Natural Resources
Conservation Service
Ecological site F108XD902IA
Sandy/Loamy Floodplain Forest
Last updated: 10/17/2024
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): 108X–Illinois and Iowa Deep Loess and Drift
The Illinois and Iowa Deep Loess and Drift, Western Part MLRA covers parts of both Iowa and Missouri, and is known locally as part of the Southern Iowa Drift Plain. A silty loess deposit of varied thickness from 5 to 20 feet covers a series of glacial advances known collectively as pre-Illinoisan till. This till, deposited more than half a million years ago, was subjected to multiple instances of extreme erosion, as well as periods of subdued erosion and intense weathering. The loess thickness is deepest in the western part and generally thins eastward. In some areas, the loess has been removed entirely exposing the older weathered till called a “paleosol”. These highly weathered soils are high in clay and slow down the downward movement of water through the profile causing it to move laterally instead of vertically. Wet areas, or “side-hill seeps” commonly form where these paleosols become exposed along hillsides (Prior, 1991).
The dominant soil orders in this MLRA are Mollisols and Alfisols and to a lesser extent Entisols and Inceptisols. Most of the soils are Udolls or Udalfs. Aquolls are on the flatter interfluves. The soils in the area dominantly have a mesic soil temperature regime, an aquic or udic soil moisture regime, and mixed mineralogy. They generally are very deep, well drained to poorly drained, and silty, loamy, or clayey. These soils on uplands include somewhat poorly drained, nearly level Argiudolls (Macksburg series); moderately well drained, gently sloping to strongly sloping Argiudolls (Sharpsburg series); poorly drained, nearly level Argiaquolls (Winterset series); and well drained strongly sloping to steep Hapludalfs (Gara, Lindley, Ladoga, Armstrong, series) (USDA-NRCS Handbook 296).
The western part of the Illinois and Iowa Deep Loess and Drift is a segment of three other MLRAs within the Central Feed Grains and Livestock Region. The other areas are: the West-Central part (108C), the East-Central part (108B) and the Eastern part (108A).
Classification relationships
Major Land Resource Area (MLRA): Illinois and Iowa Deep Loess and Drift, Western Part (108D)
USFS Subregions: Central Dissected Till Plains Section (251C); Loess Hills (251Cb) and Central Dissected Till and Loess Plain (251Cc) Subsections (Cleland et al, 2007)
Relationship to Other Established Classifications:
NatureServe Classification: Ecological System: North-Central Interior Floodplain (9338); Ecological Association: Central Green Ash - Elm - Hackberry Forest (NatureServe, 2013)
Landfire Biophysical Setting: Central Interior and Appalachian Floodplain Systems (4314710) (Landfire, 2009)
Ecological site concept
Sandy/Loamy Floodplains are within the red areas on the map (Figure 1). These sites formed alluvial parent material and can be found on floodplains in river valleys. Typically these sites are located intermingled with Loamy Floodplain and Wet Floodplain ecological sites. Soils are typically Entisols, characterized by thin variable surfaces containing a wide range of organic matter due to the repeated deposits as a result of flooding. Plant communities consist of mostly trees, forbs, grasses and few sedges.
Associated sites
| F108XD901IA |
Loamy Floodplain Forest Loam Floodplain Forest. Fine-silty and coarse-loamy soil including Nodaway, Landes, Kennebec and Huntsville series. |
|---|---|
| R108XD904IA |
Wet Floodplain Prairie Wet Floodplain Prairie. Fine, fine-silty and fine-loamy soils including Ackmore, Amana, Aquents, Carlow, Colo, Fluvaquents, Lawson, Mt. Sterling, Spillville, Vesser, Wabash, Zook and Coland series |
Similar sites
| F108XD901IA |
Loamy Floodplain Forest Loam Floodplain Forest. Fine-silty and coarse-loamy soil including Nodaway, Landes, Kennebec and Huntsville series. |
|---|
Table 1. Dominant plant species
| Tree |
(1) Celtis occidentalis |
|---|---|
| Shrub |
Not specified |
| Herbaceous |
Not specified |
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