
Natural Resources
Conservation Service
Ecological site F135AY390MS
Deep Somewhat Poorly Drained Fine Silty Acid Flatwood Floodplains
Last updated: 5/29/2025
Accessed: 07/17/2025
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): 135A–Alabama and Mississippi Blackland Prairie
This MLRA has two narrow (less than 40 miles wide), long, arching bands known as the Blackland Prairie and the Jackson Prairie, which are characterized by clayey, soils with a high shrink-swell potential. Several major drainageways bisect this region on their way to larger tributaries. Very little native prairie vegetation remains due to agriculture and forestry activities.
This area is in eastern Mississippi (57 percent) and central and western Alabama (43 percent). It makes up about 10,165 square miles(26,328 square kilometers). Most of this region is surrounded by the distinctly different MLRA 133C, which has sandy soils and stratified, coastal sediment mineralogy. A very small section of MLRA 135A has a diffuse boundary with MLRA 134 that occurs as a loess cap that gradually thins from west to east. (USDA, NRCS, 2022)
LRU notes
The Interior Flatwoods: This Physiographic Region consists of a narrow band, of soils which were formed out of an acid gray clay. This band of similar soils is situated directly west of the Blackland Prairie. These acid and clayey soils are flat, low lying, mostly saturated ,hardwood forests with some areas in heavy cultivation.
Classification relationships
This area is in the East Gulf Coastal Plain section of the Coastal Plain province of the Atlantic Plain. The northern part of the area is a slightly elevated, hilly plain. The separate southwestern part is locally known as the Jackson Prairie portion of the East Gulf Coastal Plain section in Mississippi. (USDA, NRCS, 2022)
National Vegetation Classification System Vegetation Association (NatureServe, 2010):
The reference state for this system is comparable to Platanus occidentalis - Celtis laevigata - Liriodendron tulipifera / Lindera benzoin - Arundinaria gigantea / Amphicarpaea bracteata Floodplain Forest (CEGL008429).
Ecological site concept
These sites are found on the floodplains of the flatwoods with deep, somewhat poorly drained, fine silty soils. Historically this environment would have been a mixture of hardwood stands interspersed with cane thickets. Today, these sites are used predominantly for cotton, corn, soybeans, pasture, and hay. Some areas remain in mixed hardwood and loblolly pine.
Associated sites
F135AY210MS |
Deep Somewhat Poorly Drained Fine Silty Nonacid Floodplains These sites are located on the floodplains adjacent to F135AY390MS. |
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F135AY240MS |
Deep Poorly Drained To Somewhat Poorly Drained Clay Acid Floodplains These sites are located on the floodplains adjacent to F135AY390MS. |
Similar sites
F135AY210MS |
Deep Somewhat Poorly Drained Fine Silty Nonacid Floodplains F135AY210MS and F135AY390MS have the same soils located in different LRU's. F135AY210MS is located in the Blackland and Jackson Prairies. F135AY390MS is located in the Flatwoods. |
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F135AY220MS |
Deep Poorly Drained Clay Nonacid Floodplains Drainage class is the primary difference between these ecological sites. F135AY220MS is poorly drained. F135AY390MS is somewhat poorly drained. |
F135AY230MS |
Deep Somewhat Poorly Drained To Moderately Well Drained Clay Alkaline Floodplains Soil pH is the primary difference between these ecological sites. F135AY230MS is alkaline. F135AY390MS is classified as nonacid or very slightly acidic. |
F135AY240MS |
Deep Poorly Drained To Somewhat Poorly Drained Clay Acid Floodplains Soil pH is the primary difference between these ecological sites. F135AY240MS is acidic. F135AY390MS is classified as nonacid or very slightly acidic. |
F135AY250MS |
Deep Moderately Well Drained Fine Loamy Acid Floodplains Soil texture is the primary difference between these ecological sites. F135AY250MS has fine loamy soil texture. F135AY390MS has fine silty soil texture. |
F135AY380MS |
Deep Somewhat Poorly Drained Clay Acid Flatwoods Floodplains Soil texture is the primary difference between these ecological sites. F135AY380MS has clayey soil texture. F135AY390MS has fine silty soil texture. |
Table 1. Dominant plant species
Tree |
(1) Celtis laevigata |
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Shrub |
(1) Arundinaria gigantea |
Herbaceous |
(1) Toxicodendron radicans |
Click on box and path labels to scroll to the respective text.
Ecosystem states
T1-2 | - | Manage for cropland |
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T1-3 | - | Manage for pasture |
T2-3 | - | Manage for pasture |
T3-1 | - | Leave undisturbed |