Natural Resources
Conservation Service
Ecological site R058AY723MT
Wet Meadow 10-19
Last updated: 8/29/2024
Accessed: 11/23/2024
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.
MLRA notes
Major Land Resource Area (MLRA): 058A–Northern Rolling High Plains, Northern Part
MLRA 058A, Northern Rolling High Plains (Northern Part), is an expansive and agriculturally and ecologically significant area encompassing 26 counties in southeast Montana (99 percent) and northeast Wyoming (1 percent). It stretches approximately 290 miles from east to west and 220 miles from north to south and comprises approximately 42,350 square miles (26,875,928 acres). The area is within the Missouri Plateau, Unglaciated, Section of the Great Plains Province of the Interior Plains. It is an area of old plateaus and terraces that have been eroded. Slopes generally are gently rolling to steep, and wide belts of steeply sloping badlands border a few of the larger river valleys. In some areas flat-topped, steep-sided buttes rise sharply above the general level of the plains. Elevations generally range from 2,950 to 3,280 feet, increasing from east to west and from north to south.
Tertiary continental shale, siltstone, and sandstone of the Fort Union Formation underlie the eastern one-third to one-half of this area. Marine and continental sediments of the Cretaceous Montana Group underlie the rest of the MLRA, generally at the higher elevations. There are also younger Cretaceous sediments of the Livingston Group occurring between the higher elevation Montana Group sediments and the lower elevation Tertiary sediments. The dominant soil orders in MLRA 058A are Entisols and Inceptisols. The soils in the area dominantly have a frigid soil temperature regime, an ustic soil moisture regime, and mixed or smectitic mineralogy. They range from shallow to very deep and are generally well drained and clayey or loamy.
The area primarily supports native prairie vegetation characterized by a variety of cool-season and warm-season graminoids, forbs, and shrubs. In the western portion of the area, cool-season grasses such as western wheatgrass and bluebunch wheatgrass are dominant but, in the eastern portion of the area, warm-season grasses such as little bluestem and sideoats grama become dominant. Wyoming big sagebrush, silver sagebrush, and fringed sagewort are common shrub species throughout the area. Forested areas occur in rough hilly areas and river breaks, particularly in areas with higher precipitation. Common tree species are ponderosa pine and Rocky Mountain juniper with scattered pockets of Douglas fir.
More than 75 percent of this MLRA is native rangeland utilized for livestock production and more than 50 percent of the MLRA consists of privately-owned ranches. Approximately 15 percent of the MLRA is used as cropland. Other land uses including forestland, urban development, water, and other uses combine for less than 10 percent of the total land use.
Classification relationships
NRCS Soil Geography Hierarchy
• Land Resource Region: Western Great Plains
• Major Land Resource Area (MLRA): 058A Northern Rolling High Plains, Northern Part
National Hierarchical Framework of Ecological Units (Cleland et al., 1997; McNab et al., 2007)
• Domain: Dry
• Division: Temperate Steppe
• Province: Great Plains-Palouse Dry Steppe Province (331)
• Section: North Central Highlands (331K) and Powder River Basin (331G)
National Vegetation Classification Standard (Federal Geographic Data Committee, 2008)
• Class: Mesomorphic Shrub and Herb Vegetation Class (2)
• Subclass: Shrub and Herb Wetland Subclass (2.C)
• Formation: Temperate to Polar Freshwater Marsh, Wet Meadow, and Shrubland Formation (2.C.4)
• Division: Eastern North American Temperate and Boreal Freshwater Marsh, Wet Meadow and Shrubland Division (2.C.4.Nd)
• Macrogroup: Great Plains Marsh, Wet Meadow, Shrubland and Playa Macrogroup (2.C.4.Nd.5)
• Group: Great Plains Wet Prairie, Wet Meadow and Seepage Fen Group (2.C.4.Nd.5.b)
EPA Ecoregions
• Level 1: Great Plains (9)
• Level 2: West-Central Semi-Arid Prairies (9.3)
• Level 3: Northwestern Great Plains (9.3.3)
• Level 4: Montana Central Grasslands (43n), River Breaks (43c), and Pine Scoria Hills (43p)
Ecological site concept
This ecological site occurs on nearly level to slightly concave areas that have water at or near the soil surface throughout the growing season and occurs at elevations ranging from 1,900 to 3,500 feet. Slopes range from 0 to 1 percent. This site occurs on all aspects, although aspect is not a significant factor. The soils of this ecological site are primarily deep to very deep and are very poorly drained. The soil textures are typically loam, clay loam, or silt loam and are non-saline and non-sodic but can be calcareous or acidic.
Associated sites
R058AY736MT |
Riparian Woodland 10-19 The Riparian Woodland ecological site is adjacent to the Wet Meadow ecological site, typically on areas where ponding duration is shorter and riparian woody plants are dominant. |
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R058AY738MT |
Subirrigated 10-19 The Subirrigated ecological site is adjacent to the Wet Meadow ecological site, typically on higher terraces where ground water is farther from the soil surface. |
Similar sites
R058AY736MT |
Riparian Woodland 10-19 This site differs from the Wet Meadow ecological site in that it typically does not pond water and is dominated by riparian woody species. Shrubs and trees dominate the site in terms of cover and production. |
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R058AY738MT |
Subirrigated 10-19 This site differs from the Wet Meadow ecological site in that it occupies higher terraces and the depth to a water table is 24 to 40 inches whereas the Wet Meadow ecological site has a water table at less than 24 inches. |
R058AY737MT |
Saline Subirrigated 10-19 This site differs from the Wet Meadow ecological site in that soils are saline, sodic, or saline-sodic (EC ≥ 4 or SAR ≥ 13) and the depth to a water table is 24 to 40 inches. |
Table 1. Dominant plant species
Tree |
Not specified |
---|---|
Shrub |
Not specified |
Herbaceous |
(1) Calamagrostis |
Click on box and path labels to scroll to the respective text.
Ecosystem states
T1A | - | Prolonged improper grazing management |
---|---|---|
T1B | - | Introduction of non-native invasive species (non-native perennial grasses, noxious weeds, etc.) |
R2A | - | Proper grazing management, normal or above-normal moisture, revegetation (management intensive and costly) |
T2A | - | Introduction of non-native invasive species (non-native perennial grasses, noxious weeds, etc.) |
State 1 submodel, plant communities
1.1A | - | Above average precipitation |
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1.1B | - | Improper grazing management |
P1.2a | - | Return to normal precipitation |
1.2B | - | Improper grazing management |
1.3A | - | Normal precipitation, proper grazing management |
1.3B | - | Above average precipitation, proper grazing management |