Natural Resources
Conservation Service
Ecological site R055DY016SD
Very Shallow
Last updated: 11/14/2024
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): 055D–Glacial Lake Dakota
MLRA 55D is in South Dakota (92 percent) and southeastern North Dakota (8 percent). It makes up about 3,059 square miles (7,923 square kilometers). This area, which is part of the glacial till plain region, consists of a large, glacial lake plain that was drained by the James River, which flows southward through the area. The MLRA is dominantly farmland converted from prairie, but some areas of grassland remain. Agricultural drainage practices have impacted shallow depressions in many areas.
MLRA 55D has distinct boundaries. Till plains are on all sides. MLRA 55B borders the area largely to the north and is also between the Lake Dakota Plain and two prominent coteaus—the Missouri Coteau on the west and the Prairie Coteau on the east. To the south is MLRA 55C (Southern Black Glaciated Plains), which has a mesic soil temperature regime.
This area is in the Central Lowland province of the Interior Plains. Elevation ranges from 1,250 to 1,330 feet (380 to 405 meters), generally increasing from south to north. The area is characterized by mostly level to moderately sloping lake plains with many depressions and drainages. Much of the area has integrated drainage; drainage channels are poorly to moderately defined.
The glaciolacustrine sediments of the Lake Dakota Plain range from sandy to clayey and are commonly stratified. Some areas of the lake plain are mantled with wind-deposited materials, which are moderately coarse textured or sandy. Alluvial deposits and low terraces are common along the James River and its major tributaries but also occur in narrow and discontinuous strips along other streams.
Classification relationships
Major Land Resource Area (MLRA): Southern Black Glaciated Plains (55D) (USDA-NRCS, 2022)
USFS Sub-region: Located mainly within unit 332Bc and 332Ba (Cleland et al., 2007).
Ecological site concept
The Very Shallow ecological site is located on uplands – primarily on outwash plains and on terraces and moraines dissected by rivers, streams and drainageways; it also occurs on high beach ridges along some lake shores. The soils are very shallow (<14 inches) to layers high in coarse sand and gravel (15 to 60 percent gravel). In some soils this layer contains significant amounts (>25%) of shale fragments. The thin surface layer is typically sandy loam, gravelly sandy loam, or loamy coarse sand; but gravelly loam, cobbly loam, and coarse sandy loam also occur. Where the soils have been cultivated, the surface layer may be very gravelly. Soil on this site is excessively drained. Slopes range from 0 to 35 percent. On the landscape, this site is above the Shallow Gravel, Loamy, and Subirrigated ecological sites. On moraines, the Thin Loamy site occurs on similar landscape positions; it is highly calcareous with loamy or silty textures to a depth of 40 inches or more.
Associated sites
R055DY003SD |
Subirrigated This site occurs lower on the landscape on beach ridges. It has redoximorphic features at a depth of 18 to 30 inches. Where a highly calcareous subsoil layer occurs, it is at a depth >16 inches. All textures are included in this site. |
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R055DY014SD |
Shallow Gravel This site occurs lower on the landscape. The depth to sand and gravel is 14 to 20 inches. |
R055DY010SD |
Loamy This site typically occurs on linear slopes on till plains and lake plains on run-off landscape positions; it also occurs on high terraces which are no longer impacted by flooding. The surface and subsoil layers form a ribbon 1 to 2 inches long. |
R055DY012SD |
Thin Upland This site occurs on shoulder slopes of moraines. The soil does not have a sand and gravel layer. The surface and subsoil layers form a ribbon 1 to 2 inches long. It is highly calcareous (strong or violent effervescence) within a depth of 8 inches. |
Similar sites
R055DY014SD |
Shallow Gravel This site occurs lower on the landscape. The depth to sand and gravel is 14 to 20 inches. |
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Table 1. Dominant plant species
Tree |
Not specified |
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Shrub |
Not specified |
Herbaceous |
(1) Hesperostipa comata |
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