by
hundreds of years [2,3].
DISCUSSION AND QUALIFICATION OF PLANT RESPONSE:
NO-ENTRY
FIRE MANAGEMENT CONSIDERATIONS:
NO-ENTRY
References for species: Larix lyallii
1. Arno, Stephen F. 1970. Ecology of alpine larch (Larix lyallii Parl.) in the Pacific Northwest. Missoula, MT: Univeristy of Montana. 264 p. Dissertation. [16708]
2. Arno, Stephen F. 1990. Larix lyallii Parl. subalpine larch. In: Burns, Russell M.; Honkala, Barbara H., technical coordinators. Silvics of North America. Volume 1. Conifers. Agric. Handb. 654. Washington, DC: U.S. Department of Agriculture, Forest Service: 152-159. [13380]
3. Arno, Stephen F.; Habeck, James R. 1972. Ecology of alpine larch (Larix lyallii Parl.) in the Pacific Northwest. Ecological Monographs. 42: 417-450. [16451]
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. Carlson, Clinton E.; Arno, Stephen F.; Menakis, James. 1990. Hybrid larch of the Carlton Ridge Research Natural Area in western Montana. Natural Areas Journal. 10(3): 134-139. [13997]
6. Carlson, Clinton E.; Blake, George M. 1969. Hybridization of western and subalpine larch. Bulletin 37. Missoula, MT: University of Montana, School of Forestry, Montana Forest and Conservation Experiment Station. 12 p. [16968]
7. Carlson, Clinton E.; Cates, Rex G.; Spencer, Stanley C. 1991. Foliar terpenes of a putative hybrid swarm (Larix occidentalis x Larix lyallii) in western Montana. Canadian Journal of Forestry. 21: 876-881. [16707]
8. Colenutt, M. E.; Luckman, B. H. 1991. Dendrochronological investigation of Larix lyallii at Larch Valley, Alberta. Canadian Journal of Forest Research. 21: 1222-1233. [15687]
9. Cooper, Stephen V.; Neiman, Kenneth E.; Roberts, David W. 1991. (Rev.) Forest habitat types of northern Idaho: a second approximation. Gen. Tech. Rep. INT-236. Ogden, UT: U.S. Department of Agriculture, Forest Service, Intermountain Research Station. 143 p. [14792]
10. Eyre, F. H., ed. 1980. Forest cover types of the United States and Canada. Washington, DC: Society of American Foresters. 148 p. [905]
11. Fischer, William C.; Bradley, Anne F. 1987. Fire ecology of western Montana forest habitat types. Gen. Tech. Rep. INT-223. Ogden, UT: U.S. Department of Agriculture, Forest Service, Intermountain Research Station. 95 p. [633]
12. Garrison, George A.; Bjugstad, Ardell J.; Duncan, Don A.; [and others]. 1977. Vegetation and environmental features of forest and range ecosystems. Agric. Handb. 475. Washington, DC: U.S. Department of Agriculture, Forest Service. 68 p. [998]
13. Hitchcock, C. Leo; Cronquist, Arthur. 1973. Flora of the Pacific Northwest. Seattle, WA: University of Washington Press. 730 p. [1168]
14. Holland, W. D.; Coen, G. M., editors. 1982. Ecological (Biophysical) land classification of Banff and Jasper National Parks. Volume II: soil and vegetation resources. Publication No. SS-82-44. Edmonton, AB: The University of Alberta, Alberta Institute of Pedology. [Total pages unknown]. [17279]
15. Knudsen, Gerhard M. 1968. Chemotaxonomic investigation of hybridization between Larix occidentalis and Larix lyallii: A preliminary investigation. Missoula, MT: University of Montana. ? p. Thesis. [17111]
16. Knudsen, Gerhard M.; Arno, Stephen F.; Habeck, James R.; Blake, George M. 1968. Natural distribution of western larch (Larix occidentalis) and subalpine larch (Larix lyallii). Res. Note 7. Missoula, MT: University of Montana, School of Forestry, Montana Forest and Conservation Experiment Station. 4 p. [16991]
17. 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]
18. Lackschewitz, Klaus. 1991. Vascular plants of west-central Montana--identification guidebook. Gen. Tech. Rep. INT-227. Ogden, UT: U.S. Department of Agriculture, Forest Service, Intermountain Research Station. 648 p. [13798]
19. Leiberg, J. B. 1900. The Bitterroot Forest Reserve. U.S. Geological Survey, 20th Ann. Rep., Part V. 1: 317-428. [25093]
20. Little, Elbert L., Jr. 1979. Checklist of United States trees (native and naturalized). Agric. Handb. 541. Washington, DC: U.S. Department of Agriculture, Forest Service. 375 p. [2952]
21. 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]
22. Patterson, Patricia A.; Neiman, Kenneth E.; Tonn, Jonalea. 1985. Field guide to forest plants of northern Idaho. Gen. Tech. Rep. INT-180. Ogden, UT: U.S. Department of Agriculture, Forest Service, Intermountain Research Station. 246 p. [1839]
23. Pfister, Robert D.; Kovalchik, Bernard L.; Arno, Stephen F.; Presby, Richard C. 1977. Forest habitat types of Montana. Gen. Tech. Rep. INT-34. Ogden, UT: U.S. Department of Agriculture, Forest Service, Intermountain Forest and Range Experiment Station. 174 p. [1878]
24. Raunkiaer, C. 1934. The life forms of plants and statistical plant geography. Oxford: Clarendon Press. 632 p. [2843]
25. Richards, James Harlan. 1991. Ecophysiology of a deciduous timberline tree, Larix lyallii Parl. Edmonton, AB: The University of Alberta: v-vi. Dissertation abstract. [16706]
26. Shearer, Raymond C. 1961. A method of overcoming seed dormancy in subalpine larch. Journal of Forestry. July: 513-514. [16720]
27. U.S. Department of Agriculture, Soil Conservation Service. 1975. Soil taxonomy: A basic system of soil classification for making and interpreting soil surveys. Agric. Handb. No. 436. Washington, DC. 754 p. [15931]
28. U.S. Department of Agriculture, Soil Conservation Service. 1982. National list of scientific plant names. Vol. 1. List of plant names. SCS-TP-159. Washington, DC. 416 p. [11573]
29. Thompson, Robert S.; Anderson, Katherine H.; Bartlein, Patrick J. 1999. Digital representations of tree species range maps from "Atlas of United States trees" by Elbert L. Little, Jr. (and other publications). In: Atlas of relations between climatic parameters and distributions of important trees and shrubs in North America. Denver, CO: U.S. Geological Survey, Information Services (Producer). On file at: U.S. Department of Agriculture, Forest Service, Rocky Mountain Research Station, Fire Sciences Laboratory, Missoula, MT; FEIS files. [92575]
FEIS Home Page
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