Natural Resources
Conservation Service
-
Search
Major Land Resource Area or ecological site by name and/or ID.
PreviousSectionsNextGeneral information
Provisional. A provisional ecological site description has undergone quality control and quality assurance review. It contains a working state and transition model and enough information to identify the ecological site.
Click to explore map
Figure 1. Mapped extent
Areas shown in blue indicate the maximum mapped extent of this ecological site. Other ecological sites likely occur within the highlighted areas. It is also possible for this ecological site to occur outside of highlighted areas if detailed soil survey has not been completed or recently updated.
Table 1. Dominant plant species
Tree Not specified
Shrub (1) Artemisia tridentata ssp. tridentata
(2) Artemisia tridentata ssp. wyomingensisHerbaceous (1) Pseudoroegneria spicata ssp. spicata
Physiographic features
This site occurs on north facing side-slopes of basin hills and low mountains. Slopes range from 10-80%, with gradients of 20 to 70% being most common. Elevations vary from 4400-5500 feet.
Table 2. Representative physiographic features
Landforms (1) Hill
(2) Mountain slope
Flooding frequency None Ponding frequency None Elevation 4400 – 5500 ft Slope 20 – 70 % Aspect N Climatic features
The annual precipitation averages 8-10 inches, most of which occurs during the months of October through March. The mean annual air temperature is 48 degrees F. Temperature extremes range from 110 to -30 degrees F. The period for optimum Plant growth is from April through early June.
Table 3 Representative climatic features
Frost-free period (average) 0 days Freeze-free period (average) 0 days Precipitation total (average) 0 in BarLineFigure 2. Monthly precipitation range
BarLineFigure 3. Monthly average minimum and maximum temperature
Figure 4. Annual precipitation pattern
Figure 5 Annual average temperature pattern
">Influencing water features
Soil features
The soils of this site are shallow to very shallow over a strongly cemented duripan, bedrock, or clay layer. Typically the surface is a very gravelly or cobbly sandy clay
loam over a very cobbly clay loam subsoil. Permeability is moderate to moderately slow. The available water holding capacity is about .5 to 3 inches for the profile. The potential for erosion is high. See Appendix II for soils that correlate to this site.Table 4. Representative soil features
Surface texture (1) Very cobbly sandy clay loam
(2) Very gravelly sandy clay loam
Family particle size (1) Clayey
Permeability class Moderately slow to moderate Available water capacity
(0-40in)0.5 – 3 in Ecological dynamics
Four states have been identified for this site: a reference state; a state with the presence of annuals; a state with a shrub/annual co-dominance; and a state with annual dominance.
Reference: Plant community phase change is driven by infrequent fire. Wyoming and basin big sagebrush decline after fire while Thurber’s needlegrass, Indian ricegrass and other grasses increase. May see a temporary increase in rabbitbrush after fire. Time facilitates the reintroduction of sagebrush. The introduction of invasive annual grasses and forbs transitions into the state 2.
State 2: Compositionally similar to the reference state with a trace of cheatgrass and weedy forbs. Ecological function has not changed, however the resiliency of the state has been reduced by the presence of invasive weeds. Prescribed grazing and infrequent fire (> 50 year return interval) maintain state dynamics. The timing and/or intensity of grazing or prolonged drought favors Wyoming and basin big sagebrush, squirreltail and Sandberg’s bluegrass. Prescribed grazing and/or release from drought may reverse the decline in needlegrass and Indian ricegrass production. Infrequent fire reduces the shrub community and promotes the bunchgrass component. Mismanaged grazing and/or prolonged drought leads to a biotic threshold and into state 3.
State 3: Wyoming and basin big sagebrush is decadent with little recruitment. The perennial grass component is significantly reduced in both density and productivity. Cheatgrass and/or annual forbs and/or Sandberg’s bluegrass along with sagebrush control site resources and drive ecological dynamics. Bare ground is abundant. Spatial and temporal energy capture and nutrient cycling has been truncated. Infiltration may be reduced due to lack of ground cover. Risk of soil erosion by both wind and water is increased. Catastrophic wildfire will lead to an abiotic threshold and into state 4.
State 4: Cheatgrass and/or annual weed dominated plant community with limited to no shrub or perennial grass component. Soil erosion and redistribution along with changes in dynamic soil properties affect the hydrologic cycle and thus the nutrient cycle. Harsh environmental factors increase state resiliency to change.
State and transition model
Custom diagramStandard diagram
Figure 6. Group 6, STM
More interactive model formats are also available. View Interactive Models
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 native plant community is dominated by Wyoming big sagebrush and bluebunch wheatgrass. Thurber’s needlegrass and Cusick’s bluegrass are prominent. Spiny hopsage, Sandberg bluegrass, bottlebrush squirreltail and a variety of forbs are present. Vegetative composition of the community is approximately 70 percent grasses, 10 percent forbs and 20 percent shrubs. The approximate ground cover is 50 to 60 percent (basal and crown).
Figure 7. 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 250 400 500 Shrub/Vine 200 320 400 Forb 50 80 100 Total 500 800 1000 Additional community tables
Table 6. Community 1.1 plant community composition
Group Common name Symbol Scientific name Annual production () Foliar cover (%) Grass/Grasslike1 Perennial, moderately deep rooted, bunchgrass 240–360 bluebunch wheatgrass PSSPS Pseudoroegneria spicata ssp. spicata 240–360 – 2 Perennial, moderately deep rooted, bunchgrass 0–64 Thurber's needlegrass ACTH7 Achnatherum thurberianum 0–40 – Idaho fescue FEID Festuca idahoensis 0–24 – 3 Perennial, shallow rooted, bunchgrass 40–80 Sandberg bluegrass POSE Poa secunda 40–80 – milkvetch ASTRA Astragalus 3–6 – lupine LUPIN Lupinus 3–6 – 4 Other perennial bunchgrass 16–40 basin big sagebrush ARTRT Artemisia tridentata ssp. tridentata 37–75 – yellow rabbitbrush CHVIS5 Chrysothamnus viscidiflorus ssp. viscidiflorus var. stenophyllus 4–19 – silver sagebrush ARCA13 Artemisia cana 4–19 – spiny hopsage GRSP Grayia spinosa 4–19 – Indian ricegrass ACHY Achnatherum hymenoides 0–16 – squirreltail ELEL5 Elymus elymoides 0–16 – greasewood SAVE4 Sarcobatus vermiculatus 0–8 – rubber rabbitbrush ERNAS Ericameria nauseosa ssp. nauseosa var. salicifolia 0–4 – Forb5 Perennial forbs 16–80 common yarrow ACMI2 Achillea millefolium 0–16 – pussytoes ANTEN Antennaria 0–16 – rockcress ARABI2 Arabis 0–16 – milkvetch ASTRA Astragalus 0–16 – arrowleaf balsamroot BASA3 Balsamorhiza sagittata 0–16 – mariposa lily CALOC Calochortus 0–16 – Indian paintbrush CASTI2 Castilleja 0–16 – tapertip hawksbeard CRAC2 Crepis acuminata 0–16 – fleabane ERIGE2 Erigeron 0–16 – buckwheat ERIOG Eriogonum 0–16 – lupine LUPIN Lupinus 0–16 – phlox PHLOX Phlox 0–16 – deathcamas ZIGAD Zigadenus 0–16 – Shrub/Vine6 Dominant, evergreen, non-sprouting shrubs 96–200 basin big sagebrush ARTRT Artemisia tridentata ssp. tridentata 80–160 – Wyoming big sagebrush ARTRW8 Artemisia tridentata ssp. wyomingensis 16–40 – 7 Common, evergreen, non-sprouting shrub 8–24 spiny hopsage GRSP Grayia spinosa 8–24 – 8 Other shrubs 16–48 yellow rabbitbrush CHVI8 Chrysothamnus viscidiflorus 0–16 – rubber rabbitbrush ERNA10 Ericameria nauseosa 0–16 – spineless horsebrush TECA2 Tetradymia canescens 0–16 – littleleaf horsebrush TEGL Tetradymia glabrata 0–16 – Interpretations
Supporting information
Contributors
Bob Gillaspy
C TackmanRangeland 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
-
Number and extent of rills:
-
Presence of water flow patterns:
-
Number and height of erosional pedestals or terracettes:
-
Bare ground from Ecological Site Description or other studies (rock, litter, lichen, moss, plant canopy are not bare ground):
-
Number of gullies and erosion associated with gullies:
-
Extent of wind scoured, blowouts and/or depositional areas:
-
Amount of litter movement (describe size and distance expected to travel):
-
Soil surface (top few mm) resistance to erosion (stability values are averages - most sites will show a range of values):
-
Soil surface structure and SOM content (include type of structure and A-horizon color and thickness):
-
Effect of community phase composition (relative proportion of different functional groups) and spatial distribution on infiltration and runoff:
-
Presence and thickness of compaction layer (usually none; describe soil profile features which may be mistaken for compaction on this site):
-
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:
-
Amount of plant mortality and decadence (include which functional groups are expected to show mortality or decadence):
-
Average percent litter cover (%) and depth ( in):
-
Expected annual annual-production (this is TOTAL above-ground annual-production, not just forage annual-production):
-
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:
-
Perennial plant reproductive capability:
Print Options
Sections
Font
AAAAOther
PrintThe Ecosystem Dynamics Interpretive Tool is an information system framework developed by the USDA-ARS Jornada Experimental Range, USDA Natural Resources Conservation Service, and New Mexico State University.
Accessibility statement
