The following description of scabland sagebrush provides characteristics that may be relevant to fire ecology, and is not meant for identification. Keys for identification are available (e.g. [17,18,30,32]).
Scabland sagebrush is a native, deciduous shrub. It is low and spreading with a conspicuously woody base. The base is often heaved from the soil by frost action. The trunk is very irregular, spreading above the base in a dense cluster of short, rigid, and rather brittle branches up to 16 inches (40 cm) in length. Flowering stems elongate up to 1 foot (30 cm). Vegetative leaves are 0.4 to 1.6 inches (1-4 cm) long, with a narrow base and 3 conspicuous, narrowly linear lobes forming a trident. The fruit is a ribbed achene 1.5 mm long [8,38,59].
Most of the roots of scabland sagebrush are concentrated in rock fractures, and 80% of the roots of scabland sagebrush occur in the first 2 to 9 inches (5-23 cm) of soil [33].
Fire adaptations: Scabland sagebrush is killed by fire [23].
FIRE REGIMES: There is no specific information in the literature concerning FIRE REGIMES for scabland sagebrush. Researchers agree the vegetation on scabland sagebrush sites is so depauperate, it won't support fire. Agee [1] describes a scabland sagebrush/Sandberg's bluegrass plant series in the Columbia River Basin and concludes it has such low biomass productivity (125-335 kg/ha [33]) that it would not carry fire and probably "rarely" burned. Bunting and others [14] classify stiff sagebrush as a "dwarf" sagebrush and state there is seldom sufficient fuel to carry a fire. Tisdale and Hironaka [56] report the sparse herbaceous understory of scabland sagebrush stands make them virtually immune to fire. Humphrey [47] states stiff sagebrush is small in stature and typically occurs on poorly drained sites with few grasses or other potentially flammable growth. These stands are often restricted in area and do not provide an opportunity for extensive burns.
FIRE REGIMES for plant communities and ecosystems in which scabland sagebrush occurs are summarized below. Find further 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".
Community or Ecosystem Dominant Species Fire Return Interval Range (years) sagebrush steppe Artemisia tridentata/Pseudoroegneria spicata 20-70 [43] basin big sagebrush Artemisia tridentata var. tridentata 12-43 [48] mountain big sagebrush Artemisia tridentata var. vaseyana 15-40 [5,15,41] Wyoming big sagebrush Artemisia tridentata var. wyomingensis 10-70 (40**) [58,62] curlleaf mountain-mahogany* Cercocarpus ledifolius 13-1,000 [7,49] western juniper Juniperus occidentalis 20-70 Rocky Mountain juniper Juniperus scopulorum < 35 pinyon-juniper Pinus-Juniperus spp. < 35 [43] Jeffrey pine Pinus jeffreyi 5-30 Pacific ponderosa pine* Pinus ponderosa var. ponderosa 1-47 [4] mountain grasslands Pseudoroegneria spicata 3-40 (10**) [3,4] Rocky Mountain Douglas-fir* Pseudotsuga menziesii var. glauca 25-100 [4,5,6] *fire return interval varies widely; trends in variation are noted in the species summaryBecause fuel is rarely sufficient to carry a fire, scabland sagebrush stands can frequently be used as natural fire breaks. Care must be taken in above average production years because scabland sagebrush stands may be able to carry a fire at that time [14].
Since scabland sagebrush is a preferred browse plant for livestock and wildlife, prescribed burning in scabland sagebrush communities cannot be widely recommended [14]. Johnson and Simon [33] state scabland sagebrush has a high value to wildlife and should not be eradicated.
Johnson and Simon [33] conclude the intershrub distances in scabland sagebrush stands coupled with discontinuous grass cover make fire a difficult tool to use.
Scabland sagebrush occurs on harsh, unproductive sites [34]. It is restricted to shallow, stony sites over basaltic bedrock [21,22] with severe moisture saturation during winter and severe frost heaving [28,31]. Where subsoils exist they are strongly developed of clay and permeability is extremely low [31]. In a scabland sagebrush/Sandberg bluegrass habitat type in the Wallowa-Whitman National Forest in Washington and Idaho, average depth of the soil to bedrock is 4 to 9 inches (10-23 cm) [33].
Miller and Eddleman [40] describe annual precipitation at scabland sagebrush sites as 7.9 to 15.7 inches (200-400 mm). Precipitation on a habitat type of scabland sagebrush/Sandberg bluegrass in southern Idaho ranges from 12 to 20 inches (305-508 mm) [31].
Several elevational ranges for scabland sagebrush have been delineated:
Miller and Eddleman [40] describe the elevational range of scabland sagebrush, in general, as 755 to 4,265 feet (230-1,300 m).
Beetle [8] gives the elevational range of scabland sagebrush on rocky scablands as between 3,000 to 5,000 feet (914-1,424 m).
Hall [27] describes the elevational range of scabland sagebrush in the Blue Mountains of Eastern Oregon and southeastern Washington as 4,000 to 5,600 feet (1,219-1,707 m).
In the Wallowa-Whitman National Forest, scabland sagebrush sites occur from 3,300 to 5,500 feet (1,006-1,676 m) with a mean altitude of 4,600 feet (1,400 m) [33].
In Oregon, Winward [61] describes the elevational range of stiff sagebrush as 3,000 to 7,000 feet (914-2,134 m).
Scabland sagebrush sites have low above ground annual plant production, 123 to 246 kg/ha [40]. However, because scabland sagebrush sites are commonly along exposed ridge sites where snowmelt occurs rapidly, these communities may supply the only available forage to big game animals in early spring months; consequently scabland sagebrush has a high value to wildlife [33]. Bunting and others [14] state scabland sagebrush is a preferred browse plant for both livestock and wildlife.
Daubenmire [21] states scabland sagebrush is preferred browse for elk and that domestic livestock also consume scabland sagebrush readily when grass forage is not plentiful. Daubenmire [23] notes the angularity of the basaltic blocks which comprise so much of the surface in scabland sagebrush stands makes footing uncomfortable for livestock during the rainy grazing season in Washington. Consequently, grass-dominated communities in the vegetation mosaic are utilized "rather completely" before scabland sagebrush bushes are browsed to "compact mats."
Western sage-grouse in Washington use stiff sage-brush as food [54]. Willis and others [60] state western sage-grouse in Oregon use stiff sagebrush; the authors don't delineate whether it is used for food, cover, or both.
Palatability/nutritional value: Both livestock and wildlife find scabland sagebrush palatable. Daubenmire [23] describes scabland sagebrush as "rather palatable" to livestock and Hall [28] states scabland sagebrush is highly palatable to big game and livestock. Seedheads of scabland sagebrush in August and September seem to be a prized forage. Hironaka and others [31] describe scabland sagebrush sites as heavily grazed, even in winter, when protein content of scabland sagebrush is "relatively low."
Cover value: Bare ground and rock usually account for greater than 60% of the ground cover in scabland sagebrush stands, so hiding cover is typically sparse [40]. Dealy and others [24] state the low stature and wide dispersion of scabland sagebrush stands in southeastern Oregon do not provide cover of any consequence for animals larger than horned larks or ground squirrels. Lack of leaves in winter severely reduces the little cover scabland sagebrush offers. However, Tirhi [54] states western sage-grouse in Washington use scabland sagebrush for cover.
Bryce and Omernik [13] use scabland sagebrush and Sandberg
bluegrass (Poa Secunda) as natural vegetation to define the Channeled
Scablands [12] subregion of the Columbia Plateau in Oregon and Washington.
The most common associate of scabland sagebrush in Oregon is Sandberg bluegrass.
Biscuitroots (Lomatium spp.) are also common. Cheatgrass (Bromus
tectorum) and other annual grasses and forbs become major increasers on
disturbed sites of scabland sagebrush [61]. Also in Oregon, in the Blue Mountains,
Hall [29] describes the most common associates of
scabland sagebrush in a western juniper (Juniperus occidentalis ssp.
occidentalis)/scabland sagebrush/bluegrass (Poa spp.) plant community in good range
condition as Sandberg bluegrass, onespike oatgrass (Danthonia unispicata),
and often bighead clover (Trifolium macrocephalum). He states cheatgrass
and western yarrow (Achillea millefolium) are absent from range sites in
poor condition because of site limitations. Also in the Blue Mountains of Oregon,
Hall [28] lists Sandberg bluegrass, wheatgrass (Triticeae), dwarf squirreltail (Elymus
elymoides ssp. hordeoides), and bighead clover as vegetation
dominants in scabland sagebrush stands.
In Idaho Hironaka and others [31] list a
habitat type of scabland sagebrush/Sandberg bluegrass as occurring on shallow,
basalt-derived soils. Other species associated with this habitat type include
bottlebrush squirreltail (E. elymoides), crested wheatgrass (A.
cristatum), tapertip onion (Allium acuminatum), bulbous woodland-star
(Lithophragma glabrum), Bailey's buckwheat (Eriogonum baileyi),
and low-growing biscuitroots. Cheatgrass and/or medusahead (Taeniatherum
caput-medusae) occur sparsely in all stands, even when fully protected from
all grazing.
Clary and others [16] describe a habitat type of scabland sagebrush/Sandberg
bluegrass in the Pole Creek drainage in Oregon that is restricted to rocky,
basalt sites with shallow soil. Agee [1] describes a scabland
plant series in the Columbia Basin of scabland sagebrush/Sandberg bluegrass.
A plant association of stiff
sagebrush/bluegrass (Poa spp.) in eastern Washington and northern Idaho
is described as an edaphic climax community along the brows of hills on thin,
stony soils [46]. Similarly, Culver [19] describes an edaphic climax plant
association of scabland sagebrush/Sandberg bluegrass in Oregon. In Washington
Daubenmire [21] delineates
a scabland sagebrush/Sandberg bluegrass habitat type where the soil is always thin
and stony with balsaltic bedrock immediately below.
Other classification systems describing plant communities in which scabland sagebrush
is a dominant species are listed below:
Wallowa-Whitman National Forest (Oregon) [33]
Meeks Table Research Natural Area (Washington) [53]
Canyon grasslands and associated shrublands of west-central Idaho and adjacent
areas [55]
Very little information about regeneration processes of scabland sagebrush is available in the literature. Where information about sagebrush (Artemisia spp.) in general is applicable, it is included.
Breeding system: Pendleton and others [44] describe sagebrush as monoecious.
Pollination: Scabland sagebrush is wind pollinated [37].
Seed production: All sagebrushes produce achenes "in profusion" [8]. No specific information about seed production of scabland sagebrush is available.
Seed dispersal: Sagebrush seed in general has very poor dispersal. It lacks appendages for airborne transport by wind or attachment to animals. Most seed falls beneath the plant and the plant community moves 3 feet (0.9 m) or less per generation [50]. There are no specific references to dispersal of scabland sagebrush seeds in the literature.
Seed banking: No information on seed banking of scabland sagebrush is available. Mueggler [42] found that after fire, big sagebrush (A. tridentata) seedlings arose from seed stored in the soil. Beetle [8] states seed of mountain silver sagebrush (A. cana ssp. viscidula) stored for 4 years under ordinary room temperatures was still viable.
Germination: In a discussion of sagebrush seed in general, Beetle [8] states sagebrush seed can germinate in 48 hours. Seed exposed to light resulted in germination percentages 3 times higher than sagebrush seed germinated in the dark. There is no evidence that sagebrush seed that survives the summer germinates in the fall under field conditions. Under field conditions, fluctuating extremes of temperatures (which are the rule in early spring) may be of less importance than the duration of a high noon temperature.
Seedling establishment/growth: Germinated sagebrush seeds can have fully exposed cotyledons within 4 days [8]. Shade from the canopy of mature sagebrush plants is a strong factor in seedling survival. Seedlings in direct sun have higher mortality.
Survival of sagebrush seedlings is directly related to the litter layer. With less litter there is a better likelihood of sagebrush seedlings establishing.
Asexual regeneration: Scabland sagebrush is not known to rootsprout or to layer [11,38,59].
Scabland sagebrush is part of the climax vegetation on sites where it occurs. Johnson [34] describes scabland sagebrush as "clearly" the climax vegetation of very harsh, unproductive range sites.
On scabland sites on the Bridge Creek Wildlife Management Area in northeastern Oregon, scabland sagebrush is part of a climax plant community [2]. In eastern Washington and northern Idaho scabland sagebrush is described as part of an edaphic climax community along the brows of hills on thin, stony soils [46]. Culver [19] also describes an edaphic climax vegetation association in Oregon where scabland sagebrush is the only shrub present.
Artemisia rigida is a species of flowering plant in the aster family known by the common names scabland sagebrush[2] and stiff sagebrush. It is native to the northwestern United States, in Washington, Idaho, and Oregon.[3] It has been recorded in western Montana but these sightings may have been misidentifications.[4]
Artemisia rigida is a small, spreading, deciduous shrub with many woody branches up to 40 centimeters long. The stems mature to gray and hairy and are often reddish during early growth.[2] The leaves are up to 4 centimeters long and trident-shaped. They are grayish in color from their coat of silvery hairs. The similar Artemisia tripartita leaf typically has shorter woolly hairs. The plant is "mildly"[2] to "pungently"[5] scented. The flower heads are somewhat bell-shaped and measure about half a centimeter wide. They contain 4 to 8 yellow-red to red florets.[2]
Artemisia rigida grows in harsh substrates where few other plants survive. The soil is generally very shallow and covers bedrock. The bedrock is always basalt, never granite.[6] The roots of the plant are within the shallow soil layer with some anchoring in rock fractures. There is also sometimes a layer of impermeable clay. The substrate commonly undergoes frost heaving, which breaks it up. On these unproductive sites, which occur in the Channeled Scablands, for example, this plant is a climax species. It is an indicator of scabland habitat.[4] In the Columbia Basin it often dominates regions with thin rocky soils, and has Sandberg's bluegrass as the main understory species along with various low herbaceous plants such as Viola trinervata and small Lomatium species.[7]
Artemisia rigida provides food for wildlife because it is often the only plant exposed as the snow melts in the spring on mostly barren landscapes. Livestock also like it, especially the seedheads.[4]
Artemisia rigida is a species of flowering plant in the aster family known by the common names scabland sagebrush and stiff sagebrush. It is native to the northwestern United States, in Washington, Idaho, and Oregon. It has been recorded in western Montana but these sightings may have been misidentifications.
Artemisia rigida là một loài thực vật có hoa trong họ Cúc. Loài này được (Nutt.) A.Gray mô tả khoa học đầu tiên năm 1883.[1]
Artemisia rigida là một loài thực vật có hoa trong họ Cúc. Loài này được (Nutt.) A.Gray mô tả khoa học đầu tiên năm 1883.
