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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 Unpublished report.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: 35.120.05 - Low Sagebrush/Idaho Fescue
Sawyer, J.O. and T. Keeler-Wolf. 1995. A Manual of California Vegetation. California Native Plant Society, Sacramento, CA. Low Sagebrush Series.
Associated sites
R021XE206CA Mountain Shoulders 30+ P.Z.
R021XE210CA Mahogany Savanna
R021XE221CA Claypan 30+ P.Z.
R021XE222CA Loamy Slope 30+ P.Z.
Similar sites
R021XE209CA Ashy Claypan 16-30 P.Z.
More productive site. PSSPS dominant grass.
R021XE221CA Claypan 30+ P.Z.
More productive site.
R021XE227CA Cobbly Claypan 30+ P.Z.
Less productive site; POSE dominant grass.
R021XE212CA Scabland 30+ P.Z.
Less productive site. ERMIA2 and POSE are dominant plants.
R021XE214CA Claypan 16-30 P.Z.
Lower elevations and less productive site; PSSPS dominant grass.
Table 1. Dominant plant species
Tree Not specified
Shrub (1) Artemisia arbuscula ssp. arbuscula
Herbaceous (1) Festuca idahoensis
(2) Poa secundaPhysiographic features
This site occurs on gently sloping mountain sideslopes. Slopes are 2 to 15 percent. Elevations range from 5600 to 8300 feet.
Table 2. Representative physiographic features
Landforms (1) Mountain slope
Elevation 5600 – 8300 ft Slope 2 – 15 % Aspect Aspect is not a significant factor Climatic features
The climate is subhumid with cold, moist winters and warm, dry summers. 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. Most storms have strong winds from the southwest or west, which blow substanial amounts of snow off south and west facing slopes (particularly steep slopes or slopes with short vegetation), and increase snow accumulations on adjacent north and/or east facing slopes, and/or in nearby concave depressions. Average annual precipitation is greater than 30 inches with most occurring during the winter months. Approximately half the precipitation falls as snow; half as rain. The mean annual air temperature is 38 to 44 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
Soils of this site are very shallow to shallow and well drained. The soils are formed in volcanic ash and colluvium over residium derived from glassy tuff or tuff-breccia. There are high amounts of vitric volcanic ash and glass throughout the soil profile which enhances water holding capacity. These soils are usually moist in winter, spring, and early summer, and are dry later in summer and fall. They have a xeric soil moisture regime and a frigid temperature regime. The soil profile is modified by 60 to 80 percent rock fragments, mainly gravel. A mollic epipedon occurs from the mineral soil surface to 13 inches. Soil series associated with this site include Fingerridge.
Table 4. Representative soil features
Parent material (1) Colluvium – tuff
Surface texture (1) Ashy loam
Family particle size (1) Loamy
Drainage class Well drained Permeability class Moderately rapid Soil depth 7 – 14 in Surface fragment cover <=3" 55 – 75 % Surface fragment cover >3" 5 – 12 % Available water capacity
(0-40in)1.7 – 1.8 in Calcium carbonate equivalent
(0-40in)Not specified Electrical conductivity
(0-40in)Not specified Sodium adsorption ratio
(0-40in)Not specified Soil reaction (1:1 water)
(0-40in)6.1 – 7.3 Subsurface fragment volume <=3"
(Depth not specified)60 – 75 % Subsurface fragment volume >3"
(Depth not specified)0 – 5 % Ecological dynamics
Fire Ecology:
Presettlement mean fire return intervals for low sagebrush-Idaho fescue communities ranged from 3 to 30 years. Fires usually occurred after a series of wet years and were usually initiated by lightning strikes.
Fire Effects:
Low sagebrush is very susceptible to fire damage. Low sagebrush is usually killed by fire and does not re-sprout. The recovery in burned areas is usually via small, light, wind-dispersed seed for all low sagebrush subspecies. Partially injured low sagebrush may re-grow from living branches, but sprouting does not occur.
Sandberg bluegrass is generally unharmed by fire. It produces little litter, and its small bunch size and sparse litter reduces the amount of heat transferred to perennating buds in the soil. Its rapid maturation in the spring also reduces fire damage, since it is dormant when most fires occur.
Idaho fescue grows in a dense, fine-leaved tuft. Fires tend to burn within the accumulated fine leaves at the base of the plant and may produce temperatures sufficient to kill some of the root crown. Mature Idaho fescue plants are commonly reported to be severely damaged by fire in all seasons.
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 CommunityThe reference plant community is characterized by an open canopy of low-statured shrubs 0.2 to 0.5 meters tall and an abundance of perennial grasses and forbs. The plant community is dominated by low sagebrush, Idaho fescue, and bluegrasses. Potential vegetative composition is about 40 percent grasses, 20 percent forbs and 40 percent shrubs. Approximate ground cover (basal and canopy) is 40 to 45 percent.
Figure 3. 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 200 280 360 Shrub/Vine 200 280 360 Forb 100 140 180 Total 500 700 900 Table 6. Soil surface cover
Tree basal cover 0% Shrub/vine/liana basal cover 0-10% Grass/grasslike basal cover 10-10% Forb basal cover 0-10% Non-vascular plants 0% Biological crusts 0-10% Litter 20-20% Surface fragments >0.25" and <=3" 60-80% Surface fragments >3" 10-10% Bedrock 0% Water 0% Bare ground 0-10% Additional community tables
Table 7. Community 1.1 plant community composition
Group Common name Symbol Scientific name Annual production () Foliar cover (%) Grass/Grasslike1 Primary Perennial Grasses 175–315 Idaho fescue FEID Festuca idahoensis 140–210 – Sandberg bluegrass POSE Poa secunda 35–105 – 2 Secondary Perennial Grasses/Grasslikes 28–98 Lemmon's needlegrass ACLE8 Achnatherum lemmonii 4–14 – Letterman's needlegrass ACLE9 Achnatherum lettermanii 4–14 – Thurber's needlegrass ACTH7 Achnatherum thurberianum 4–14 – sedge CAREX Carex 4–14 – squirreltail ELEL5 Elymus elymoides 4–14 – slender wheatgrass ELTRT Elymus trachycaulus ssp. trachycaulus 4–14 – bluebunch wheatgrass PSSPS Pseudoroegneria spicata ssp. spicata 4–14 – Forb3 Primary Perennial Forbs 70–105 spreading phlox PHDID2 Phlox diffusa ssp. diffusa 35–70 – spiny phlox PHHO Phlox hoodii 35–70 – slender wheatgrass ELTRT Elymus trachycaulus ssp. trachycaulus 4–14 – 4 Secondary Perennial Forbs 32–168 pussytoes ANTEN Antennaria 4–21 – rockcress ARABI Arabidopsis 4–21 – loosehead sandwort ARCOS2 Arenaria congesta var. subcongesta 4–21 – balloonpod milkvetch ASWH Astragalus whitneyi 4–21 – hawksbeard CREPI Crepis 4–21 – buckwheat ERIOG Eriogonum 4–21 – lupine LUPIN Lupinus 4–21 – owl's-clover ORTHO Orthocarpus 4–21 – 5 Annual 7–35 Shrub/Vine6 Primary Shrubs 175–245 little sagebrush ARAR8 Artemisia arbuscula 175–245 – 7 Secondary Shrubs 35–140 mountain big sagebrush ARTRV Artemisia tridentata ssp. vaseyana 7–28 – yellow rabbitbrush CHVI8 Chrysothamnus viscidiflorus 7–28 – sulphur-flower buckwheat ERUM Eriogonum umbellatum 7–28 – antelope bitterbrush PUTR2 Purshia tridentata 7–28 – spineless horsebrush TECA2 Tetradymia canescens 7–28 – Interpretations
Animal community
Livestock Interpretations:
This site is suitable for grazing by cattle and sheep during the summer and fall. Grazing should be keyed to perennial grass and palatable shrub production. Domestic sheep and to much lesser degree cattle consume low sagebrush, particularly during the spring, fall and winter. Idaho fscue is an important forage species for all classes of domestic livestock. 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. Where management results in abusive livestock use, low sagebrush, rabbitbrush, and Sandberg bluegrass increase along with mat-forming forbs. Moderate to heavy sheep use of this site will decrease abundance of Idaho fescue, needlegrass and bluegrasses.
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:
This site supports a variety of wildlife species, including mule deer, elk, and sage grouse. Low sagebrush is considered a valuable browse plant during the spring, fall, and winter. In some locations, low sagebrush is of little to no value in the winter due to heavy snow. Low sagebrush is an important food source for sage grouse throughout the year, especially between October and April. This site also produces a high percentage of forbs and grasses desirable for sage grouse. Low sagebrush also provides valuable cover for sage grouse, other birds and small mammals. Idaho fesue and Sandbergs bluegrass are important forage species to many species of wildlife. Mule deer may also use this site as fawning and fawn-rearing areas.Hydrological functions
Runoff is high. Rills and gullies are none to rare. A few small rills may be present on steeper slopes. Waterflow patterns are none to rare, due to high rock cover on the surface. A few may be expected on steeper slopes. Perennial herbaceous plants (especially deep-rooted bunchgrasses) slow runoff and increase infiltration. Low stature and sparseness of shrub canopy, coupled with high velocity ridge-top winds limit snow catch and accumulation on this site.
Recreational uses
This site derives aesthetic value from its topgraphic position, affording an unobstructed view of the surrounding mountains and valleys. The open vistas and abundant forbs offer rewarding opportunities to photographers. Other recreational uses include hiking, bird watching, and hunting.
Other information
Low sagebrush can be successfully transplanted or broadcast seeded in restoration. Transplanting is successful, either in spring or fall.
Supporting information
Type locality
Location 1: Modoc County, CA Township/Range/Section T44N R15E S3 Latitude 41° 37′ 9″ Longitude 120° 10′ 7″ General legal description Northeast of Bald Mountain, on the Modoc National Forest in the Warner Mountains, Modoc County, CA. 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) P. Novak-Echenique Contact for lead author State Rangeland Management Specialist Date 09/02/2005 Approved by Approval date Composition (Indicators 10 and 12) based on Annual Production Indicators
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Number and extent of rills:
None to rare. A few small rills may be present on steeper slopes. -
Presence of water flow patterns:
None to rare, due to high rock cover on the surface. A few may be expected on steeper slopes. -
Number and height of erosional pedestals or terracettes:
None to rare. Frost heaving of shallow rooted plants is common and should not be mistaken for pedestalling due to erosion. -
Bare ground from Ecological Site Description or other studies (rock, litter, lichen, moss, plant canopy are not bare ground):
Bare ground is 1-10%; surface cover of rock fragments 60-85%; shrub canopy 5-15%; basal and foliar cover of perennials 40-50%. -
Number of gullies and erosion associated with gullies:
None -
Extent of wind scoured, blowouts and/or depositional areas:
None -
Amount of litter movement (describe size and distance expected to travel):
Fine litter is expected to move the distance of slope length during intense summer convection storms or rapid snowmelt events. Persistent litter (large woody material) will remain in place except during catastrophic runoff events. -
Soil surface (top few mm) resistance to erosion (stability values are averages - most sites will show a range of values):
Soil stability values should be 3 to 6 on most soil textures found on this site. Needs to be field tested. -
Soil surface structure and SOM content (include type of structure and A-horizon color and thickness):
Surface structure is weak, fine subangular blocky. Soil surface colors are dark and soils are usually typified by a mollic epipedon. Organic matter is 1 to 2 percent. -
Effect of community phase composition (relative proportion of different functional groups) and spatial distribution on infiltration and runoff:
Perennial herbaceous plants (especially deep-rooted bunchgrasses) slow runoff and increase infiltration. Low stature and sparseness of shrub canopy, coupled with high velocity ridge-top winds limit snow catch and accumulation on this site. -
Presence and thickness of compaction layer (usually none; describe soil profile features which may be mistaken for compaction on this site):
Not typical. Subsoil argillic horizons are not to be interpreted as compaction. -
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:
Deep-rooted cool-season perennial grasses=low shrubsSub-dominant:
deep-rooted, cool-season perennial forbs>associated shrubs=shallow-rooted, cool-season perennial bunchgrassesOther:
fibrous, shallow-rooted, cool-season, perennial and annual forbs.Additional:
-
Amount of plant mortality and decadence (include which functional groups are expected to show mortality or decadence):
Dead branches within individual shrubs common; standing dead shrub canopy material may be as much as 15% of total woody canopy, some of the mature bunchgrasses (<10%) have dead centers. -
Average percent litter cover (%) and depth ( in):
Between plant interspaces - 15-20% -
Expected annual annual-production (this is TOTAL above-ground annual-production, not just forage annual-production):
For normal or average growing season ~ 700lbs/ac. -
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:
Cheatgrass is an invader on this site. Yellow rabbitbrush and spineless horsebrush are increasers on this site. -
Perennial plant reproductive capability:
All functional groups should reproduce in average and above average growing seasons.
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