Regularity: Regularly occurring
Regional Distribution in the Western United States
This species can be found in the following regions of the western United States (according to the Bureau of Land Management classification of Physiographic Regions of the western United States):
BLM PHYSIOGRAPHIC REGIONS :
5 Columbia Plateau
6 Upper Basin and Range
7 Lower Basin and Range
8 Northern Rocky Mountains
9 Middle Rocky Mountains
10 Wyoming Basin
11 Southern Rocky Mountains
12 Colorado Plateau
13 Rocky Mountain Piedmont
Occurrence in North America
Gray low sagebrush and alkali sagebrush have been described as dwarf sagebrushes, generally growing only 4 to 16 inches (10-40 cm) high [47,49]. The species is "evergreen," much-branching, and grows in mounded form . Lahontan sagebrush is slightly taller, growing 1 to 3 feet (30-90 cm) high with flowering stalks more erect than those of gray low sagebrush . Hotsprings sagebrush is shorter than the other subspecies: it grows 6 to 9 inches (15-23 cm) high in Wyoming . The foliage of all subspecies is aromatic and light grayish-green, darkening later in the season .
Leaves are up to 1.5 cm long; in hotsprings sagebrush leaves are deeply cleft in three while gray low sagebrush's leaves are variably cleft [47,49]. The inflorescence is a spike-like, narrow panicle 0.6 inch (1.5 cm) wide . Gray low sagebrush has 4 to 9 flowers per head [49,113]. Alkali sagebrush has 6 to 11 flowers per head . Numerous ecotypes, phases, races, and forms of low sagebrush have been described [48,73,93,112]. Both small-headed and later blooming large-headed forms have been noted [36,112], as have green and gray forms which differ in palatability [73,93]. Not much is known of the longevity of low sagebrush but members of the genus are generally long-lived, sometimes up to 150 years . The Flora of North America provides a morphological description and identification key for low sagebrush .
Roots: Sagebrush may be either arbuscular mycorrhizal or ectomycorrhizal . Low sagebrush has an extensive fibrous root system down to about 8 inches (20 cm); roots are generally tolerant of poor aeration and more efficient at removing water from this soil depth than big or black sagebrush's root systems [80,114].
Key Plant Community Associations
Low sagebrush species cover approximately 28 million acres (11.2 million ha) in the western
United States . Recognized habitat types include gray low sagebrush/bluebunch wheatgrass
(Pseudoroegneria spicata), gray low sagebrush/Idaho
fescue (Festuca idahoensis), gray
low sagebrush/Thurber's needlegrass (Achnatherum thurberianum), gray low
sagebrush/bitterbrush (Purshia tridentata)/bluebunch wheatgrass, hotsprings sagebrush/Idaho fescue,
sagebrush/bluebunch wheatgrass, and alkali sagebrush/Idaho fescue . Lahontan sagebrush
grows with many of the same associates; Lahontan sagebrush is an ecosystem
dominant on about 500,000
acres (200,000 ha) .
Washington: In eastern Washington low sagebrush grows with stiff sagebrush (A.
rigida) and mountain big sagebrush (A. t. ssp. vaseyana) with
an understory of elk sedge (Carex geyeri),
Idaho fescue, Sandberg bluegrass (Poa secunda), and bluebunch wheatgrass
. Low sagebrush is not particularly common and, for the most part,
is restricted to Chelan, Kittias, and Yakima
Oregon: On the Deschutes, Winema, and Fremont National Forests, low sagebrush (with 5-15% canopy cover) grows with Idaho fescue (2-16%
cover) and bluebunch wheatgrass, Sandberg bluegrass, bottlebrush squirreltail (Elymus
elymoides), and low
pussytoes (Antennaria dimorpha). Such habitats in
"poor condition" are characterized by increasing rabbitbrush (Chrysothamnus spp.) and cheatgrass
(Bromus tectorum); on mesic
sites antelope bitterbrush, California oatgrass
(Danthonia californica), and prairie Junegrass (Koeleria
macrantha) are present [33,51,110]. Forbs present in the communities include rosy pussytoes (Antennaria
microphylla), fleabane (Erigeron spp.), rockcress (Arabis spp.), and
spp.). On sites slightly drier than those occupied by ponderosa pine (Pinus
ponderosa) forests, low sagebrush and antelope bitterbrush are dominant with
green rabbitbrush (Chrysothamnus viscidiflorus) and rubber
rabbitbrush (C. nauseosus) as minor shrubs where soils
are deeper. The most prominent grass is Thurber's needlegrass. Low sagebrush is an occasional component of silver sagebrush (A. cana)/mat
muhly (Muhlenbergia richardsonis) communities . Other
associates of low sagebrush in eastern Oregon are stiff sagebrush, snowberry (Symphoricarpos spp.),
wax currant (Ribes cereum), and Saskatoon serviceberry (Amelanchier
California: On the Modoc Plateau of northeastern California, common
understory associates in low sagebrush stands
are Idaho fescue, bitterbrush (Purshia spp.), bluebunch wheatgrass,
Thurber's needlegrass, prairie Junegrass, phlox (Phlox spp.), pussytoes (Antennaria
spp.), fleabane, blue-eyed Mary (Collinsia spp.), Ross' sedge
and rushes (Juncus spp.). Shrubs frequently associated are western juniper (Juniperus occidentalis), green
rabbitbrush, gray horsebrush (Tetradymia canescens), and longflower snowberry (S.
longiflorus). Cheatgrass, garlic mustard (Alliaria petiolata), and
medusahead (Taeniatherum caput-medusae) are prominent weedy species after grazing; historically
bottlebrush squirreltail and/or Sandberg bluegrass had greater canopy cover .
Low sagebrush is more common in
western juniper stands than in pinyon (Pinus spp.)/juniper (Juniperus spp.)
stands; big sagebrush is much more frequently found in pinyon-juniper stands . In the White Mountains of eastern California in Rocky Mountain
bristlecone pine (Pinus aristata), limber pine (P. flexilis), and
quaking aspen (Populus tremuloides) stands with
discontinuous sparse cover, low sagebrush grows with big sagebrush, green
rabbitbrush, curlleaf mountain-mahogany (Cercocarpus ledifolius),
littleleaf mountain-mahogany (C. intricatus), fernbush (Chamaebatiaria millefolium),
oceanspray (Holodiscus discolor), and desert gooseberry (Ribes velutinum).
Grasses present include are prairie Junegrass, bottlebrush squirreltail, mat
muhly, and timblerline bluegrass (Poa glauca var. rupicola) .
sagebrush grows in Utah in Box Elder, Cache, Millard, Rich,
Salt Lake, Summit, and Toole counties in Colorado pinyon (Pinus edulis)/juniper, mountain brush,
sagebrush, and, to a lesser extent, in openings in white fir (Abies concolor),
quaking aspen, and Engelmann spruce (Picea engelmannii)-white fir communities. Alkali sagebrush is found in sagebrush
grassland communities in Rich and Summit
counties . In the interior ponderosa pine (P. p. var. scopulorum)/black
sagebrush habitat type, trees present are limber pine (in
Utah only), Colorado pinyon, and Rocky Mountain juniper (Juniperus scopulorum).
Dominant shrubs include low sagebrush, green rabbitbrush, Gambel oak (Quercus
gambelii), gray horsebrush, and blue grama (Bouteloua
gracilis) . In Uintah County of northeastern Utah, low sagebrush grows in
Colorado pinyon/Utah juniper (Juniperus osteosperma)
communities with big sagebrush, fourwing saltbrush (Atriplex canescens),
shadscale (Atriplex confertifolia), true mountain-mahogany (Cercocarpus
montanus), birchleaf mountain-mahogany (Cercocarpus betuloides),
and ephedra (Ephedra spp.). Important grasses are purple threeawn (Aristida
purpurea), saltgrass (Distichlis spicata), Indian
ricegrass (Achnatherum hymenoides), Sandberg bluegrass,
needle-and-thread grass (Hesperostipa comata), bottlebrush
squirreltail; forbs include Fendler's sandwort (Arenaria fendleri),
rose heath (Chaetopappa ericoides), thickstem wild cabbage (Caulanthus
crassicaulis), cryptantha (Cryptantha spp.), Fendler's
springparsley (Cymopterus acaulis var. fendleri),
prickly-pear (Opuntia spp.), and others .
Montana: Low sagebrush is found only in southwestern Montana. Gray low sagebrush is in Beaverhead, Madison, and Deer Lodge counties
[13,79]. Common associates include slender wheatgrass (Elymus
Idaho fescue . Alkali sagebrush is present in only a few isolated
stands in Beaverhead and Madison counties [17,79]. Alkali sagebrush occurs with Idaho fescue, western wheatgrasss
(Pascopyrum smithii), thickspike wheatgrass (Elymus lanceolatus),
wheatgrass, and alkali cordgrass (Spartina gracilis) .
Idaho: The gray low sagebrush/bluebunch wheatgrass habitat type supports bluebunch
wheatgrass, Sandberg bluegrass, bottlebrush squirreltail, Hood's phlox (Phlox
hoodii), tapertip hawksbeard (Crepis acuminata)
and prairie Junegrass [48,94]. The gray low sagebrush/Idaho fescue type is
widespread in western Idaho in the same elevation zone; forb associates are
phlox, rosy pussytoes, tapertip hawksbeard, lambstongue ragwort (Senecio integerrimus), and Hooker balsamroot (Balsamorhiza
hookeri); bluebunch wheatgrass is abundant on some sites and absent
on others. The gray low sagebrush/Sandberg bluegrass habitat type
occurs where soils are too shallow to support Idaho fescue or bluebunch
wheatgrass. In this type, Sandberg bluegrass and gray low sagebrush have increased with grazing
pressure and species diversity has been reduced. In the Dautrich
Memorial Desert Preserve in southeastern Idaho, low sagebrush sometimes grows with
big sagebrush, fourwing saltbrush, shadscale, littleleaf horsebrush (Tetradymia glabrata),
grayball sage (Salvia dorrii), and basin wildrye (Leymus cinereus) . The
alkali sagebrush/Idaho fescue type occurs on and near the Owyhee Plateau; associated grasses are bluebunch wheatgrass
and Thurber's needlegrass (with variable presence and cover) and Sandberg
bluegrass. Forbs are small bluebells (Mertensia longiflora),
narrowleaf pussytoes (Antennaria
stenophylla), alpine ionactis (Ionactis alpina), tapertip
onion (Allium accuminatum), and Holboell's rockcress (Arabis holboellii) .
Hotsprings sagebrush is only known in Custer County, Idaho . The hotsprings
sagebrush/Idaho fescue habitat type occupies glacial outwashes and ridges with
thin soil; bluebunch wheatgrass is sometimes present. In some areas grazing
pressure has caused Idaho fescue to be replaced by Letterman needlegrass (Achnatherum
lettermanii) . Other associates include Sandberg bluegrass, bottlebrush
squirreltail, fleabane, rosy pussytoes, Hood's phlox, and snowline springparsley (Cymopterus
Wyoming: Gray low sagebrush grows in Lincoln and Teton counties, and hotsprings
sagebrush grows in Lincoln and Teton counties and Yellowstone National Park . Alkali sagebrush is in Carbon, Hot Springs, Lincoln, Sublette, Teton
and Uinta counties . Beetle  estimated that in Wyoming gray low
sagebrush covers about 2,000 square miles (510,000 ha) and alkali sagebrush covers the same;
hotspring sagebrush covers about 100 square miles (26,000 ha). Gray low sagebrush and alkali
sagebrush are confined primarily to
the western part of the state; hotsprings sagebrush is in the northwestern part. Common understory grasses are western wheatgrass, thickspike
wheatgrass, Idaho fescue, prairie Junegrass, Cusick's bluegrass (Poa cusickii),
mutton grass (Poa fendleriana), and
Sandberg bluegrass .
Nevada: Alkali sagebrush is present in Elko and Humboldt counties
alkali sagebrush/Idaho fescue habitat type is common in Elko County; the type is
very similar to the composition of the
gray low sagebrush/Idaho
fescue type described above, but Thurber's needlegrass is generally more prominent
Gray low sagebrush is best represented in northern Nevada; in
southern Nevada this variety is a component of singleleaf pinyon (Pinus monophylla)/Utah
juniper stands . In the gray low sagebrush/Sandberg bluegrass
habitat type species present include fleabane,
phlox, bitterroot (Lewisia rediviva), milkvetch, Idaho fescue, and curlleaf mountain-mahogany. In singleleaf
pinyon/Utah juniper communities low sagebrush grows with
big sagebrush, green rabbitbrush, antelope bitterbrush, cheatgrass, bottlebrush
squirreltail, California brome (Bromus carinatus), Sandberg
bluegrass, bushy bird's beak (Cordylanthus ramosus), tapertip
onion, longleaf phlox (Phlox longifolia), sego lily (Calochortus nuttallii),
largeflower hawksbeard (Crepis occidentalis), and pinyon
groundsmoke (Gayophytum ramosissimum)
In the Ruby Mountains gray low sagebrush communities typical species
Idaho fescue, bottlebrush squirreltail, green rabbitbrush, Sandberg
bluegrass, fleabane, granite prickly phlox (Leptodactylon
pungens), spike fescue (Leucopoa kingii), lupines (Lupinus
spp.), Wyoming Indian paintbrush (Castilleja linariifolia),
colddesert phlox (Phlox stansburyii), and
The gray low sagebrush/Thurber's needlegrass habitat type is common in northwestern
Nevada; subdominant grasses are Sandberg bluegrass,
bottlebrush squirreltail, and Idaho fescue. Forbs present are fleabane,
Hood's phlox, alpine ionactus, and woollypod milkvetch (Astragalus purshii) .
New Mexico: Gray low sagebrush grows on dry plains, mountain
slopes, and ridges in northwestern and west-central New Mexico . With Utah juniper frequently codominant, low sagebrush grows with big sagebrush,
fourwing saltbush, Stansbury cliffrose (Purshia mexicana var. stansburiana),
broom snakeweed (Gutierrezia sarothrae), prickly-pear, and pingue
richardsonii). Common grasses are blue grama, hairy grama (Bouteloua
hirsuta), sideoats grama (B. curtipendula), galleta (Pleuraphis
jamesii), threeawn (Aristida spp.), western wheatgrass,
bottlebrush squirreltail, and Indian ricegrass .
Colorado: In the White River-Arapaho National Forest the low sagebrush/arrowleaf
balsamroot (Balsamorhiza sagittata) habitat type occurs on warm aspects; associated shrubs are Utah
serviceberry (Amelanchier utahensis), longflower rabbitbrush (Chrysothamnus
depressus), and mountain snowberry (Symphoricarpos oreophilus). Prominent grasses include prairie
Junegrass, mutton grass, Sandberg bluegrass, and bottlebrush squirreltail, and
forbs of importance are pale agoseris (Agoseris glauca), Geyer's
onion (Allium geyeri), Gunnison's mariposa lily (Calochortus gunnisonii),
largeflower hawksbeard, Gray's biscuitroot (Lomatium grayi), and
lambstongue ragwort .
Alkali sagebrush grows in Garfield, Jackson, Routt, Moffat, and Rio
Blanco counties . The alkali sagebrush/Sandberg bluegrass habitat type
occurs in central Colorado.
Grasses present (in
descending importance) are bottlebrush squirreltail, mutton grass (Poa fendleriana),
bluebunch wheatgrass, western wheatgrass, pine needlegrass (Achnatherum pinetorum),
needle-and-thread grass, prairie Junegrass, cheatgrass, and
basin wildrye . Other important shrubs are green rabbitbrush,
mountain snowberry, fringed sagebrush
(Artemisia frigida), winterfat (Krascheninnikovia lanata),
broom snakeweed, and Vasey's rabbitbrush (Chrysothamnus vaseyi). Forbs present are phlox,
mat penstemon (Penstemon caespitosus), and fleabane .
Classifications describing plant communities in which low sagebrush is a
dominant species are as follows:
Habitat: Rangeland Cover Types
This species is known to occur in association with the following Rangeland Cover Types (as classified by the Society for Range Management, SRM):
More info for the terms: association, cover
SRM (RANGELAND) COVER TYPES :
101 Bluebunch wheatgrass
102 Idaho fescue
104 Antelope bitterbrush-bluebunch wheatgrass
105 Antelope bitterbrush-Idaho fescue
107 Western juniper/big sagebrush/bluebunch wheatgrass
109 Ponderosa pine shrubland
110 Ponderosa pine-grassland
302 Bluebunch wheatgrass-Sandberg bluegrass
304 Idaho fescue-bluebunch wheatgrass
305 Idaho fescue-Richardson needlegrass
306 Idaho fescue-slender wheatgrass
314 Big sagebrush-bluebunch wheatgrass
315 Big sagebrush-Idaho fescue
316 Big sagebrush-rough fescue
317 Bitterbrush-bluebunch wheatgrass
318 Bitterbrush-Idaho fescue
319 Bitterbrush-rough fescue
320 Black sagebrush-bluebunch wheatgrass
321 Black sagebrush-Idaho fescue
322 Curlleaf mountain-mahogany-bluebunch wheatgrass
324 Threetip sagebrush-Idaho fescue
401 Basin big sagebrush
402 Mountain big sagebrush
403 Wyoming big sagebrush
404 Threetip sagebrush
405 Black sagebrush
406 Low sagebrush
407 Stiff sagebrush
408 Other sagebrush types
412 Juniper-pinyon woodland
413 Gambel oak
414 Salt desert shrub
415 Curlleaf mountain-mahogany
416 True mountain-mahogany
504 Juniper-pinyon pine woodland
509 Transition between oak-juniper woodland and mahogany-oak association
Habitat: Cover Types
This species is known to occur in association with the following cover types (as classified by the Society of American Foresters):
More info for the term: cover
SAF COVER TYPES :
209 Bristlecone pine
219 Limber pine
220 Rocky Mountain juniper
237 Interior ponderosa pine
238 Western juniper
244 Pacific ponderosa pine-Douglas-fir
Habitat: Plant Associations
This species is known to occur in association with the following plant community types (as classified by Küchler 1964):
More info for the term: shrub
KUCHLER  PLANT ASSOCIATIONS:
K010 Ponderosa shrub forest
K011 Western ponderosa forest
K018 Pine-Douglas-fir forest
K019 Arizona pine forest
K022 Great Basin pine forest
K023 Juniper-pinyon woodland
K024 Juniper steppe woodland
K031 Oak-juniper woodland
K032 Transition between K031 and K037
K037 Mountain-mahogany-oak scrub
K038 Great Basin sagebrush
K053 Grama-galleta steppe
K054 Grama-tobosa prairie
K055 Sagebrush steppe
K056 Wheatgrass-needlegrass shrubsteppe
K063 Foothills prairie
K065 Grama-buffalo grass
This species is known to occur in the following ecosystem types (as named by the U.S. Forest Service in their Forest and Range Ecosystem [FRES] Type classification):
FRES21 Ponderosa pine
FRES30 Desert shrub
FRES34 Chaparral-mountain shrub
FRES36 Mountain grasslands
FRES38 Plains grasslands
FRES42 Annual grasslands
Low sagebrush grows on "dry plains and hills," on sites generally less productive than those dominated by other sagebrushes [49,115]. In many areas, surface soils are highly eroded . Annual precipitation at gray low sagebrush sites ranges from 7 to 18 inches (180-460 mm) . In Nevada the driest sites are occupied by black sagebrush; slightly wetter sites by low sagebrush, and even more moist sites by basin big sagebrush or mountain big sagebrush . Hotsprings sagebrush often occurs on dry, shallow, infertile and rocky ridgetops or benches [48,113], but it also grows well in the cold, dry mountain valleys of central and eastern Idaho, northern Utah, and northeastern Wyoming [113,117]. Hotsprings sagebrush dominates extensive, nearly uniform communities in many areas including parts of Yellowstone and Grand Teton National Parks , but also grows in openings in patchy conifer forests [13,117]. The elevational range of gray low sagebrush is from 2,300 to more than 11,500 feet (700-3,500 m) . In the Intermountain region, gray low sagebrush grows most commonly at lower elevations but may be found above 10,000 feet (3,050 m) on warmer and drier sites . Elevation ranges by state are listed below:
|California||gray low sagebrush: 4,900 to 12,400 feet; hotsprings sagebrush: 7,200 to 8,200 feet|||
|Colorado||low sagebrush: 7,000 to 8,000 feet||[81,114,117,124]|
|Idaho||low sagebrush: 6,000 to 9,800 feet||[94,117]|
|Montana||Gray low sagebrush and alkali sagebrush: 7,000 to 8,000 feet|||
|New Mexico||gray low sagebrush: 7,000 to 8,000 feet|||
|Nevada||Low sagebrush: 2,300 to 11,500 feet; hotsprings sagebrush: 5,900 to 8,000 feet|||
|Oregon||gray low sagebrush: 3,000 to 9,000 feet; hotsprings sagebrush: 5,000 to 9,000 feet; Lahontan sagebrush: 4,300 to 6,400 feet.||[116,117]|
|Utah||gray low sagebrush: 4,500 to 8,400 feet; alkali sagebrush: 5,500 to 8,000 feet|||
|Wyoming||gray low sagebrush: 5,000 to 7,000 feet; alkali sagebrush: 6,000 to 8,000 feet|||
Soils: The distribution of low sagebrush is greatly influenced by edaphic factors: generally low sagebrush grows where soil has a clay pan, cobble layer, or bedrock within about 8 to 13 inches (20-33 cm) of the surface [9,43,47,48,96,105,124]. Gray low sagebrush and hotsprings sagebrush typically grow on soils with less than 13 inches (33 cm) to a B horizon of impermeable clay or 30% or more gravel and cobbles [96,124]. Alkali sagebrush occurs on shallow, poorly-drained soils with dense clay B horizons at depths averaging 8 inches (20 cm) [104,105].
Gray low sagebrush sites are characterized by large amounts of bare ground and exposed surface rock . Root-zone aeration is poor in many areas because claypans allow development of a perched water table in spring and winter . Low sagebrush sites often flood in spring and dry with a hard veneer crust by mid- to late summer .
Ecotones between big sagebrush (A. tridentata) and low sagebrush communities are often defined by soil properties [43,105]. On sites with shallow soils underlain by a dense clay layer or bedrock, low productivity low sagebrush communities occur; big sagebrush, with higher productivity, is dominant on deeper soils [9,48,103,124]. In Elko County, Nevada, big sagebrush communities with herbage production between 800 to 970 pounds per acre (900-1,100 kg/ha) grew where the subsurface horizons were penetrable; alkali sagebrush communities with herbage production ranging from 620 to 800 pounds per acre (700-900 kg/ha) occurred where subsurface was less penetrated by roots .
Low sagebrush communities have been described on soils derived from basalt, andesite, sandstone, limestone, granite, and pumice [47,51,110,117]. Gray low sagebrush grows on soils derived from dolomite, sandstone, and granite in California's White Mountains, although growth is relatively poor on the dolomitic soils . Gray low sagebrush occupies dry, infertile, or alkaline sites in the Great Basin; in Wyoming it is confined to glacial alluvium and gravels [17,100,114]. Hotsprings sagebrush is very much favored by impermeable soils derived from alkaline shale but also occurs on more neutral sites . In central Idaho, hotsprings sagebrush grows on glacial outwash, dry alluvium, terraces, or on poorly-drained mountainous sites .
Fire Management Considerations
Historically there has been interest in controlling or eliminating low sagebrush [77,95]. More recently authorities, from the perspectives of wildlife conservation and long-term site productivity, have recommended against widespread control efforts [20,27,123]. Sage-grouse in particular can be adversely impacted when large, contiguous blocks of low sagebrush are burned . Even when conditions allow fire spread, prescribed burning in low sagebrush sites often produces few benefits [20,123]. Predicted increases in forage have in some cases only come belatedly or not at all . Erosion may also be a problem on many harsh sites where revegetation proceeds very slowly.
Blaisdell and others  state that prescribed burning of sagebrush range to improve forage production is useful only when: 1) soils are stable and slopes less than 30%, 2) sagebrush is dense and is more than 33% of plant cover (scattered brush does not limit range productivity), 3) Fire resistant grasses and forbs are more than 20% of cover, and 4) wildlife issues have been taken into consideration as sagebrush is an important part of diets in some areas. They also recommend that burned sagebrush sites (accidental or prescribed) be protected from grazing for 1 or 2 growing seasons. To minimize impacts to wildlife, particularly sage-grouse, burning in patches rather than large areas is recommended . Fall burning is most advantageous from the perspective of conserving desirable grasses for forage, but if weather is conducive, spring burning also kills sagebrush with minimal damage to other species .
Generally sagebrush grasslands carry fire only when herbaceous fuels exceed 600 to 700 pounds per acre (674-786 kg/ha) . Because forage production is often much lower in low sagebrush habitat types, these types have been used successfully as a firelines where they are adjacent to big sagebrush or other communities where fire is prescribed [12,118,120].
Plant Response to Fire
Recovery time of gray low sagebrush following fire is variable . After fire, if regeneration conditions are favorable, low sagebrush recovers in 2 to 5 years, generally by seed wind-dispersed from another site [23,123]. Regeneration is aided by grasses and forbs that develop in the 1st 2 growing seasons after fire . On harsh sites where cover is low to begin with and/or erosion occurs after fire, recovery may require more than 10 years [20,123]. Slow regeneration may subsequently worsen erosion . Neuenschwander  states sagebrush increases in cover after fire to 10% of control in 12 years and to 100% of control in 30 years. This general estimate may be more applicable to larger species than to the dwarf sagebrushes; big sagebrush was observed to "gain dominance of herbaceous layer" in 5 to 30 years .
Immediate Effect of Fire
Low sagebrush is severely damaged by fire , but because fire is rare where it is dominant, there have been few studies of the physiological effects of fire on low sagebrush. Fires in northwestern Utah conducted in September with relative humidity of 15 to 20%, temperature of 75 degree Fahrenheit (41.6 Â°C), wind of 5 to 10 miles per hour (8-16 kilometers per hour), and fuel loading of 100 lb/acre (112 kg/ha) "essentially eliminated" the low sagebrush that was dominant (other species present were Sandberg bluegrass, bluebunch wheatgrass, and western juniper) . Monsen and Shaw  described effects of a fire prescribed in mid-June using a brush burner held a meter above alkali sagebrush. Fuels were so sparse that fires spread only 20 to 30 feet (6-9 m) before burning out. Within this zone fire was "patchy" because of the distribution of alkali sagebrush and Idaho fescue; alkali sagebrush cover was reduced 26% (measured 1 year after the burn). Some shrubs survived and produced seed. A large number of the burned shrubs recovered via regrowth from living branches. Because of the ignition method these findings are not necessarily applicable to natural or most prescribed fires.
POSTFIRE REGENERATION STRATEGY :
Initial off-site colonizer (off-site, initial community)
Fire adaptations: Dwarf sagebrushes (including black, stiff, low, pygmy sagebrush (A. pygmaea), and other sagebrushes) are very susceptible to fire damage [25,27]. Low sagebrush is usually killed by fire and does not sprout [11,84]. Though alkali sagebrush sometimes layers, recovery in burned areas is usually via small, light, wind-dispersed seed for all low sagebrush subspecies [23,123]. Partially injured low sagebrush may regrow from living branches, but sprouting does not occur .
FIRE REGIMES: Where dwarf sagebrush species are ecosystem dominants, grass productivity is often limited by adverse soil physical properties: stands generally lack enough fuels to carry a fire [12,20,27]. In addition to low fine fuel loading, wide shrub spacing makes fire infrequent or difficult to prescribe in dwarf sagebrush types [25,27,31,84,86,123]. On the Modoc plateau of northeastern California, low sagebrush burned less frequently than big sagebrush because of wide shrub spacing in low sagebrush types and possibly because of a less flammable herbaceous composition . The case is similar in Craters of the Moon National Monument, where low productivity and sparse herbaceous cover in ridgetop low sagebrush communities make them an effective firebreak except in particularly productive years or microsites . Even in late August low sagebrush communities on the Humboldt National Forest lacked sufficient fine fuels to carry a fire . These communities surrounded big sagebrush communities that were prescribed burned in spring; construction of firelines was not required [12,25]. Mountain big sagebrush communities grew in draws or other areas with deeper soil to support more herbaceous growth while low sagebrush communities were generally confined to areas with shallow soils .
Fire in low sagebrush habitat types is restricted to more mesic sites or above average productivity years . Where low sagebrush occurs as dominant or component of Colorado pinyon and/or western juniper stands, about 600 to 700 pounds per acre (680-800 kg/ha) of fine fuels are required to carry fire [23,118]. Fine fuel loads generally average 100 to 400 pounds per acre (110-450 kg/ha) but are occasionally as high as 600 pounds per acre (680 kg/ha) in low sagebrush habitat types [67,94].
Where low sagebrush occurs in the understory of Colorado pinyon-western juniper stands (or where Colorado pinyon and/or western juniper have increased on low sagebrush communities) surface fine fuel loadings of 600 to 1000 pounds per acre (530-880 kg/ha) are common, particularly in younger or more open stands that allow greater understory development. These early-successional, open stands support fire that kills non-sprouting shrubs, including low sagebrush, particularly when cheatgrass and/or medusahead are present. Low sagebrush recovers from these fires via seedling establishment. Establishment of sagebrush generally occurs after annual and perennial grass and forb development; pinyon and juniper either survive low-severity fire or, after crown fire, grow from seed after shrubs and grasses have established . Surface fire is not common in later-successional pinyon-juniper stands as fine fuels are generally too sparse; closed-canopy stands, however, may carry a crown fire if adjacent sites have enough fuel to support one.
Invasion and increase of western juniper and Colorado pinyon on low sagebrush sites has been a result of livestock grazing and decreasing fire frequency . Burkhardt and Tisdale  investigated the fire history of a big sagebrush/gray low sagebrush mosaic habitat on the Owyhee plateau of Idaho. Between 1840 and 1910 mean fire interval was about 4 years (the authors did not separate the 2 habitats in analysis). Of the 4 sites studied, 2 had not burned since 1910, and 2 had burned once. Western juniper invasion of these habitats began in about 1870, increased with fire cessation, and peaked in about 1940. Though fire is not the only control over invasion, it is estimated that in northern California in low sagebrush habitats a fire interval of 50 years would stop encroachment .
Low sagebrush fire intervals declined as native perennial grasses were grazed [23,121]. In some overgrazed stands grasses are almost entirely confined to areas with shrub canopies . In some cases grazing has increased less palatable annual cheatgrass and medusahead invasion, making fire more frequent rather than less. There is a positive feedback system in that fire reduces sagebrush cover and allows further increase of annuals and subsequent increased risk of fire. Herbaceous production, including desirable and undesirable species, may increase 100% following fire . The possibility of fire is increased during years of above-average precipitation and increased herbaceous growth [27,120].
Fire history information of sagebrush habitats is often limited . Miller and Rose  described fire history of a low sagebrush steppe in south-central Oregon by determining the years in which western juniper had died from fire injury. Before 1897 mean fire intervals ranged from 12 to 15 years with intervals ranging from 3 to 28 years. Fire generally occurred after years of high radial growth rates (measured in western juniper), indicating that fires occurred during wet years with high forage production, and the most recent fire was 1897. In Lassen County, California, fire history was constructed by observing scar analysis on invading western juniper. The western junipers observed had established in a low sagebrush community between 1600 and 1800 and persist now with a density of 69 trees per acre (28 trees/ha). Fire was evidently sporadic temporally and spatially: only 0.4% of western juniper had fire scars. Some had multiple scars indicating that fires were very small and/or patchy with return intervals that ranged from 10 to 90 years . FIRE REGIMES for ecosystems and communities of which low sagebrush is a component are listed below. See the FEIS species summaries of the ecosystem dominants listed below for more information.
|Community or Ecosystem||Dominant Species||Fire Return Interval Range (years)|
|sagebrush steppe||Artemisia tridentata/Pseudoroegneria spicata||20-70 |
|basin big sagebrush||Artemisia tridentata var. tridentata||12-43 |
|mountain big sagebrush||Artemisia tridentata var. vaseyana||15-40 [29,44,74]|
|Wyoming big sagebrush||Artemisia tridentata var. wyomingensis||10-70 (40**) [109,121]|
|saltbush-greasewood||Atriplex confertifolia-Sarcobatus vermiculatus|
|curlleaf mountain-mahogany*||Cercocarpus ledifolius||13-1000 [5,98]|
|mountain-mahogany-Gambel oak scrub||Cercocarpus ledifolius-Quercus gambelii|
|California steppe||Festuca-Danthonia spp.|
|western juniper||Juniperus occidentalis||20-70|
|Rocky Mountain juniper||Juniperus scopulorum|
|Colorado pinyon||Pinus edulis||10-49 |
|Pacific ponderosa pine*||Pinus ponderosa var. ponderosa||1-47 |
|interior ponderosa pine*||Pinus ponderosa var. scopulorum||2-30 [3,8,64]|
|mountain grasslands||Pseudoroegneria spicata||3-40 (10**) [2,3]|
More info for the terms: competition, cover, density, fire exclusion, forb, shrub, shrubs, stand-replacement fire, succession
Gray low sagebrush occurs in late succession in a number of drier sagebrush grassland and forest habitat types. Gray low sagebrush is also well represented in early successional stages of many big sagebrush communities and is an early pioneer species in some old stream bottoms . Where dry, rocky, or otherwise restrictive soils of some sites prevent the establishment of big sagebrush, gray low sagebrush persists as a dominant .
Though not tolerant of fire damage, low sagebrush tolerates (or increases) with disturbance by grazing. Low sagebrush has increased where present in grazed areas, and low sagebrush has invaded adjacent short grasslands where grazing reduces competition . In Nevada, the community composition of almost all gray low sagebrush and hotsprings sagebrush shrubsteppes have been "greatly altered" by grazing . The increase in low sagebrush may not be striking: on the Craters of the Moon National Monument low sagebrush cover seldom exceeds 13%, even with grazing and fire exclusion . Even where an increase in low sagebrush is not caused by grazing, low sagebrush becomes more prominent as trampling restricts desirable grasses to growth only under shrub canopies [48,110]. Though moderate use may lead to increase, gray low sagebrush may decrease in cover if severely overbrowsed .
Pinyons and junipers invade or have invaded some communities historically dominated low sagebrush and big sagebrush. Whether in a low sagebrush community being invaded or in a mid-successional-species community historically dominated by pinyons and junipers, low sagebrush aids the establishment of juniper and pinyon by ameliorating conditions for seedlings . Western juniper is the most common invader of low sagebrush steppes; its increase is thought to be a result of livestock introduction, and, to a lesser extent, fire exclusion. Wet periods of a few years also aid western juniper seedling establishment. Much of the increase occurred with grazing that took place before this century and it is therefore difficult to find quantitative support for the modalities of western juniper increase . In Lassen County, California, a study of western juniper increase on sagebrush steppe showed that since approximately 1600, western juniper density increased from 0 to 28 trees/hectare on low sagebrush sites, and 0 to 150 trees/ha on big sagebrush sites. Establishment, measured as time required for doubling of canopy cover, slowed after 1800 .
After stand-replacement fire in juniper or pinyon/juniper stands in Colorado and Utah succession begins with an annual grass stage. This is followed by perennial grass and forb development. Low sagebrush and other shrubs develop after perennial grasses have established; pinyons and junipers establish after low sagebrush and other shrubs, often beneath their canopies. Pinyon and juniper may eventually grow closed canopy and restrict understory production .
Breeding system: Low sagebrush flowers are perfect . Some sagebrush species generally have perfect flowers but sometimes have outer flowers that are female and central flowers that are sterile . It is not known whether this occurs in low sagebrush.
Pollination: No information
Seed production: Reproduction of low sagebrush is generally by seed, even though alkali sagebrush layers occasionally . There are frequent large seed crops; seeds are light, wind-dispersed cypselas . Cleaned seed averages 980,000 per pound (2,160/g) [13,71]. Fruits are about 0.08 inch (2 mm) long. Seed viability is about 4 to 6 years in dry storage .
Seed banking: No information
Germination: Germination requires warm temperatures following a cold period of stratification. A 10-day chilling at 36 degrees Fahrenheit (2 Â°C) is used for stratification in nurseries . Highest germination rates are between 73 and 86 degrees Fahrenheit (23-30 Â°C). Seed from California germinated on many soil types under a wide temperature range . Light is required for germination .
Seedling establishment/growth: There is high mortality in the 1st year of growth . Establishment is probably greatest when seeds are covered by a thin layer of soil. Best practices for planting seed are 0.25 inch (0.6 cm) deep planting in fall or winter on sites with sun exposure and shallow clayey soils .
Asexual regeneration: Low sagebrush does not sprout; layering occurs infrequently [71,73,95,112]. Alkali sagebrush layers more frequently than the typical variety . In Sublette County, Wyoming an undescribed form of sagebrush thought to be a stable hybrid of alkali sagebrush and Wyoming big sagebrush is characterized by more frequent layering . In laboratory tests, stem cuttings of gray low sagebrush failed to root .
Growth Form (according to Raunkiær Life-form classification)
Life History and Behavior
More info for the terms: ecotype, phenology, phenotype
In low sagebrush new growth starts in May, young flower heads develop in July, and flowers open in August and September with seed ripening in October and November [13,73,93,95]. Alkali sagebrush has an earlier phenology than gray low sagebrush or other sagebrushes . New growth of alkali sagebrush begins in May, young heads appear in June, and flowering and seed ripening occur in July and August; this is about 1 month earlier than for other low sagebrushes [13,71,93]. Alkali sagebrush is the only sagebrush that blooms this early .
Seasonal development of hotsprings sagebrush is poorly known. Some maintain that hotsprings sagebrush exhibits earlier phenological development , but Shultz  reports that hotsprings sagebrush blooms in late summer and fall. Seed matures from late August through October, and ripens by October or November [13,117].
In all subspecies, early season growth is generally terminal bud growth; as soil moisture declines over summer, axillary growth becomes more important. If fall moisture is present, any late season growth is axillary. Leaves persist through winter and up to mid-season the following year; leaves from the previous year are shed during moisture stress .
Phenology may vary by phenotype as well as by geographic area. Eckert  reported that in Oregon, a small-headed ecotype of low sagebrush blooms from August to September, whereas a large-headed form flowers during July and August.
National NatureServe Conservation Status
Rounded National Status Rank: NNR - Unranked
NatureServe Conservation Status
Rounded Global Status Rank: G5 - Secure
Reasons: Widespread and common on clay soils in valleys and slopes.
There have historically been extensive efforts including burning, disking,
chaining, and herbicide spraying aimed at reducing sagebrush cover in favor
of more desirable forage [77,95]. Much of this has harmed sage-grouse habitat
. Additionally, grasses have generally not responded favorably
to sagebrush removal.
Revegetation of drier sites may be extremely difficult because of moisture
stress and a short growing season. This was especially true
where poor condition low sagebrush/bottlebrush squirreltail range was treated in
northern Nevada; these sites showed
little increase in forage production for 2 to 4 years even with grazing practices conducive to grass
establishment . Severely disturbed gray low
sagebrush communities, particularly those on heavy clay soils, are susceptible
to invasion by medusahead [32,120,122]. There are some reports of low sagebrush
removal improving the productivity of grasses such as Idaho fescue, bluebunch
wheatgrass, and Thurber neeedlegrass , but in most cases the low potential gain in
forage is offset by negative consequences [20,27,123]. Shrub removal may
also increase erosion to further reduce grass establishment . In addition,
even when control is successful, sagebrush reinvasion cannot be prevented by good grazing management
(but is hastened by poor management) .
The shallow, claypan soils in low sagebrush stands restrict drainage and root
growth, resulting in low productivity and limited use. Severe trampling damage
to supersaturated soils could occur if sites are used in early spring when there
is abundant snowmelt. Trampling damage in low sagebrush habitat types is
greatest when high clay content soils are wet. In drier areas with more gravelly soils, no serious trampling
damage occurs, even when the soils are wet . Light spring grazing is
Also during early spring, frost heaving, due to the saturated conditions, may
adversely affect seedling establishment .
Weeds: Medusahead, an annual grass native to Asia, is of concern in
low sagebrush communities because it decreases forage for livestock and wild
game and increases fire frequency . Like low sagebrush, medusahead
exhibits a strong preference for clay soils . In northeastern
California and northwestern Nevada, clayey soils have supported Lahontan
sagebrush. Establishment of Lahontan sagebrush increased the deposition and
residence time of aeolian dust. The veneer and cryptobiotic soil crust on
aeolian dust are more hardy than those on clay soils without aeolian deposition.
The crust protecting the aeolian dust has been disturbed by grazing. This
process has facilitated invasion and growth of medusahead .
Herbicides: All varieties are susceptible to 2,4-D, particularly in spring .
Spraying is more effective if it is done before vegetative growth is
completed. Early season spraying also causes less damage to broadleaf herbs in
the understory. Chemical removal of gray
low sagebrush can increase herbaceous production on some sites but on most sites
it is counterproductive [17,120]. Treatment of smaller blocks can
minimize adverse impacts on wildlife. Alkali sagebrush has an earlier phenology than most other sagebrush species, and
this could affect effectiveness of herbicidal control where it is mixed with
other species of sagebrush .
Relevance to Humans and Ecosystems
Value for rehabilitation of disturbed sites
Low sagebrush can be successfully transplanted or seeded in restoration . Low sagebrush reproduces via layering but this has not been extensively studied with respect to revegetation purposes . Transplanting is commonly successful, either in spring or fall [73,87]. Broadcast seeding is also used . Low sagebrush establishment from seed has been rated as "medium," and establishment from transplants as "very good." Seed production and handling are rated as "medium" because seeds are small. Natural spread by seed and vegetatively is "good." Gray low sagebrush and hotsprings sagebrush are well-adapted to disturbance and are able to stabilize soil . Alkali sagebrush has been useful in rehabilitating basic mine spoils produced from oil shale works .
Low sagebrush and big sagebrush are important cover for sage-grouse throughout its range [10,20]. Gray low sagebrush has some value as cover, especially for small birds and mammals. Sage-grouse use low sagebrush communities for nesting, roosting, and resting sites , as well as for escape cover. Mule deer use gray low sagebrush communities in Oregon as fawning and fawn-rearing areas . Cover values for various wildlife species have been rated as follows [34,66]:
|small nongame birds||poor||poor||----||fair||good|
|upland game birds||----||poor||----||fair||good|
Crude protein, fat, and fiber contents of hotsprings sagebrush leaves and stems
are 6.40%, 4.40%, and 34.54%, respectively .
Percent crude protein varied from 10 to 13% in low sagebrush in central Oregon,
peaking in April when use by mule deer is highest . Alkali sagebrush has a more rapid seasonal drop in percent crude protein than
other, later blooming sagebrushes . Nutrient
values were measured as follows :
|leaves||stems||leaves and stems|
|crude protein (%)||10.41||3.67||10.69|
|crude fat (%)||9.11||1.21||7.73|
|crude fiber (%)||18.26||26.79||56.79|
Artemisia arbuscula is a species of sagebrush known by the common names little sagebrush, low sagebrush, or black sagebrush.
It is native to the western United States from Washington to California to Colorado, where it grows in open, exposed habitat on dry, sterile soils high in rock and clay content. This is a gray-green to gray shrub forming mounds generally no higher than 30 centimetres (12 in). Its many branches are covered in hairy leaves each less than a centimeter long. The inflorescence is a spike-shaped array of clusters of hairy flower heads. Each head contains a few pale yellow disc florets. The fruit is a tiny achene less than a millimeter wide.
Names and Taxonomy
The currently accepted scientific name of low sagebrush is Artemisia
arbuscula Nutt. (Asteraceae). Currently recognized subspecies
Artemisia arbuscula ssp. arbuscula (Nutt.) H. & C. gray low sagebrush
Artemisia arbuscula ssp. longicaulis Winward &McArthur Lahontan sagebrush
Artemisia arbuscula ssp. longiloba (Osterhout) L. Shultz alkali sagebrush
Artemisia arbuscula ssp. thermopola Beetle hotsprings sagebrush
Alkali sagebrush has been previously classified as a
separate species (A. longiloba (Osterh.) Beetle) and as a variant of low sagebrush
(A. a. var. longiloba (Osterhout) Dorn)
[58,113]. Black sagebrush
(A. nova) used to be included as a variant or subspecies of low sagebrush
A. a. var. nova (A. Nels.) Cronq.;
A. a. ssp. nova (A. Nels.) G.H. Ward) because of apparent
intergradation between the 2 taxa. The species were separated when genetic analyses
showed that black sagebrush
is tetraploid while low sagebrush is diploid
[58,71]. In this
species summary, the common name low sagebrush is used when information applies to all
subspecies, otherwise subspecies' common names are used.
Hybridization has apparently occurred between low sagebrush and tall threetip
sagebrush (A. tripartita ssp.
tripartita), basin big sagebrush (A. tridentata ssp. tridentata),
and Wyoming big sagebrush (A. t. ssp. wyomingensis) [71,73]. Previously it was assumed that
alkali sagebrush did not hybridize because of its early phenology relative to other sagebrushes
(Artemisia spp.) . More recently, populations in Sublette County, Wyoming,
have been described as stable hybrids of alkali sagebrush and Wyoming big
sagebrush . Beetle 
speculated thathotsprings sagebrush originated as a
hybrid of tall threetip sagebrush and the gray low sagebrush. Lahontan sagebrush is thought to
possibly be a stable hybrid of gray low sagebrush and Wyoming big sagebrush
. Intermediates between gray low sagebrush and alkali
sagebrush have been reported .
gray low sagebrush
grey low sagebrush
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