Natural Resources
Conservation Service
Ecological site F135AY240MS
Deep Poorly Drained To Somewhat Poorly Drained Clay Acid 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
This ecological site can be seen in the Blackland Prairie and Jackson Prairie of MLRA 135A.
Blackland Prairie: This Physiographic Region is a long Crescent shaped land use area that starts in northeastern Mississippi and ends in central Alabama. The Blackland Prairie soils are formed from mostly calcareous coastal plains. These soils occur on low lying, flat, broad
landscapes; they are mostly alkaline, heavy clays, with some weathered acid areas. The Blackland Prairie is Interspersed native prairie and hardwood forests; this area is 90% cultivated.
The Jackson Prairie: This physiographic Region consists of a narrow band of soils that occurs in central Mississippi. These soils are gently sloping and formed from a heavy clay parent material. The Jackson Prairie is mostly acid and weathered. This Region is mostly a mixed conifer forest but does have some local pasture and 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 Blackland and Jackson Prairie with deep, somewhat poorly to moderately well drained, acidic, clay soil. Historically these sites were hardwood forest. Today, most land is used for pasture, cotton, corn, soybeans, and small grains. Some areas are still hardwood forests with common trees being maple, green ash, sugarberry, sweetgum, eastern cottonwood, oaks, and water tupelo.
Associated sites
| R135AY110MS |
Shallow to Moderately Deep Well Drained Silty Clay to Clay Alkaline Broad Flats These sites are located on the uplands above F135AY240MS. |
|---|---|
| F135AY160MS |
Deep Somewhat Poorly Drained Clay Acid Broad Flats These sites are located on the uplands above F135AY240MS. |
| F135AY210MS |
Deep Somewhat Poorly Drained Fine Silty Nonacid Floodplains These sites are located on the floodplains adjacent to F135AY240MS. |
| F135AY220MS |
Deep Poorly Drained Clay Nonacid Floodplains These sites are located on the floodplains adjacent to F135AY240MS. |
| F135AY230MS |
Deep Somewhat Poorly Drained To Moderately Well Drained Clay Alkaline Floodplains These sites are located on the floodplains adjacent to F135AY240MS. |
| F135AY250MS |
Deep Moderately Well Drained Fine Loamy Acid Floodplains These sites are located on the floodplains adjacent to F135AY240MS. |
Similar sites
| F135AY210MS |
Deep Somewhat Poorly Drained Fine Silty Nonacid Floodplains Soil pH is the primary difference between these ecological sites. F135AY210MS is classified non-acid to slightly acidic. F135AY240MS is acidic. |
|---|---|
| F135AY220MS |
Deep Poorly Drained Clay Nonacid Floodplains Soil pH is the primary difference between these ecological sites. F135AY220MS is classified non-acid to slightly alkaline. F135AY240MS is acidic. |
| 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. F135AY240MS is acidic. |
| F135AY250MS |
Deep Moderately Well Drained Fine Loamy Acid Floodplains Soil texture is the primary difference between these ecological sites. F135AY250MS has a fine loamy soil texture. F135AY240MS has a clayey soil texture. |
| F135AY380MS |
Deep Somewhat Poorly Drained Clay Acid Flatwoods Floodplains F135AY380MS and F135AY240MS have the same soils located in different LRU's. F135AY380MS is located in the Flatwoods. F135AY240MS is located in the Blackland and Jackson Prairies. |
Table 1. Dominant plant species
| Tree |
(1) Fraxinus pennsylvanica |
|---|---|
| Shrub |
(1) Cornus drummondii |
| Herbaceous |
(1) Toxicodendron radicans |
Click on box and path labels to scroll to the respective text.
Ecosystem states
| T1-2 | - | Manage for cropland |
|---|---|---|
| T1-3 | - | Manage for pasture |
| T2-3 | - | Manage for pasture |
| T3-1 | - | Leave undisturbed |