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Draft. A draft ecological site description is either incomplete or has not undergone quality control and quality assurance review.
Classification relationships
Holland, R.F. 1986. Preliminary descriptions of the terrestrial natural communities of California. Unpublished report. State of California, The Resources Agency, Department of Fish and Game, Natural Heritage Division, Sacramento, CA. (Updated September 2003). Element Code: Big Sagebrush 35.110.02.
Sawyer, J.O. and T. Keeler-Wolf. 1995. A Manual of California Vegetation. California Native Plant Society, Sacramento, CA. Big Sagebrush Series.
Table 1. Dominant plant species
Tree Not specified
Shrub (1) Artemisia tridentata ssp. vaseyana
(2) Symphoricarpos rotundifoliusHerbaceous (1) Bromus marginatus
(2) AchnatherumPhysiographic features
This site occurs on mountain slopes. Slopes range from 4 to 15 percent. Elevations range from 7000 to 9000 feet.
Table 2. Representative physiographic features
Landforms (1) Mountain slope
Elevation 7000 – 9000 ft Slope 4 – 15 % Aspect Aspect is not a significant factor Climatic features
The climate of this site is temperate, characterized by warm, dry summers and cold, moist winters. The area's precipitation comes mostly from winter Pacific cyclonic storms, with a very slight summer monsoonal season that is erratic but can be locally significant. Average annual precipitation is 30 to 50 inches with most occurring during the winter months. Approximately half the precipitation falls as snow; half as rain. The mean annual air temperature is 39 to 42 degrees F. The average growing season is about 30 to 60 days.
Table 3 Representative climatic features
Frost-free period (average) 60 days Freeze-free period (average) 0 days Precipitation total (average) 50 in BarLineFigure 1. Monthly precipitation range
BarLineFigure 2. Monthly average minimum and maximum temperature
">Influencing water features
There are no influencing water features associated with this site.
Soil features
This site occurs on deep, well drained soils that formed in colluvium and residium derived from glacial debris, volcanic ash and andesitic tuff and similiar volcanic rocks. These soils are usually moist in winter, spring, and early spring, dry later in summer and fall. These soils have high amounts of vitric volcanic ash and glass throughout the soil profile which enhances the water holding capacity of these soils. Mollic epipedon 30 to 60 inches in thickness. Soil series associated with this site include Paynepeak.
Table 4. Representative soil features
Parent material (1) Colluvium – andesite
Surface texture (1) Gravelly loam
Family particle size (1) Loamy
Drainage class Well drained Permeability class Moderately rapid Soil depth 40 – 60 in Surface fragment cover <=3" 15 – 20 % Surface fragment cover >3" Not specified Soil reaction (1:1 water)
(0-40in)6.5 – 6.7 Subsurface fragment volume <=3"
(Depth not specified)30 – 50 % Subsurface fragment volume >3"
(Depth not specified)10 – 15 % Ecological dynamics
Where management results in abusive use by livestock, platable grasses decrease as snowberry and mountain big sagebrush increase in the overstory.
Fire effects:
Presettlement fire return intervals in mountain big sagebrush communities varied from 15-25 years. Mountain big sagebrush is highly susceptible to injury from fire. Plants are readily killed in all seasons, even light severity fires. Mountain big sagebrush plants top-killed by fire will not resprout.
Fires top-kill roundleaf snowberry. Although plant survival may be variable, mountain snowberry root crowns usually survive even severe fires. Roundleaf snowberry sprouts from basal buds at the root crown following fire.
Little specific information is available on adaptations of Letterman's needlegrass to fire. It is morphologically similar to Columbia needlegrass, which is only slightly to moderately damaged by fire. Season of burn affects the plant's ability to survive a fire. Needlegrass tends to be more susceptible to fire when burned during mid-summer. Post fire regeneration is through seeding and tillering.
Thurber needlegrass is classified as moderately resistant, but depending on season of burn, phenology, and fire severity, this perennial bunchgrass is moderately to severely damaged by fire. Burning has been found to decrease the vegetation and reproductive vigor. Early season burning is more damaging to this needlegrass than late season burning.State and transition model
More interactive model formats are also available. View Interactive Models
Click on state and transition labels to scroll to the respective textEcosystem states
State 1 submodel, plant communities
State 1
Reference StateCommunity 1.1
Reference Plant Community
Figure 3. Loamy Slope
The reference plant community is dominated by mountain big sagebrush, roundleaf snowberry, mountain brome and needlegrasses. Potential vegetative composition is about 45% grasses, 20% forbs and 35% shrubs.
Figure 4. Annual production by plant type (representative values) or group (midpoint values)
Table 5. Annual production by plant type
Plant type Low
(lb/acre)Representative value
(lb/acre)High
(lb/acre)Grass/Grasslike 495 675 810 Shrub/Vine 385 525 630 Forb 220 300 360 Total 1100 1500 1800 Additional community tables
Table 6. Community 1.1 plant community composition
Group Common name Symbol Scientific name Annual production () Foliar cover (%) Grass/Grasslike1 Primary Perennial Grasses 330–675 mountain brome BRMA4 Bromus marginatus 150–300 – Letterman's needlegrass ACLE9 Achnatherum lettermanii 50–100 – western needlegrass ACOCO Achnatherum occidentale ssp. occidentale 50–100 – Thurber's needlegrass ACTH7 Achnatherum thurberianum 50–100 – Sandberg bluegrass POSE Poa secunda 30–75 – 2 Secondary Perennial Grasses 64–240 sedge CAREX Carex 8–30 – blue wildrye ELGL Elymus glaucus 8–30 – big squirreltail ELMU3 Elymus multisetus 8–30 – Idaho fescue FEID Festuca idahoensis 8–30 – prairie Junegrass KOMA Koeleria macrantha 8–30 – basin wildrye LECI4 Leymus cinereus 8–30 – melicgrass MELIC Melica 8–30 – bluebunch wheatgrass PSSPS Pseudoroegneria spicata ssp. spicata 8–30 – Forb3 Perennial Forbs 112–420 common yarrow ACMI2 Achillea millefolium 8–30 – pale agoseris AGGL Agoseris glauca 8–30 – milkvetch ASTRA Astragalus 8–30 – sagebrush mariposa lily CAMAM9 Calochortus macrocarpus var. macrocarpus 8–30 – castilla CASTI Castilla 8–30 – clarkia CLARK Clarkia 8–30 – tapertip hawksbeard CRAC2 Crepis acuminata 8–30 – ballhead waterleaf HYCAC Hydrophyllum capitatum var. capitatum 8–30 – Lewis flax LILE3 Linum lewisii 8–30 – lupine LUPIN Lupinus 8–30 – Brown's peony PABR Paeonia brownii 8–30 – beardtongue PENST Penstemon 8–30 – cold-desert phlox PHST11 Phlox stansburyi 8–30 – woolly mule-ears WYMO Wyethia mollis 8–30 – 4 Annual Forbs 16–60 grand collomia COGR4 Collomia grandiflora 8–30 – cryptantha owl's-clover ORCUC2 Orthocarpus cuspidatus ssp. cryptanthus 8–30 – Shrub/Vine5 Primary Shrubs 300–495 mountain big sagebrush ARTRV Artemisia tridentata ssp. vaseyana 225–375 – roundleaf snowberry SYRO Symphoricarpos rotundifolius 75–120 – 6 Secondary Shrubs 135–270 Utah serviceberry AMUT Amelanchier utahensis 15–30 – big sagebrush ARTRS2 Artemisia tridentata ssp. spiciformis 15–30 – curl-leaf mountain mahogany CELE3 Cercocarpus ledifolius 15–30 – yellow rabbitbrush CHVI8 Chrysothamnus viscidiflorus 15–30 – antelope bitterbrush PUTR2 Purshia tridentata 15–30 – wax currant RICE Ribes cereum 15–30 – American black elderberry SANIC4 Sambucus nigra ssp. canadensis 15–30 – Interpretations
Animal community
Livestock Interpretations:
This site is suited for grazing during the spring, summer and fall. Attentive grazing management is required due to steep slopes and erosive soil surface conditions. Grazing management should be keyed to mountain brome and needlegrass production. Big sagebrush is eaten by domestic sheep and cattle, but has long been considered to be of low palatability to domestic livestock, a competitor with more desirable species, and a physical impediment to grazing. Snowberry is readily eaten by all classes of livestock, particularly domestic sheep. Needlegrass and mountain brome provide important forage for domestic livestock.
Stocking rates vary over time depending upon season of use, climate variations, site, and previous and current management goals. A safe starting stocking rate is an estimated stocking rate that is fine tuned by the client by adaptive management through the year and from year to year.
Wildlife Interpretations:
Big sagebrush is highly preferred and nutritious winter forage for mule deer. Sage grouse are also highly dependent on big sagebrush for both food and cover. Snowberry is an important forage species for deer and elk on high elevation summer ranges. Snowberry is frequently one of the first species to leaf out, making it a highly sought after food in the early spring. Needlegrass and mountain brome provide important forage for several wildlife species.Hydrological functions
Runoff is medium.
Other products
Native peoples used big sagebrush leaves and branches for medicinal teas, and the leaves as a fumigant. Bark was woven into mats, bags and clothing.
Other information
Mountain big sagebrush has potential for range restoration and soil stabilization.
Supporting information
Type locality
Location 1: Modoc County, CA Township/Range/Section T48N R16E S32 Latitude 41° 59′ 16″ Longitude 120° 9′ 15″ General legal description On the Modoc National Forest in the Warner Mountains Other references
Fire Effects Information System [Online]. http://www.fs.fed.us/feis
Miles, S.R. and C.B. Goudey. 1997. Ecological Subregions of California Section and Subsection Descriptions. United States Department of Agriculture Forest Service, Pacific Southwest Region R5-EM-TP-005. Subsection M261Gf-Warner Mountains.
Modoc Elk Working Group. 2000. The Greater Modoc Area A Strategic Plan for Elk Management. Modoc County, CA
Contributors
P.NOVAK-ECHENIQUE
Rangeland health reference sheet
Interpreting Indicators of Rangeland Health is a qualitative assessment protocol used to determine ecosystem condition based on benchmark characteristics described in the Reference Sheet. A suite of 17 (or more) indicators are typically considered in an assessment. The ecological site(s) representative of an assessment location must be known prior to applying the protocol and must be verified based on soils and climate. Current plant community cannot be used to identify the ecological site.
Author(s)/participant(s) Contact for lead author Date Approved by Approval date Composition (Indicators 10 and 12) based on Annual Production Indicators
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Number and extent of rills:
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Presence of water flow patterns:
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Number and height of erosional pedestals or terracettes:
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Bare ground from Ecological Site Description or other studies (rock, litter, lichen, moss, plant canopy are not bare ground):
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Number of gullies and erosion associated with gullies:
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Extent of wind scoured, blowouts and/or depositional areas:
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Amount of litter movement (describe size and distance expected to travel):
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Soil surface (top few mm) resistance to erosion (stability values are averages - most sites will show a range of values):
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Soil surface structure and SOM content (include type of structure and A-horizon color and thickness):
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Effect of community phase composition (relative proportion of different functional groups) and spatial distribution on infiltration and runoff:
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Presence and thickness of compaction layer (usually none; describe soil profile features which may be mistaken for compaction on this site):
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Functional/Structural Groups (list in order of descending dominance by above-ground annual-production or live foliar cover using symbols: >>, >, = to indicate much greater than, greater than, and equal to):
Dominant:
Sub-dominant:
Other:
Additional:
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Amount of plant mortality and decadence (include which functional groups are expected to show mortality or decadence):
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Average percent litter cover (%) and depth ( in):
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Expected annual annual-production (this is TOTAL above-ground annual-production, not just forage annual-production):
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Potential invasive (including noxious) species (native and non-native). List species which BOTH characterize degraded states and have the potential to become a dominant or co-dominant species on the ecological site if their future establishment and growth is not actively controlled by management interventions. Species that become dominant for only one to several years (e.g., short-term response to drought or wildfire) are not invasive plants. Note that unlike other indicators, we are describing what is NOT expected in the reference state for the ecological site:
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Perennial plant reproductive capability:
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