Index of Species Information
SPECIES: Salix glauca
SPECIES: Salix glauca
AUTHORSHIP AND CITATION :
Uchytil, Ronald J. 1992. Salix glauca. In: Fire Effects Information System, [Online].
U.S. Department of Agriculture, Forest Service,
Rocky Mountain Research Station, Fire Sciences Laboratory (Producer).
Available: http://www.fs.fed.us/database/feis/ .
Salix pseudolapponum Seemann
SCS PLANT CODE :
COMMON NAMES :
The currently accepted scientific name of grayleaf willow is Salix
glauca L. [3,18]. Because it exhibits considerable geographic variation
across its extensive range, it has been divided into numerous varieties
or subspecies. Argus  recognizes three varieties:
Salix glauca var. villosa (Hooker) Anderson
Salix glauca var. acutifolia (Hooker) Schneider
Salix glauca var. glauca
Alternately, Hulten  recognizes four subspecies:
Salix glauca subsp. acutifolia (Hook.) Hult.
Salix glauca subsp. callicarpaea (Trautv.) Bocher
Salix glauca subsp. desertorum (Richards.) Anderss.
Salix glauca subsp. glabrescens (Anderss.) Hult.
LIFE FORM :
FEDERAL LEGAL STATUS :
No special status
OTHER STATUS :
Grayleaf willow is ranked as a critically endangered plant in Idaho and
Washington under The Nature Conservancy's Natural Heritage ranking
DISTRIBUTION AND OCCURRENCE
SPECIES: Salix glauca
GENERAL DISTRIBUTION :
Grayleaf willow grows throughout most of Alaska except for the Aleutian
Islands and along the southeastern coast . It grows through much of
northern Canada from Newfoundland northwest to the northern Yukon
Territory, and south to southern British Columbia and Alberta. In the
contiguous United States, it grows in alpine and subalpine habitats in
Montana, Wyoming, eastern Idaho, Colorado, Utah, and northern New Mexico
FRES11 Spruce - fir
FRES23 Fir - spruce
AK CO ID MT NM UT WY AB BC LB
MB NB NT ON PQ SK YT
BLM PHYSIOGRAPHIC REGIONS :
8 Northern Rocky Mountains
9 Middle Rocky Mountains
10 Wyoming Basin
11 Southern Rocky Mountains
KUCHLER PLANT ASSOCIATIONS :
K015 Western spruce - fir forest
K052 Alpine meadows and barren
SAF COVER TYPES :
12 Black spruce
107 White spruce
201 White spruce
204 Black spruce
206 Engelmann spruce - subalpine fir
251 White spruce - aspen
253 Black spruce - white spruce
SRM (RANGELAND) COVER TYPES :
HABITAT TYPES AND PLANT COMMUNITIES :
In Alaska and northwestern Canada, grayleaf willow dominates or
codominates numerous seral willow (Salix spp.) and mixed-shrub
floodplain communities. Riparian community associates include Alaska
willow (S. alaxensis), littletree willow (S. arbusculoides), Richardson
willow (S. lanata), diamondleaf willow (S. planifolia), and green alder
(Alnus crispa) . It also codominates in some mixed-shrub tundra
communities with birches (Betula spp.), alders (Alnus spp.), and other
willows . In the Rocky Mountain States, grayleaf willow/tufted
hairgrass (Deschampsia cespitosa) communities occupy well-drained, open
alpine and upper subalpine habitats [20,27].
Grayleaf willow occurs as scattered individuals in many boreal forests
and woodlands. It is seldom an understory dominant, except in early
seral stages. Douglas , however, described a 130- to 160-year-old
white spruce (Picea glauca)/grayleaf willow community in southwestern
Classifications listing grayleaf willow as a dominant in community types
(cts) and habitat types (hts) are presented below:
Area Classification Authority
AK general veg. cts Viereck & Dyrness 1980
sw YT montane veg. cts Douglas 1974
CO: Gunnison & general veg. hts Komarkova 1986
UT, se ID riparian cts Padgett & others 1989
Forest Service R-2 forest, shrub, grass Wasser & Hess 1982
& forb hts
SPECIES: Salix glauca
IMPORTANCE TO LIVESTOCK AND WILDLIFE :
Grayleaf willow is a moderately important moose browse in some areas
primarily because of its abundance [11,29]; in other areas it is poorly
utilized [14,25]. Caribou use is probably moderate at best, and
primarily in the summer . In some areas, grayleaf willow makes up a
large part of the winter diet of snowshoe hares .
Willows are generally a preferred food and building material of beaver
. Willow shoots, catkins, leaves, and buds are eaten by numerous
small mammals and birds .
In interior Alaska, grayleaf willow is less palatable to moose than
Alaska willow, littletree willow, diamondleaf willow, or sandbar willow
(S. interior). Moose browse grayleaf willow lightly in comparison with
the others in areas where they grow together . Grayleaf is more
palatable to moose than aspen (Populus tremuloides), balsam poplar
(Populus balsamifera), or paper birch (Betula papyrifera) .
NUTRITIONAL VALUE :
Grayleaf willow is a relatively high-quality food for wintering
ungulates. Winter stem crude protein content is about 6.4 percent.
Grayleaf willow is also a good source of calcium and phosphorus, and its
digestibility is relatively high [29,30].
COVER VALUE :
In thickets grayleaf willow may provide cover for small animals, but its
small stature limits its value as cover for large mammals.
VALUE FOR REHABILITATION OF DISTURBED SITES :
Densmore and Zasada  reported that under laboratory conditions
grayleaf willow stem cuttings taken in the fall or spring rarely produce
roots and, therefore, do not recommend planting grayleaf willow stem
cuttings for rehabilitation purposes. However, grayleaf willow stem
cuttings were successfully used to revegetate unstable sand dunes in
northern Alberta .
Seeding disturbed sites with this species may be a useful establishment
measure. Grayleaf willow has been observed naturally invading barrow
pits and mine tailings in arctic regions [19,35]. The seeds may be
stored for up to 3 years, and require cold stratification before sowing
OTHER USES AND VALUES :
All willows produce salacin, which is closely related chemically to
aspirin. Native Americans used various preparations from willow to
treat tooth ache, stomach ache, diarrhea, dysentery, and dandruff .
Native Americans also used flexible willow stems for making baskets,
bows, arrows, scoops, snares, and fish and muskrat traps [17,21].
OTHER MANAGEMENT CONSIDERATIONS :
Grayleaf willow is tolerant of heavy browsing .
BOTANICAL AND ECOLOGICAL CHARACTERISTICS
SPECIES: Salix glauca
GENERAL BOTANICAL CHARACTERISTICS :
Grayleaf willow commonly grows as an erect shrub 3 to 4 feet (0.9-1.2 m)
tall. On exposed tundra sites it grows as a low, semiprostrate shrub,
and on favorable sites it sometimes grows up to 20 feet (6 m) in height
and 5 inches (12 cm) in diameter . The bark is gray and smooth but
may become rough and furrowed on larger individuals. Male and female
flowers occur on separate plants in 3/4- to 2-inch-long (2-5 cm) catkins
that persist over the summer. The fruit is a 1/32- to 1/16-inch-long
(0.8-1.6 mm) two-valved capsule .
Two growth forms occur in the Rocky Mountains. In somewhat sheltered
locations in subalpine environments, plants are upright and taller,
while semiprostrate plants that are often difficult to distinguish from
arctic willow (S. arctica) grow in more exposed, alpine situations .
RAUNKIAER LIFE FORM :
REGENERATION PROCESSES :
Grayleaf willow's primary mode of reproduction is sexual. It produces
an abundance of small, lightweight seeds. Like most willows, it
probably begins seed production at an early age (between 2 and 10 years)
. Seeds are not shed as they ripen but remain on the plant
throughout the summer and are dispersed in the fall. Each seed has a
cottony down which aids in dispersal by wind and water. Unlike willow
seeds dispersed in summer, grayleaf willow seeds overwinter under snow
and germinate in the spring soon after snowmelt [9,41]. This cold
stratification promotes good germination; seeds germinate over a wide
range of temperatures (from 41 to 77 degrees F [5-25 C]) . Spring
germination is advantageous in arctic and alpine environments; the
growing season of grayleaf willow seedlings is 3 to 6 weeks longer than
that of summer-dispersing willows . Exposed mineral soils are
required for good germination and seedling establishment . Forest
litter generally inhibits germination and establishment.
Vegetative Reproduction: Grayleaf willow sprouts from the root crown or
stembase if aboveground stems are broken or destroyed by cutting or fire
SITE CHARACTERISTICS :
In Alaska and northern Canada, grayleaf willow grows on both uplands and
lowlands. In arctic tundra it often grows along river and streambanks,
on sandy and gravelly floodplains, and on old benches [3,35]. In boreal
environments, it grows as scattered shrubs in white and black spruce
(Picea mariana) woodlands, in black spruce muskegs, and on river
In the Rocky Mountains grayleaf willow is restricted to open, alpine and
subalpine habitats that commonly have rocky, well-drained soils [10,27].
SUCCESSIONAL STATUS :
Grayleaf willow is an early seral species. It pioneers freshly
deposited river alluvium, glacial outwash, and disturbed areas with
exposed mineral soil, such as road cuts and mine tailings . It is
also common in spruce woodlands following fire, especially in stands
about 20 to 30 years old [14,23]. It has been found in 160-year-old
open spruce woodlands , but it is usually displaced in densely
forested stands because of its shade intolerance.
SEASONAL DEVELOPMENT :
Grayleaf willow catkins appear with the leaves. In Alaska and the
Yukon, flowering generally occurs in June, the fruits ripen in July and
August, and the seeds are dispersed in late August and September [9,35].
SPECIES: Salix glauca
FIRE ECOLOGY OR ADAPTATIONS :
Grayleaf willow is a fire-adapted species. Most plants sprout from the
root crown following top-kill by fire. Viereck and Schandelmeier 
reported that even old, decadent willows sprouted prolifically
immediately after fire. The sprouting ability of willows is apparently
more vigorous and prolific than that of birches or alders .
Grayleaf willow's abundant, wind-dispersed seeds are important in
colonizing burned areas. Seeds are dispersed in the fall, overwinter
under snow, and germinate in the spring. Thus seedling establishment
cannot begin until postfire year 2.
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 :
survivor species; on-site surviving root crown or caudex
off-site colonizer; seed carried by wind; postfire years 1 and 2
off-site colonizer; seed carried by animals or water; postfire yr 1&2
FIRE MANAGEMENT CONSIDERATIONS :
SPECIES: Salix glauca
IMMEDIATE FIRE EFFECT ON PLANT :
Grayleaf willows that occur in white and black spruce forests can be
killed by severe fires that completely remove soil organic layers and
char the roots . Less severe fires only top-kill plants.
DISCUSSION AND QUALIFICATION OF FIRE EFFECT :
PLANT RESPONSE TO FIRE :
Grayleaf willow is one of the most abundant willows following fire in
white spruce forests of interior Alaska . There are commonly
several thousand stems per acre by 10 years after fire. However, its
abundance is short-lived, and it is often absent by year 40 as dense
white spruce sapling stands develop . Grayleaf willow is also
common on mesic black spruce sites after fire. One ll-year-old burn
near the Tanana River had about 4,700 grayleaf, Alaska, and diamondleaf
willow stems per acre (11,500/ha), and lesser amounts of spruce and
DISCUSSION AND QUALIFICATION OF PLANT RESPONSE :
Fire severity can affect the mode of willow postfire recovery.
Following light fires most willows recover quickly, sending up new
shoots from undamaged root crowns. Few if any seedlings establish
following this type of burn because organic soil layers are only
partially consumed, which prevents seedling establishment. Following
severe fires, however, the primary mode of recovery is seedling
establishment. Severe fires that burn deep into organic soils kill
willows but expose mineral soils, which provide excellent seedbeds.
For information on prescribed fire and postfire responses of many
plant species, including grayleaf willow, see this Research Project
SPECIES: Salix glauca
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