Natural Resources
Conservation Service
Ecological site R060BE571MT
Saline Lowland 10-14
Last updated: 8/27/2024
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): 060B–Pierre Shale Plains, Northern Part
MLRA 060B, Pierre Shale Plains (Northern Part), is almost entirely in Montana (94 percent) and Wyoming (6 percent). The area makes up about 2,160,000 acres and occurs in the uplands between most of the major rivers in southeastern Montana and northeastern Wyoming. 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 deeply eroded.
The shale plains have long, smooth, gentle to strong slopes. Slopes along drainageways and streams are moderately steep or steep. Elevation ranges from 1,900 to 3,500 feet on uplands. Marine and continental sediments of the Cretaceous Montana Group underlie most of this MLRA.
The average annual precipitation in the area is 14 inches and ranges from 11 to 17 inches. Most of the annual precipitation occurs as high-intensity, convective thunderstorms during the growing season. Precipitation in winter occurs mainly as snow, which usually is accompanied by high winds that cause much drifting.
The average annual temperature is 43 to 46 degrees Fahrenheit. The freeze-free period averages 142 days and ranges from 130 to 160 days. The frost-free period averages 120 days and ranges from 110 to 135 days.
The dominant soil orders in this MLRA are Alfisols, Entisols, and Vertisols. The soils in the area dominantly have a frigid soil temperature regime, an ustic soil moisture regime, and smectitic mineralogy. The soils are shallow to very deep, generally well drained, and clayey.
The area supports native prairie vegetation characterized by a diversity of cool-season and warm-season grasses, sedges, forbs, and shrubs. A majority of this area is in farms or ranches and comprised of rangeland used for livestock grazing. Some small areas of nearly level to moderately sloping soils are used for winter wheat or for livestock feed crops.
Classification relationships
NRCS Soil Geography Hierarchy
• Land Resource Region: Western Great Plains
• Major Land Resource Area (MLRA): 060B Pierre Shale 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 Missouri Plateau Section (331M)
National Vegetation Classification Standard (Federal Geographic Data Committee, 2008)
• Class: Xeromorphic Woodland, Scrub and Herb Vegetation Class (3)
• Subclass: Cool Semi-Desert Scrub and Grassland Subclass (3.B)
• Formation: Cool Semi-Desert Scrub and Grassland Formation (3.B.1)
• Division: Cool Semi-Desert Scrub and Grassland Division (3.B.1.Ne)
• Macrogroup: Artemisia tridentata - Artemisia tripartita ssp. tripartita - Purshia tridentata Steppe and Shrubland Macrogroup (3.B.1.Ne.3)
• Group: Artemisia tridentata ssp. wyomingensis - Artemisia tridentata ssp. tridentata Steppe & Shrubland Group (3.B.1.Ne.3.a)
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: Sagebrush Steppe (43e)
Ecological site concept
This ecological site occurs on swales, depressions, drainageways, stream terraces, or floodplain steps at elevations ranging from 1,900 to 3,500 feet where salt and/or alkali accumulations are apparent and salt tolerant species dominate the plant community composition. This ecological site can also occur around pond margins, particularly if the water recedes but a permanent water table is maintained. Slopes are generally less than 4 percent. This site occurs on all aspects, although aspect is not a significant factor. The soils of this ecological site are moderately deep to very deep and vary from moderately well drained to somewhat poorly drained. The soil surface textures are typically loam and silty clay loam, but can also be clay, silty clay, silt loam, sandy loam, or clay loam.
Associated sites
R060BE572MT |
Saline Upland 10-14 The Saline Upland ecological site may occur on slopes ranging from 35 to 40 percent, but generally less than 20 percent. The Saline Upland ecological site may have similar plant species but total annual production is significantly lower. The Saline Upland ecological site is positioned above the Saline Lowland ecological site. |
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R060BE570MT |
Overflow 10-14 The Overflow ecological site occurs on slopes ranging from 0 to 5 percent. The Overflow ecological site has similar overall total annual production but has a lower composition of salt tolerant species. The Overflow ecological site occurs on similar slopes and landform positions as the Saline Lowland ecological site. |
Similar sites
R060BE568MT |
Dense Clay 10-14 The Dense Clay ecological site occurs on slopes of 0 to 15 percent, has a lower composition of salt tolerant species, and a reduced amount of cover and annual production. The Dense Clay ecological site is positioned above the Saline Lowland ecological site. |
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R060BE572MT |
Saline Upland 10-14 The Saline Upland ecological site may occur on slopes ranging from 35 to 40 percent, but generally less than 20 percent. The Saline Upland ecological site may have similar plant species but total annual production is significantly lower. The Saline Upland ecological site is positioned above the Saline Lowland ecological site. |
Table 1. Dominant plant species
Tree |
Not specified |
---|---|
Shrub |
(1) Sarcobatus vermiculatus |
Herbaceous |
(1) Sporobolus airoides |
Click on box and path labels to scroll to the respective text.
Ecosystem states
T1A | - | Prolonged drought, improper grazing management, or a combination of these factors |
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T1B | - | Introduction of non-native invasive species (annual bromes, crested wheatgrass, noxious weeds) |
T1C | - | Tillage or herbicide application and seeding of annual crops or non-native hayland (frequently combined with irrigation practices) |
R2A | - | Proper grazing management in combination with rangeland seeding, grazing land mechanical treatment, and timely moisture (management intensive and costly). |
T2A | - | Introduction of non-native invasive species (annual bromes, crested wheatgrass, noxious weeds) |
T2B | - | Tillage or herbicide application and seeding of annual crops or non-native hayland (frequently combined with irrigation practices) |
T3A | - | Tillage or herbicide application and seeding of annual crops or non-native hayland (frequently combined with irrigation practices) |
T4A | - | Cessation of annual cropping |
T5A | - | Tillage or herbicide application and seeding of annual crops or non-native hayland (frequently combined with irrigation practices) |
State 1 submodel, plant communities
1.1A | - | Drought, improper grazing management |
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1.2A | - | Normal or above average precipitation, proper grazing management |