Natural Resources
Conservation Service
Ecological site DX032X01W178
Wetland (WL) Big Horn Basin Wet
Last updated: 10/04/2019
Accessed: 11/21/2024
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): 032X–Northern Intermountain Desertic Basins
Major land resource area (MLRA):
032X – Northern Intermountain Desertic Basins – This MLRA is comprised of two major Basins, the Big Horn and Wind River. These two basins are distinctly different and are split by LRU’s to allow individual ESD descriptions. These warm basins are surrounded by uplifts and rimmed by mountains, creating a unique set of plant responses and communities. Unique characteristics of the geology and geomorphology single these two basins out.
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):
32X01W (WY): This LRU is the Big Horn Basin within MLRA 32. This LRU is lower in elevation, slightly warmer and receives slightly less overall precipitaiton than the Wind River Basin (LRU 02). This LRU was originally divided into two LRU's - LRU A which was the core and LRU B which was the rim. With the most current standards, this LRU is divided into two Subsets. This group is ambigous of the two official subsets and will be referred to as Subset W, capturing those sites that are a factor of water or other processes outside of the general subset divisions (climate). As the LRU shifts outer edges, aspect and relation to the major bodies of water and taller landforms create minor shifts in soil chemistry influencing the variety of ecological sites and plant interactions. 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: Aquic, typic aridic, or ustic aridic.
Temperature Regime: Mesic
Dominant Cover: Rangeland, with Saltbush flats the dominant vegetative cover for this MLRA.
Representative Value (RV) Effective Precipitation: 5-14 inches (127 – 355 mm)
RV Frost-Free Days: 105-150 days
Classification relationships
Relationship to Other Established Classification Systems:
National Vegetation Classification System (NVC):
3 Xeromorphic Woodland, Scrub & Herb Vegetation Class
3.B Cool Semi-Desert Scrub & Grassland Subclass
3.B.1 Cool Semi-Desert Scrub & Grassland formation
3.B.1.NE Western North American Cool Semi-Desert Scrub & Grassland Division
M169 Great Basin & Intermountain Tall Sagebrush Shrubland & Steppe Macrogroup
Ecoregions (EPA):
Level I: 10 North American Deserts
Level II: 10.1 Cold Deserts
Level III: 10.1.18 Wyoming Basin
Level IV: 10.1.18.g Big Horn Salt Desert Shrub Basin
Ecological site concept
• Site is controlled by a water table that is above the soil surface for part but not all of the growing season.
• Slope is <6%.
• Soils are:
o Textures range from Silt Loam to clay in top 4” (10 cm) of mineral soil surface
o Clay content is <40% within the top 4” (10 cm) of mineral soil surface
o All subsurface horizons in the particle size control section have a weighted average of <60% 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) that are poorly to very poorly drained.
o Surface layer of soil contains a high organic matter content.
o None to Slightly effervescent throughout top 20” (50 cm) of mineral soil surface
o Non-saline, sodic, or saline-sodic
Associated sites
| R032XY128WY |
Lowland (LL) 5-9” Big Horn Basin Precipitation Zone Lowland sites exist with inclusions of wetlands or may be a step above the wetlands, but they co-exist within the drainage networks of the eroded basin floor. |
|---|---|
| R032XY138WY |
Saline Lowland (SL) 5-9” Big Horn Basin Precipitation Zone Saline Lowland sites exist with inclusions of wetlands or may be a step above the wetlands, but they co-exist within the drainage networks of the eroded basin floor, specifically where there is influence from the marine sedimentary parent material. |
| R032XY142WY |
Saline Subirrigated (SS) 5-9” Big Horn Basin Precipitation Zone Saline subirrigated sites generally surround or are part of the complex dynamic of fluvial systems and are directly associated together as a gradual transition from the wetland to lowland sites. |
Similar sites
| R032XY378WY |
Wetland (WL) 10-14" East Precipitation Zone Wetland 10-14” Foothills and Basins East P.Z., 032XY378WY has higher production. |
|---|
Table 1. Dominant plant species
| Tree |
Not specified |
|---|---|
| Shrub |
Not specified |
| Herbaceous |
(1) Carex nebrascensis |
Legacy ID
R032XA178WY
Physiographic features
This site normally occurs on level to nearly level bottomlands near springs, seeps and sloughs.
Table 2. Representative physiographic features
| Landforms |
(1)
Intermontane basin
> Drainageway
(2) Intermontane basin > Oxbow (3) Intermontane basin > Stream terrace |
|---|---|
| Flooding duration | Very brief (4 to 48 hours) to long (7 to 30 days) |
| Flooding frequency | Occasional to frequent |
| Ponding duration | Brief (2 to 7 days) to very brief (4 to 48 hours) |
| Ponding frequency | Frequent |
| Elevation | 3,700 – 6,000 ft |
| Slope | 6% |
| Ponding depth | 12 in |
| Water table depth | 18 in |
| Aspect | Aspect is not a significant factor |
Climatic features
Annual precipitation and modeled relative effective annual precipitation ranges from 5 to 14 inches (127 – 355 mm). The normal precipitation pattern shows peaks in May and June and a secondary peak in September. The noted peaks account for approximately 50% of the mean annual precipitation. Much of the moisture that falls in the latter part of the summer is lost by evaporation and much of the moisture that falls during the winter is lost by sublimation.
Average snowfall is about 20 inches annually. 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, 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. Extreme storms may occur during the winter, but most severely affect ranch operations during late winter and spring. High winds are generally blocked from the basin by high mountains but can occur in conjunction with an occasional thunderstorm.
Growth of native cool-season plants begins approximately on April 1st and continues through to July 1st. Cool weather and moisture in September may produce some green up of cool season plants that will continue to late October. For detailed information visit the Natural Resources Conservation Service National Water and Climate Center at http://www.wcc.nrcs.usda.gov/. “Basin”, "Clark 3NE", "Cody", "Cody 12SE", "Emblem", "Greybull", "Heart Mtn", “Lovell”, "Powelll Fld Stn", "Worland FAA AP", and “Worland” are the representative weather stations for LRU A. 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) | 92-115 days |
|---|---|
| Freeze-free period (characteristic range) | 116-138 days |
| Precipitation total (characteristic range) | 7-9 in |
| Frost-free period (actual range) | 90-118 days |
| Freeze-free period (actual range) | 112-147 days |
| Precipitation total (actual range) | 7-10 in |
| Frost-free period (average) | 105 days |
| Freeze-free period (average) | 129 days |
| Precipitation total (average) | 8 in |
Figure 2. Monthly precipitation range
Figure 3. Monthly minimum temperature range
Figure 4. Monthly maximum temperature range
Figure 5. Monthly average minimum and maximum temperature
Figure 6. Annual precipitation pattern
Figure 7. Annual average temperature pattern
Climate stations used
-
(1) BASIN [USC00480540], Basin, WY
-
(2) EMBLEM [USC00483031], Burlington, WY
-
(3) GREYBULL [USC00484080], Greybull, WY
-
(4) LOVELL [USC00485770], Lovell, WY
-
(5) WORLAND [USW00024062], Worland, WY
-
(6) WORLAND [USC00489770], Worland, WY
-
(7) POWELL FLD STN [USC00487388], Powell, WY
-
(8) HEART MTN [USC00484411], Powell, WY
-
(9) CLARK 3NE [USC00481775], Powell, WY
-
(10) CODY [USC00481840], Cody, WY
-
(11) CODY 12SE [USC00481850], Meeteetse, WY
Influencing water features
The characteristics of these soils have influence from ground water (water table above 12 inches (30 cm)) and water will be above the soil surface for part but not all of the growing season. These soils are moderately deep to deep and poorly to very poorly drained.
Wetland description
System: Palustrine
Subsystem: None
Class: Emergent Wetland
Sub-class: Persistent
Stream type: C (Rosgen)
Soil features
This site consists of deep to very deep poorly drained soils formed in alluvium with a water table above the surface for part but not all of the growing season. They are on nearly level to slightly depressed areas with poor surface drainage. In some places the surface layers have high organic matter content. The soil characteristics having the most influence on the plant community are depth to a water table at or near the surface for all of the growing season.
Major Soil Series correlated to this site include: Fluvaquents
Table 4. Representative soil features
| Parent material |
(1)
Alluvium
–
sandstone and shale
|
|---|---|
| Surface texture |
(1) Mucky clay (2) Clay loam (3) Loam (4) Silt loam (5) Silty clay loam |
| Family particle size |
(1) Loamy |
| Drainage class | Poorly drained |
| Permeability class | Slow to moderate |
| Soil depth | 20 – 60 in |
| Available water capacity (0-40in) |
2.2 – 6.6 in |
| Calcium carbonate equivalent (0-40in) |
5 – 15% |
| Electrical conductivity (0-40in) |
4 – 16 mmhos/cm |
| Sodium adsorption ratio (0-40in) |
15 |
| Soil reaction (1:1 water) (0-40in) |
6.6 – 8.4 |
Ecological dynamics
Potential vegetation on this site is dominated by plants that can tolerate soils which have a water table near the surface for most of the growing season and are slightly saline. The expected potential composition for this site is about 80% grasses, 10% forbs and 10% woody plants. The composition and production will vary naturally due to historical use, fluctuating precipitation and fire frequency.
As this site deteriorates, species such as willows, rushes, and bulrush increase. Grasses such as Nebraska sedge and tufted hairgrass will decrease in frequency and production.
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
More interactive model formats are also available.
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Click on state and transition labels to scroll to the respective text
Ecosystem states
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 6 submodel, plant communities
State 7 submodel, plant communities
State 1
Nebraska Sedge, Tufted Hairgrass Plant Community
Community 1.1
Nebraska Sedge, Tufted Hairgrass Plant Community
The interpretive plant community for this site is the Historic Climax Plant Community. This state evolved with grazing by large herbivores and a perched water table. Potential vegetation is about 80% grasses or grass-like plants, 10% forbs, and 10% woody plants. The major grasses/grass-likes include Nebraska sedge, water sedge, beaked sedge, and tufted hairgrass. Grasses/grasslikes of lesser importance are Baltic rush, reed canarygrass and alkali cordgrass. A variety of forbs also occurs in this state and plant diversity is high (see Plant Composition Table). The total annual production (air-dry weight) of this state is about 4500 pounds per acre, but it can range from about 3000 lbs. /acre in unfavorable years to about 6000 lbs. /acre in above average years. The state is well adapted to the Northern Intermountain Desertic Basins climatic conditions. It is a critical state providing water and habitat for the surrounding area. The diversity in plant species provides a variety of habitats for wildlife. It is resistant to drought due to a dependable water supply. 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: • Moderate, continuous season-long grazing will convert this plant community to the Mid-sedge/Willow Plant Community.
Figure 8. Annual production by plant type (representative values) or group (midpoint values)
Figure 9. Plant community growth curve (percent production by month). WY0503, 5-9BH Free water sites - WL, Sb, SS.
| 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 | 30 | 30 | 20 | 5 | 5 | 5 |
State 2
Mid-Sedge/Willow Plant Community
Community 2.1
Mid-Sedge/Willow Plant Community
Historically, this plant community evolved under moderate grazing by large ungulates and low fire frequency. Currently, this site is normally found under a moderate, season-long grazing regime and in the absence of fire or brush control. Prolonged drought can also play an important role and will exacerbate these conditions. Flood tolerant perennial plants make up the dominant species in this plant community. Dominant grasses include water and beaked sedges, reed canarygrass, alkali cordgrass, bulrush and rushes. Willows comprise the majority of the shrubs, but wild rose can also be found near the dryer edges of this state. Forbs commonly found in this plant community include blue-eyed grass, smooth horsetail, seaside arrowgrass, and common plaintain. Some annuals as well as cattails may have invaded the site, but are in isolated pockets. When compared to the Historical Climax Plant Community, Nebraska sedge and tufted hairgrass have decreased. Lower growing sedges, bulrush, and rush have increased. Total production shows only minimal reduction as willows offset the reduction in some perennial species. The total annual production (air-dry weight) of this state is about 4250 pounds per acre, but it can range from about 2750 lbs. /acre in unfavorable years to about 5500 lbs. /acre in above average years. The state is reasonable stable but certain weedy species can quickly invade with minimal disturbance. This site is protected from excessive erosion and the biotic integrity of this plant community is intact. The watershed is functioning. Transitional pathways leading to other plant communities are as follows: • Prescribed grazing over the long-term will result in a plant community very similar to the Historic Climax Plant Community. • Frequent and Severe grazing plus no encroachment of cattails, saltcedar or Russian olive will convert this plant community to the Low-Sedge/Baltic Rush Plant Community. • Encroachment plus no fire on more saline soils will convert this plant community to the Sedge/Saltcedar and/or Russian Olive Plant Community. Frequent and severe or moderate season long grazing may increase the likelihood of this occurring but is not necessary for this to occur. • Seasonal ponding plus encroachment on less saline soils will convert this plant community to the Sedge/Cattail Plant Community. Frequent and severe grazing or moderate season long grazing may increase the likelihood of this occurring. Drought will exacerbate this occurrence.
Figure 10. Plant community growth curve (percent production by month). WY0503, 5-9BH Free water sites - WL, Sb, SS.
| 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 | 30 | 30 | 20 | 5 | 5 | 5 |
State 3
Low-Sedge/Baltic Rush Plant Community
Community 3.1
Low-Sedge/Baltic Rush Plant Community
This plant community is the result of long-term improper grazing use. Baltic rush and low growing sedges plus a host of forbs dominate this state. These forbs include both native and introduced. Shrubs are not a significant component of this state. The main grasses or grass-like plants are Baltic rush, low growing sedges, alkali cordgrass, bulrush, and rushes. Forbs are pervasive and include both native and introduced species. The kind of forbs species present depends on the available seed source and the soluble salt content of the soil. Native forb species can include American licorice, wild iris, seaside arrowgrass, smooth horsetail, and silverweed cinquefoil. Introduced forb species include curly dock, swainsonpea, and smartweed. Cattails may be encroaching on the site but have not yet become established. This is especially true on less saline soils. If a seed source is available recruits of saltcedar and Russian olive may begin establishing on the more saline sites. Plant diversity is moderate to poor. When compared to the Historic Climax Plant Community, the mid-sedges and tall and medium grasses are significantly reduced or absent. Forbs and weedy annuals have significantly increased. Production has decreased and bare ground has increased. The total annual production (air-dry weight) of this state is about 2000 pounds per acre, but it can range from about 1200 lbs. /acre in unfavorable years to about 2500 lbs. /acre in above average years. This plant community is susceptible to change and species composition can be altered through long-term overgrazing and encroachment by weedy species. The herbaceous component is unstable and plant vigor and replacement capabilities may or may not be sufficient. The biotic community may or may not be intact as some of the mid sedges may be absent. Plant diversity is moderate to low. Soils are mostly stabilized and soil loss is minimal. Incidence of pedestalling is evident. The watershed may or may not be functional. Transitional pathways leading to other plant communities are as follows: • Prescribed Grazing over the long-term and possibly seeding will return this state to near Historic Climax Plant Community. If a seed source for saltcedar, Russian olive, or cattails are available or plants exist on adjacent lands or in small patches on site this will require vigilant treatment to reduce the likelihood of colonization of the site. • Encroachment plus seasonal ponding on less saline soils will convert this plant community to the Cattail/Low-Sedge Plant Community. Frequent and severe or moderate long-term grazing may increase the likelihood of this occurring. • Encroachment plus frequent and severe grazing plus no fire on more saline soils will convert this plant community to the Dense Saltcedar and/or Russian Olive Stand Plant Community.
Figure 11. Plant community growth curve (percent production by month). WY0503, 5-9BH Free water sites - WL, Sb, SS.
| 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 | 30 | 30 | 20 | 5 | 5 | 5 |
State 4
Cattail/Low-Sedge Plant Community
Community 4.1
Cattail/Low-Sedge Plant Community
This plant community occurs where cattails encroach into a Low-Sedge Baltic Rush Plant Community and become established. This encroachment occurs on less saline soils and is exacerbated by seasonal ponding or fluctuating water levels. Encroachment occurs with or without grazing and is the result of conditions conducive to the colonization by this plant. Increase in bare ground is likely to increase the potential for colonization. However, areas that have been deferred or removed from grazing and had a relatively healthy stand of sedges can be infested. Flood tolerant plants make up the dominant understory species in this plant community. Dominant grasses and grass-like plants include cattails, mid and/or low sedges, alkali cordgrass, bulrush, reedgrasses, and Baltic rush. Forbs commonly found in this plant community include alkali seepweed, silverweed, American licorice, seaside arrowgrass, and smooth horsetail. Willows comprise the majority of the woody species and make up less than 35% of the annual production. When compared to the Historical Climax Plant Community, the mid-sedges have been reduced. Cattails, low growing sedges, and forbs have increased. Willows have probably increased. Total production is lower as the mid sedges have decreased but the increase in cattails compensates for some of the loss. The total annual production (air-dry weight) of this state is about 3250 pounds per acre, but it can range from about 2750 lbs. /acre in unfavorable years to about 4000 lbs. /acre in above average years. This plant community is mostly resistant to change, but species composition will be altered through semi-ponding and flooding but can be exacerbated by drought and improper grazing. The herbaceous component may or may not be stable and plant vigor and replacement capabilities may or may not be sufficient. The biotic community is not intact due to the encroachment of these invasive species. Plant diversity is moderate. The state is stable and protected from excessive erosion as cattails are good soil stabilizers. Only minimal occurrences of water flow patterns and litter movement is evident. Incidence of pedestalling is minimal. Soils are mostly stable and the surface shows minimum soil loss. The watershed may or may not be functional. Transitional pathways leading to other plant communities are as follows: • Semi-permanent ponding plus chemical control of cattails and possibly seeding plus prescribed grazing will convert the plant community to a Sedge/Cattail Plant Community. Control of cattails is the key to this occurring and may require continued treatments to reduce the stand to allow other wetland plants to establish. • Recovery to near Historic Climax Plant Community condition is impractical and continued suppression or containment of cattails is optimal. Any methods of control should be followed by revegetation to reduce regeneration of these two species and other weeds.
Figure 12. Plant community growth curve (percent production by month). WY0503, 5-9BH Free water sites - WL, Sb, SS.
| 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 | 30 | 30 | 20 | 5 | 5 | 5 |
State 5
Sedge/Cattail Plant Community
Community 5.1
Sedge/Cattail Plant Community
This plant community occurs where control of cattails has been successful and the cattails are confined to localized patches. Mid-sedges and other perennial grasses have been allowed to reestablish. Flood tolerant plants make up the dominant understory species in this plant community. Dominant grasses and grass-like plants include mid and low sedges, tufted hairgrass, reedgrasses, alkali cordgrass, and Baltic rush. Forbs commonly found in this plant community include blue-eyed grass, alkali seepweed, silverweed, American licorice, seaside arrowgrass, and smooth horsetail. Willows comprise the majority of the woody species and make up less than 35% of the annual production. When compared to the Historical Climax Plant Community, the production of mid-sedges and perennial grasses are only slightly less. Cattails, low growing sedges, and forbs have increased. Willows may or may not have increased. Total production is only slightly lower. The total annual production (air-dry weight) of this state is about 4000 pounds per acre, but it can range from about 3000 lbs. /acre in unfavorable years to about 5000 lbs. /acre in above average years. This plant community is mostly resistant to change, but species composition can be altered through a change in water levels and improper grazing. The herbaceous component is stable, but does not comprise the composition of HCPC. Plant vigor and replacement capabilities are sufficient. The biotic community is not intact because of the cattail infestation. Plant diversity is moderate. Soils are mostly stable and recent soil loss is minimal. Water flow patterns and litter movement is stable. Incidence of pedestalling is improving. The watershed may or may not be functioning Transitional pathways leading to other plant communities are as follows: • Moderate continued season long grazing plus encroachment will convert this plant community to the Cattail/Low-Sedge Plant Community. Drought will exacerbate this conversion. • Recovery to near Historic Climax Plant Community condition is impractical and continued suppression or containment of cattails is optimal. Any methods of control should be followed by revegetation to reduce regeneration of these two species and other weeds.
Figure 13. Plant community growth curve (percent production by month). WY0503, 5-9BH Free water sites - WL, Sb, SS.
| 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 | 30 | 30 | 20 | 5 | 5 | 5 |
State 6
Sedge/Saltcedar and/or Russian Olive Plant Community
Community 6.1
Sedge/Saltcedar and/or Russian Olive Plant Community
This plant community occurs where saltcedar and/or Russian olive encroaches into a wetland site and becomes established. This encroachment occurs mostly on mildly to moderately saline soils. Encroachment occurs with or without grazing and is the result of conditions conducive to the colonization of these two plants. Increase in bare ground is likely to increase the potential for colonization. However, areas that have been deferred or removed from grazing and had a healthy stand of sedges can be infested. Flood tolerant and mild to moderate saline perennial plants make up the dominant understory species in this plant community. Dominant grasses and grass-like plants include mid and/or low sedges, alkali cordgrass, Bulrush, reedgrasses, and Baltic rush. Forbs commonly found in this plant community include alkali seepweed, silverweed, American licorice, seaside arrowgrass, and smooth horsetail. Saltcedar and/or Russian olive comprise the majority of the woody species and make up less than 35% of the annual production. Invasion of saltcedar or Russian olive should be considered serious and should be controlled. Weedy herbaceous species are likely present. When compared to the Historical Climax Plant Community, the mid-sedges have been reduced. Low growing sedges and forbs have increased. Saltcedar and Russian olive have invaded. Willows have been replaced. Total production is slightly lower as the mid sedges have decreased but the wood species have increased. The total annual production (air-dry weight) of this state is about 3000 pounds per acre, but it can range from about 2750 lbs. /acre in unfavorable years to about 4000 lbs. /acre in above average years. This plant community is mostly resistant to change, but species composition will be altered through further encroachment by saltcedar and/or Russian olive and long-term overgrazing can exacerbate this occurrence. The herbaceous component is or is not stable and plant vigor and replacement capabilities may or may not be sufficient. The biotic community is not intact due to the encroachment of these invasive species. Plant diversity is moderate. Soils are mostly stabilized. Only minimal occurrences of water flow patterns and litter movement is evident. Incidence of pedestalling is minimal. Soils are mostly stable and the surface shows minimum soil loss. The watershed may or may not be functional. Transitions or pathways leading to other plant communities are as follows: • Further encroachment plus frequent and severe grazing plus no fire will convert the plant community to the Dense Saltcedar and/or Russian Olive Stand Plant Community. • Recovery to near Historic Climax Plant Community condition is impractical and suppression or containment of these two species optimal. Any methods of control should be followed by revegetation to reduce regeneration of these two species and other weeds.
Figure 14. Plant community growth curve (percent production by month). WY0503, 5-9BH Free water sites - WL, Sb, SS.
| 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 | 30 | 30 | 20 | 5 | 5 | 5 |
State 7
Dense Saltcedar and/or Russian Olive Stand Plant Community
Community 7.1
Dense Saltcedar and/or Russian Olive Stand Plant Community
This plant community evolved under frequent and severe grazing with the absence of fire and encroachment of saltcedar and/or Russian olive. Saltcedar and/or Russian olive dominate this plant community. Most of the tall and medium grasses are eliminated and an understory of weedy herbaceous plants is prevalent. The interspaces between the woody plants have expanded, leaving more bare ground and more soil surface exposed to erosive elements or invaders. The weedy plants, such as foxtail barley, curly dock, kochia, halogeton, swainsonpea, and Russian knapweed, make up the dominant understory. Total annual production is mostly from shrubs and these weedy plants. Saltcedar and/or Russian olive make up greater than 35% of the total annual production. When compared with the HCPC, the annual production is slightly less due to the removal of the perennial grass and amount of bare ground. The increase in woody species, however, compensates for some of this loss. The total annual production (air-dry weight) of this state is about 2000 pounds per acre, but it can range from about 1750 lbs. /acre in unfavorable years to about 2500 lbs. /acre in above average years. This plant community is resistant to change as the stand becomes more decadent. These areas may actually be more resistant to fire as less fine fuels are available and the bare ground between the shrubs is increased. Continued frequent and severe grazing or the removal of grazing does not seem to affect the plant composition or structure of the plant community. Saltcedar, Russian olive, annual grasses, weedy species and bare ground compromise the biotic integrity. Plant diversity is poor and the potential for native grasses to reproduce is absent. The shift in the vegetative structure and function is extreme and the biotic integrity is lost. The soil of this state is not protected as erosion has accelerated because of increased bare ground. Water flow patterns and pedestalling are obvious. Infiltration is reduced and runoff is increased. Rill channels may be noticeable in the interspaces and gullies may be establishing where rills have concentrated. The watershed is not functional due to excessive runoff, erosion and bare ground. Transitional pathways leading to other plant communities are as follows: • Semi-permanent ponding or Brush management and prescribed grazing will result in a Sedge/ Saltcedar and/or Russian Olive Plant Community. Controlling both saltcedar and Russian olive is a priority if these species have invaded. • Recovery to near Historic Climax Plant Community condition is impractical and suppression or containment of these two species is optimal. Any methods of control should be followed by revegetation to reduce regeneration of these two species.
Figure 15. Plant community growth curve (percent production by month). WY0503, 5-9BH Free water sites - WL, Sb, SS.
| 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 | 30 | 30 | 20 | 5 | 5 | 5 |
Additional community tables
Table 5. Community 1.1 plant community composition
| Group | Common name | Symbol | Scientific name | Annual production (lb/acre) | Foliar cover (%) | |
|---|---|---|---|---|---|---|
|
Grass/Grasslike
|
||||||
| 1 | 1125–1575 | |||||
| Nebraska sedge | CANE2 | Carex nebrascensis | 1125–1575 | – | ||
| 2 | 450–1125 | |||||
| water sedge | CAAQ | Carex aquatilis | 450–1125 | – | ||
| 3 | 450–1125 | |||||
| beaked sedge | CARO6 | Carex rostrata | 450–1125 | – | ||
| 4 | 225–675 | |||||
| tufted hairgrass | DECE | Deschampsia cespitosa | 225–675 | – | ||
| 5 | 225–675 | |||||
| Grass, perennial | 2GP | Grass, perennial | 0–225 | – | ||
| American sloughgrass | BESY | Beckmannia syzigachne | 0–225 | – | ||
| reedgrass | CALAM | Calamagrostis | 0–225 | – | ||
| northern reedgrass | CASTI3 | Calamagrostis stricta ssp. inexpansa | 0–225 | – | ||
| flatsedge | CYPER | Cyperus | 0–225 | – | ||
| fowl mannagrass | GLST | Glyceria striata | 0–225 | – | ||
| mountain rush | JUARL | Juncus arcticus ssp. littoralis | 0–225 | – | ||
| rush | JUNCU | Juncus | 0–225 | – | ||
| reed canarygrass | PHAR3 | Phalaris arundinacea | 0–225 | – | ||
| bluegrass | POA | Poa | 0–225 | – | ||
| bulrush | SCIRP | Scirpus | 0–225 | – | ||
| alkali cordgrass | SPGR | Spartina gracilis | 0–225 | – | ||
|
Forb
|
||||||
| 6 | 225–450 | |||||
| Forb, perennial | 2FP | Forb, perennial | 0–225 | – | ||
| silverweed cinquefoil | ARAN7 | Argentina anserina | 0–225 | – | ||
| smooth horsetail | EQLA | Equisetum laevigatum | 0–225 | – | ||
| Rocky Mountain iris | IRMI | Iris missouriensis | 0–225 | – | ||
| rough bugleweed | LYAS | Lycopus asper | 0–225 | – | ||
| waterhorehound | LYCOP4 | Lycopus | 0–225 | – | ||
| wild mint | MEAR4 | Mentha arvensis | 0–225 | – | ||
| common plantain | PLMA2 | Plantago major | 0–225 | – | ||
| alkali buttercup | RACY | Ranunculus cymbalaria | 0–225 | – | ||
| sagebrush buttercup | RAGL | Ranunculus glaberrimus | 0–225 | – | ||
| blue-eyed grass | SISYR | Sisyrinchium | 0–225 | – | ||
| marsh hedgenettle | STPA | Stachys palustris | 0–225 | – | ||
| seaside arrowgrass | TRMA20 | Triglochin maritima | 0–225 | – | ||
|
Shrub/Vine
|
||||||
| 7 | 225–675 | |||||
| Shrub (>.5m) | 2SHRUB | Shrub (>.5m) | 0–225 | – | ||
| Woods' rose | ROWO | Rosa woodsii | 0–225 | – | ||
| narrowleaf willow | SAEX | Salix exigua | 0–225 | – | ||
| willow | SALIX | Salix | 0–225 | – | ||
Interpretations
Animal community
Wildlife Interpretations
Nebraska sedge/Tufted Hairgrass Plant Community: The predominance of grasses in this plant community favors grazers and mixed-feeders, such as bison, elk, and antelope. Suitable thermal and escape cover for deer may be limited due to the low quantities of woody plants. This plant community may provide brood rearing/foraging areas for upland game birds. Other birds that would frequent this plant community include red-wing blackbirds, sand hill cranes, Wilson snipe, western meadowlarks, and golden eagles. Many small mammals would occur here.
Mid-Sedge/Willow Plant Community: The abundant production and proximity to water make this state important for livestock and wildlife such as birds, mule deer, and whitetail deer. This plant community is useful for the same large grazers that would use the Historic Climax Plant Community. The increase in willow production makes this even more attractive to some wildlife due to the increase in thermal and escape cover. It can provide foraging and nesting opportunities for upland game birds and songbirds.
Low-Sedge/Baltic Rush Plant Community: The abundant production and proximity to water make this state important for livestock and wildlife such as birds, mule deer and whitetail deer.
This plant community may be useful for the same large grazers 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. It may provide some foraging opportunities for upland game birds and songbirds, when it occurs proximal to woody cover.
Cattail/Low Sedge Plant Community: The abundant production and proximity to water make this state important for livestock and wildlife such as birds, mule deer, and whitetail deer. This plant community is useful for the same large grazers that would use the Historic Climax Plant Community. The increase in cattail production makes this even more attractive to some wildlife due to the increase in thermal and escape cover. It can provide foraging and nesting opportunities for upland game birds and songbirds.
Sedge/Cattail Plant Community: The abundant production and proximity to water make this state important for livestock and wildlife such as birds, mule deer, and whitetail deer. This plant community is useful for the same large grazers that would use the Historic Climax Plant Community. The increase in cattail production makes this even more attractive to some wildlife due to the increase in thermal and escape cover. It can provide foraging and nesting opportunities for upland game birds and songbirds.
Sedge/Saltcedar and/or Russian Olive Plant Community: The abundant production and proximity to water make this state important for livestock and wildlife such as birds, mule deer, and whitetail deer. This plant community is useful for the same large grazers that would use the Historic Climax Plant Community. The increase in tall shrub production makes this even more attractive to some wildlife due to the increase in thermal and escape cover. It can provide foraging and nesting opportunities for upland game birds and songbirds. Some species utilize the Russian olive berries for food and are attracted to these colonized areas.
Dense Saltcedar and/or Russian Olive Stand Plant Community: The proximity to water makes this state important for wildlife such as birds, mule deer, and whitetail deer. This is useful for the same large grazers that would use the Historic Climax Plant Community. The low production of herbaceous understory of this plant community decreases the foraging potential and cover for many wildlife species. The increase in tall shrubs, however, makes this an attractive site for thermal and escape cover for large grazers and upland birds. It can provide foraging and nesting opportunities for songbirds. Some species utilize the Russian olive berries for food and are attracted to these colonized areas.
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)
Historic Climax Plant Community 3000-6000 2.5
Mid-Sedge/Willow 2750-5500 1.8
Low-Sedge/Baltic Rush 1200-2500 0.8
Cattail/Low Sedge 2750-4000 1.0
Sedge/Cattail 3000-5000 1.2
Sedge/Saltcedar and/or Russian Olive 3000-5000 1.2
Dense Saltcedar and/or Russian Olive Stand 1750-2500 0.5
* - 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
Climate is the principal factor limiting forage production on this site. This site is dominated by soils in hydrologic group D. Infiltration rate is slow and runoff potential high for the soils of this site due to a high water table and saturated soil conditions. However, high forage production on this site diminishes runoff potential as long as site is managed for maintaining adequate residual vegetation. (Refer to Part 630, NRCS National Engineering Handbook for detailed hydraulic information).
Rills and gullies should not typically be present. Water flow patterns may be present if associated with a perennial flowing stream. Litter typically falls in place, and signs of movement are not common unless associated with a perennial flowing stream. Chemical and physical crusts are rare to non-existent.
Recreational uses
This site provides hunting opportunities for upland game species. The wide varieties 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.
Other products
None noted.
Supporting information
Inventory data references
Information presented here has been derived from NRCS inventory data. Field observations from range trained personnel were also used. Other sources used as references include: USDA NRCS Water and Climate Center, USDA NRCS National Range and Pasture Handbook, and USDA NRCS Soil Surveys from various counties.
Inventory Data References
Data Source Number of Records Sample Period State County
SCS-RANGE-417 19 1965-1986 WY Park & others
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) | Ray Gullion |
|---|---|
| Contact for lead author | ray.gullion@wy.usda.gov |
| Date | 05/02/2008 |
| Approved by | Marji Patz |
| Approval date | |
| Composition (Indicators 10 and 12) based on | Annual Production |
Indicators
-
Number and extent of rills:
Rills should not be present -
Presence of water flow patterns:
Barely observable -
Number and height of erosional pedestals or terracettes:
Essentially non-existent -
Bare ground from Ecological Site Description or other studies (rock, litter, lichen, moss, plant canopy are not bare ground):
Bare ground is less than 5% -
Number of gullies and erosion associated with gullies:
Active gullies should not be present -
Extent of wind scoured, blowouts and/or depositional areas:
None -
Amount of litter movement (describe size and distance expected to travel):
Little to no plant litter movement. Plant litter remains in place and is not moved by erosional forces. -
Soil surface (top few mm) resistance to erosion (stability values are averages - most sites will show a range of values):
Plant cover and litter is at 95% or greater of soil surface and maintains soil surface integrity. Soil Stability class is anticipated to be 5 or greater. -
Soil surface structure and SOM content (include type of structure and A-horizon color and thickness):
Use Soil Series description for depth and color of A-horizon -
Effect of community phase composition (relative proportion of different functional groups) and spatial distribution on infiltration and runoff:
Grass canopy and basal cover should reduce raindrop impact and slow overland flow providing increased time for infiltration to occur. Healthy deep rooted native grasses enhance infiltration and reduce runoff. Infiltration varies from moderate to low and runoff is high since the soil is usually saturated. -
Presence and thickness of compaction layer (usually none; describe soil profile features which may be mistaken for compaction on this site):
No compaction layer or soil surface crusting should be present. -
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:
Tall Grasses and GrasslikeSub-dominant:
Mid stature Grasses/Grasslike = Shrubs/TreesOther:
ForbsAdditional:
-
Amount of plant mortality and decadence (include which functional groups are expected to show mortality or decadence):
Very Low -
Average percent litter cover (%) and depth ( in):
Average litter cover is 50-55% with depths of 0.75 to 1.5 inches -
Expected annual annual-production (this is TOTAL above-ground annual-production, not just forage annual-production):
4500 lbs/ac -
Potential invasive (including noxious) species (native and non-native). List species which BOTH characterize degraded states and have the potential to become a dominant or co-dominant species on the ecological site if their future establishment and growth is not actively controlled by management interventions. Species that become dominant for only one to several years (e.g., short-term response to drought or wildfire) are not invasive plants. Note that unlike other indicators, we are describing what is NOT expected in the reference state for the ecological site:
Baltic rush, Bulrush, Arrowgrass, Horsetails, Kentucky Bluegrass, Saltcedar, Russian olive, Cattails, Annuals, other Exotics, and other Species found on Noxious Weed List. -
Perennial plant reproductive capability:
All species are capable of reproducing
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