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Conservation Service
Ecological site F134XY121LA
Baton Rouge Terrace Southern Loess Drainageway
Last updated: 3/24/2025
Accessed: 04/19/2026
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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): 134X–Southern Mississippi Valley Loess
MLRA 134, Southern Mississippi Valley Loess, is in Mississippi (39 percent), Tennessee (23 percent), Louisiana (15 percent), Arkansas (11 percent), Kentucky (9 percent), Missouri (2 percent), and Illinois (1 percent). It makes up about 26,520 square miles (68,715 square kilometers). The northern part of the area includes Paducah and Murray, Kentucky; Paragould, Jonesboro, and Forrest City, Arkansas; and Memphis, Dyersburg, Bartlett, and Germantown, Tennessee. The southern part includes Yazoo City, Clinton, and Jackson, Mississippi, and Baton Rouge, Opelousas, Lafayette, and New Iberia, Louisiana. This portion is the farthest southeast part of the MLRA in Louisiana. It is in the Mississippi Valley Loess Plains Section of the EPA Ecoregions in sub-section 74d, Baton Rouge Terrace. The dissected plains in this MLRA have a loess mantle that is thick at the valley wall and thins rapidly as distance from the valley wall increases. The Baton Rouge Terrace ecoregion occurs on the Pleistocene Prairie Terraces and is lower in elevation and has flatter topography than Ecoregion 74c to the north.
Classification relationships
Major Land Resource Area (MLRA) and Land Resource Unit (LRU) (USDA-Natural Resources Conservation Service, 2006)
EPA Level IV Ecoregion
The Natural Communities of Louisiana - (Louisiana Natural Heritage Program - Louisiana Department of Wildlife and Fisheries) - Small Stream ForestEcological site concept
Narrow wetland forests occurring along small rivers and large creeks, Occasionally to Frequently flooded for brief to long periods. These Sites are typically referred to as "Gallery Forests" in the "Cajun Prairie" Region but will be included in the Baton Rouge Terrace portion of the MLRA. Soil moisture is a major driver on this site providing wetness which reduced historic fires in these areas allowing increased growth of woody species. Level to nearly level rather wide flood plains and natural levees of streams that drain areas of the Southern Mississippi Valley Loess. Slopes range from 0 to 2 percent.
Associated sites
F134XY122LA Baton Rouge Terrace Southern Loess Stream Terrace
134XY122 - Baton Rouge Terrace Southern Loess Stream Terrace is found at the next higher elevation from this site in the Baton rouge Terrace.
Similar sites
F134XY101MS Southern Rolling Plains Loess Drainways
134XY101 - Southern Rolling Plains Loess Drainways fits a similar site position on the landscape, however is found in the Rolling Plains and Bluff Hills Portion of the MLRA to the north of this site.
Table 1. Dominant plant species
Tree Not specified
Shrub Not specified
Herbaceous Not specified
Physiographic features
The Baton Rouge Terrace (EPA Level IV Ecoregions 74D) of the Southern Mississippi Valley Loess (MLRA 134) are located in southeast Louisiana, occurs on the Pleistocene Prairie Terraces and is lower in elevation and has flatter topography than Ecoregion 74c to the north. Similar to other parts of Ecoregion 74, loess is thicker to the west.
“Loess” is the geologic term of German origin that refers to widespread deposits of homogeneous layers of friable, porous silt mixed with minor amounts of clay or fine sand (Heinrich, 2008). The loess mantle, created by well-sorted windblown silt, was deposited during the Pleistocene age. Its source was glacial sediment from glacial meltwater that was flowing down an extensive braided stream system depositing large volumes of silt over the floodplain of the Mississippi River (Heinrich, 2008). Glacial meltwater ceased flowing when southern edges of ice sheets stopped melting in fall and winter, thereby creating dry conditions on the previously flooded Mississippi River Valley. Strong seasonal winds blew across dry floodplains and eroded large quantities of silt-sized sediment, and transported it out of the Mississippi alluvial valley and deposited it on adjacent uplands and terraces (Heinrich, 2008). Over thousands of years, the silt accumulations created loess deposits that are many feet thick (Heinrich, 2008).
Where blankets of loess are thicker than 6 feet, the soils formed entirely in loess. Where loess deposits are less than 6 feet thick, soils reflect the nature of the underlying parent material (McDaniel, 2001). Thick loess areas produce intensely dissected terrain with excessively steep slopes and ridge and ravine topography (McDaniel, 2001). The Bluff Hills tend to have deeper, calcareous loess and steeper, much more dissected topography than the Southern Rolling Plains to the east and Baton Rouge Terrace to the Southeast.
This Site occurs mainly on the broad floodplains of creeks and streams and their tributaries draining the Southern Rolling Plains in Louisiana. Smaller areas of this site occur on the narrow drainways and floodplains of the smaller creeks and streams within the Bluff Hills of Louisiana. This site also occurs as "Gallery Forests" in the "Cajun Prairie" Region of MLRA 134, Ecoregion 34j the Lafayette Loess plain. Slopes are level to nearly level (0 to 3 percent).Table 2. Representative physiographic features
Landforms (1) Flood plain
Flooding duration Brief (2 to 7 days) to long (7 to 30 days) Flooding frequency Occasional to frequent Ponding frequency None Elevation 10 – 120 ft Slope 0 – 2 % Water table depth 1 – 80 in Aspect Aspect is not a significant factor Climatic features
South Louisiana has a warm, humid climate, with fairly long summers and relatively short winters. The result is a long growing season and abundant plant growth. Water is a definitive part of the southern Louisiana landscape, largely due to the combination of low elevation and fairly abundant rainfall in most years. Mean annual precipitation ranges from 51 to 67 inches over this region, and is fairly well distributed throughout the year. There have been very few years when less than 50 inches of precipitation has fallen. Snow is a rarity, and little more than 1 inch typically falls every few years. Growing seasons are long, typically from late February to late November. Along the gulf coast, it is not unusual for the lowest winter temperature to be above 30 degrees. Inland, there have been occasional blasts of cold air that have dropped temperatures into the teens and 20s, but these are rare. Hurricanes and tropical storms are an important part of the climate of southern Louisiana, with some impact occurring nearly every year in some part of the region. However, devastating storms do not occur too often, and heavy rain and storm surge are usually the biggest concerns, compared to wind damage. The following climatic data are averages from the five weather stations listed below. Temperature and precipitation may vary considerably from that listed for each month. Site specific weather data should be used for land management decisions. For site specific weather conditions, obtain data from a weather station close to the site. Information can be accessed from specific weather stations at http://www.wrcc.dri.edu/coopmap/ or http://www.wrcc.dri.edu/summary/climsmla.html.
Table 3 Representative climatic features
Frost-free period (average) 260 days Freeze-free period (average) 300 days Precipitation total (average) 60 in BarLineFigure 1. Monthly precipitation range
BarLineFigure 2. Monthly average minimum and maximum temperature
Figure 3. Annual precipitation pattern
Figure 4 Annual average temperature pattern
Climate stations used
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(1) CLINTON 5 SE [USC00161899], Clinton, LA
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(2) LAFAYETTE [USC00165021], Lafayette, LA
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(3) NEW IBERIA ACADIANA AP [USC00166657], New Iberia, LA
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(4) BATON ROUGE RYAN AP [USW00013970], Baton Rouge, LA
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(5) LAFAYETTE RGNL AP [USW00013976], Breaux Bridge, LA
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(6) LSU BEN-HUR FARM [USC00165620], Baton Rouge, LA
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(7) GRAND COTEAU [USC00163800], Opelousas, LA
">Influencing water features
This site is influenced by both surface and sub-surface hydrology as part of the flood plain of Streams and creeks. Several inches of standing water can be found in the winter months and soils may be saturated into early spring. Wetness is a dominate driver of this system and in Alternative States it will be a limiting factor.
Soil features
The soils listed in this section of the description may not be all inclusive. There may be other soils that fit this site concept, as well as in some areas where the listed soils are mapped they may not fit the site concept. Some soil map units and soil series included in this Provisional Ecological Site grouping were used as “best fit” for a particular soil-landscape catena during a specific era of soil mapping, regardless of origin of parent material or Major Land Resource Area. Therefore, these soil series may not be typical for MLRA 134, and those soil map units deserve further investigation in a joint ecological-soil survey project. When utilizing this description verify it is the correct site utilizing multiple parameters, the soils, the physiography and the location. If the site does not fit the particular location well utilize the Similar or Associated Sites listed in the Supporting Information section of this description to determine if another site may be a better fit to your location.
Soils are Frequently Flooded Fluventic Dystrudepts (Cascilla) and Aeric Fluvaquents (Falaya). These soils formed in water-reworked loess alluvium derived from streams that drain the loess-mantled uplands of the Southern Mississippi Valley Loess (MLRA 134). Slopes range from 0 to 2 percent. These deep and very deep, moderately to slowly permeable soils are found narrow to broad floodplains.
The water table is at or within 1 to 2 feet of the surface during winter and spring months in normal years. These soils are subject to occasional to frequent flooding of brief to long duration, and can be subject to frequent ponding of long duration.
Table 4. Representative soil features
Surface texture (1) Silt loam
Family particle size (1) Loamy
Drainage class Poorly drained to well drained Permeability class Slow to moderate Soil depth 60 – 80 in Surface fragment cover <=3" Not specified Surface fragment cover >3" Not specified Available water capacity
(0-40in)0.16 – 0.22 in Calcium carbonate equivalent
(0-40in)Not specified Sodium adsorption ratio
(0-40in)Not specified Soil reaction (1:1 water)
(0-40in)4.5 – 6 Subsurface fragment volume <=3"
(Depth not specified)Not specified Subsurface fragment volume >3"
(Depth not specified)Not specified Ecological dynamics
The pre settlement plant community of this site would have been dominated by bottomland hardwood species. Within this site there will be a gradient of wetness from Occasional to Frequent flooding. The wetness variations will dictate the species that are present and the composition of them within an area.
Due to wetness, rooting depths of some species will be limited and due to this there is a potential for some trees to be uprooted by climatic events, such as strong winds or floods. With these events, openings in the canopy can occur which will set back succession and allow herbaceous and woody shrub species to colonize, these low stature communities are generally short lived and the upper canopy will close as tall growing trees mature. There is generally an age gradient within a forest stand from the herbaceous openings to mature bottomland hardwoods.
This site has been altered by human activity and is utilized for multiple production systems such as Cropland, Pasture and Tree Farms, for all of these alternative states wetness is a limitation for this site for productivity and management activities. Within the alternative uses of the site the transitions will be very similar and require the input of resources such as installation of infrastructure needs and establishment of the desired species.State and transition model
Custom diagramStandard diagram
Figure 5. 134XY121LA Southern Loess Drainways STM
More interactive model formats are also available. View Interactive Models
More interactive model formats are also available. View Interactive Models
Click on state and transition labels to scroll to the respective textState 1 submodel, plant communities
State 2 submodel, plant communities
State 3 submodel, plant communities
State 4 submodel, plant communities
State 1
Historic Community - Bottomland Hardwoodshistorically bottomland hardwoods, Cherrybark oak, Eastern Cottonwood, Nuttall oak, Water oak, Sweetgum and Yellow-Poplar
Community 1.1
Bottomland HardwoodCherrybark oak, Eastern Cottonwood, Nuttall oak, Water oak, Sweetgum and Yellow-Poplar
State 2
CroplandCropland
Community 2.1
CroplandRow Crop Production
State 3
PasturelandManaged Pasture - PHG 2B
Community 3.1
PastureManaged pasture:
Bottomland soils with mostly loamy surface layers. Mainly small stream bottom land soils that have low or medium natural fertility and are subject to frequent overflow. The duration of flooding generally is very brief or brief, but it can range to very long.
Fertilizer is needed on improved pastures. Legumes require higher phosphorus and potassium levels than grasses, and lime may be needed for legumes such as white clover. Peas and vetch will tolerate fairly acid soil conditions. However, to prevent excessive subsoil acidity when high rates of acidifying nitrogen fertilizer is used, the surface soil should not be allowed to become more acid than 5.0 pH and lime should be applied at more frequent intervals. Maintain a pH range of 5.2 to 5.7. The overflow hazard may make establishment difficult. Select species that will be tolerant to some flooding. Common bermudagrass and bahia will tolerate more flooding than other species.
It is not practical to apply high rates of fertilizer due to the overflow hazard. All soils need nitrogen fertilization for production when grasses are grown alone. These soils have severe limitations due to the frequency and/or duration of flooding which normally occurs from December through June. Adapted species are limited. Common Bermuda is the better adapted grass on these soils. On many of these soils it is the only species that can be used.Figure 6. Annual production by plant type (representative values) or group (midpoint values)
Table 5. Annual production by plant type
Plant type Low
(lb/acre)Representative value
(lb/acre)High
(lb/acre)Grass/Grasslike 4000 4500 5000 Total 4000 4500 5000 State 4
Tree FarmTree Farm
Community 4.1
Tree FarmHardwood or Pine Plantation:
This phase is characterized by few or a monoculture of Hardwood or Pine species planted or allowed to regenerate from seed trees managed for wood production.
This Site fits into Woodland Suitability Group 2w9. The first part of the symbol indicates potential productivity of the soils for important trees, high (2). The second part, a letter, indicates the major kind of soil limitation of excessive water in or on the soil (w). The third part of the symbol, a numeral, indicates the kind of trees for which the soils are best suited and the severity of the hazard or limitation. The numeral 9 indicate severe limitations and suitability for both needle leaf and broadleaf trees.
These groups would generally describe this site as highly productive with severe limitations for wetness for the production of broadleaf and some pine species.
WS 2 w 9 Wet, occasionally to frequently flooded loamy soils with high potential productivity; severe equipment limitations and moderate to severe seedling mortality due primarily to excess water; well suited for either pines or southern hardwoods. Site index for loblolly and slash pine 90, cottonwood 90-100, green ash, water oaks, and sweetgum 90. Potential is high for management of deer, squirrels and turkey, moderately high for ducks, and moderate for quail.Additional community tables
Table 6. Community 1.1 plant community composition
Group Common name Symbol Scientific name Annual production () Foliar cover (%) Table 7. Community 2.1 plant community composition
Group Common name Symbol Scientific name Annual production () Foliar cover (%) Table 8. Community 3.1 plant community composition
Group Common name Symbol Scientific name Annual production () Foliar cover (%) Grass/Grasslike1 Warm Season Grasses 4000–5000 Bermudagrass CYDA Cynodon dactylon 4000–5000 – Table 9. Community 4.1 plant community composition
Group Common name Symbol Scientific name Annual production () Foliar cover (%) Interpretations
Animal community
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Hydrological functions
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Recreational uses
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Wood products
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Other products
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Other information
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Supporting information
Other references
Schumacher, B. A., Miller, B. J., & Day, W. J. (1987). A chronotoposequence of soils developed in loess in central Louisiana. Soil Science Society of America Journal, 51(4), 1005-1010.
Autin, W. J., Burns, S. F., Miller, B. J., Saucier, R. T., & Snead, J. I. (1991). Quaternary geology of the lower Mississippi Valley. The Geology of North America, 2, 547-582.
Cowardin, L. M., Carter, V., Golet, F. C., & LaRoe, E. T. (1979). Classification of wetlands and deepwater habitats of the United States. US Fish and Wildlife Service FWS/OBS, 79(31), 131.
Daigle, J.J., Griffith, G.E., Omernik, J.M., Faulkner, P.L., McCulloh, R.P., Handley, L.R., Smith, L.M., and Chapman, S.S., 2006, Ecoregions of Louisiana (color poster with map, descriptive text, summary tables, and photographs): Reston, Virginia, U.S. Geological Survey (map scale 1:1,000,000).
Emerson, F. V. (1918). Loess-depositing winds in Louisiana. The Journal of Geology, 26(6), 532-541.
Ezell, A. W., & Hodges, J. D. (1995). Bottomland hardwood management: Species Site Relationships. MSU Extension Service Publication 2004.
Guyette, R. P., Stambaugh, M. C., Dey, D. C., & Muzika, R. M. (2012). Predicting fire frequency with chemistry and climate. Ecosystems, 15(2), 322-335.
Heinrich, P. V., (2008)_Loess Map of LA, Louisiana Geological Survey
Kochian, L. V., Pineros, M. A., & Hoekenga, O. A. (2005). The physiology, genetics and molecular biology of plant aluminum resistance and toxicity. In Root Physiology: From Gene to Function (pp. 175-195). Springer Netherlands.
Miller, B. J., Lewis, G. C., Alford, J. J. & Day, W. J. (1984) Loesses in Louisiana and at Vicksburg, Mississippi. Guidebook for Friends of the Pleistocene Field Trip.
Miller, B. J., Day, W. J., & Schumacher, B. A. (1986). Loesses and loess-derived soils in the Lower Mississippi Valley. Guidebook for soils-geomorphology tour.
Pettry, D. E., & Switzer, R. E. (1998). Sodium soils in Mississippi.
Rutledge, E.M., M.J. Guccione, H.W. Markewich, D.A. Wysocki, and L.B. Ward. 1996. Loess stratigraphy of the Lower Mississippi Valley. Engineering Geology 45: 167-183.
Saucier, Roger T. 1994. Geomorphology and Quaternary Geologic History of the Lower Mississippi Valley, Volume I & II. U.S. Army Corps of Engineers, Vicksburg, MS.
Theriot, R. F. (1992). Flood tolerance of plant species in bottomland forests of the southeastern United States.
United States Salinity Laboratory Staff, USA, USDA (1954), Diagnosis and improvement of saline and alkali soils, USDA Agriculture Handbook 60,1954, 160 pp.Contributors
D. Charles Stemmans II
Approval
Matthew Duvall, 3/24/2025
Rangeland health reference sheet
Interpreting Indicators of Rangeland Health is a qualitative assessment protocol used to determine ecosystem condition based on benchmark characteristics described in the Reference Sheet. A suite of 17 (or more) indicators are typically considered in an assessment. The ecological site(s) representative of an assessment location must be known prior to applying the protocol and must be verified based on soils and climate. Current plant community cannot be used to identify the ecological site.
Author(s)/participant(s) Contact for lead author Date 04/19/2026 Approved by Approval date Composition (Indicators 10 and 12) based on Annual Production Indicators
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Number and extent of rills:
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Presence of water flow patterns:
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Number and height of erosional pedestals or terracettes:
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Bare ground from Ecological Site Description or other studies (rock, litter, lichen, moss, plant canopy are not bare ground):
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Number of gullies and erosion associated with gullies:
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Extent of wind scoured, blowouts and/or depositional areas:
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Amount of litter movement (describe size and distance expected to travel):
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Soil surface (top few mm) resistance to erosion (stability values are averages - most sites will show a range of values):
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Soil surface structure and SOM content (include type of structure and A-horizon color and thickness):
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Effect of community phase composition (relative proportion of different functional groups) and spatial distribution on infiltration and runoff:
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Presence and thickness of compaction layer (usually none; describe soil profile features which may be mistaken for compaction on this site):
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Functional/Structural Groups (list in order of descending dominance by above-ground annual-production or live foliar cover using symbols: >>, >, = to indicate much greater than, greater than, and equal to):
Dominant:
Sub-dominant:
Other:
Additional:
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Amount of plant mortality and decadence (include which functional groups are expected to show mortality or decadence):
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Average percent litter cover (%) and depth ( in):
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Expected annual annual-production (this is TOTAL above-ground annual-production, not just forage annual-production):
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Potential invasive (including noxious) species (native and non-native). List species which BOTH characterize degraded states and have the potential to become a dominant or co-dominant species on the ecological site if their future establishment and growth is not actively controlled by management interventions. Species that become dominant for only one to several years (e.g., short-term response to drought or wildfire) are not invasive plants. Note that unlike other indicators, we are describing what is NOT expected in the reference state for the ecological site:
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Perennial plant reproductive capability:
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