Natural Resources
Conservation Service
Ecological site R043BY178WY
Wetland High Mountains
Accessed: 12/22/2024
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.
Associated sites
| R043BY174WY |
Subirrigated High Mountains Subirrigated |
|---|
Similar sites
| R043BY174WY |
Subirrigated High Mountains Subirrigated (Sb) 20+M has a lower water table and more shrubs. |
|---|---|
| R043BY278WY |
Wetland Foothills and Mountains West Wetland (WL) 15-19W has lower production. |
Table 1. Dominant plant species
| Tree |
Not specified |
|---|---|
| Shrub |
Not specified |
| Herbaceous |
Not specified |
Physiographic features
This site occurs on level or gently-sloping land near springs, seeps or sloughs.
Table 2. Representative physiographic features
| Landforms |
(1)
Drainageway
(2) Oxbow (3) Stream terrace |
|---|---|
| Flooding duration | Very brief (4 to 48 hours) to brief (2 to 7 days) |
| Flooding frequency | Occasional to frequent |
| Ponding duration | Brief (2 to 7 days) to very long (more than 30 days) |
| Ponding frequency | Frequent |
| Elevation | 1,981 – 3,658 m |
| Slope | 0 – 10% |
| Ponding depth | 0 – 30 cm |
| Water table depth | 0 – 46 cm |
Climatic features
Annual precipitation is fairly evenly distributed through the year and averages over 20 inches. Snows are heavy and usually remain in place during the winter. Annual snowfall averages 150 to 200 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.
Prevailing winds are from the southwest, and strong winds are less frequent than over other areas of Wyoming. Occasional storms, however, can bring brief periods of high winds with gusts exceeding 50 mph.
Growth of native cool season plants begins about June 1 at lower elevations, as late as July 15 at higher elevations, and continues until the beginning of September.
The following information is from the “Moran 5 WNW” climate station:
Minimum Maximum 5 yrs. out of 10 between
Frost-free period (days): 31 78 June 30 – August 24
Freeze-free period (days): 65 118 June 5 – September 9
Annual Precipitation (inches): <20.78 >29.35 (2 years in 10)
Mean annual precipitation: 25.23 inches
Mean annual air temperature: 36.5?F (22.1?F Avg. Min. to 50.9?F Avg. Max.)
For detailed information visit the Natural Resources Conservation Service National Water and Climate Center at http://www.wcc.nrcs.usda.gov/cgibin/state.pl?state=wy website. Other climate station representative of this precipitation zone include ”Alta 1 NW”, “Lake Yellowstone”, “Moose”, “Old Faithful”, and “Snake River” in Teton County; “Bedford 3 SE” in Lincoln County; and “Bondurant” in Sublette County.
Table 3. Representative climatic features
| Frost-free period (average) | 78 days |
|---|---|
| Freeze-free period (average) | 118 days |
| Precipitation total (average) | 737 mm |
Figure 2. Monthly average minimum and maximum temperature
Influencing water features
Stream type: C (Rosgen)
Soil features
The soils of this site are deep and poorly drained with a water table above the surface for part, but not all, of the growing season. They are nearly level to slightly depressional areas with poor surface drainage. Surface textures range from moderately coarse to fine, but commonly are medium and moderately fine with dark color and high organic content.
Table 4. Representative soil features
| Surface texture |
(1) Gravelly loam (2) Clay loam (3) Sandy clay loam |
|---|---|
| Family particle size |
(1) Loamy |
| Drainage class | Poorly drained |
| Permeability class | Slow to moderate |
| Soil depth | 51 – 152 cm |
| Surface fragment cover <=3" | 0 – 20% |
| Surface fragment cover >3" | 0 – 5% |
| Available water capacity (0-101.6cm) |
5.72 – 15.24 cm |
| Calcium carbonate equivalent (0-101.6cm) |
0 – 15% |
| Electrical conductivity (0-101.6cm) |
0 – 8 mmhos/cm |
| Sodium adsorption ratio (0-101.6cm) |
0 – 5 |
| Soil reaction (1:1 water) (0-101.6cm) |
6.1 – 8.4 |
| Subsurface fragment volume <=3" (Depth not specified) |
0 – 40% |
| Subsurface fragment volume >3" (Depth not specified) |
0 – 15% |
Ecological dynamics
As this site deteriorates, species such as upland sedges and rushes increase. Grasses and grass-like plants such as Nebraska sedge, northern reedgrass, and tufted hairgrass will decrease in frequency and production. Willows and water birch, when present, will lose density and age diversity with heavy browsing.
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
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Click on state and transition labels to scroll to the respective text
State 1 submodel, plant communities
State 2 submodel, plant communities
State 3 submodel, plant communities
State 1
Sedge Plant Community (HCPC)
Community 1.1
Sedge Plant Community (HCPC)
The interpretive plant community for this site is the Historic Climax Plant Community. This state evolved with grazing by large herbivores and is well suited for grazing by domestic livestock. Potential vegetation is estimated at 70% grasses or grass-like plants, 15% forbs, and 15% woody plants. The major grasses and grass-like plants include Nebraska sedge, tufted hairgrass, and northern reedgrass. Other grasses and grass-like plants that may occur on this site include alpine timothy, tall and American mannagrass, Baltic rush, bearded wheatgrass, big bluegrass, blue wildrye, inland sedge, nodding brome, bluejoint reedgrass, and other wetland sedge species. Willows are the major woody species. Other woody species may include woods rose, bog kalmia (alpine laurel), currant and water birch. A typical plant composition for this state consists of Nebraska sedge 10-25%, tufted hairgrass 15-25%, northern reedgrass 10-25%, other grasses and grass-like plants 10-20%, perennial forbs 5-15%, and up to 15% woody plants. Ground cover, by ocular estimate, varies from 85-100%. The total annual production (air-dry weight) of this state is about 6500 pounds per acre, but it can range from about 5500 lbs./acre in unfavorable years to about 7500 lbs./acre in above average years. The following is the growth curve of this plant community expected during a normal year: Growth curve number: WY0103 Growth curve name: 20+M, FREE WATER SITES Growth curve description: WL, SB, SS FREE WATER SITES JAN FEB MAR APR MAY JUN JUL AUG SEP OCT NOV DEC 0 0 0 0 5 30 40 20 5 0 0 0 (Monthly percentages of total annual growth) The state is well adapted to the Central Rocky Mountains 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: • Nonuse will convert this plant community to the Willow/Sedge State. • Heavy Continuous Season-long Grazing will convert this plant community to the Upland Sedge/Rush State.
Figure 3. Annual production by plant type (representative values) or group (midpoint values)
Figure 4. Plant community growth curve (percent production by month). WY0103, 20+ free water 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 | 30 | 40 | 20 | 5 |
State 2
Willow/Sedge Plant Community
Community 2.1
Willow/Sedge Plant Community
This plant community results from nonuse. Willows increase and often will inhibit herbaceous forage availability by creating a physical barrier to grazing animals. Nebraska sedge, water sedge, beaked sedge, and dogwood are often present in the protected understory. 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 following is the growth curve of this plant community expected during a normal year: Growth curve number: WY0103 Growth curve name: 20+M, FREE WATER SITES Growth curve description: WL, SB, SS FREE WATER SITES JAN FEB MAR APR MAY JUN JUL AUG SEP OCT NOV DEC 0 0 0 0 5 30 40 20 5 0 0 0 (Monthly percentages of total annual growth) The state is very stable and protected from excessive erosion. The biotic integrity of this plant community is intact. The watershed is functioning. Transitional pathways leading to other plant communities are as follows: • Brush Management followed by deferment for 1 to 2 years as part of a Prescribed Grazing plan will result in a plant community very similar to the Historic Climax Plant Community (Sedge State). Care should be taken when planning brush management to consider wildlife habitat and critical winter ranges. • Brush Management followed by Continuous Season-long Grazing will convert this plant community to the Upland Sedge/Rush State.
Figure 5. Plant community growth curve (percent production by month). WY0103, 20+ free water 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 | 30 | 40 | 20 | 5 |
State 3
Upland Sedge/Rush Plant Community
Community 3.1
Upland Sedge/Rush Plant Community
This plant community evolved under heavy continuous season-long grazing by domestic livestock. Species such as Baltic rush, inland sedge, horsetail, elephanthead, and Rocky Mountain iris often dominate this state. Willows are greatly diminished and lack a diversity of age classes or are completely missing from the plant community. The total annual production (air-dry weight) of this state is about 2500 pounds per acre, but it can range from about 1500 lbs./acre in unfavorable years to about 3500 lbs./acre in above average years. The following is the growth curve of this plant community expected during a normal year: Growth curve number: WY0103 Growth curve name: 20+M, FREE WATER SITES Growth curve description: WL, SB, SS FREE WATER SITES JAN FEB MAR APR MAY JUN JUL AUG SEP OCT NOV DEC 0 0 0 0 5 30 40 20 5 0 0 0 (Monthly percentages of total annual growth) The state is vulnerable to downcutting and excessive erosion. The biotic integrity of this plant community is at risk due to the replacement of deep rooted wetland species with shallow rooted grasses and forbs. The watershed is at risk from downcutting activity. Transitional pathways leading to other plant communities are as follows: It is not often practicable or economically feasible to convert this plant community.
Figure 6. Plant community growth curve (percent production by month). WY0103, 20+ free water 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 | 30 | 40 | 20 | 5 |
Additional community tables
Table 5. Community 1.1 plant community composition
| Group | Common name | Symbol | Scientific name | Annual production (kg/hectare) | Foliar cover (%) | |
|---|---|---|---|---|---|---|
|
Grass/Grasslike
|
||||||
| 1 | 729–1821 | |||||
| Nebraska sedge | CANE2 | Carex nebrascensis | 729–1821 | – | ||
| 2 | 729–1821 | |||||
| northern reedgrass | CASTI3 | Calamagrostis stricta ssp. inexpansa | 729–1821 | – | ||
| 3 | 1093–1821 | |||||
| 4 | 729–1457 | |||||
| Grass, perennial | 2GP | Grass, perennial | 0–364 | – | ||
| American sloughgrass | BESY | Beckmannia syzigachne | 0–364 | – | ||
| mountain brome | BRMA4 | Bromus marginatus | 0–364 | – | ||
| Porter brome | BRPO2 | Bromus porteri | 0–364 | – | ||
| water sedge | CAAQA | Carex aquatilis var. aquatilis | 0–364 | – | ||
| bluejoint | CACA4 | Calamagrostis canadensis | 0–364 | – | ||
| inland sedge | CAIN11 | Carex interior | 0–364 | – | ||
| dunhead sedge | CAPH2 | Carex phaeocephala | 0–364 | – | ||
| beaked sedge | CARO6 | Carex rostrata | 0–364 | – | ||
| spikerush | ELEOC | Eleocharis | 0–364 | – | ||
| blue wildrye | ELGL | Elymus glaucus | 0–364 | – | ||
| slender wheatgrass | ELTRS | Elymus trachycaulus ssp. subsecundus | 0–364 | – | ||
| mannagrass | GLYCE | Glyceria | 0–364 | – | ||
| alpine timothy | PHAL2 | Phleum alpinum | 0–364 | – | ||
| reed canarygrass | PHAR3 | Phalaris arundinacea | 0–364 | – | ||
| bulrush | SCIRP | Scirpus | 0–364 | – | ||
| cattail | TYPHA | Typha | 0–364 | – | ||
|
Forb
|
||||||
| 5 | 364–1093 | |||||
| Forb, perennial | 2FP | Forb, perennial | 0–364 | – | ||
| columbine | AQUIL | Aquilegia | 0–364 | – | ||
| white marsh marigold | CALEL7 | Caltha leptosepala ssp. leptosepala | 0–364 | – | ||
| water hemlock | CICUT | Cicuta | 0–364 | – | ||
| shootingstar | DODEC | Dodecatheon | 0–364 | – | ||
| horsetail | EQUIS | Equisetum | 0–364 | – | ||
| gentian | GENTI | Gentiana | 0–364 | – | ||
| common sneezeweed | HEAU | Helenium autumnale | 0–364 | – | ||
| waterleaf | HYDRO4 | Hydrophyllum | 0–364 | – | ||
| rubberweed | HYMEN7 | Hymenoxys | 0–364 | – | ||
| Rocky Mountain iris | IRMI | Iris missouriensis | 0–364 | – | ||
| wild mint | MEAR4 | Mentha arvensis | 0–364 | – | ||
| bluebells | MERTE | Mertensia | 0–364 | – | ||
| monkeyflower | MIMUL | Mimulus | 0–364 | – | ||
| ragwort | PACKE | Packera | 0–364 | – | ||
| elephanthead lousewort | PEGR2 | Pedicularis groenlandica | 0–364 | – | ||
| plantain | PLANT | Plantago | 0–364 | – | ||
| American bistort | POBI6 | Polygonum bistortoides | 0–364 | – | ||
| knotweed | POLYG4 | Polygonum | 0–364 | – | ||
| cinquefoil | POTEN | Potentilla | 0–364 | – | ||
| dock | RUMEX | Rumex | 0–364 | – | ||
| western coneflower | RUOC2 | Rudbeckia occidentalis | 0–364 | – | ||
| ragwort | SENEC | Senecio | 0–364 | – | ||
| blue-eyed grass | SISYR | Sisyrinchium | 0–364 | – | ||
| clover | TRIFO | Trifolium | 0–364 | – | ||
| violet | VIOLA | Viola | 0–364 | – | ||
|
Shrub/Vine
|
||||||
| 6 | 364–1093 | |||||
| Shrub, deciduous | 2SD | Shrub, deciduous | 0–364 | – | ||
| Shrub, evergreen | 2SE | Shrub, evergreen | 0–364 | – | ||
| Tree, deciduous | 2TD | Tree, deciduous | 0–364 | – | ||
| Tree, evergreen | 2TE | Tree, evergreen | 0–364 | – | ||
| water birch | BEOC2 | Betula occidentalis | 0–364 | – | ||
| dogwood | CORNU | Cornus | 0–364 | – | ||
| alpine laurel | KAMI | Kalmia microphylla | 0–364 | – | ||
| currant | RIBES | Ribes | 0–364 | – | ||
| Woods' rose | ROWOW | Rosa woodsii var. woodsii | 0–364 | – | ||
| willow | SALIX | Salix | 0–364 | – | ||
Interpretations
Animal community
Animal Community – Wildlife Interpretations
Sedge Plant Community (HCPC): This plant community is very important for most wildlife in the area. Over 80% of all wildlife use this site to fulfill some part of their habitat needs. It provides forage and thermal and hiding cover for mule deer, elk, and moose. It provides nesting habitat for shorebirds, songbirds, and waterfowl as well as ground nesting birds such as harriers. Dense ground cover provides escape cover, forage, and breeding areas for small mammals which draw predators such as raptors, red fox and coyote. Other birds that would frequent this plant community include red-wing blackbirds, sandhill cranes, western meadowlarks, neo-tropical migrants, and golden eagles.
Willow/Sedge Plant Community: This plant community is beneficial for the same wildlife that would use the Historic Climax Plant Community. However, dominance of woody species may improve thermal and hiding cover for all species, especially structural diversity needed for neo-tropical migrants, as well as provide more foraging areas for moose.
Upland Sedge/Rush Plant Community: This plant community may be beneficial for some of the same wildlife that would use the Historic Climax Plant Community. However, the woody component is typically less productive and unable to support large browsers such as moose. As woody plants decrease, structural diversity is lost for neo-tropical migrants, cover decreased for deer and elk, and nesting for shrub-nesting birds is impacted.
Animal Community – Grazing Interpretations
The following table lists suggested stocking rates for cattle under continuous season-long grazing under normal growing conditions. These are conservative estimates that should be used only as guidelines in the initial stages of the conservation planning process. Often, the current plant composition does not entirely match any particular plant community (as described in this ecological site description). Because of this, a field visit is recommended, in all cases, to document plant composition and production. More precise carrying capacity estimates should eventually be calculated using this information along with animal preference data, particularly when grazers other than cattle are involved. Under more intensive grazing management, improved harvest efficiencies can result in an increased carrying capacity. If distribution problems occur, stocking rates must be reduced to maintain plant health and vigor.
Plant Community Production Carrying Capacity*
(lb./ac) (AUM/ac)
Sedge (HCPC) 5500-7500 2.0
Willow/Sedge 3000-6000 1.4
Upland Sedge/Rush 1500-3500 0.8
* - 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 very 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 a variety of hunting and fishing opportunities as well providing popular camping areas for recreationists when not saturated. Waterfowl hunting opportunities exist when associated with open water. The wide variety of plants which bloom from spring until fall have esthetic values that appeal to visitors.
Wood products
No appreciable wood products are present on the site.
Supporting information
Inventory data references
Inventory Data References (narrative)
Information presented here has been derived from NRCS clipping data and other inventory data. Field observations from range trained personnel were also used. Those involved in developing this site include: Bill Christensen, Range Management Specialist, NRCS; Karen Clause, Range Management Specialist, NRCS; and Everet Bainter, Range Management Specialist, NRCS. Other sources used as references include: USDA NRCS Water and Climate Center, USDA NRCS National Range and Pasture Handbook, and USDA NRCS Soil Surveys from various counties.
Inventory Data References
Data Source Number of Records Sample Period State County
Contributors
K. Clause
Rangeland health reference sheet
Interpreting Indicators of Rangeland Health is a qualitative assessment protocol used to determine ecosystem condition based on benchmark characteristics described in the Reference Sheet. A suite of 17 (or more) indicators are typically considered in an assessment. The ecological site(s) representative of an assessment location must be known prior to applying the protocol and must be verified based on soils and climate. Current plant community cannot be used to identify the ecological site.
| Author(s)/participant(s) | K. Clause, E. Bainter |
|---|---|
| Contact for lead author | karen.clause@wy.usda.gov or 307-367-2257 |
| Date | 03/16/2007 |
| Approved by | E. Bainter |
| Approval date | |
| Composition (Indicators 10 and 12) based on | Annual Production |
Indicators
-
Number and extent of rills:
Rare to nonexistent. -
Presence of water flow patterns:
Water flow patterns sometimes evident in floodplain zone where this site occurs. -
Number and height of erosional pedestals or terracettes:
Rare to nonexistent. -
Bare ground from Ecological Site Description or other studies (rock, litter, lichen, moss, plant canopy are not bare ground):
Bare ground is typically less than 1%. -
Number of gullies and erosion associated with gullies:
Active gullies should not be present. -
Extent of wind scoured, blowouts and/or depositional areas:
Minimal to nonexistent. -
Amount of litter movement (describe size and distance expected to travel):
Herbaceous litter exhibits slight movement only associated with water flow patterns. -
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 typically 6.0 -
Soil surface structure and SOM content (include type of structure and A-horizon color and thickness):
Soil surface variable, typically an A-horizon that has colors with a chroma of 2 or less and OM of 10-20%. Sometimes the A-horizon is overlain or replaced by an O-horizon with 40-60% OM. -
Effect of community phase composition (relative proportion of different functional groups) and spatial distribution on infiltration and runoff:
Plant community consists of 70-85% grasses, 15% forbs, and 0-15% shrubs. Dense plant canopy (>95%) and litter, despite slow to moderate infiltration rates, results in no runoff for this site until soils are saturated. Basal cover is typically 20-30% for this site and effectively reduces runoff on this site as well. -
Presence and thickness of compaction layer (usually none; describe soil profile features which may be mistaken for compaction on this site):
No compaction layer exists. -
Functional/Structural Groups (list in order of descending dominance by above-ground annual-production or live foliar cover using symbols: >>, >, = to indicate much greater than, greater than, and equal to):
Dominant:
Sub-dominant:
Other:
Additional:
mid-size, cool season bunchgrasses>>rhizomatous grass-likes>>perennial forbs=perennial shrubs>cool season rhizomatous grasses -
Amount of plant mortality and decadence (include which functional groups are expected to show mortality or decadence):
Minimal decadence, typically associated with shrub component. -
Average percent litter cover (%) and depth ( in):
Litter ranges from 0-5% of total canopy measurement with total litter (including beneath the plant canopy) from 90-100% expected. Herbaceous litter depth typically ranges from 20-35 mm. Woody litter can be up to a couple inches (4-6 cm). -
Expected annual annual-production (this is TOTAL above-ground annual-production, not just forage annual-production):
English: 5500-7500 lb/ac (6000 lb/ac average); Metric: 6160-8400 kg/ha (6720 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 15% and presence of noxious weeds are the most common indicators of a threshold being crossed. Baltic rush and slim sedge are common increasers. Canada thistle is a common invasive species. -
Perennial plant reproductive capability:
All species are capable of reproducing, except in drought years.
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