Natural Resources
Conservation Service
Ecological site DX034A05X122
Loamy Beaver Rim (Ly BR)
Last updated: 9/28/2023
Accessed: 11/13/2024
General 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.
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.
MLRA notes
Major Land Resource Area (MLRA): 034A–Cool Central Desertic Basins and Plateaus
34A-Cool Central Desertic Basins and Plateaus
For further information regarding MLRAs, refer to:
http://soils.usda.gov/survey/geography/mlra/index.html
Land Resource Unit(LRU) 34A-F:
(Please refer to LRU document for further explanation)
Moisture Regime: aridic ustic
Temperature Regime: frigid
Dominant Cover: rangeland
Representative Value (RV) Effective Precipitation: 9-12 inches
RV Frost-Free Days: 75-100 days
Classification relationships
Site Name: Loamy Beaver Rim
Site Type: Rangeland
Site ID: R034AF122WY
Precipitation or Climate Zone: 9-12” P.Z
National Vegetation Classification System (NVC):
3 Semi-Desert
3.B.1 Cool Semi-Desert Scrub & Grassland
D040 Western North American Cool Semi-Desert Scrub & Grassland
M169 Great Basin & Intermountain Tall Sagebrush Shrubland & Steppe Group
CEGL001009 Artemisia tridentata ssp. wyomingensis / Pseudoroegneria spicata Shrubland
Ecoregions (EPA):
Level I: 10 North American Deserts
Level II: 10.1 Cold Deserts
Level III: 10.1.4 Wyoming Basin
Ecological site concept
Site does not receive any additional water.
Soils are:
not saline or saline-sodic.
moderately deep, deep, with < 3% stone (10-25”) and boulder (>25”) cover.
not skeletal within 20” of soil surface.
not strongly or violently effervescent in surface mineral 10”.
textures usually range from very fine sandy loam to clay loam in surface mineral 4”.
Slope is < 15%.
Clay content is = <32% in surface mineral 3”.
Site does not have an argillic horizon with > 35% clay.
Associated sites
R034AY322WY |
Loamy High Plains Southeast (Ly) |
---|
Similar sites
R034AY350WY |
Sandy High Plains Southeast (Sy) |
---|
Table 1. Dominant plant species
Tree |
Not specified |
---|---|
Shrub |
(1) Artemisia tridentata subsp. wyomingensis |
Herbaceous |
(1) Pseudoroegneria spicata |
Legacy ID
R034AF122WY
Physiographic features
The Loamy Beaver Rim (Ly) ecological site (R034AF122WY) is located within LRU “F” in MLRA “34A.” This ecological site occurs in intermontane basin landscapes on hill, pediment, and fan remnant landforms (see definitions below). The slope ranges from level to 15%. This site occurs on all aspects.
fan remnant – A general term for landforms that are the remaining parts of older fan-landforms, such as alluvial fans, fan aprons, inset fans, and fan skirts, that either have been dissected (erosional fan-remnants) or partially buried (nonburied fan-remnants). An erosional fan remnant must have a relatively flat summit that is a relict fan-surface.
intermontane basin – A generic term for wide structural depressions between mountain ranges that are partly filled with alluvium and called "valleys" in the vernacular.
hills – A landscape dominated by hills and associated valleys. The landform term is singular (hill).
Table 2. Representative physiographic features
Landforms |
(1)
Hill
(2) Fan remnant (3) Terrace |
---|---|
Flooding frequency | None |
Ponding frequency | None |
Elevation | 1,646 – 2,286 m |
Slope | 0 – 15% |
Water table depth | 152 cm |
Aspect | Aspect is not a significant factor |
Climatic features
Annual precipitation ranges from 9-12 inches per year. Wide fluctuations may occur in yearly precipitation and result in more dry years than those with more than normal precipitation. Temperatures show a wide range between summer and winter and between daily maximums and minimums. This is predominantly due to the high elevation and dry air, which permits rapid incoming and outgoing radiation. Cold air outbreaks in winter move rapidly from northwest to southeast and account for extreme minimum temperatures.
Much of the precipitation accumulation (45%) comes in the winter in the form of snow (Oct to April). The wettest month is May (1.61 inches). The growing season is short (75-100 day) and cool: primary growth typically occurs between May and June. The dominant plants (sagebrush and cool season grasses) are well adapted to these conditions.
Daytime winds are generally stronger than nighttime and occasional strong storms may bring brief periods of high winds with gusts to more than 50 mph.
Growth of native cool season plants begins about mid-April and continues to approximately early-July. Some green up of cool season plants usually occurs in September with adequate fall moisture.
Table 3. Representative climatic features
Frost-free period (average) | 81 days |
---|---|
Freeze-free period (average) | 112 days |
Precipitation total (average) | 254 mm |
Figure 2. Monthly precipitation range
Figure 3. Monthly average minimum and maximum temperature
Figure 4. Annual precipitation pattern
Figure 5. Annual average temperature pattern
Climate stations used
-
(1) JEFFREY CITY [USC00484925], Jeffrey City, WY
Influencing water features
None
Soil features
The soils of this site are moderately deep to very deep (greater than 20" to bedrock), and well-drained. The most common textures include loam, sandy clay loam, and clay loam (<35% clay content) in the subsurface to a depth of 17 inches. The soil commonly has a soil surface that is 3 to 5 inches thick and is underlain by an argillic horizon that is clay loam or loam. The clay increase between the surface horizon and the underlying argillic horizon is less than 15 percent. Depth to diagnostic calcic horizon ranges from 17 to 33 inches beneath the mineral soil surface. Depth to free carbonates ranges from 17 to 35 inches beneath the mineral soil surface.
Major taxonomic subgroup correlated to this site includes: calcidic haplustalfs and aridic haplustalfs. Particle size class in fine-loamy.
Table 4. Representative soil features
Parent material |
(1)
Alluvium
–
sandstone and shale
(2) Residuum – conglomerate |
---|---|
Surface texture |
(1) Loam (2) Fine sandy loam (3) Very fine sandy loam |
Family particle size |
(1) Loamy |
Drainage class | Well drained |
Permeability class | Moderate |
Soil depth | 152 cm |
Surface fragment cover <=3" | 0 – 5% |
Surface fragment cover >3" | 0 – 3% |
Available water capacity (0-101.6cm) |
8.38 – 14.22 cm |
Calcium carbonate equivalent (0-101.6cm) |
0 – 20% |
Electrical conductivity (0-101.6cm) |
0 – 2 mmhos/cm |
Sodium adsorption ratio (0-101.6cm) |
0 – 5 |
Soil reaction (1:1 water) (0-101.6cm) |
6.7 – 7.9 |
Subsurface fragment volume <=3" (Depth not specified) |
0 – 15% |
Subsurface fragment volume >3" (Depth not specified) |
0 – 5% |
Ecological dynamics
This ecological site is dominated (species composition by dry weight) by big sagebrush and perennial grasses with forbs as a minor component. The site consists of five states: the Reference State (1), Grazing Resistant State (2), Bare Ground State (3), Disturbed State (4), and Highly Disturbed State (5).
The Reference State is a collection of 3 distinct Plant Communities that exist on a continuum relative to disturbances, primarily grazing, pests, and drought with no disturbance causing successional changes as well over time. These Plant Communities represent the best adapted plant communities to the soils and climate found on the site, and they represent the best estimation of ecological dynamics present on this site at the time of European settlement.
The Reference Plant Community (big sage/bunchgrass) of this site is dominated by Wyoming big sagebrush (Artemisia tridentata var. wyomingensis) and cool-season perennial bunchgrass species, primarily bluebunch wheatgrass (Pseudoarigena spicata), muttongrass (Poa fendleriana) and Needleandthread (Hesperostipa comata)and rhizomatous grasses like western wheatgrass wheatgrass (Pascopyron smithii) as a subdominant. Minor components include short-statured bunchgrasses such as Sandberg bluegrass, perennial forbs, and shrubs, including green rabbitbrush (Chrysothamnus viscidiflorus).
After a sagebrush killing disturbance (i.e. drought, insect, disease, herbivory, etc.), the Reference Plant Community transitions to the Bunchgrass Plant Community which is dominated by the mid-stature bunchgrasses mentioned above. Sagebrush is a minor component of this Plant Community, and only time without a sagebrush killing disturbance will advance this to the Bunchgrass/Big Sagebrush which is an intermediate Plant Community described because of the time this site spends with this species composition, its value to resource managers, and often it is the most prone to some sagebrush killing disturbances, such as fire, which are thought be fairly infrequent on this site (Bukowski & Baker, 2013). The Bunchgrass/Big Sagebrush Plant Community, as a mid-seral stage, is often considered to have the most diversity and provide the most ecosystem services (i.e. wildlife habitat, livestock forage, etc.) in a multiple use management system. Mid-stature bunchgrasses act as decreaser species in the Reference Community because they decrease in response to grazing pressure. Low stature bunchgrasses and rhizomatous grasses tolerate higher grazing pressure and grow on less fertile soils (USDA/NRCS 2007) than mid stature bunchgrasses. They often fill in the vegetation gaps created when mid stature bunchgrasses decline, hence they are collectively referred to as increaser species.
Big sagebrush is the dominant shrub on this site. Wyoming big sagebrush is the sub-species present. Snow catchment is a significant hydrologic component of this site, and the hydrology changes when shrubs are removed from this site.
The Beaver Rim area of MLRA 34A in Fremont County has a long history of grazing and/or herbivory. Early accounts show that the area was used by grazing and browsing wildlife such as; elk, deer, pronghorn antelope, bison, and small mammals. The first herds of cattle and sheep were brought into the area in the 1870’s after the gold boom in the South Pass area. (http://www.wyohistory.org/encyclopedia/fremont-county-wyoming)
Thorough descriptions of each state, transition, plant community, and pathway are found after the State and Transition Model (STM) diagram in this document. Experts base this model on available experimental research, field observations, professional consensus, and interpretations. While based on the best available information, the STM will change over time as knowledge of ecological processes increases.
Plant communities within the same ecological site differ across the LRU due to the naturally occurring variability in weather, soils, and aspect. Not all managers will choose the reference community as the management goal. Other plant communities may be desired to meet land management objectives. This is valid as long as the Rangeland Health attributes assessment departures are slight to moderate or none to slight for the Reference State. The biological processes on this site are complex; therefore, representative values are presented in a land management context. The species lists are representative and are not botanical descriptions of all species occurring, or potentially occurring, on this site. They are not intended to cover every situation or the full range of conditions, species, and responses for the site.
Both percent species composition by weight and percent canopy cover are used in this ESD. Most observers find it easier to visualize or estimate percent cover for woody species (trees and shrubs). Foliar cover drives the transitions between communities and states because of the influence of shade and interception of rainfall. Species composition by dry weight remains an important descriptor of the herbaceous community and of site productivity as a whole. Woody species are included in species composition by weight for the site. Calculating similarity index requires use of species composition by dry weight.
Although there is considerable qualitative experience supporting the pathways and transitions within the State and Transition Model (STM), no quantitative information exists that specifically identifies threshold parameters between reference states and degraded states in this ecological site. For information on STMs, see the following citations: Bestelmeyer el al. 2003, Bestelmeyer et al. 2004, Bestelmeyer and Brown 2005, Stringham et al. 2003.
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 text
Ecosystem states
States 1, 5 and 2 (additional transitions)
State 1 submodel, plant communities
State 2 submodel, plant communities
State 3 submodel, plant communities
State 4 submodel, plant communities
State 5 submodel, plant communities
State 1
Reference State
Community 1.1
Big Sagebrush/Bunchgrass Plant Community
The Big Sagebrush/Bunchgrass Community (1.1) is well adapted to Cool Central Desertic Basins and Plateaus climatic conditions. The diversity in plant species allows for drought tolerance, and natural plant mortality is very low. These plants have strong, healthy root systems that allow production to increase significantly with favorable moisture conditions. Abundant plant litter is available for soil building and moisture retention. Plant litter is properly distributed with very little movement off-site. Biological soil crusts play an important role in protecting the soil surface as well as carbon, nutrient, and water cycles, particularly moss and lichen under the sagebrush canopy and cyanobacteria in the interspaces. This plant community provides for soil stability and a properly functioning hydrologic cycle. The soils associated with this site are fertile and hold moderately large amounts of soil moisture, providing a very favorable soil-water-plant relationship. Plant community phases can occur in large contiguous blocks or in a small to large mosaic pattern, but typically this plant community is maintained within a larger mosaic at the landscape level with the other plant communities phases identified in the Reference State. This community can occur over time without disturbance (i.e. “natural succession”), or it can be accelerated with moderate herbaceous grazing pressure. Wyoming big sagebrush is dominant with sagebrush foliar cover ranging from 15% to 25%. At this level of sagebrush cover in this precipitation zone, there is competition between the shrub over-story and the herbaceous understory. (Winward, 2007) A Big Sagebrush/Bunchgrass Community with a degraded understory is an “at-risk” community. There are generally few canopy gaps, and most basal gaps are moderate (3-6 feet). Rock cover on the soil surface is low. Most plant interspaces have canopy or litter cover. Production of grasses is much lower than in the Bunchgrass Community (1.3) and slightly lower than in the Bunchgrass/Big Sagebrush Community (1.2).
Figure 7. Annual production by plant type (representative values) or group (midpoint values)
Table 5. Annual production by plant type
Plant type | Low (kg/hectare) |
Representative value (kg/hectare) |
High (kg/hectare) |
---|---|---|---|
Shrub/Vine | 280 | 392 | 504 |
Grass/Grasslike | 224 | 314 | 404 |
Forb | 56 | 78 | 101 |
Total | 560 | 784 | 1009 |
Table 6. Ground cover
Tree foliar cover | 0% |
---|---|
Shrub/vine/liana foliar cover | 0% |
Grass/grasslike foliar cover | 0% |
Forb foliar cover | 0% |
Non-vascular plants | 0% |
Biological crusts | 0% |
Litter | 40-60% |
Surface fragments >0.25" and <=3" | 0% |
Surface fragments >3" | 0% |
Bedrock | 0% |
Water | 0% |
Bare ground | 15-25% |
Table 7. Canopy structure (% cover)
Height Above Ground (m) | Tree | Shrub/Vine | Grass/ Grasslike |
Forb |
---|---|---|---|---|
<0.15 | – | – | 20-55% | 2-15% |
>0.15 <= 0.3 | – | – | 20-55% | 2-5% |
>0.3 <= 0.6 | – | 15-30% | – | – |
>0.6 <= 1.4 | – | – | – | – |
>1.4 <= 4 | – | – | – | – |
>4 <= 12 | – | – | – | – |
>12 <= 24 | – | – | – | – |
>24 <= 37 | – | – | – | – |
>37 | – | – | – | – |
Figure 8. Plant community growth curve (percent production by month). WY0901, 34AI, Upland Sites. All Upland Sites.
Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec |
---|---|---|---|---|---|---|---|---|---|---|---|
J | F | M | A | M | J | J | A | S | O | N | D |
0 | 0 | 0 | 10 | 35 | 40 | 10 | 0 | 5 | 0 | 0 | 0 |
Community 1.2
Bunchgrass/Big Sagebrush Community
The Bunchgrass/Big Sagebrush Community (1.2) is well adapted to Cool Central Desertic Basins and Plateaus climatic conditions. The diversity in plant species allows for drought tolerance, and natural plant mortality is very low. These plants have strong, healthy root systems that allow production to increase significantly with favorable moisture conditions. Abundant plant litter is available for soil building and moisture retention. Plant litter is properly distributed with very little movement off-site. This plant community provides for soil stability and a properly functioning hydrologic cycle. The soils associated with this site are fertile and hold moderately large amounts of soil moisture, providing a very favorable soil-water-plant relationship. Plant community phases can occur in large contiguous blocks or in a small to large mosaic pattern, but typically this plant community is maintained within a larger mosaic at the landscape level with the other plant communities phases identified in the Reference State. This community can occur after a sagebrush thinning event, such as drought, insects, or disease, or it can take longer to occur after a stand replacing event. Mid-stature bunchgrasses co-dominate with Wyoming big sagebrush, with sagebrush cover ranging from 5% to 15%. At this sagebrush canopy level in this precipitation zone, there is little if any competition between the shrub overstory and the herbaceous understory. In fact, there is evidence to suggest that the understory receives more benefit from the sage over-story than negative effects. (Winward, 2007) There are generally few canopy gaps, and most basal gaps are generally (3-6 feet). Rock cover on the soil surface is low to moderate. Many plant interspaces have canopy or litter cover. Production of grasses is slightly less than in the Bunchgrass Community (1.3), but shrub production is higher. Mechanical and chemical treatment of shrubs have replaced natural sagebrush killing events in many cases. However, chemical treatments impact non-target species, particularly broad-leafed species (forbs and shrubs) differently than natural events such as drought or fire. Fire tends to result in a short-term increase in forbs, but chemical treatments with 2,4-D can result in a short-term or long-term reduction in forb density and diversity. Chemical treatment of sagebrush with tebuthiuron can have impacts on the understory, depending on application rate.
Figure 10. Annual production by plant type (representative values) or group (midpoint values)
Table 8. Annual production by plant type
Plant type | Low (kg/hectare) |
Representative value (kg/hectare) |
High (kg/hectare) |
---|---|---|---|
Grass/Grasslike | 336 | 471 | 605 |
Shrub/Vine | 168 | 235 | 303 |
Forb | 56 | 78 | 101 |
Total | 560 | 784 | 1009 |
Table 9. Ground cover
Tree foliar cover | 0% |
---|---|
Shrub/vine/liana foliar cover | 0% |
Grass/grasslike foliar cover | 0% |
Forb foliar cover | 0% |
Non-vascular plants | 0% |
Biological crusts | 0% |
Litter | 45-65% |
Surface fragments >0.25" and <=3" | 0% |
Surface fragments >3" | 0% |
Bedrock | 0% |
Water | 0% |
Bare ground | 15-25% |
Table 10. Canopy structure (% cover)
Height Above Ground (m) | Tree | Shrub/Vine | Grass/ Grasslike |
Forb |
---|---|---|---|---|
<0.15 | – | – | 20-55% | 2-15% |
>0.15 <= 0.3 | – | – | 20-55% | 2-5% |
>0.3 <= 0.6 | – | 25-30% | – | – |
>0.6 <= 1.4 | – | – | – | – |
>1.4 <= 4 | – | – | – | – |
>4 <= 12 | – | – | – | – |
>12 <= 24 | – | – | – | – |
>24 <= 37 | – | – | – | – |
>37 | – | – | – | – |
Figure 11. Plant community growth curve (percent production by month). WY0901, 34AI, Upland Sites. All Upland Sites.
Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec |
---|---|---|---|---|---|---|---|---|---|---|---|
J | F | M | A | M | J | J | A | S | O | N | D |
0 | 0 | 0 | 10 | 35 | 40 | 10 | 0 | 5 | 0 | 0 | 0 |
Community 1.3
Bunchgrass Community
The Bunchgrass Community (1.3) is dominated by mid-stature cool-season bunchgrasses mixed with a minor component of forbs and shrubs. Wyoming big sagebrush along with several other shrubs are present as a part of this community, but they are a minor component with 0 to 5% foliar cover. Sprouting shrubs such as green rabbitbrush (Chrysothamnus viscidiflorus) may appear more visible and dominant with reduced sagebrush cover, but they are not dominant compared to the herbaceous component. The Bunchgrass Community (1.3) generally occurs immediately following a stand replacing sagebrush killing event such as drought, insects, browse, or fire. Chemical, mechanical, and biological control can be effective tools to achieve this plant community.
Figure 13. Annual production by plant type (representative values) or group (midpoint values)
Table 11. Annual production by plant type
Plant type | Low (kg/hectare) |
Representative value (kg/hectare) |
High (kg/hectare) |
---|---|---|---|
Grass/Grasslike | 420 | 588 | 757 |
Shrub/Vine | 84 | 118 | 151 |
Forb | 56 | 78 | 101 |
Total | 560 | 784 | 1009 |
Table 12. Ground cover
Tree foliar cover | 0% |
---|---|
Shrub/vine/liana foliar cover | 0% |
Grass/grasslike foliar cover | 0% |
Forb foliar cover | 0% |
Non-vascular plants | 0% |
Biological crusts | 0% |
Litter | 30-50% |
Surface fragments >0.25" and <=3" | 0% |
Surface fragments >3" | 0% |
Bedrock | 0% |
Water | 0% |
Bare ground | 10-20% |
Table 13. Canopy structure (% cover)
Height Above Ground (m) | Tree | Shrub/Vine | Grass/ Grasslike |
Forb |
---|---|---|---|---|
<0.15 | – | – | 25-75% | 2-15% |
>0.15 <= 0.3 | – | 0-10% | 25-60% | 2-5% |
>0.3 <= 0.6 | – | – | – | – |
>0.6 <= 1.4 | – | – | – | – |
>1.4 <= 4 | – | – | – | – |
>4 <= 12 | – | – | – | – |
>12 <= 24 | – | – | – | – |
>24 <= 37 | – | – | – | – |
>37 | – | – | – | – |
Figure 14. Plant community growth curve (percent production by month). WY0901, 34AI, Upland Sites. All Upland Sites.
Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec |
---|---|---|---|---|---|---|---|---|---|---|---|
J | F | M | A | M | J | J | A | S | O | N | D |
0 | 0 | 0 | 10 | 35 | 40 | 10 | 0 | 5 | 0 | 0 | 0 |
Pathway 1.1-1.2
Community 1.1 to 1.2
The trigger for a community shift from the Big Sagebrush/Bunchgrass Community (1.1) to the Bunchgrass/Big Sagebrush Community (1.2) is a sagebrush thinning event, such as drought, insects, disease, chemical, mechanical or biological control of sagebrush that favors the existing herbaceous vegetation while only removing a portion of the sagebrush canopy so that 5-15% sagebrush cover remains. Indicators include the increase in density and vigor of mid-stature bunchgrasses to the point that they co-dominate species composition by weight with Wyoming big sagebrush.
Pathway 1.1-1.3
Community 1.1 to 1.3
The trigger for a community shift from the Big Sagebrush/Bunchgrass Community (1.1) to the Bunchgrass Community (1.3) is a stand replacing sagebrush killing event, such as fire, drought, insects, disease, chemical, mechanical or biological control of sagebrush that favors the existing herbaceous vegetation and removes sagebrush canopy to <5%. Indicators include the increase in density and vigor of mid-stature bunchgrasses to the point that they dominate species composition by weight.
Pathway 1.2-1.1
Community 1.2 to 1.1
The trigger for a community shift from the Bunchgrass/Big Sagebrush Community (1.2) to the Big Sagebrush/Bunchgrass Community (1.1) is natural succession, or lack of disturbance over time. Indicators include an increase in shrub cover and decline in overall under-story.
Pathway 1.2-1.3
Community 1.2 to 1.3
The trigger for a community shift from the Bunchgrass/Big Sagebrush Community (1.2) to the Bunchgrass Community (1.3) is a sagebrush killing event, such as fire, drought, chemical, mechanical or biological control of sagebrush that favors the existing herbaceous vegetation. Indicators include an increase in density and vigor of mid-stature bunchgrasses to the point that they dominate species composition by weight.
Pathway 1.3-1.2
Community 1.3 to 1.2
The trigger for a community shift from the Bunchgrass Community (1.3) to the Bunchgrass/Big Sagebrush Community (1.2) is natural succession, or lack of disturbance over time. Indicators include an increase in shrub cover and decline in overall under-story. Natural succession results in sagebrush cover increasing in response to annual climatic differences and a certain amount of herbivory. Succession can be accelerated with proper herbaceous grazing (fully stocked, according to suggested stocking rate numbers, and a system that varies the time and timing of grazing to provide for periodic deferment during the critical growth period) and natural events such as drought/wet cycles.
State 2
Grazing Resistant State
Community 2.1
Big Sagebrush/Rhizomatous Wheatgrass- Bluegrass Plant Community
The Big Sagebrush/Rhizomatous Wheatgrass-Bluegrass Plant Community (2.1) is characterized by an herbaceous component dominated by Sandberg bluegrass, rhizomatous wheatgrass and/or mat forbs, with limited mid-stature bunchgrasses. Once these key species becomes scarce, it is unlikely to have sufficient reproductive capability (seed source, tillering, or resprouting) to recover dominance in a reasonable time frame without extra energy being added to the system. The plant community is highly resilient to changes in composition, due to the dominance and competition of established bluegrass, rhizomatous wheatgrass, and/or mat forbs. However, the community can shift back to the Big Sagebrush/Bunchgrass Community (1.3) over time with fire and/or brush control and/or deferment. This community is shrub dominated. Sagebrush canopy may be as high as 25 percent or higher. The dominant shrub is Wyoming big sagebrush. The Big Sagebrush/Rhizomatous Wheatgrass-Sandberg Bluegrass-Mat Forb Community occurs if the herbaceous component has been degraded. Areas that catch and retain snow are more likely to have higher shrub cover. Range Health Indicators: Production is considerably lower than in Reference State (1), leading to lower soil organic matter content and therefore lower soil stability than in the Reference State. Ground cover is still high. Infiltration is lower than in the Reference State and the water cycle has reduced function due to decreased soil organic matter.
Figure 16. Annual production by plant type (representative values) or group (midpoint values)
Table 14. Annual production by plant type
Plant type | Low (kg/hectare) |
Representative value (kg/hectare) |
High (kg/hectare) |
---|---|---|---|
Grass/Grasslike | 112 | 224 | 364 |
Shrub/Vine | 90 | 179 | 291 |
Forb | 22 | 45 | 73 |
Total | 224 | 448 | 728 |
Table 15. Ground cover
Tree foliar cover | 0% |
---|---|
Shrub/vine/liana foliar cover | 0% |
Grass/grasslike foliar cover | 0% |
Forb foliar cover | 0% |
Non-vascular plants | 0% |
Biological crusts | 0% |
Litter | 45-65% |
Surface fragments >0.25" and <=3" | 0% |
Surface fragments >3" | 0% |
Bedrock | 0% |
Water | 0% |
Bare ground | 20-40% |
Table 16. Canopy structure (% cover)
Height Above Ground (m) | Tree | Shrub/Vine | Grass/ Grasslike |
Forb |
---|---|---|---|---|
<0.15 | – | – | 20-50% | 2-10% |
>0.15 <= 0.3 | – | – | 20-40% | 2-5% |
>0.3 <= 0.6 | – | 20-40% | – | – |
>0.6 <= 1.4 | – | – | – | – |
>1.4 <= 4 | – | – | – | – |
>4 <= 12 | – | – | – | – |
>12 <= 24 | – | – | – | – |
>24 <= 37 | – | – | – | – |
>37 | – | – | – | – |
Figure 17. Plant community growth curve (percent production by month). WY0901, 34AI, Upland Sites. All Upland Sites.
Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec |
---|---|---|---|---|---|---|---|---|---|---|---|
J | F | M | A | M | J | J | A | S | O | N | D |
0 | 0 | 0 | 10 | 35 | 40 | 10 | 0 | 5 | 0 | 0 | 0 |
State 3
Eroded State
Community 3.1
Big Sagebrush/Bare Ground Community
Herbaceous canopy cover in the Big Sagebrush/Bare Ground Community (3.1) is significantly reduced. Annual production is approximately half of the Bunchgrass Plant Community (1.1). Perennial grass species (e.g., Indian ricegrass and needleandthread, bluebunch wheatgrass) may exist only in patches and are typically low in vigor. This community tends to be dominated by big sagebrush (>25% cover) and bare ground in large patches in the interspaces of the shrub canopy. The majority of annual production is from big sagebrush so this site provides very little value for grazing. The Big Sagebrush/Bare Ground Community (3.1) rarely produces sufficient quantity of fine fuels necessary to carry a fire. Therefore, fire no longer influences community dynamics. The Big Sagebrush/Bare Ground Community (3.1) differs from other communities, because it is characterized by sparse plant cover and soil surface erosion. Sparse vegetation creates low levels of foliar and basal cover. This, in turn, leads to low litter production, which is combined with reduced ability to retain litter on site. Soil is exposed to wind and water erosion in the plant interspaces. These factors combine to create a decrease in soil organic matter. Reduced litter cover, combined with reduced herbaceous cover, results in higher soil temperature, poor water infiltration rates, and high evaporation, thus favoring species which are more adapted to drier conditions. Soil fertility is reduced, soil compaction is increased, and resistance to soil surface erosion has declined compared to the other states. This community has lost most, if not all, of the attributes of a functioning, healthy rangeland, including good infiltration, minimal erosion and runoff, nutrient cycling, and energy flow.
Figure 18. Annual production by plant type (representative values) or group (midpoint values)
Table 17. Annual production by plant type
Plant type | Low (kg/hectare) |
Representative value (kg/hectare) |
High (kg/hectare) |
---|---|---|---|
Shrub/Vine | 56 | 168 | 280 |
Grass/Grasslike | 45 | 135 | 224 |
Forb | 11 | 34 | 56 |
Total | 112 | 337 | 560 |
Figure 19. Plant community growth curve (percent production by month). WY0301, 34AC, Upland Sites. All Upland Sites.
Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec |
---|---|---|---|---|---|---|---|---|---|---|---|
J | F | M | A | M | J | J | A | S | O | N | D |
5 | 40 | 50 | 5 |
State 4
Disturbed State
This state contains one community, the Big Sagebrush/Bare Ground Community (3.1). It is characterized by sparse herbaceous plant cover dominated by big sagebrush and bare ground. Communities in the Eroded State (3) have crossed a threshold (T1-3 or T2-3) because of soil erosion, loss of soil fertility, and/or degradation of soil properties. Soil erosion affects the hydrology, soil chemistry, soil microorganisms, and soil physics to the point where intensive restoration is required to restore the site to another state or community. Simply changing grazing management may not create sufficient change to restore the site within a reasonable period. It will require a considerable input of energy to move the site back to the Reference State (1). The Eroded State (3) is at high risk of weed invasion due to the high percentage of bare ground. Many invasive species are adapted to low soil fertility, high soil temperatures and low soil moisture content. This puts the community at risk of transitioning to the Disturbed State (4).
Community 4.1
Big Sagebrush/Rabbitbrush Community
The Big Sagebrush/Rabbitbrush Community (4.1) has had the disturbance regime accelerated or altered in the past, but no recent sagebrush killing events. Wyoming big sagebrush and green rabbitbrush are co-dominant with a sparse understory. This community is found in areas of historical disturbance (i.e. homesteads, gravel pits, emigrant trails) where the disturbances that caused the initial dominance of rabbitbrush have ceased
Community 4.2
Rabbitbrush/Bare Ground/Annuals Community
The Rabbitbrush/Rhizomatous Wheatgrass Community (4.2) is often in a perpetual state of disturbance. The disturbance regime of the site has been accelerated often with the addition of ground disturbing activities (i.e. gravel pits, pasture corners where livestock are gathered, continual sagebrush removal techniques, and/or consecutive fires. Seeding may be used to restore functional structural groups, but rabbitbrush is likely to continue as a dominant shrub into the foreseeable future with no restoration pathway identified at this time due to irreversible changes to soil dynamic properties (structure, organic matter, infiltration, bulk density, and/or water holding capacity).
Pathway 4.2-4.1
Community 4.2 to 4.1
The trigger for a community shift from the Rabbitbrush/Rhizomatous Wheatgrass Community (4.2) to the Big Sagebrush/Rabbitbrush Community (4.1) is time without sagebrush killing disturbances. This shift can be accelerated with high utilization levels by grazers, particularly during the critical growth period.
State 5
Highly Disturbed State
Community 5.1
Annuals/Bare Ground Community
The Annuals/Bare Ground Community (5.1) occurs after severe disturbance, most often physical soil disturbance that removes all topsoil, but it can also occur as a transition from the Eroded State (3) after severe drought, flooding, pests, or disease kills sagebrush, leaving the site with no perennial vegetation. Populations of annual and/or invasive weeds reach critical levels and impact the ecological processes on the site until restoration of the site occurs. As part of succession, all sites that are severely disturbed will go through this plant community as part of the restoration process.
Community 5.2
Reclaimed Community
This plant community is highly variable based on weather conditions during restoration activities, the management practices used to implement the restoration, the seed mix, and how soil was stockpiled during the disturbance
Pathway 5.1-5.2
Community 5.1 to 5.2
The trigger for a community shift from the Annuals/Bare Ground Community (5.1) to the Reclaimed Community (5.2) is a variety of reclamation and restoration techniques that include seedbed preparation, seeding, and often post-planting weed control. Weather is the largest determining factor in determining time and success, but the process can be accelerated with Best Management Practices for site restoration (http://www.uwyo.edu/wrrc/ ).
Transition T1-2
State 1 to 2
The driver for transition from the Reference State to the Grazing Resistant State (T1-2) is continuous spring grazing and/or long-term drought. Continuous spring grazing and/or extended drought can lead to a decline in palatable mid-stature bunchgrasses. Indian ricegrass, a short-lived perennial that requires more frequent seed production to provide an adequate seedbank, and bluebunch wheatgrass, a long-lived perennial that has elevated growth points, are typically the first species to decline (Natural Resources Conservation Service). Bottlebrush squirreltail will also decline with grazing pressure and lack of disturbances that kill sagebrush. Needleandthread is more grazing tolerant, but will eventually decline in plant density and vigor. As bunchgrasses diminish or die during periods of stress, low- stature bunchgrasses and rhizomatous grasses gain a competitive advantage, creating a shift in species composition towards less productive, shorter species. While bare ground may not change significantly, the pattern of bare ground will shift to larger gaps in the canopy and fewer herbaceous plants between shrubs. Many of the remaining desirable bunchgrasses will be only found in the understory of the sagebrush canopy. Once mid-stature bunchgrasses species become scarce, it is unlikely that they have sufficient reproductive capability (seed source, tillering, or re-sprouting) to recover dominance in a reasonable time frame without extra energy being added to the system. When the understory vegetation has been degraded to this point, the transition to the Grazing Resistant State (2) can occur from either the Bunchgrass/Big Sagebrush Plant Community (1.2) or the Big Sagebrush/Bunchgrass Plant Community (1.1). The transition is not dependent on the increase of woody canopy cover, but rather on the lack of mid-stature bunchgrasses in the canopy interspaces. Management should focus on grazing management strategies that will prevent further degradation. This can be achieved through a grazing management scheme that varies the season of use to provide periodic deferment during the critical growth period (roughly May-June). Forage quantity and/or quality in the Grazing Resistant State (2) may be substantially reduced compared to the Reference State, and will dramatically fluctuate in dry vs. wet years.
Transition T1-3
State 1 to 3
The driver for transition from the Reference State to the Eroded State (T1-3) is continuous high intensity early season grazing. Drought can accelerate this transition. Indicators of this transition include significant decline in plant canopy cover or total annual aboveground biomass production below 200 pounds per acre. The primary indicator of this transition is the loss of understory, which creates open spots with bare soil between the sagebrush canopy. Soil erosion causes decreased soil fertility and infiltration, triggering the transition to the Eroded State. Several other key factors signal the approach of a threshhold: an increase in soil physical crusting, a decrease in soil surface aggregate stability, and/or evidence of erosion, including water flow patterns, development of pedestals, and litter movement.
Transition T1-4
State 1 to 4
The driver for transition from the Reference State to the Disturbed State (T1-4) is an increase in the disturbance cycle (i.e. grazing, drought, fire, mechanical, chemical or biological treatments), often in combination with grazing management that does not provide periodic deferment during the critical growth period. The transition can occur if multiple soil disturbing activities occur over a relatively short time period. This could be high intensity/high frequency grazing, machinery, and/or multiple sagebrush treatments. Indicators include an increase in rabbitbrush to dominant levels in the plant community due to ground disturbance that could be either natural (i.e. water movement) or manmade (i.e. high density/high frequency stocking, mechanical treatments or heavy equipment operations). If introduced to the site, invasive species, such as cheatgrass, may be present. To prevent this transition, the site will require proper reclamation after disturbance using the most current science and technology available to restore native vegetation and prevent invasive dominance. In cases where topsoil loss occurs, it may be unavoidable to prevent this transition. Long-term stress conditions for native species (e.g., improper grazing management, drought, and fire) will alter plant community composition and production over time and may hasten the transition. The resulting lower biomass production, reduced litter, and increased bare ground in this community can promote invasion of undesirable species such as, plains pricklypear.
Transition T1-5
State 1 to 5
The driver for transition from the Reference State to the Highly Disturbed State (T1-5) is a topsoil removing event with mechanical equipment. Examples include construction sites, oil and gas activity, and borrow areas
Restoration pathway R2-1
State 2 to 1
The drivers for this restoration pathway are reduction of woody species and restoration of native herbaceous species by mechanical or chemical treatment of sagebrush, and grazing rest or deferment. If some mid stature bunchgrasses remain under the sage canopy, proper grazing management can move the site back to the Reference State (1) combined with a mechanical or chemical sagebrush treatment. Most probable restoration pathway is from Big Sagebrush/Rhizomatous Wheatgrass Community (2.1) to the Bunchgrass Community (1.3). This could take multiple generations of management or could be accelerated with rest or deferment combined with successive wet springs conducive to seed germination and seedling establishment. (Derner, Schuman, Follett, & Vance, 2014).
Transition T2-3
State 2 to 3
The driver for transition from the Grazing Resistant State to the Eroded State (T2-3) is continuous high intensity early season grazing from the Big Sagebrush/Rhizomatous Wheatgrass Community (2-1). Examples include calving pastures and small acreage horse pastures where rotational grazing is not employed, but stocking densities are high. Extended drought periods accelerate this transition. Indicators include very old sagebrush stands with very little understory between the sagebrush canopy. Bare ground patch sizes are very large and comprise the majority of the interspaces between sagebrush plants.
Transition T2-4
State 2 to 4
The driver for transition from the Grazing Resistant State to the Disturbed State (T2-4) is an increase in the disturbance cycle (i.e. grazing, drought, fire, mechanical, chemical, biological treatments) combined with continuous high intensity grazing. Examples include calving pastures and small acreage horse pastures where rotational grazing is not employed combined with sagebrush treatment (mechanical, chemical, or biological). High stocking densities are soil disturbing, and adding sagebrush treatment(s) to this regime result in a an increase in the disturbance cycle. Removal of shrubs without proper grazing management can lead to an increase in bare ground and erosion of the upper soil horizon, and the site can degrade to the Disturbed State (4). Consequences of this transition are decreased soil fertility or even soil erosion, soil crusting, and decrease of soil surface aggregate stability. Indicators of the Disturbed state are a shift in shrub dominance away from sagebrush and toward sprouting shrubs such as green rabbitbrush (Chrysothamnus viscidiflorus).
Transition T2-5
State 2 to 5
The driver for transition from the Grazing Resistant to the Highly Disturbed State (T2-5) is a topsoil removing event with mechanical equipment. Examples include construction sites, oil and gas activity, and borrow areas.
Restoration pathway R3-1
State 3 to 1
The Eroded State (3) has lost soil or vegetation attributes to the point that recovery to the Reference State (1) will require a combination of grazing management (changing season of use to allow frequent rest or deferment during the critical growth period) and chemical, biological or mechanical treatments, and reseeding. Seeding may be cost prohibitive as a restoration practice used alone. With reduced organic matter and loss of soil, soil amendments and/or mulch may be needed for restoration success. Restoration has occurred by mowing without re-seeding, but the grazing regime in this instance is low stocking density and winter only use.
Restoration pathway R3-2
State 3 to 2
Restoration from the Eroded State (3) to the Grazing Resistant State (2) is possible with mechanical, biological and chemical treatments and temporary rest or deferment post-treatment. Due to loss of soil fertility, structure, and organic matter, reference community plants are slow to repopulate the site. Success of this restoration is highly dependent upon climatic factors, and may require successive wet years. This restoration pathway is often unintentionally achieved when the goal is the Reference State (1) because post-treatment management is not sustained in a manner that allows frequent critical growth period rest and/or use levels and recovery periods are not adequate to sustain mid-stature bunchgrasses.
Transition T3-4
State 3 to 4
The driver for this transition is a sagebrush killing event with continuous high intensity early season grazing. The event could be severe drought, flooding, insects, disease, or a sagebrush treatment such as mechanical (including heavy equipment/construction or a mowing/chaining/harrow type sage treatment), chemical (including 2,4-D or tebuthiron), or biological (including browse and/or insects). Fire is not usually possible due to lack of understory fuels to carry the fire. In fact, the Eroded State (3) is characterized by monotypic decadent sagebrush stands because they are fireproof.
Transition T3-5
State 3 to 5
The driver for transition from the Reference State to the Highly Disturbed State (T1-5) is a topsoil removing event with mechanical equipment, but it can also occur after severe drought, flooding, pests, or disease kills sagebrush, leaving the site with no perennial vegetation. Examples include construction sites, oil and gas activity, and borrow areas. Evidence of climate as a cause for this transition has been documented after the 2012 drought (Clause & Randall, 2015).
Transition T4-5
State 4 to 5
The driver for transition from the Disturbed State to the Highly Disturbed State (T4-5) is a topsoil removing event with mechanical equipment. Examples include construction sites, oil and gas activity, and borrow areas.
Restoration pathway R5-1
State 5 to 1
The Highly Disturbed State (5) can be restored to the Reference State (1) if appropriate seedbed preparation and seed mixes are used, and weather conditions are conducive to seedling establishment. Weather is the largest determining factor in determining time and success, but the process can be accelerated with Best Management Practices for site restoration (http://www.uwyo.edu/wrrc/ ). There is low potential for recovery without significant inputs of energy and resources if topsoil has been removed. Seeding is needed to restore functional structural groups, and proper seedbed preparation is key to restoring ecological processes on the site.
Restoration pathway R5-2
State 5 to 2
The Highly Disturbed State (5) is often restored to the Grazing Resistant State (2) unintentionally when inappropriate seed mixes are used and post-seeding grazing management does not provide adequate and periodic critical growth period rest. Weather is the largest determining factor in determining time and success, but the process can be accelerated with Best Management Practices for site restoration (http://www.uwyo.edu/wrrc/ ). There is low potential for recovery without significant inputs of energy and resources if topsoil has been removed. Seed mixes that mimic an adjacent “reference area” rather than the site potential as described in the Reference State (1) will often result in a plant community resembling the Grazing Resistant State (2) due to past and post-seeding grazing management of the area.
Restoration pathway R5-3
State 5 to 3
The Highly Disturbed State (5) can transition the Eroded State (3) if disturbed areas result in total topsoil removal and are abandoned and climate is favorable for seedling establishment. Wyoming big sagebrush will eventually colonize the site, but because soil conditions are severely altered, little to no under-story can be found. An example of this transition can be found on abandoned oil and gas wells that are 30+ years old where topsoil was not stockpiled and re-spread on the site after proper contouring and ripping, and either no seeding was done or the planting was a failure. If topsoil was not physically removed, and there is a viable seedbank in the soil, recovery is possible without re-seeding as long as adequate rest from herbivory is provided to allow seedling establishment. Rest from herbivory is recommended during dry years to prevent further soil loss as well as in wet years to allow seedling establishment.
Restoration pathway R5-4
State 5 to 4
The Highly Disturbed State (5) can transition the Disturbed State (4) if disturbed areas result in only partial topsoil removal, leaving rootstock available for sprouting species such as rabbitbrush. This is common for gravel pits and areas disturbed as stockpile areas where soil is placed on the area for any amount of time, and then removed with equipment that scrapes some of the soil surface during the removal process.
Additional community tables
Table 18. Community 1.1 plant community composition
Group | Common name | Symbol | Scientific name | Annual production (kg/hectare) | Foliar cover (%) | |
---|---|---|---|---|---|---|
Grass/Grasslike
|
||||||
1 | Perennial Mid-Size Cool Season Grasses | 78–235 | ||||
bluebunch wheatgrass | PSSP6 | Pseudoroegneria spicata | 78–118 | 10–15 | ||
muttongrass | POFE | Poa fendleriana | 39–118 | 5–15 | ||
needle and thread | HECO26 | Hesperostipa comata | 39–78 | 5–10 | ||
prairie Junegrass | KOMA | Koeleria macrantha | 8–39 | 1–5 | ||
green needlegrass | NAVI4 | Nassella viridula | 0–39 | 0–5 | ||
Indian ricegrass | ACHY | Achnatherum hymenoides | 0–39 | 0–5 | ||
squirreltail | ELEL5 | Elymus elymoides | 8–39 | 1–5 | ||
2 | Rhizomatous Grasses | 39–78 | ||||
thickspike wheatgrass | ELLAL | Elymus lanceolatus ssp. lanceolatus | 39–78 | 5–10 | ||
western wheatgrass | PASM | Pascopyrum smithii | 39–78 | 5–10 | ||
3 | Misc Grasses/Grasslikes | 39–78 | ||||
needleleaf sedge | CADU6 | Carex duriuscula | 0–39 | 0–5 | ||
threadleaf sedge | CAFI | Carex filifolia | 0–39 | 0–5 | ||
Sandberg bluegrass | POSE | Poa secunda | 8–39 | 1–5 | ||
Grass, perennial | 2GP | Grass, perennial | 0–39 | 0–5 | ||
Forb
|
||||||
4 | Perennial Forbs | 31–71 | ||||
hawksbeard | CREPI | Crepis | 8–39 | 1–5 | ||
buckwheat | ERIOG | Eriogonum | 0–39 | 0–5 | ||
scarlet globemallow | SPCO | Sphaeralcea coccinea | 0–39 | 0–5 | ||
stemless mock goldenweed | STAC | Stenotus acaulis | 0–24 | 0–3 | ||
spiny phlox | PHHO | Phlox hoodii | 8–24 | 1–3 | ||
longleaf phlox | PHLOL2 | Phlox longifolia ssp. longifolia | 0–24 | 0–3 | ||
fleabane | ERIGE2 | Erigeron | 0–24 | 0–3 | ||
hoary tansyaster | MACA2 | Machaeranthera canescens | 0–24 | 0–3 | ||
flaxleaf plainsmustard | SCLI | Schoenocrambe linifolia | 0–24 | 0–3 | ||
pussytoes | ANTEN | Antennaria | 8–24 | 1–3 | ||
sandwort | ARENA | Arenaria | 8–24 | 1–3 | ||
milkvetch | ASTRA | Astragalus | 0–24 | 0–3 | ||
western yarrow | ACMIO | Achillea millefolium var. occidentalis | 0–24 | 0–3 | ||
textile onion | ALTE | Allium textile | 0–8 | 0–1 | ||
balsamroot | BALSA | Balsamorhiza | 0–8 | 0–1 | ||
sego lily | CANU3 | Calochortus nuttallii | 0–8 | 0–1 | ||
Indian paintbrush | CASTI2 | Castilleja | 0–8 | 0–1 | ||
pale bastard toadflax | COUMP | Comandra umbellata ssp. pallida | 0–8 | 0–1 | ||
rockcress | ARABI2 | Arabis | 0–8 | 0–1 | ||
larkspur | DELPH | Delphinium | 0–8 | 0–1 | ||
wormleaf stonecrop | SEST2 | Sedum stenopetalum | 0–8 | 0–1 | ||
lambstongue ragwort | SEIN2 | Senecio integerrimus | 0–8 | 0–1 | ||
ragwort | SENEC | Senecio | 0–8 | 0–1 | ||
rayless tansyaster | MAGR2 | Machaeranthera grindelioides | 0–8 | 0–1 | ||
bluebells | MERTE | Mertensia | 0–8 | 0–1 | ||
tufted evening primrose | OECA10 | Oenothera caespitosa | 0–8 | 0–1 | ||
beardtongue | PENST | Penstemon | 0–8 | 0–1 | ||
phacelia | PHACE | Phacelia | 0–8 | 0–1 | ||
yellow fritillary | FRPU2 | Fritillaria pudica | 0–8 | 0–1 | ||
scarlet gilia | IPAG | Ipomopsis aggregata | 0–8 | 0–1 | ||
bitter root | LERE7 | Lewisia rediviva | 0–8 | 0–1 | ||
Lewis flax | LILE3 | Linum lewisii | 0–8 | 0–1 | ||
desertparsley | LOMAT | Lomatium | 0–8 | 0–1 | ||
silvery lupine | LUAR3 | Lupinus argenteus | 0–8 | 0–1 | ||
lupine | LUPIN | Lupinus | 0–8 | 0–1 | ||
sagebrush buttercup | RAGL | Ranunculus glaberrimus | 0–8 | 0–1 | ||
hollyleaf clover | TRGY | Trifolium gymnocarpon | 0–8 | 0–1 | ||
violet | VIOLA | Viola | 0–8 | 0–1 | ||
deathcamas | ZIGAD | Zigadenus | 0–8 | 0–1 | ||
Forb, perennial | 2FP | Forb, perennial | 0–8 | 0–1 | ||
5 | Annual Forbs | 0–8 | ||||
rockjasmine | ANDRO3 | Androsace | 0–8 | 0–1 | ||
bushy bird's beak | CORA5 | Cordylanthus ramosus | 0–8 | 0–1 | ||
Forb, annual | 2FA | Forb, annual | 0–8 | 0–1 | ||
Shrub/Vine
|
||||||
6 | Shrubs | 157–275 | ||||
Wyoming big sagebrush | ARTRW8 | Artemisia tridentata ssp. wyomingensis | 157–275 | 15–25 | ||
7 | Misc Shrubs | 16–39 | ||||
prairie sagewort | ARFR4 | Artemisia frigida | 0–39 | 0–5 | ||
yellow rabbitbrush | CHVI8 | Chrysothamnus viscidiflorus | 8–39 | 1–5 | ||
winterfat | KRLA2 | Krascheninnikovia lanata | 0–39 | 0–5 | ||
plains pricklypear | OPPO | Opuntia polyacantha | 0–8 | 0–1 | ||
Shrub (>.5m) | 2SHRUB | Shrub (>.5m) | 0–8 | 0–1 | ||
rubber rabbitbrush | ERNA10 | Ericameria nauseosa | 0–8 | 0–1 | ||
black sagebrush | ARNO4 | Artemisia nova | 0–8 | 0–1 | ||
mountain big sagebrush | ARTRV | Artemisia tridentata ssp. vaseyana | 0–8 | 0–1 |
Table 19. Community 1.2 plant community composition
Group | Common name | Symbol | Scientific name | Annual production (kg/hectare) | Foliar cover (%) | |
---|---|---|---|---|---|---|
Grass/Grasslike
|
||||||
1 | Perennial Mid-Size Cool Season Grasses | 141–314 | ||||
bluebunch wheatgrass | PSSP6 | Pseudoroegneria spicata | 118–157 | 15–20 | ||
muttongrass | POFE | Poa fendleriana | 39–118 | 5–15 | ||
needle and thread | HECO26 | Hesperostipa comata | 39–78 | 5–10 | ||
prairie Junegrass | KOMA | Koeleria macrantha | 8–39 | 1–5 | ||
green needlegrass | NAVI4 | Nassella viridula | 0–39 | 0–5 | ||
Indian ricegrass | ACHY | Achnatherum hymenoides | 0–39 | 0–5 | ||
squirreltail | ELEL5 | Elymus elymoides | 8–39 | 1–5 | ||
2 | Rhizomatous Grasses | 39–78 | ||||
thickspike wheatgrass | ELLAL | Elymus lanceolatus ssp. lanceolatus | 39–78 | 5–10 | ||
western wheatgrass | PASM | Pascopyrum smithii | 39–78 | 5–10 | ||
3 | Misc Grasses/Grasslikes | 39–78 | ||||
needleleaf sedge | CADU6 | Carex duriuscula | 0–39 | 0–5 | ||
threadleaf sedge | CAFI | Carex filifolia | 0–39 | 0–5 | ||
Sandberg bluegrass | POSE | Poa secunda | 8–39 | 1–5 | ||
Grass, perennial | 2GP | Grass, perennial | 0–39 | 0–5 | ||
Forb
|
||||||
4 | Perennial Forbs | 31–71 | ||||
buckwheat | ERIOG | Eriogonum | 0–39 | 0–5 | ||
hawksbeard | CREPI | Crepis | 8–39 | 1–5 | ||
scarlet globemallow | SPCO | Sphaeralcea coccinea | 0–39 | 0–5 | ||
stemless mock goldenweed | STAC | Stenotus acaulis | 0–24 | 0–3 | ||
flaxleaf plainsmustard | SCLI | Schoenocrambe linifolia | 0–24 | 0–3 | ||
fleabane | ERIGE2 | Erigeron | 0–24 | 0–3 | ||
hoary tansyaster | MACA2 | Machaeranthera canescens | 0–24 | 0–3 | ||
spiny phlox | PHHO | Phlox hoodii | 8–24 | 1–3 | ||
longleaf phlox | PHLOL2 | Phlox longifolia ssp. longifolia | 0–24 | 0–3 | ||
western yarrow | ACMIO | Achillea millefolium var. occidentalis | 0–24 | 0–3 | ||
sandwort | ARENA | Arenaria | 8–24 | 1–3 | ||
milkvetch | ASTRA | Astragalus | 0–24 | 0–3 | ||
pussytoes | ANTEN | Antennaria | 8–24 | 1–3 | ||
rockcress | ARABI2 | Arabis | 0–8 | 0–1 | ||
balsamroot | BALSA | Balsamorhiza | 0–8 | 0–1 | ||
sego lily | CANU3 | Calochortus nuttallii | 0–8 | 0–1 | ||
Indian paintbrush | CASTI2 | Castilleja | 0–8 | 0–1 | ||
textile onion | ALTE | Allium textile | 0–8 | 0–1 | ||
sagebrush buttercup | RAGL | Ranunculus glaberrimus | 0–8 | 0–1 | ||
rayless tansyaster | MAGR2 | Machaeranthera grindelioides | 0–8 | 0–1 | ||
bluebells | MERTE | Mertensia | 0–8 | 0–1 | ||
tufted evening primrose | OECA10 | Oenothera caespitosa | 0–8 | 0–1 | ||
beardtongue | PENST | Penstemon | 0–8 | 0–1 | ||
phacelia | PHACE | Phacelia | 0–8 | 0–1 | ||
pale bastard toadflax | COUMP | Comandra umbellata ssp. pallida | 0–8 | 0–1 | ||
larkspur | DELPH | Delphinium | 0–8 | 0–1 | ||
yellow fritillary | FRPU2 | Fritillaria pudica | 0–8 | 0–1 | ||
scarlet gilia | IPAG | Ipomopsis aggregata | 0–8 | 0–1 | ||
bitter root | LERE7 | Lewisia rediviva | 0–8 | 0–1 | ||
Lewis flax | LILE3 | Linum lewisii | 0–8 | 0–1 | ||
desertparsley | LOMAT | Lomatium | 0–8 | 0–1 | ||
silvery lupine | LUAR3 | Lupinus argenteus | 0–8 | 0–1 | ||
lupine | LUPIN | Lupinus | 0–8 | 0–1 | ||
wormleaf stonecrop | SEST2 | Sedum stenopetalum | 0–8 | 0–1 | ||
lambstongue ragwort | SEIN2 | Senecio integerrimus | 0–8 | 0–1 | ||
ragwort | SENEC | Senecio | 0–8 | 0–1 | ||
hollyleaf clover | TRGY | Trifolium gymnocarpon | 0–8 | 0–1 | ||
violet | VIOLA | Viola | 0–8 | 0–1 | ||
deathcamas | ZIGAD | Zigadenus | 0–8 | 0–1 | ||
Forb, perennial | 2FP | Forb, perennial | 0–8 | 0–1 | ||
5 | Annual Forbs | 0–8 | ||||
rockjasmine | ANDRO3 | Androsace | 0–8 | 0–1 | ||
bushy bird's beak | CORA5 | Cordylanthus ramosus | 0–8 | 0–1 | ||
Forb, annual | 2FA | Forb, annual | 0–8 | 0–1 | ||
Shrub/Vine
|
||||||
6 | Shrubs | 94–196 | ||||
Wyoming big sagebrush | ARTRW8 | Artemisia tridentata ssp. wyomingensis | 94–196 | 10–15 | ||
7 | Misc Shrubs | 16–39 | ||||
prairie sagewort | ARFR4 | Artemisia frigida | 0–39 | 0–5 | ||
yellow rabbitbrush | CHVI8 | Chrysothamnus viscidiflorus | 8–39 | 1–5 | ||
rubber rabbitbrush | ERNA10 | Ericameria nauseosa | 0–8 | 0–1 | ||
winterfat | KRLA2 | Krascheninnikovia lanata | 0–8 | 0–1 | ||
plains pricklypear | OPPO | Opuntia polyacantha | 0–8 | 0–1 | ||
Shrub (>.5m) | 2SHRUB | Shrub (>.5m) | 0–8 | 0–1 | ||
black sagebrush | ARNO4 | Artemisia nova | 0–8 | 0–1 | ||
mountain big sagebrush | ARTRV | Artemisia tridentata ssp. vaseyana | 0–8 | 0–1 |
Table 20. Community 1.3 plant community composition
Group | Common name | Symbol | Scientific name | Annual production (kg/hectare) | Foliar cover (%) | |
---|---|---|---|---|---|---|
Grass/Grasslike
|
||||||
1 | Perennial Mid-Size Cool Season Grasses | 235–392 | ||||
bluebunch wheatgrass | PSSP6 | Pseudoroegneria spicata | 196–275 | 25–35 | ||
muttongrass | POFE | Poa fendleriana | 118–196 | 15–25 | ||
needle and thread | HECO26 | Hesperostipa comata | 39–78 | 5–10 | ||
prairie Junegrass | KOMA | Koeleria macrantha | 0–39 | 0–5 | ||
green needlegrass | NAVI4 | Nassella viridula | 0–39 | 0–5 | ||
Indian ricegrass | ACHY | Achnatherum hymenoides | 0–39 | 0–5 | ||
squirreltail | ELEL5 | Elymus elymoides | 0–39 | 0–5 | ||
2 | Rhizomatous Grasses | 39–78 | ||||
thickspike wheatgrass | ELLAL | Elymus lanceolatus ssp. lanceolatus | 39–78 | 5–10 | ||
western wheatgrass | PASM | Pascopyrum smithii | 39–78 | 5–10 | ||
3 | Misc Grasses/Grasslikes | 39–118 | ||||
needleleaf sedge | CADU6 | Carex duriuscula | 0–39 | 0–5 | ||
threadleaf sedge | CAFI | Carex filifolia | 0–39 | 0–5 | ||
Sandberg bluegrass | POSE | Poa secunda | 8–39 | 1–5 | ||
Grass, perennial | 2GP | Grass, perennial | 0–39 | 0–5 | ||
Forb
|
||||||
4 | Perennial Forbs | 31–71 | ||||
scarlet globemallow | SPCO | Sphaeralcea coccinea | 0–39 | 0–5 | ||
buckwheat | ERIOG | Eriogonum | 0–39 | 0–5 | ||
pussytoes | ANTEN | Antennaria | 8–24 | 1–3 | ||
hawksbeard | CREPI | Crepis | 8–24 | 1–3 | ||
sandwort | ARENA | Arenaria | 8–24 | 1–3 | ||
milkvetch | ASTRA | Astragalus | 0–24 | 0–3 | ||
fleabane | ERIGE2 | Erigeron | 0–24 | 0–3 | ||
stemless mock goldenweed | STAC | Stenotus acaulis | 0–24 | 0–3 | ||
western yarrow | ACMIO | Achillea millefolium var. occidentalis | 0–24 | 0–3 | ||
hoary tansyaster | MACA2 | Machaeranthera canescens | 0–24 | 0–3 | ||
spiny phlox | PHHO | Phlox hoodii | 8–24 | 1–3 | ||
longleaf phlox | PHLOL2 | Phlox longifolia ssp. longifolia | 0–24 | 0–3 | ||
flaxleaf plainsmustard | SCLI | Schoenocrambe linifolia | 0–24 | 0–3 | ||
wormleaf stonecrop | SEST2 | Sedum stenopetalum | 0–8 | 0–1 | ||
lambstongue ragwort | SEIN2 | Senecio integerrimus | 0–8 | 0–1 | ||
ragwort | SENEC | Senecio | 0–8 | 0–1 | ||
sagebrush buttercup | RAGL | Ranunculus glaberrimus | 0–8 | 0–1 | ||
lupine | LUPIN | Lupinus | 0–8 | 0–1 | ||
rayless tansyaster | MAGR2 | Machaeranthera grindelioides | 0–8 | 0–1 | ||
bluebells | MERTE | Mertensia | 0–8 | 0–1 | ||
tufted evening primrose | OECA10 | Oenothera caespitosa | 0–8 | 0–1 | ||
beardtongue | PENST | Penstemon | 0–8 | 0–1 | ||
phacelia | PHACE | Phacelia | 0–8 | 0–1 | ||
textile onion | ALTE | Allium textile | 0–8 | 0–1 | ||
hollyleaf clover | TRGY | Trifolium gymnocarpon | 0–8 | 0–1 | ||
violet | VIOLA | Viola | 0–8 | 0–1 | ||
deathcamas | ZIGAD | Zigadenus | 0–8 | 0–1 | ||
Forb, perennial | 2FP | Forb, perennial | 0–8 | 0–1 | ||
balsamroot | BALSA | Balsamorhiza | 0–8 | 0–1 | ||
sego lily | CANU3 | Calochortus nuttallii | 0–8 | 0–1 | ||
Indian paintbrush | CASTI2 | Castilleja | 0–8 | 0–1 | ||
pale bastard toadflax | COUMP | Comandra umbellata ssp. pallida | 0–8 | 0–1 | ||
larkspur | DELPH | Delphinium | 0–8 | 0–1 | ||
rockcress | ARABI2 | Arabis | 0–8 | 0–1 | ||
yellow fritillary | FRPU2 | Fritillaria pudica | 0–8 | 0–1 | ||
scarlet gilia | IPAG | Ipomopsis aggregata | 0–8 | 0–1 | ||
bitter root | LERE7 | Lewisia rediviva | 0–8 | 0–1 | ||
Lewis flax | LILE3 | Linum lewisii | 0–8 | 0–1 | ||
desertparsley | LOMAT | Lomatium | 0–8 | 0–1 | ||
silvery lupine | LUAR3 | Lupinus argenteus | 0–8 | 0–1 | ||
5 | Annual Forbs | 0–8 | ||||
rockjasmine | ANDRO3 | Androsace | 0–8 | 0–1 | ||
bushy bird's beak | CORA5 | Cordylanthus ramosus | 0–8 | 0–1 | ||
Forb, annual | 2FA | Forb, annual | 0–8 | 0–1 | ||
Shrub/Vine
|
||||||
6 | Shrubs | 39–78 | ||||
Wyoming big sagebrush | ARTRW8 | Artemisia tridentata ssp. wyomingensis | 39–78 | 1–10 | ||
7 | Misc Shrubs | 16–39 | ||||
yellow rabbitbrush | CHVI8 | Chrysothamnus viscidiflorus | 8–39 | 1–5 | ||
prairie sagewort | ARFR4 | Artemisia frigida | 0–39 | 0–5 | ||
black sagebrush | ARNO4 | Artemisia nova | 0–8 | 0–1 | ||
mountain big sagebrush | ARTRV | Artemisia tridentata ssp. vaseyana | 0–8 | 0–1 | ||
rubber rabbitbrush | ERNA10 | Ericameria nauseosa | 0–8 | 0–1 | ||
winterfat | KRLA2 | Krascheninnikovia lanata | 0–8 | 0–1 | ||
plains pricklypear | OPPO | Opuntia polyacantha | 0–8 | 0–1 | ||
Shrub (>.5m) | 2SHRUB | Shrub (>.5m) | 0–8 | 0–1 |
Table 21. Community 2.1 plant community composition
Group | Common name | Symbol | Scientific name | Annual production (kg/hectare) | Foliar cover (%) | |
---|---|---|---|---|---|---|
Grass/Grasslike
|
||||||
1 | Perennial Mid-Size Cool Season Grasses | 9–22 | ||||
green needlegrass | NAVI4 | Nassella viridula | 0–22 | 0–5 | ||
muttongrass | POFE | Poa fendleriana | 4–22 | 1–5 | ||
bluebunch wheatgrass | PSSP6 | Pseudoroegneria spicata | 0–22 | 0–5 | ||
Indian ricegrass | ACHY | Achnatherum hymenoides | 0–22 | 0–5 | ||
squirreltail | ELEL5 | Elymus elymoides | 0–22 | 0–5 | ||
needle and thread | HECO26 | Hesperostipa comata | 0–22 | 0–5 | ||
prairie Junegrass | KOMA | Koeleria macrantha | 0–22 | 0–5 | ||
2 | Rhizomatous Grasses | 39–90 | ||||
thickspike wheatgrass | ELLAL | Elymus lanceolatus ssp. lanceolatus | 45–90 | 10–20 | ||
western wheatgrass | PASM | Pascopyrum smithii | 45–90 | 10–20 | ||
3 | Misc Grasses/Grasslikes | 45–112 | ||||
Sandberg bluegrass | POSE | Poa secunda | 22–67 | 5–15 | ||
threadleaf sedge | CAFI | Carex filifolia | 22–45 | 5–10 | ||
Grass, perennial | 2GP | Grass, perennial | 0–22 | 0–5 | ||
needleleaf sedge | CADU6 | Carex duriuscula | 0–22 | 0–5 | ||
Forb
|
||||||
4 | Perennial Forbs | 18–40 | ||||
hawksbeard | CREPI | Crepis | 4–22 | 1–5 | ||
buckwheat | ERIOG | Eriogonum | 0–22 | 0–5 | ||
scarlet globemallow | SPCO | Sphaeralcea coccinea | 0–22 | 0–5 | ||
stemless mock goldenweed | STAC | Stenotus acaulis | 0–13 | 0–3 | ||
flaxleaf plainsmustard | SCLI | Schoenocrambe linifolia | 0–13 | 0–3 | ||
fleabane | ERIGE2 | Erigeron | 0–13 | 0–3 | ||
spiny phlox | PHHO | Phlox hoodii | 4–13 | 1–3 | ||
longleaf phlox | PHLOL2 | Phlox longifolia ssp. longifolia | 0–13 | 0–3 | ||
hoary tansyaster | MACA2 | Machaeranthera canescens | 0–13 | 0–3 | ||
pussytoes | ANTEN | Antennaria | 4–13 | 1–3 | ||
sandwort | ARENA | Arenaria | 4–13 | 1–3 | ||
milkvetch | ASTRA | Astragalus | 0–13 | 0–3 | ||
western yarrow | ACMIO | Achillea millefolium var. occidentalis | 0–13 | 0–3 | ||
textile onion | ALTE | Allium textile | 0–4 | 0–1 | ||
balsamroot | BALSA | Balsamorhiza | 0–4 | 0–1 | ||
sego lily | CANU3 | Calochortus nuttallii | 0–4 | 0–1 | ||
Indian paintbrush | CASTI2 | Castilleja | 0–4 | 0–1 | ||
pale bastard toadflax | COUMP | Comandra umbellata ssp. pallida | 0–4 | 0–1 | ||
rockcress | ARABI2 | Arabis | 0–4 | 0–1 | ||
larkspur | DELPH | Delphinium | 0–4 | 0–1 | ||
rayless tansyaster | MAGR2 | Machaeranthera grindelioides | 0–4 | 0–1 | ||
bluebells | MERTE | Mertensia | 0–4 | 0–1 | ||
tufted evening primrose | OECA10 | Oenothera caespitosa | 0–4 | 0–1 | ||
beardtongue | PENST | Penstemon | 0–4 | 0–1 | ||
phacelia | PHACE | Phacelia | 0–4 | 0–1 | ||
sagebrush buttercup | RAGL | Ranunculus glaberrimus | 0–4 | 0–1 | ||
yellow fritillary | FRPU2 | Fritillaria pudica | 0–4 | 0–1 | ||
scarlet gilia | IPAG | Ipomopsis aggregata | 0–4 | 0–1 | ||
bitter root | LERE7 | Lewisia rediviva | 0–4 | 0–1 | ||
Lewis flax | LILE3 | Linum lewisii | 0–4 | 0–1 | ||
desertparsley | LOMAT | Lomatium | 0–4 | 0–1 | ||
silvery lupine | LUAR3 | Lupinus argenteus | 0–4 | 0–1 | ||
lupine | LUPIN | Lupinus | 0–4 | 0–1 | ||
wormleaf stonecrop | SEST2 | Sedum stenopetalum | 0–4 | 0–1 | ||
lambstongue ragwort | SEIN2 | Senecio integerrimus | 0–4 | 0–1 | ||
ragwort | SENEC | Senecio | 0–4 | 0–1 | ||
hollyleaf clover | TRGY | Trifolium gymnocarpon | 0–4 | 0–1 | ||
violet | VIOLA | Viola | 0–4 | 0–1 | ||
deathcamas | ZIGAD | Zigadenus | 0–4 | 0–1 | ||
Forb, perennial | 2FP | Forb, perennial | 0–4 | 0–1 | ||
5 | Annual Forbs | 0–4 | ||||
rockjasmine | ANDRO3 | Androsace | 0–4 | 0–1 | ||
bushy bird's beak | CORA5 | Cordylanthus ramosus | 0–4 | 0–1 | ||
Forb, annual | 2FA | Forb, annual | 0–4 | 0–1 | ||
Shrub/Vine
|
||||||
6 | Shrubs | 67–157 | ||||
Wyoming big sagebrush | ARTRW8 | Artemisia tridentata ssp. wyomingensis | 67–157 | 15–25 | ||
7 | Misc Shrubs | 9–22 | ||||
prairie sagewort | ARFR4 | Artemisia frigida | 0–22 | 0–5 | ||
yellow rabbitbrush | CHVI8 | Chrysothamnus viscidiflorus | 4–22 | 1–5 | ||
rubber rabbitbrush | ERNA10 | Ericameria nauseosa | 0–4 | 0–1 | ||
winterfat | KRLA2 | Krascheninnikovia lanata | 0–4 | 0–1 | ||
plains pricklypear | OPPO | Opuntia polyacantha | 0–4 | 0–1 | ||
Shrub (>.5m) | 2SHRUB | Shrub (>.5m) | 0–4 | 0–1 | ||
black sagebrush | ARNO4 | Artemisia nova | 0–4 | 0–1 | ||
mountain big sagebrush | ARTRV | Artemisia tridentata ssp. vaseyana | 0–4 | 0–1 |
Interpretations
Animal community
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, but recovery time for upland sites is much longer than in a low intensity system. If distribution problems occur, stocking rates must be reduced or facilitating conservation practices applied (i.e. cross-fencing, water development) to maintain plant health and vigor.
Plant Community Production Carrying Capacity*
(lb./ac) (AUM/ac) (AC/AUM)
Big Sagebrush/Bunchgrass (Reference) 500-700-900 (.10) (10)
Bunchgrass/Big Sage 500-700-900 (.12) (8)
Bunchgrass 300-500-700 (.14) (7)
Big Sage/Rhizomatous Wheatgrass 200-400-650 (.05) (20)
Big Sage/Bare Ground 100-300-500 (.03) (33.3)
Rabbitbrush/Bare Ground 100-300-500 (.03) (33.3)
Big Sage/Rabbitbrush 100-300-500 (.03) (33.3)
* - Continuous, season-long grazing by cattle under average growing conditions.
**Calculation for stocking rates are as follows: using RV values for production, take forage palatable to grazing cattle multiply by 0.25 harvest efficiency and divide by 912.5 (air dried weight) to arrive at carrying capacity.
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.
Distance to water, shrub density, and slope can affect grazing capacity within a management unit. Adjustments should be made for the area that is considered necessary for reduction of animal numbers. For example, 30% of a management unit may have 25% slopes and distances of greater than 1 mile from water; therefore the adjustment is only calculated for 30% of the unit (i.e. 50% reduction on 30% of the management unit). Fencing, slope length, management, access, terrain, kind and class of livestock, and breeds are all factors that can increase or decrease the percent of graze-able acres within a management unit. Adjustments should be made that incorporate these factors when calculating stocking rates.
Wildlife Community
The Loamy (Ly) ecological site in 34A Cool Central Desertic Basins and Plateaus, LRU F (Beaver Rim) provides suitable and valuable habitat for a variety of wildlife species. In most cases, the greater the density and diversity in grass, forb, and shrub species within the site, the greater the diversity of wildlife the site can support including insects which many wildlife species depend on for their dietary requirements.
Mid-sized cool season bunchgrasses provide forage and cover for big game species, small mammals, birds, and reptiles. Wildlife such as elk, cottontails, jackrabbits, and prairie dogs depend largely on grass for forage. Birds nest among the bunchgrasses and utilize the grass as screening cover from predatory wildlife. Mule deer, pronghorn, greater sage-grouse, and songbirds utilize the taller grasses amongst the shrubs as hiding cover for their young.
Sagebrush, which can approach 15% protein and 4060% digestibility, provides important winter forage
for greater sagegrouse, mule deer, and pronghorn. Yearround habitat is provided for sage-grouse
and other sagebrush obligate species such as cottontails, pygmy rabbit, sagebrush vole, shorthorned lizard, and pronghorn. Seasonal habitat needs are provided for migrants such as sage sparrow,
Brewer’s sparrow, and sage thrasher and other sagebrush obligate songbirds.. Other birds that
frequent this plant community include horned larks and golden eagles.
Forbs are an important component of this habitat type, providing an early food source for sage-grouse chicks both nutritionally and via the insects that forbs attract. Forbs provide necessary moisture to wildlife in arid landscapes. Mule deer and pronghorn are dependent on abundant forbs to aid in the production of milk to nurse fawns and as forage for fawn development and health.
Reference State:
1.1 Big Sagebrush/Bunchgrass: This plant community provides optimal winter habitat for sage-
grouse, mule deer, pronghorn, and other species that depend on shrubs that stand up through the snow
for forage. These areas also provide high quality bird nesting habitat where sagebrush canopy and residual bunchgrasses hide nests and young from predators. Forbs are necessary in the understory
of this plant community to attract insects that are a highly nutritious spring food source for
sage-grouse chicks and other sagebrush obligate bird species.
1.2 Bunchgrass/WY Big Sagebrush: This vegetation community tends to have higher herbaceous plant
diversity that may attract more diverse wildlife use. The state provides suitable forage and cover for sagebrush obligate species. The more open canopy promotes higher diversity and quantity of forbs that are important for early sage-grouse broodrearing habitat. A reduced sagebrush canopy may result in a slightly lower nesting frequency by sagegrouse and songbirds. Winter use by mule deer and pronghorn may be significant and some shrubs may become hedged over time with excessive browsing. Yearlong elk use in these areas can be high due to the abundance of bunchgrass.
1.3 Bunchgrass Community: This plant community provides foraging habitat for sagegrouse when in
proximity to areas with denser sagebrush cover. Due to the higher production of perennial cool-
season grasses, this vegetation type provides high forage value for wintering elk. Mule deer and
pronghorn may transition through these habitats during their annual migrations between summer and
winter ranges. It also provides suitable habitat for burrowing animals.
Grazing Resistant State:
2.1 Big Sagebrush/Rhizomatous WheatgrassSandberg BluegrassMat Forb: This plant
community is variable in its value to wildlife. The value of the sagebrush community is similar to the reference state but the value of the grass community decreases. In periods of high plant vigor, the grass plants can provide cover for nesting birds and small mammals. In periods of drought and low plant vigor and diversity, especially low forb availability, grass plants are too short and not dense enough to provide adequate cover and the wildlife value of these areas declines. Mat-forming forbs often occupy the space and nutrients needed for more desirable forbs such as globemallow, bitterroot, and yarrow.
Eroded State:
3.1 Big Sagebrush/Bare Ground: This plant community provides suitable winter habitat for
foraging big game and sagegrouse when sagebrush is in a healthy state and stands above winter snows. The lack of herbaceous species limits the value of the site for birds and small mammals due to the lack of cover in the interspaces of the sagebrush plants. The lack of plant diversity limits the diversity of insects used by wildlife species.
Disturbed State:
4.1 Rabbitbrush/Bare Ground/Annuals: This plant community is capable of producing a high number of insects which are important for pollination and bird forage. In some areas, rabbitbrush is used heavily by wintering mule deer, especially when other preferred winter forages are unavailable or in poor vigor due to over-use or drought. Annual plants have little nutritive value and are typically too short to provide hiding cover for wildlife. Big game animals may garner some early spring or fall benefit from newly sprouted annual forage, but the timing is short where wildlife can benefit, especially from cheatgrass sprouts. Chukars are a species that utilizes cheatgrass seed as a food source, and they may benefit from areas of cheatgrass invasion. This state is vulnerable to repeated wildfire which can result in a complete loss of value for wildlife. Bare ground provides essentially no habitat value for wildlife. In addition, bare ground may be more susceptible to invasion of non-native species, further degrading the value for wildlife.
4.2 Big Sagebrush/Rabbitbrush: The value of the big sagebrush in this state is similar as described in the previous states. Depending on the subspecies of rabbitbrush found in this plant community it can provide forage value in transitional and winter ranges for big game species. Sage-grouse and
other birds may forage within this plant community where insect quantity and diversity is high. The
lack of an herbaceous community limits the value as bird and small mammal hiding cover and forage for grazing animals.
Highly Disturbed State:
5.1 Annuals/Bare Ground: As described in the Rabbitbrush/Bare Ground/Annuals state above, annuals and bare ground hold little value for wildlife due to the lack of suitable forage and cover. This state is vulnerable to an increase in weedy species that can migrate into adjacent areas, degrading the adjacent areas’ value for wildlife.
5.2 Reclaimed: How the site was reclaimed, the species planted, and the time it takes for plants to establish will determine the value of the site for wildlife. A fully reclaimed site containing a diversity of herbaceous and woody plants should provide the same wildlife habitat benefits as the reference state. In most cases, grasses and forbs establish early in the reclamation process, whereas shrubs take significantly longer to establish. Wildlife species dependent on a herbaceous plant community for forage and cover (elk, prairie dogs, chukars, and swift fox) will benefit from reclamation sooner than those species dependent on a shrub/grass community. Suitable habitat for wildlife species which require tall, dense sagebrush (greater sage-grouse, pronghorn, mule deer, and sagebrush obligate songbirds) will likely not benefit from reclamation for a decade or longer, providing shrub species were planted and/or seed from shrubs adjacent to the area have established on-site.
Hydrological functions
Water is the principal factor limiting forage production on this site. This site is dominated by soils in hydrologic group B (infiltration rate of 0.15-0.3 in/hr), with localized areas in hydrologic groups A (infiltration rate of 0.3 in/hr) and C (infiltration rate of 0.05-0.15 in/hr). 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. Cryptogrammic crusts are present, but only cover 1-2% of the soil surface.
Recreational uses
This site provides some limited recreational opportunities for hiking, horseback riding, bird watching, and upland game hunting. The forbs have a variety of colors and shapes that appeal to photographers. This site provides valuable open space when located in large, unfragmented landscapes.
Wood products
None
Other products
None
Supporting information
Type locality
Location 1: Fremont County, WY | |
---|---|
UTM zone | N |
UTM northing | 4722976 |
UTM easting | 728677 |
Other references
Bestelmeyer, B., & Brown, J. (2005). State-and-transition models 101: a fresh look at vegetation change. The Quivira Coalition Newsletter, Vol. 7, No. 3.
Bestelmeyer, B., Brown, J., Havstad, K., Alexander, B., Chavez, G., & Herrick, J. (2003). Development and use of state and transition models for rangeland. Journal of Range Management, 56(2): 114-126.
Bestelmeyer, B., Herrick, J., Brown, J., Trujillo, D., & Havstad, K. (2004). Land management in the American Southwest: a state-and-transition approach to ecosystem complexity. Environmental Management, 34(1): 38-51.
Bromley, C., NHT Reference
Cagney, J., Bainter, E., Budd, B., Christiansen, T., Herren, V., Holloran, M., et al. (2010). Grazing Influence, Objective Development, and Management in Wyoming's Greater Sage-Grouse Habitat. Unpublished, 36.
Derner, J. D., Schuman, G. E., Follett, R. F., & Vance, G. F. (2014). Plant and Soil Consequences of Shrub Management in a Big Sagebrush-Dominated Rangeland Ecosystem. Environment and Natural Resources Research, 19-30.
GMCA Hearing Transcript.
Natural Resouces Conservation Service. (n.d.). USDA Plants Database. Retrieved from http://plants.usda.gov/java/
Stiver, S., Rinkes, E., & Naugle, D. (2010). Sage-Grouse Habitat Assessment Framework. Unpublished, 100-106.
Stringham, T., Kreuger, W., & Shaver, P. (2003). State and transition modeling: an ecological process approach. Journal of Range Management, 56(2): 106-113.
Winward, A. (2007). Boulder, Squaretop Area Field Notes. Unpublished.
USDI [United States Department of the Interior] (2014) WY-050-11-01 Consolidated Appeal Decision on Final Grazing Decision involving the Arapahoe Creek, Antelope Hills and Alkali Creek Sheep Allotments. Office of the Regional Solicitor, Denver, CO, USA, pp. 1512-1516 and pp. 2035-2038.
Contributors
Bryan Christensen
Approval
Kirt Walstad, 9/28/2023
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) |
Wyoming NRCS Wyoming BLM Wyoming State Lands Wyoming Game and Fish Department Jim Haverkamp, WY NRCS Dan Mattke, WY NRCS Dan Perkins, NRCS Curtis Bryan, WY BLM Sue Oberlie, WY BLM John Likins, WY BLM Retired Stacie Thompson, WY State Lands Amy Andersen, WY G&F |
---|---|
Contact for lead author |
Bryan Christensen MLRA 34A SSO 1625 W Pine Street Pinedale, WY 82941 307-367-2257 bryan.christensen@wy.usda.gov |
Date | 09/30/2015 |
Approved by | Kirt Walstad |
Approval date | |
Composition (Indicators 10 and 12) based on | Annual Production |
Indicators
-
Number and extent of rills:
Not common, but can be present, particularly at the upper end of the slope range for this site. When present, rills are short and widely spaced relative to slope distance. -
Presence of water flow patterns:
Water patterns can be present, but are very small and not connected beyond 2 gaps in the plant canopy. -
Number and height of erosional pedestals or terracettes:
Existing pedastals are blunt and not active, less than 2 inches (5cm) and typically found at the drip line of the shrub canopy. Terracettes are not present. -
Bare ground from Ecological Site Description or other studies (rock, litter, lichen, moss, plant canopy are not bare ground):
Bare ground is typically <30%, but can be dependent on plant community phase within the reference state. Higher bare ground is expected directly following a sagebrush killing disturbance, but returns to <30% within 2 years post-disturbance. Canopy gaps comprise <20% of the ground surface, and are primarily in the 1-2 foot category (>70%). No canopy gaps >6 feet should be present. -
Number of gullies and erosion associated with gullies:
Active gullies should not be present on this site, but sometimes there is erosion or deposition associated with adjacent steeper sites -
Extent of wind scoured, blowouts and/or depositional areas:
Minimal wind scour or deposition may be present with wind scour found in canopy gaps and deposition found on the leeward side of shrubs. It is only occasional and does not occur as repeating pattern across the landscape, but is localized to exposed topography. -
Amount of litter movement (describe size and distance expected to travel):
Herbaceous litter expected to move only in small amounts (to leeward side of shrubs) due to wind. Large woody debris from sagebrush will show no movement except for minimal debris damming after large rain or snowmelt events on slopes >6%. -
Soil surface (top few mm) resistance to erosion (stability values are averages - most sites will show a range of values):
Soil Stability Index ratings are highly variable. Values of 6 are typical when sample includes soil biological crusts, but are often 1 when a sandy loam cap exists on the site. When consistent values of 6 are encountered, it is important to consider if the soil surface has degraded to the argillic subsurface layer (higher clay content will result in higher soil stability). Overall, the biotic component (plants and soil biological crusts) provide stability for this site. -
Soil surface structure and SOM content (include type of structure and A-horizon color and thickness):
Soil organic matter (SOM) <2% is common. Typically soil surface consists of an A-horizon of 3-12 inches (7-30 cm) thick with weak to medium sub-angular blocky or sometimes granular or platy structure that is brown to grayish brown (i.e. 10YR 5/3 or 5/2) in color. Field indicators of departure from the reference condition include exposure of subsoil as evidenced by excessive pedastalling and/or surface disturbance. -
Effect of community phase composition (relative proportion of different functional groups) and spatial distribution on infiltration and runoff:
The reference state consists of 20-60% grasses, 5-15% forbs, and 5-50% shrubs composition by dry weight. The sagebrush canopy is evenly distributed with cover ranging from 5-25%. When sage canopy is at the high end, herbaceous understory diminishes in the plant interspaces, but desirable bunchgrasses can still be found in the interspaces of sage canopy as well as litter to reduce runoff potential. Infiltration is moderate to moderately rapid infiltration rates resulting in minimal runoff. Basal cover is typically less than 5% for this site and does very little to effect 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. A coarse, dry subsurface will often refuse a probe, causing misidentification of a compaction layer. Most soil profiles must be described by hand dug holes. -
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 bunchgrassesSub-dominant:
cool season rhizomatous grasses=perennial shrubs>perennial forbs>short, cool season bunchgrassesOther:
Additional:
-
Amount of plant mortality and decadence (include which functional groups are expected to show mortality or decadence):
Minimal decadence can be observed and is typically associated with shrub component. It is common to find dead matter accumulated in bunchgrasses such as bluebuch wheatgrass, but live plant matter quantity should exceed standing dead except for in times of severe drought. Sagebrush canopy will often have occasional dead branches, but it should not exceed 10% or be found on most plants. -
Average percent litter cover (%) and depth ( in):
Litter ranges from 5-35% of total canopy measurement with total litter (including beneath the plant canopy) 30-60% expected. Herbaceous litter depth is typically very shallow, approximately 1-2mm. Woody litter can be up to a couple inches in diameter (4-6cm), but is sporadically distributed. -
Expected annual annual-production (this is TOTAL above-ground annual-production, not just forage annual-production):
English: 300-700 lb/ac (500 lb/ac average); Metric: 137-318 kg/ha (227 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 50% is the most common indicator of a threshold being crossed. When dominant, rabbitbrush, which is typically found in small quantities on this site, indicates a change in disturbance regime and a threshold being crossed. Greasewood can invades this site when adjacent to a drainage bottom. Annual weeds such as cheatgrass, kochia, lambsquarter, flixweed, and Russian thistle are common invasive species in disturbed sites. -
Perennial plant reproductive capability:
All species are capable of reproducing, except in drought years. Western/Thickspike wheatgrass will commonly reproduce by underground rhizomes and not by seed production.
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The 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.
Click on box and path labels to scroll to the respective text.