Natural Resources
Conservation Service
Ecological site EX043B23C150
Sandy (Sy)
Absaroka Subalpine Zone
Last updated: 10/04/2019
Accessed: 07/02/2026
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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.
MLRA notes
Major Land Resource Area (MLRA): 043B–Central Rocky Mountains
Major Land Resource Unit (MLRA) 43B: Central Rocky Mountains
43B – Central Rocky Mountains – The Central Rocky Mountains extends from northern Montana to southern extent of Wyoming and from Idaho to central Wyoming. The southern extent of 43B is comprised of a combination of metamorphic, igneous, and sedimentary mountains and foothills. Climatic changes across this extent are broad and create several unique breaks in the landscape.
Further information regarding MLRAs, refer to: United States Department of Agriculture, Natural Resources Conservation Service. 2006. Land Resource Regions and Major Land Resource Areas of the United States, the Caribbean, and the Pacific Basin. U.S. Department of Agriculture Handbook 296.
Available electronically at: http://www.nrcs.usda.gov/wps/portal/nrcs/detail/soils/ref/?cid=nrcs142p2_053624#handbook.LRU notes
Land Resource Unit (LRU) 43B23C: Absaroka Subalpine Zone
Based on the shifts in geology, precipitation patterns and other climatic factors, as well as elevation and vegetation, the Absaroka Range was divided into LRU 23. Further division of this LRU is necessary due to the gradient moving from the foothills to the summit, as well as aspect shifts (north/east face versus south/west face). Subset C is the high elevation zone noted for dense timber interspersed with open parks and longer persisting snowpack (within timberline). Precipitation can range from 18 to 20 plus inches and is more noted for the duration of snow cover and shorter growing season. To verify or identify Subset C (the referenced subset for this ecological site), refer to the Wyoming LRU matrix key contained within the Ecological Site Key.
This LRU/Subset occurs on the eastern divide of the Absaroka Range. This LRU starts north of Clark, WY and runs to the Thermopolis, WY area. Once the Absaroka Range merges with the Owl Creek and Wind River Ranges, the climatic patterns and elevational changes shifts the plant community and creates a break in the LRU/Subset.
The extent of soils currently correlated to this ecological site does not fit within the digitized boundary. Many of the noted soils are provisional and will be reviewed and corrected in mapping update projects. Other map units are correlated as small inclusions within other MLRA’s/LRU’s based on elevation, landform, and biological references.
Moisture Regime: Typic Ustic
Temperature Regime: Cryic
Dominant Cover: Rangeland – Sagebrush Steppe (major species is Mountain Big Sagebrush)
Representative Value (RV) Effective Precipitation: 20+ inches (508 mm)
RV Frost-Free Days: 31-65 daysClassification relationships
Relationship to Other Established Classification Systems:
National Vegetation Classification System (NVC):
2 Shrub & Herb Vegetation Class
2.B Temperate & Boreal Grassland & Shrubland Subclass
2.B.2 Temperate Grassland & Shrubland Formation
2.B.2.Na Western North American Grassland & Shrubland Division
M048 Central Rocky Mountain Montane-Foothill Grassland & Shrubland Macro-group
G273 Central Rocky Mountain Lower Montane, Foothill & Valley Grassland Group
Ecoregions (EPA):
Level I: 6 North Western Forested Mountains
Level II: 6.2 Western Cordillera
Level III: 6.2.10 Middle Rockies
Level IV: 6.2.17ao – Absaroka Volcanic Subalpine Zone
6.2.17i – Absaroka – Gallatin Volcanic MountainsEcological site concept
• Site receives no additional water.
• Slope is < 30%
• Soils are:
o Textures range from loamy sand to very fine sandy loam in top 4” (10 cm) of mineral soil surface
o Clay content is ≤18% in top 4” (10 cm) of mineral soil surface
o All subsurface horizons in the particle size control section have a weighted average of <18% clay. (The particle size control section is the segment of the profile from either the start of an argillic horizon for 50 cm’s or from 25-100 cm’s).
o Moderately deep to very deep (20-80+ in. (50-200+ cm))
o <3% stone and boulder cover and 20% or less cobble and gravel cover
o Not skeletal (<35% rock fragments) within 20” (50 cm) of mineral soil surface
o None to Slightly effervescent throughout top 20” (50 cm) of mineral soil surface
o Non-saline, sodic, or saline-sodic
The Sandy ecological site concept is based on minimal (none to slight) influence from salts, carbonates, gypsum or other chemistry within the top 20 inches (50 cm) of the mineral soil surface. The main soil characteristic is a moderately deep to very deep soil that is coarse textured with less than 18% clay throughout the soil profile; the dominant soil textural classes are loamy sand to sandy loam in the subsurface. The plant community transitions from sandy to loamy as the control section increases above 18% clays with increased rhizomatous wheatgrasses, additional forb species, and increased ground cover.
The sandy site can be found in several different catenas throughout the basin. In an escarpment catena it occurs with shallow and very shallow soils. Hillslope catenas have sandy and loamy occurring in a complex mosaic pattern where the geology is controlled by inter-bedded sandstone and shale; or in areas where the parent material is alluvial. Locations controlled by primarily sandstone bedrock, sandy sites can be found in structural-controlled stable areas adjacent to sandstone rock outcrop.Associated sites
R043BY130WY Overflow High Mountains
Overflow
R043BY162WY Shallow Loamy High Mountains
Shallow Loamy
Similar sites
R043BY222WY Loamy Foothills and Mountains West
Loamy (Ly) 15-19W has lower production.
Table 1. Dominant plant species
Tree Not specified
Shrub (1) Artemisia tridentata ssp. vaseyana
Herbaceous (1) Festuca idahoensis
(2) Achnatherum nelsoniiLegacy ID
R043BX750WY
Physiographic features
This site occurs on gentle to steep mountain slopes.
Table 2. Representative physiographic features
Landforms (1) Mountain range > Hill
(2) Mountain range > Alluvial fan
(3) Mountain range > Stream terrace
Runoff class Negligible to very high Elevation 6500 – 12000 ft Slope 2 – 30 % Aspect Aspect is not a significant factor Climatic features
Annual precipitation and modeled relative effective annual precipitation range from 18 to 35 inches (457 – 889 mm). The normal precipitation pattern is evenly distributed through the year and averages over 20 inches. Annual snowfall averages 150 to 200 inches annually. Wide fluctuations may occur in yearly precipitation and result in more dry years than those with more than normal precipitation.
Because of the varied topography, the wind will vary considerably for different parts of the area. Prevailing winds are from the southwest, and strong winds are less frequent than over other areas of
Wyoming. Occasional storms, however, can bring brief periods of high winds with gusts exceeding 50
mph.
Temperatures show a wide range between summer and winter and between daily maximums and minimums, due to the high elevation and dry air, which permits rapid incoming and outgoing radiation. Cold air outbreaks from Canada in winter move rapidly from northwest to southeast and account for extreme minimum temperatures. Chinook winds may occur in winter and bring rapid rises in temperature. High winds are generally blocked by high mountains but occur in conjunction with thunderstorms, which are common in late summer. Growth of native cool-season plants begins about June 1, but can be as late as July 15, and continues until the beginning of September.
For detailed information visit the Natural Resources Conservation Service National Water and Climate Center at http://www.wcc.nrcs.usda.gov/. Climate station representative of this precipitation zone include: “Cooke City 2W” and “Tower Falls”. The following graphs and charts are a collective sample representing the averaged normals and 30-year annual rainfall data for the selected weather stations from 1981 to 2010.Table 3 Representative climatic features
Frost-free period (characteristic range) 0-0 days Freeze-free period (characteristic range) 20-50 days Precipitation total (characteristic range) 20-20 in Frost-free period (actual range) 0-0 days Freeze-free period (actual range) 20-50 days Precipitation total (actual range) 20-20 in Frost-free period (average) 0 days Freeze-free period (average) 40 days Precipitation total (average) 20 in Characteristic rangeActual rangeBarLineFigure 1. Monthly precipitation range
Characteristic rangeActual rangeBarLineFigure 2. Monthly minimum temperature range
Characteristic rangeActual rangeBarLineFigure 3. Monthly maximum temperature range
BarLineFigure 4. Monthly average minimum and maximum temperature
Figure 5. Annual precipitation pattern
Figure 6 Annual average temperature pattern
Climate stations used
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(1) COOKE CITY 2 W [USC00241995], Gardiner, MT
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(2) TOWER FALLS [USC00489025], Yellowstone National Park, WY
">Influencing water features
The characteristics of these upland soils have no influence from ground water (water table below 60 inches (150 cm)) and have minimal influence from surface water/overland flow. There may be isolated features that are affected by snow pack that persists longer than surrounding areas due to position on the landform (shaded/protected pockets).
Soil features
The soils of this site are moderately deep (greater than 20" to bedrock) to very deep and well-drained with textures ranging from very fine sandy loams through Sands. Some soils have a lime horizon below 3 feet. The overlying soil is usually noncalcareous.
Table 4. Representative soil features
Parent material (1) Alluvium – igneous, metamorphic and sedimentary rock
(2) Residuum – sandstone
Surface texture (1) Gravelly loamy sand
(2) Loam
(3) Fine sandy loam
(4) Sand
Family particle size (1) Coarse-loamy
Drainage class Moderately well drained to well drained Permeability class Moderately slow to moderate Soil depth 20 – 60 in Surface fragment cover <=3" 0 – 20 % Available water capacity
(0-40in)2.5 – 6 in Calcium carbonate equivalent
(0-40in)0 – 15 % Electrical conductivity
(0-40in)0 – 8 mmhos/cm Sodium adsorption ratio
(0-40in)0 – 5 Soil reaction (1:1 water)
(0-40in)6.6 – 8.4 Subsurface fragment volume <=3"
(Depth not specified)0 – 10 % Subsurface fragment volume >3"
(Depth not specified)0 – 5 % Ecological dynamics
As this site deteriorates due to a combination of frequent and severe grazing, species such as three-tip and mountain big sagebrush, buckwheat, and yarrow will increase. Rhizomatous wheatgrass and less palatable grasses such as Letterman needlegrass increase. Kentucky bluegrass may invade. Cool-season grasses such as bluebunch wheatgrass and Columbia needlegrass will decrease in frequency and production.
Mountain big sagebrush will become dominant with the absence of fire. Wildfires are often actively controlled so chemical control using herbicides has replaced the historic role of fire on this site. Recently, prescribed burning has regained some popularity.
The Historic Climax Plant Community (description follows the plant community diagram) has been determined by study of rangeland relic areas, or areas protected from excessive disturbance. Trends in plant communities going from heavily grazed areas to lightly grazed areas, seasonal use pastures, and historical accounts have also been used.
The following is a State and Transition Model Diagram that illustrates the common plant communities (states) that can occur on the site and the transitions between these communities. The ecological processes will be discussed in more detail in the plant community narratives following the diagram.State and transition model
Custom diagramStandard diagram
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 2 submodel, plant communities
State 3 submodel, plant communities
State 4 submodel, plant communities
State 1
Mixed Grass/Mountain Big Sage Plant Community (HCPC)Community 1.1
Mixed Grass/Mountain Big Sage Plant Community (HCPC)The interpretive plant community for this site is the Historic Climax Plant Community. This state evolved with grazing by large herbivores and is well suited for grazing by domestic livestock. Potential vegetation is estimated at 70% grasses or grass-like plants, 20% forbs, and 10% woody plants.
The major grasses include Idaho fescue, Columbia needlegrass, slender wheatgrass, and bluebunch wheatgrass. Other grasses may include mutton and Cusick bluegrass, bentgrass, prairie junegrass, Letterman, Richardson, and western needlegrass, sun and dunehead sedge, one-spike and timber oatgrass, thickspike wheatgrass, mountain and nodding brome, tufted hairgrass, spike trisetum, and oniongrass. Mountain big sagebrush is the dominant woody plant. Other woody species may include snowberry, serviceberry, silver and three-tip sagebrush, and green rabbitbrush.
A typical plant composition for this state consists of Idaho fescue 15-25%, Columbia needlegrass 15-25%, slender wheatgrass 10-20%, bluebunch wheatgrass 10-15%, other grasses and grass-like plants 10-20%, perennial forbs 10-20%, mountain big sagebrush 5-10%, and 5-10% other woody species. Ground cover, by ocular estimate, varies from 70-75%.
The total annual production (air-dry weight) of this state is about 2500 lbs./acre, but it can range from about 1800 lbs./acre in unfavorable years to about 3000 lbs./acre in above average years.
The following is the growth curve of this plant community expected during a normal year:
Growth curve number: WY0101
Growth curve name: 20+M, UPLAND SITES
Growth curve description: ALL UPLAND SITES
JAN FEB MAR APR MAY JUN JUL AUG SEP OCT NOV DEC
0 0 0 0 5 30 40 20 5 0 0 0
(Monthly percentages of total annual growth)
This plant community is extremely stable and well adapted to the Central Rocky Mountains climatic conditions. The diversity in plant species allows for high drought tolerance. This is a sustainable plant community (site/soil stability, watershed function, and biologic integrity).
Transitions or pathways leading to other plant communities are as follows:
• Nonuse and No Fire will convert this plant community to the Mountain Big Sage/Mixed Grass State.
• Heavy Continuous Season-long Grazing and No Fire will convert this plant community to the Dense Shrub/Forb State.
• Wildfire with Heavy Continuous Season-long Grazing will convert this plant community to the Three-tip Sage/Rabbitbrush State.
Figure 7. Annual production by plant type (representative values) or group (midpoint values)
State 2
Mountain Big Sage/Mixed Grass Plant CommunityCommunity 2.1
Mountain Big Sage/Mixed Grass Plant CommunityThis plant community is the result of long-term protection from grazing and fire. Mountain big sagebrush dominates the site, often exceeding 20-50% annual production and lowering herbaceous forage production. Bunchgrasses such as bluebunch wheatgrass, Columbia needlegrass, Idaho fescue, and mountain brome dominate the understory.
The total annual production (air-dry weight) of this state is about 2000 pounds per acre, but it can range from about 1500 lbs./acre in unfavorable years to about 2500 lbs./acre in above average years.
The following is the growth curve of this plant community expected during a normal year:
Growth curve number: WY0101
Growth curve name: 20+M, UPLAND SITES
Growth curve description: ALL UPLAND SITES
JAN FEB MAR APR MAY JUN JUL AUG SEP OCT NOV DEC
0 0 0 0 5 30 40 20 5 0 0 0
(Monthly percentages of total annual growth)
The state is stable and protected from excessive erosion. The biotic integrity of this plant community is usually intact, however forage value will decrease and wildlife values will shift toward different species. The watershed is functioning.
Transitional pathways leading to other plant communities are as follows:
• Brush Management followed by deferment for 1 to 2 years as part of a Prescribed Grazing plan will return this state to near Historic Climax Plant Community (Mixed Grass/Mountain Big Sage State). Care should be taken when planning brush management to consider wildlife habitat and critical winter ranges.
• Brush Management followed by Heavy Continuous Season-long Grazing will convert this plant community to the Three-tip Sage/Rabbitbrush State.
• Continuous Season-long Grazing and No Fire will convert this plant community to the Dense Shrub/Forb State.
State 3
Dense Shrub/Forb Plant CommunityCommunity 3.1
Dense Shrub/Forb Plant CommunityThis plant community is the result of heavy, continuous season-long grazing and protection from fire. Mountain big sagebrush eventually dominates this plant community with its annual production often exceeding 50%. Forbs such as yarrow, phlox, lupine, larkspur, buckwheat, and pussytoes increase. Grasses such as mutton bluegrass, Letterman needlegrass, and rhizomatous wheatgrass increase in proportion to other grasses.
The total annual production (air-dry weight) of this state is about 1500 pounds per acre, but it can range from about 1000 lbs./acre in unfavorable years to about 2000 lbs./acre in above average years.
The following is the growth curve of this plant community expected during a normal year:
Growth curve number: WY0101
Growth curve name: 20+M, UPLAND SITES
Growth curve description: ALL UPLAND SITES
JAN FEB MAR APR MAY JUN JUL AUG SEP OCT NOV DEC
0 0 0 0 5 30 40 20 5 0 0 0
(Monthly percentages of total annual growth)
Soil erosion is accelerated because of increased bare ground. The biotic community has been compromised, but is relatively stable. The watershed is functioning, but is at risk of further degradation. Water flow patterns and pedestals are obvious. Infiltration is reduced and runoff is increased.
Transitional pathways leading to other plant communities are as follows:
• Brush Management followed by deferment for 1 to 2 years as part of a Prescribed Grazing plan will return this state to near Historic Climax Plant Community (Mixed Grass/Big Sage State). Care should be taken when planning brush management to consider wildlife habitat and critical winter ranges.
• Brush Management or Wildfire followed by Heavy Continuous Season-long Grazing will convert this plant community to the Three-tip Sage/Rabbitbrush State).
State 4
Three-tip Sage/Rabbitbrush Plant CommunityCommunity 4.1
Three-tip Sage/Rabbitbrush Plant CommunityThis plant community is the result of brush management or wildfire followed by improper grazing management practices. With mountain big sagebrush removed, it is dominated by sprouting shrubs such as green rabbitbrush and three-tip sage. Rhizomatous wheatgrasses, Letterman needlegrass and unpalatable annual and perennial forbs dominate the herbaceous understory. Forbs such as prairie smoke, lupine, and thistles are common. There is a substantial amount of bare ground.
The total annual production (air-dry weight) of this state is about 1000 pounds per acre, but it can range from about 500 lbs./acre in unfavorable years to about 1500 lbs./acre in above average years.
The following is the growth curve of this plant community expected during a normal year:
Growth curve number: WY0101
Growth curve name: 20+M, UPLAND SITES
Growth curve description: ALL UPLAND SITES
JAN FEB MAR APR MAY JUN JUL AUG SEP OCT NOV DEC
0 0 0 0 5 30 40 20 5 0 0 0
(Monthly percentages of total annual growth)
The soil is not protected and erosion will increase if management is not changed. The biotic integrity may be reduced due to low vegetative production. The watershed is functioning at risk.
Transitions or pathways leading to other plant communities are as follows:
It is not often practicable or economically feasible to convert this plant community.
Additional community tables
Table 5. Community 1.1 plant community composition
Group Common name Symbol Scientific name Annual production () Foliar cover (%) Grass/Grasslike1 375–625 Idaho fescue FEID Festuca idahoensis 375–625 – 2 375–625 Columbia needlegrass ACNE9 Achnatherum nelsonii 375–625 – 3 250–500 slender wheatgrass ELTR7 Elymus trachycaulus 250–500 – 4 250–375 bluebunch wheatgrass PSSP6 Pseudoroegneria spicata 250–375 – 5 250–500 Grass, perennial 2GP Grass, perennial 0–125 – Letterman's needlegrass ACLE9 Achnatherum lettermanii 0–125 – Richardson's needlegrass ACRI8 Achnatherum richardsonii 0–125 – bentgrass AGROS2 Agrostis 0–125 – mountain brome BRMA4 Bromus marginatus 0–125 – Porter brome BRPO2 Bromus porteri 0–125 – needleleaf sedge CADU6 Carex duriuscula 0–125 – threadleaf sedge CAFI Carex filifolia 0–125 – sun sedge CAINH2 Carex inops ssp. heliophila 0–125 – dunhead sedge CAPH2 Carex phaeocephala 0–125 – California oatgrass DACA3 Danthonia californica 0–125 – timber oatgrass DAIN Danthonia intermedia 0–125 – onespike danthonia DAUN Danthonia unispicata 0–125 – squirreltail ELELE Elymus elymoides ssp. elymoides 0–125 – thickspike wheatgrass ELLAL Elymus lanceolatus ssp. lanceolatus 0–125 – prairie Junegrass KOMA Koeleria macrantha 0–125 – basin wildrye LECI4 Leymus cinereus 0–125 – oniongrass MEBU Melica bulbosa 0–125 – Cusick's bluegrass POCU3 Poa cusickii 0–125 – muttongrass POFE Poa fendleriana 0–125 – spike trisetum TRSP2 Trisetum spicatum 0–125 – Forb6 250–500 Forb, perennial 2FP Forb, perennial 0–125 – common yarrow ACMI2 Achillea millefolium 0–125 – giant hyssop AGAST Agastache 0–125 – agoseris AGOSE Agoseris 0–125 – onion ALLIU Allium 0–125 – pussytoes ANTEN Antennaria 0–125 – milkvetch ASTRA Astragalus 0–125 – balsamroot BALSA Balsamorhiza 0–125 – Indian paintbrush CASTI2 Castilleja 0–125 – hawksbeard CREPI Crepis 0–125 – larkspur DELPH Delphinium 0–125 – buckwheat ERIOG Eriogonum 0–125 – aster EUCEP2 Eucephalus 0–125 – elkweed FRSP Frasera speciosa 0–125 – geranium GERAN Geranium 0–125 – avens GEUM Geum 0–125 – common sneezeweed HEAU Helenium autumnale 0–125 – sunflower HELIA3 Helianthus 0–125 – pea LATHY Lathyrus 0–125 – flax LINUM Linum 0–125 – stoneseed LITHO3 Lithospermum 0–125 – desertparsley LOMAT Lomatium 0–125 – lupine LUPIN Lupinus 0–125 – creeping barberry MARE11 Mahonia repens 0–125 – bluebells MERTE Mertensia 0–125 – locoweed OXYTR Oxytropis 0–125 – ragwort PACKE Packera 0–125 – beardtongue PENST Penstemon 0–125 – phacelia PHACE Phacelia 0–125 – phlox PHLOX Phlox 0–125 – buttercup RANUN Ranunculus 0–125 – western coneflower RUOC2 Rudbeckia occidentalis 0–125 – ragwort SENEC Senecio 0–125 – meadow-rue THALI2 Thalictrum 0–125 – clover TRIFO Trifolium 0–125 – American vetch VIAM Vicia americana 0–125 – violet VIOLA Viola 0–125 – mule-ears WYAM Wyethia amplexicaulis 0–125 – mountain deathcamas ZIEL2 Zigadenus elegans 0–125 – Shrub/Vine7 125–250 mountain big sagebrush ARTRV Artemisia tridentata ssp. vaseyana 125–250 – 8 0–125 Shrub, deciduous 2SD Shrub, deciduous 0–125 – Shrub, evergreen 2SE Shrub, evergreen 0–125 – Tree, deciduous 2TD Tree, deciduous 0–125 – Tree, evergreen 2TE Tree, evergreen 0–125 – Saskatoon serviceberry AMAL2 Amelanchier alnifolia 0–125 – silver sagebrush ARCA13 Artemisia cana 0–125 – threetip sagebrush ARTR4 Artemisia tripartita 0–125 – yellow rabbitbrush CHVI8 Chrysothamnus viscidiflorus 0–125 – snowberry SYMPH Symphoricarpos 0–125 – Table 6. Community 2.1 plant community composition
Group Common name Symbol Scientific name Annual production () Foliar cover (%) Table 7. Community 3.1 plant community composition
Group Common name Symbol Scientific name Annual production () Foliar cover (%) Table 8. Community 4.1 plant community composition
Group Common name Symbol Scientific name Annual production () Foliar cover (%) Interpretations
Animal community
Animal Community – Wildlife Interpretations
Mixed Grass/Mountain Big Sage Plant Community (HCPC): This plant community provides suitable thermal and escape cover for mule deer, elk, and antelope. Sagebrush, which can approach 15% protein and 40-60% digestibility, provides important winter forage for mule deer and elk. Birds that would frequent this plant community include horned larks and golden eagles.
Mountain Big Sage/Mixed Grass Plant Community: This plant community may be useful for the same wildlife that would use the Historic Climax Plant Community.
Dense Shrub/Forb Plant Community: This plant community may be beneficial for the same wildlife that would use the Historic Climax Plant Community. However, the plant community composition is less diverse, and thus, less apt to meet the seasonal needs of these animals.
Three-tip Sage/Rabbitbrush Plant Community: This plant community provides limited forage for elk and mule deer due to low production and lack of palatable sagebrush species.
Animal Community – Grazing Interpretations
The following table lists suggested stocking rates for cattle under continuous season-long grazing under normal growing conditions. These are conservative estimates that should be used only as guidelines in the initial stages of the conservation planning process. Often, the current plant composition does not entirely match any particular plant community (as described in this ecological site description). Because of this, a field visit is recommended, in all cases, to document plant composition and production. More precise carrying capacity estimates should eventually be calculated using this information along with animal preference data, particularly when grazers other than cattle are involved. Under more intensive grazing management, improved harvest efficiencies can result in an increased carrying capacity. If distribution problems occur, stocking rates must be reduced to maintain plant health and vigor.
Plant Community Production Carrying Capacity*
(lb./ac) (AUM/ac)
Mixed Grass/Mountain Big Sage (HCPC) 1800-3000 0.8
Mountain Big Sage/Mixed Grass 1500-2500 0.6
Dense Shrub/Forb 1000-2000 0.47
Three-tip Sage/Rabbitbrush 500-1500 0.3
* - Continuous, season-long grazing by cattle under average growing conditions.
Grazing by domestic livestock is one of the major income-producing industries in the area. Rangeland in this area may provide yearlong forage for cattle, sheep, or horses. During the dormant period, the forage for livestock use needs to be supplemented with protein because the quality does not meet minimum livestock requirements.Hydrological functions
Water is the principal factor limiting forage production on this site. This site is dominated by soils in hydrologic group B, with localized areas in hydrologic groups A and C. Infiltration ranges from rapid to moderate. Runoff potential for this site varies from low to moderate depending on soil hydrologic group and ground cover. In many cases, areas with greater than 75% ground cover have the greatest potential for high infiltration and lower runoff. Areas where ground cover is less than 50% have the greatest potential to have reduced infiltration and higher runoff (refer to Part 630, NRCS National Engineering Handbook for detailed hydrology information).
Rills and gullies should not typically be present. Water flow patterns should be barely distinguishable if at all present. Pedestals are only slightly present in association with bunchgrasses and shrubs. Litter typically falls in place, and signs of movement are not common. Chemical and physical crusts are rare to non-existent. Cryptogamic crusts are present, but only cover 1-2% of the soil surface.Recreational uses
This site provides hunting opportunities for upland game species. The wide variety of plants which bloom from spring until fall have an esthetic value that appeals to visitors.
Wood products
No appreciable wood products are present on the site.
Supporting information
Inventory data references
Information presented here has been derived from NRCS clipping data and other inventory data. Field observations from range trained personnel were also used. Those involved in developing this site include: Bill Christensen, Range Management Specialist, NRCS; Karen Clause, Range Management Specialist, NRCS; and Everet Bainter, Range Management Specialist, NRCS. Other sources used as references include USDA NRCS Water and Climate Center, USDA NRCS National Range and Pasture Handbook, USDI and USDA Interpreting Indicators of Rangeland Health Version 3, and USDA NRCS Soil Surveys from various counties. Information presented here has been derived from NRCS inventory data, Field observations from range trained personnel, and the existing range site descriptions. Those involved in developing the Loamy range site include: Karen Clause, Range Management Specialist, NRCS and Everet Bainter, Range Management Specialist. Those involved in the development of the new concept for Loamy and Loamy Calcareous Ecological site include: Ray Gullion, Area Range Management Specialist, NRCS; Jim Wolf, Resource Manager, USDI-BLM; Jack Mononi, Range Management Specialist, USDI-BLM; Daniel Wood, MLRA Soil Survey Leader, NRCS; Jane Karinen, Soil Data Quality Specialist, NRCS; and Marji Patz, Ecological Site Specialist, NRCS. Inventory Data References: Ocular field estimations observed by trained personnel were completed at each site. Then sites were selected where a 100-foot tape was stretched, and the following sample procedures were completed by inventory staff. For full sampling protocol and guidelines with forms please refer to the Wyoming ESI Operating Procedures, compiled in 2012 for the Powell and Rock Springs Soil Survey Office, USDA-NRCS. • Double Sampling Production Data (4.8 square foot hoop used to estimate 10 points, clipped a minimum of 2 of these estimated points, with two 21-foot X 21-foot square extended shrub plots). • Line Point Intercept (over story and understory captured with soil cover). Height of herbaceous and woody cover is collected every three feet along established transect.) • Continuous Line Intercept (Woody Canopy Cover, with minimum gap of 0.2 of a foot for all woody species and succulents. Intercept height collected at each measurement.), • Gap Intercept (Basal Gap measured with a minimum gap requirement of 0.7 foot.), • Sample Point (10 – 1-meter square point photographs taken at set distances on transect. Red using the sample point computer program established by the High Plains Agricultural Research Center, WY). • Soil Stability (Slake Test – surface and subsurface samples collected and processed according to the soil stability guidelines provided by the Jornada Research Center, NM.)
Other references
Baker, William L. 2006. Fire and Restoration of Sagebrush Ecosystems. Wildlife Society Bulletin 34(1): 177-185.
Bestelmeyer, B., and J. R. Brown. 2005. State-and-transition models 101: a fresh look at vegetation change. The Quivira Coalition Newsletter, Vol. 7, No. 3.
Bestelmeyer, B., J. R. Brown, K. M. Havstad, B. Alexander, G. Chavez, J. E. Herrick. 2003. Development and use of state and transition models for rangelands. Journal of Range Management 56(2):114-126.
Bestelmeyer, B., J. E. Herrick, J. R. Brown, D. A. Trujillo, and K. M. Havstad. 2004. Land management in the American Southwest: a state-and-transition approach to ecosystem complexity. Environmental Management 34(1):38-51.
Herrick, J. E., J. W. Van Zee, K. M. Havstad, L. M. Burkett, and W. G. Whitford. 2005. Monitoring manual for grassland, shrubland and savanna Ecosystems. Volume I Quick Start. USDA - ARS Jornada Experimental Range, Las Cruces, New Mexico.
Herrick, J. E., J. W. Van Zee, K. M. Havstad, L. M. Burkett, and W. G. Whitford. 2005. Monitoring manual for grassland, shrubland and savanna Ecosystems. Volume II: Design, supplementary methods and interpretation. USDA - ARS Jornada Experimental Range, Las Cruces, New Mexico.
NRCS. 2014. (electronic) National Water and Climate Center. Available online at http://www.wcc.nrcs.usda.gov/
NRCS. 2014. (electronic) Field Office Technical Guide. Available online at http://efotg.nrcs.usda.gov/efotg_locator.aspx?map=WY NRCS. 2009. Plant Guide: Cheatgrass. Prepared by Skinner et al., National Plant Data Center.
Pellant, M., P. Shaver, D. A. Pyke, and J. E. Herrick. 2005. Interpreting indicators of rangeland health. Version 4. Technical Reference 1734-6.
USDI-BLM. Ricketts, M. J., R. S. Noggles, and B. Landgraf-Gibbons. 2004. Pryor Mountain Wild Horse Range Survey and Assessment. USDA-Natural Resources Conservation Service.
Schoeneberger, P. J., D. A. Wysocki, E. C. Benham, and Soil Survey Staff. 2012. Field book for describing and sampling soils, Version 3.0. Natural Resources Conservation Service, National Soil Survey Center, Lincoln, NE. (http://soils.usda.gov/technical/fieldbook/)
Stringham, T. K. and W. C. Krueger. 2001. States, transitions, and thresholds: Further refinement for rangeland applications. Agricultural Experiment Station, Oregon State University. Special Report 1024.
Stringham, T. K., W. C. Kreuger, and P. L Shaver. 2003. State and transition modeling: an ecological process approach. Journal of Range Management 56(2):106-113.
United States Department of Agriculture. Soil Survey Division Staff. 1993. Soil Survey Manual, United States Department of Agriculture Handbook No. 18, Chapter 3: Examination and Description of Soils. Pg.192-196.
USDA, NRCS. 1997. National Range and Pasture Handbook. (http://www.glti.nrcs.usda.gov/technical/publications/nrph.html)
Trlica, M. J. 1999. Grass growth and response to grazing. Colorado State University. Cooperative Extension. Range. Natural Resource Series. No. 6.108.
U.S. Department of Agriculture, Natural Resources Conservation Service (USDA/NRCS). 2007. The PLANTS Database (http://plants.usda.gov). National Plant Data Center, Baton Rouge, LA 70874-4490 USA.
U.S. Department of Agriculture, Natural Resources Conservation Service (USDA/NRCS), Soil Survey Staff. 2010. Keys to Soil Taxonomy, Eleventh Edition, 2010.
USDA/NRCS Soil survey manuals for appropriate counties within MLRA 43B.
Western Regional Climate Center. (2014) (electronic) Station Metadata. Available online at: http://www.wrcc.dri.edu/summary/climsmwy.html.Contributors
K. Clause
Approval
Scott Woodall, 10/04/2019
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) K. Clause, E. Bainter Contact for lead author karen.clause@wy.usda.gov or 307-367-2257 Date 03/16/2007 Approved by Approval date Composition (Indicators 10 and 12) based on Annual Production Indicators
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Number and extent of rills:
Rare to nonexistent. Where present, short and widely spaced. -
Presence of water flow patterns:
Barely observable. -
Number and height of erosional pedestals or terracettes:
Rare to nonexistent. -
Bare ground from Ecological Site Description or other studies (rock, litter, lichen, moss, plant canopy are not bare ground):
Bare ground can range from 0-10%. -
Number of gullies and erosion associated with gullies:
Active gullies should not be present. -
Extent of wind scoured, blowouts and/or depositional areas:
Rare to nonexistent. -
Amount of litter movement (describe size and distance expected to travel):
Herbaceous and large woody litter not expected to move. -
Soil surface (top few mm) resistance to erosion (stability values are averages - most sites will show a range of values):
Soil Stability Index ratings range from 3 (interspaces) to 6 (under plant canopy), but average values should be 4.0 or greater. -
Soil surface structure and SOM content (include type of structure and A-horizon color and thickness):
Soil data is limited for this site. Soil OM of 6-16% is expected. -
Effect of community phase composition (relative proportion of different functional groups) and spatial distribution on infiltration and runoff:
Plant community consists of 60-70% grasses, 20% forbs, and 10-20% shrubs. Evenly distributed plant canopy (60-95%) and litter plus moderate infiltration rates result in minimal runoff. Basal cover is typically greater than 15% for this site and does affect runoff on this site. -
Presence and thickness of compaction layer (usually none; describe soil profile features which may be mistaken for compaction on this site):
None. -
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:
Mid-size, cool season bunchgrasses>>Sub-dominant:
perennial shrubs=perennial forbs=cool season rhizomatous grasses>Other:
tall, cool season bunchgrasses=short cool season bunchgrassesAdditional:
-
Amount of plant mortality and decadence (include which functional groups are expected to show mortality or decadence):
Minimal decadence, typically associated with shrub component. -
Average percent litter cover (%) and depth ( in):
Litter ranges from 5-40% of total canopy measurement with total litter (including beneath the plant canopy) from 50-90% expected. Herbaceous litter depth typically ranges from 5-15mm. Woody litter can be up to a couple inches (4-6 cm). -
Expected annual annual-production (this is TOTAL above-ground annual-production, not just forage annual-production):
English: 1800-3000 lb/ac (2500 lb/ac average); Metric 2016-3360 kg/ha (2800 kg/ha average). -
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:
Bare ground greater than 30% is the most common indicator of a threshold being crossed. Rabbitbrush, Sandberg bluegrass, buckwheat, phlox, and yarrow are common increasers. Kentucky bluegrass, common dandelion, thistles, and annual weeds are common invasive species in disturbed sites. -
Perennial plant reproductive capability:
All species are capable of reproducing, except in extreme drought years.
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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.
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