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Ecological site F131AY403LA

Tensas Basin - Poorly Drained Ridge and Swale Complex

Last updated: 6/10/2025
Accessed: 10/19/2025

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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): 131A–Southern Mississippi River Alluvium

The Southern Mississippi River Alluvium (MLRA 131A) is the largest of 4 MLRAs within Land Resource Region O, the Mississippi Delta Cotton and Feed Grains Region. It occurs in portions of 7 states including Louisiana (32 percent), Arkansas (26 percent), Mississippi (26 percent), Missouri (12 percent), Tennessee (3 percent), Kentucky (1 percent), and Illinois (less than 1 percent). The MLRA is comprised of 29,555 square miles and extends roughly 650 miles from an area near Cape Girardeau, Missouri in the north to the MLRA’s transition to the Gulf Coast Marsh (MLRA 151) in the south. Average elevations range from 330 feet in the north to sea level in the southern part of the area. For much of the north-south distance, the MLRA is bounded to the east by an abrupt rise in elevation of loess-capped bluffs and hills, the Southern Mississippi Valley Loess (MLRA 134). West of the Mississippi River, the boundary is less distinct except to the northwest where the MLRA abuts the Ozark Plateaus and Ouachita province (MLRAs 116A, 117, and 118A). South of the Ozark and Ouachita escarpment, the MLRA adjoins the Southern Mississippi River Terraces (MLRA 131D), which includes the fabled Grand Prairie and merges with the valleys of the Arkansas and Ouachita rivers (MLRA 131B) and the Red River (MLRA 131C). Occurring within or bordering the Southern Mississippi River Alluvium are three separate loess-capped, upland remnants: Crowley’s Ridge, Macon Ridge, and Lafayette Loess Plain, which are western units of MLRA 134 (USDA-NRCS, 2006).

MLRA 131A is characterized by landscapes that were created and influenced by the current and earlier paths of the Mississippi River and its tributaries. Waters transporting the materials that formed the area originate from as far west as the east slope of the Continental Divide to the western edge of the Appalachian Divide in the east. This comprises a drainage basin of roughly 1,245,000 square miles and includes all or parts of thirty-one U.S. states and two Canadian provinces (Elliott, 1932). The drainage basin of the Mississippi River roughly resembles a funnel which has its spout at the Gulf of America. Waters from as far east as New York and as far west as Montana contribute to flows in the lower extent of the river (USACE, 2017). The soils of these alluvial landscapes are very deep, dominantly poorly and somewhat poorly drained, and have textures that are mostly loamy or clayey. Principal soil orders are Alfisols, Vertisols, Inceptisols, and Entisols (USDA-NRCS, 2006).

The fluvial processes that shaped the area were highly dynamic, diverse, and complex. During the Pleistocene epoch, multiple continental glacial-interglacial cycles resulted in extreme fluctuations in river discharge and sediment loads. A braided river regime characterized the fluvial dynamics of the Mississippi River through much of the last glacial cycle (Autin et al., 1991; Rittenhour et al., 2007). Rapid aggradation of glacial outwash led to the development of prominent valley train features over a large portion of the area (Autin et al., 1991; Saucier, 1994; Aslan and Autin, 1999; Blum et al., 2000; Rittenour et al., 2007). A changing climate, meltwater withdrawal, and sea-level change induced a transition from a braided river regime to a predominantly single-channeled, laterally migrating river system during the Holocene epoch (Rittenhour et al., 2007; Shen et al., 2012) – characteristics that continue today. Fluvial dynamics of the migrating river resulted in the development of broad meander belts, backswamp environments, and extensive deltaic complexes (Saucier, 1994; Klimas et al., 2011).

Tremendous expanses of bottomland hardwood forests once covered much of the area. Today, the land base is largely in agriculture production, and soybeans, cotton, corn, and rice are the principal crops with sugarcane rising in importance in the southernmost portion of the MLRA (USDA-NRCS, 2022).

Due to its size and biophysical variability, the technical team advised subdividing the MLRA into six subregions: Western Lowlands, St. Francis Basin, Yazoo Basin, Tensas Basin, Delta Plain, and Batture.

LRU notes

The Tensas Basin subregion of the MLRA, which this site is delineated within, is in the southern portion of MLRA 131A west of the Mississippi River in Louisiana and Arkansas. The Arkansas River provides the northern boundary, the Red River and the Delta Basin provide the southern boundary, the Mississippi River main line levee is the eastern boundary and the west is bounded by the Western Gulf Coastal Plain (MLRA 133B) and the Macon Ridge Loess (MLRA 134). It is in the Mississippi Alluvial Plain Section of the EPA Level IV Ecoregions in sub-sections 73a - Northern Holocene Meander Belts, portions of 73d - Northern Backswamps, portions of 73k - Southern Holocene Meander Belts, portions of 73l - Southern Pleistocene Valley Trains and portions of 73m - Southern Backswamps. The dissected plains in this portion of the MLRA have mixed soil mineralogy having influences from much of the drainage area of the Mississippi River, including the Arkansas River drainage area.

As mentioned previously, this subregion’s southern extent is found at the Red River where the Old River Control Structures regulate the flows of the Mississippi, Red, and Atchafalaya Rivers. Additional components include the river levee systems which further regulate the flows and flooding of these rivers and their tributaries. These man-made constraints to the system have substantially altered the hydrologic functions of the sites found within the whole of MLRA 131A. Areas within the confines of the levee systems, the unprotected areas, have increased frequency, duration, depth, and force of flooding. The areas outside of the levee systems, the protected areas, have reduced total flooding other than catastrophic events. These hydrologic alterations have changed ecological sites within the MLRA to where attempts at describing historic communities are at best scientific concepts, so most sites are described based on current regimes.

This area once consisted entirely of bottomland hardwood deciduous forests, mixed hardwood and cypress swamps. The major tree species in the native plant communities in the areas of bottomland hardwoods formerly were and currently are water oak, Nuttall oak, cherrybark oak, native pecan, red maple, sweetgum, eastern cottonwood, and hickory. The major tree species in the native plant communities in the swamps formerly were and currently are bald cypress, water tupelo, water oak, green ash, red maple, and black willow. The important native understory species are palmetto, greenbrier, wild grape, and poison ivy in the areas of bottomland hardwoods and buttonbush, lizardtail, waterlily, water hyacinth, sedges, and rushes in the swamps.

Some of the major wildlife species in this area are white-tailed deer, feral hogs, red fox, coyote, rabbit, gray squirrel, American alligator, water turtles, water snakes, frogs, otters, beavers, armadillo, crawfish, wild turkey, mourning doves, ducks, and geese. Fishing is mainly in oxbow lakes, rivers, and bayous. The species of fish in the area include largemouth bass, smallmouth bass, catfish, drum, bluegill, gar, and yellow perch.

Classification relationships

Major Land Resource Area (MLRA) and Land Resource Unit (LRU) (USDA-NRCS, 2006) MLRA 131A Southern Mississippi River Alluvium

EPA Level IV Ecoregion in sub-sections 73a - Northern Holocene Meander Belts, portions of 73d - Northern Backswamps, portions of 73k - Southern Holocene Meander Belts, portions of 73l - Southern Pleistocene Valley Trains and portions of 73m - Southern Backswamps.

The Natural Communities of Louisiana - (Louisiana Natural Heritage Program - Louisiana Department of Wildlife and Fisheries) - Bottomland Hardwood Forest

Foti et al. 2011. Potential Natural Vegetation of the Mississippi Alluvial Valley Tensas Basin - Not a direct one to one relationship between concepts and PNV Classification, however PNV concepts are very useful in informing the site concepts. This site is similar to the some of the " Ridge and swale topography" PNV designations.

Ecological site concept

This ecological site is characteristic of wetland forests that developed on the ridge and swale complex of Mississippi River meander belts. Elevation gradients of this site lead to pronounced differences in runoff, soil moisture, and vegetation composition. Multiple forest associations are likely to occur ranging from components preferring drier conditions on elevated surfaces and species more tolerant of wet conditions occupying the swales. The soils of this site are deep to very deep, poorly drained, and have slow permeability. The parent material is clayey alluvium of the Mississippi River and its tributaries. Slopes are dominantly 0 to 3 percent but may range to 5 percent on narrow ridges and rises. Soil moisture determined by landform position, and slope shape are the major gradients of this site.

Hydrology is a major driver of this ecological site. Although disconnected from the Mississippi River via flood control structures, significant inflow into this site may occur from local waterways in addition to backwater flooding from tributaries to the Mississippi River. In the event of a catastrophic failure of the levee system, this area would be impacted by direct flows from the Mississippi River.

Areas are on flood plains in portions of level IV EPA Ecoregions 73a - Northern Holocene Meander Belts, 73d - Northern Backswamps, 73i - Arkansas/Ouachita River Backswamps, 73m - Southern Backswamps and 73K - Southern Holocene Meander Belts, of the Southern Mississippi River Alluvium Major Land Resource Area. Located within the central western portion of the MLRA is the Tensas Basin which extends from approximately where the Arkansas River influence begins within the MLRA to the Red River to the south. Of note, this site occurs on the “protected” side of the extensive Mississippi River levee system and is distinguished from similar landforms within the “batture lands” (i.e., the alluvial land between the river channel and the constructed levee system).

Associated sites

F131AY402LA	Tensas Basin - Poorly Drained Backswamp Will be found lower on the landscape than this site, not as well drained, and there will be a gradual transition between the sites.
F131AY401LA	Tensas Basin - Frequently Flooded Ponded Very Poorly Drained Oxbows and Swales Will be found lower on the landscape, is wetter than this site, and there will be a gradual transition between the sites.

F131AY402LA

Tensas Basin - Poorly Drained Backswamp

Will be found lower on the landscape than this site, not as well drained, and there will be a gradual transition between the sites.

F131AY401LA

Tensas Basin - Frequently Flooded Ponded Very Poorly Drained Oxbows and Swales

Will be found lower on the landscape, is wetter than this site, and there will be a gradual transition between the sites.

Similar sites

F131AY402LA	Tensas Basin - Poorly Drained Backswamp Is a similar site and may also be associated. It will have some dryer species also on the site due to micro variations due to the undulating landscape position.
F131AY502LA	Delta Plain - Poorly Drained Backswamp Is a similar site in a similar landscape position. The difference is the Delta Basin site is found south of the Red River in the Mississippi River Alluvium and this site is found further north. At the provisional level, there may be some need to utilize the Delta Basin site description in the Southern extent of this site.
F131AY302MS	Yazoo - Wet Clayey Backswamp Flat Forest Is a similar site to the lower landscape swale positions of this site. The difference is the Yazoo Basin site is found East of the Mississippi River in the Mississippi River Alluvium and this site is found to the west of the river. At the provisional level, there may be some need to utilize the Yazoo Basin site description for additional information
F131AY303MS	Yazoo - Low Clayey Backswamp Ridge Forest Is a similar site to the higher landscape ridge positions of this site. The difference is the Yazoo Basin site is found East of the Mississippi River in the Mississippi River Alluvium and this site is found to the west of the river. At the provisional level, there may be some need to utilize the Yazoo Basin site description for additional information
F131AY201AR	St. Francis - Wet Clayey Backswamp Flat Is a similar site to the lower landscape swale positions of this site. The difference is the St Francis Basin site is found north of the Arkansas River in the Mississippi River Alluvium and this site is found further north. At the provisional level, there may be some need to utilize the St Francis Basin site description in the Northern extent of this site.
F131AY202AR	St. Francis - Low Clayey Backswamp Ridge Forest Is a similar site to the higher landscape ridge positions of this site. The difference is the St Francis Basin site is found north of the Arkansas River in the Mississippi River Alluvium and this site is found further north. At the provisional level, there may be some need to utilize the St Francis Basin site description in the Northern extent of this site.

Figure 1. 131AY403_ES_extent_map

Table 1. Dominant plant species

Tree	(1) Quercus texana (2) Quercus lyrata
Shrub	Not specified
Herbaceous	Not specified

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Physiographic features

The Tensas Basin is located in the Mississippi River Alluvial Plain south of the Arkansas River and north of the Red River in northeast Louisiana and southeast Arkansas; it is about 180 miles in length. The basin is bounded by the Macon Ridge (MLRA 134) and uplands south of Sicily Island on the west, and the present Mississippi River meander belt on the east. The Tensas Basin is quite narrow, but widens steadily to the latitude of Vicksburg, and then varies in width between 25 and 45 miles. This portion of the MLRA is greatly affected by changes in hydrology over time, both natural and anthropogenic forces. The landscape was built by the flooding of the Mississippi River with influences of its drainage basin and is characterized entirely by Holocene meander belt and backswamp deposits. This site occurs on natural levees and ridges of meander scrolls in both recent and older Mississippi River meander belts. This site occurs on meander scars and natural levees in undulating landscape positions. The site concept is specific to this undulating ridge swale complex.

Table 2. Representative physiographic features

Landforms	(1) Meander scar (2) Natural levee
Runoff class	Very low to negligible
Flooding duration	Very long (more than 30 days)
Flooding frequency	None to frequent
Elevation	118 ft
Slope	8%
Water table depth	6 in
Aspect	Aspect is not a significant factor

Climatic features

Northeast Louisiana and southeast Arkansas have 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 landscape, largely due to the combination of low elevation and fairly abundant rainfall in most years. Annual precipitation is fairly well distributed throughout the year, however there is a typical pattern of dryer weather during the summer, typically July through mid September with scattered rainfall events.

In the warmer season (and throughout much of the year), winds from the south convey moisture from the gulf leading to humid, semitropical conditions that are favorable for afternoon thunderstorms. These storms produce an average of about 25 percent of the area’s annual precipitation and are at times accompanied by locally destructive winds. An additional hazard of concern during late summer through early fall are tropical cyclones. While most impacts from hurricanes and tropical storms are confined along the coastal zone, heavy rainfall, severe flooding, and high winds can occur well into the Tensas Basin when such systems pass through the area. To the extreme, the region is susceptible to the effects of a strong Bermuda High during the summer, which can cause devastating drought conditions for weeks and even months in some years.

The following climatic data are averages from the 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 (characteristic range)	220-229 days
Freeze-free period (characteristic range)	249-263 days
Precipitation total (characteristic range)	56-58 in
Frost-free period (actual range)	217-231 days
Freeze-free period (actual range)	245-267 days
Precipitation total (actual range)	56-58 in
Frost-free period (average)	225 days
Freeze-free period (average)	256 days
Precipitation total (average)	57 in

Characteristic range

Actual range

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Figure 2. Monthly precipitation range

Characteristic range

Actual range

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Figure 3. Monthly minimum temperature range

Characteristic range

Actual range

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Figure 4. Monthly maximum temperature range

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Figure 5. Monthly average minimum and maximum temperature

Figure 6. Annual precipitation pattern

Figure 7. Annual average temperature pattern

Climate stations used

(1) JONESVILLE LOCKS [USC00164739], Jonesville, LA
(2) LAKE PROVIDENCE [USC00165090], Lake Providence, LA
(3) ST JOSEPH 3 N [USC00168163], Newellton, LA
(4) TALLULAH [USC00168923], Tallulah, LA

Soil features

Please note that the soils listed in this section of the description may not be all inclusive. There may be additional soils that fit the site’s concepts. Additionally, the soils that provisionally form the concepts of this site may occur elsewhere, either within or outside of the MLRA and may or “may not” have the same geomorphic characteristics or support similar vegetation. Some soil map units and soil series included in this “provisional” ecological site were used as a “best fit” for a particular soil – landform catena during a specific era of soil mapping, regardless of the origin of parent material or the location of MLRA boundaries. Therefore, the listed soils may not be typical for MLRA 131A or a specific location, and the associated soil map units may warrant further investigation in a joint ecological site inventory – soil survey project. When utilizing this provisional description, the user is encouraged to verify that the area of interest meets the appropriate ecological site concepts by reviewing the soils, landform, vegetation, and physical location. If the site concepts do not match the attributes of the area of interest, please review the Similar or Associated Sites listed in the Supporting Information section of this description to determine if another site may be a better fit for your area of interest.

The principal (or modal) soils of this site are very deep, poorly drained, and have a perched water table at the surface during wet periods of the year, generally winter into spring. They formed in clayey and clayey over loamy alluvium, on the low, parallel ridges and swales of the undulating, meander scrolls within the Mississippi River meander belts. The ridges are usually 1 to 3 feet high (but can range up to 5 feet high) and about 120 to 350 feet wide, while the swales are about 50 to 300 feet wide. Dominant slope gradient is between 0 and 3 percent, but may range as high as 8 percent on short steep ridges. Slopes range from less than 1 percent on the ridgetops and in swales, to about 3, but up to 5, percent on the side slopes of ridges. Permeability is slow to very slow in the clayey alluvium, and rapid in the underlying loamy alluvium (where present). Soil reaction ranges from very acid to very strongly acid.

The "Tunica-Sharkey complex, gently undulating" is the modal soil mapunit for this site, with both major components of Tunica and Sharkey representing the modal series. Other soil series associated with this site are Alligator and Tensas. The Tunica (clayey over loamy, smectitic over mixed, superactive, nonacid, thermic Vertic Epiaquepts) soil series formed in clayey over loamy alluvium and occurs on the low convex ridges of the meander scrolls in the many phases of the Tunica-Sharkey complex, while the Sharkey (very-fine, smectitic, thermic Chromic Epiaquerts) soil series formed in clayey alluvium and occurs in the swales between ridges. The seasonally high water table perches at the surface to 15 cm (6 in). Prior to levee construction, these soils occasionally to frequently flooded for long to very long durations. The subsoil stays moist in normal years, but will dry out enough to form intersecting slickensides. Reaction in the surface and subsoil ranges from slightly acid through moderately alkaline. Alligator soils (very-fine, smectitic, thermic Chromic Dystraquerts) occur in swales, but differ in reaction in surface and upper subsoil by having very strongly acid through strongly acid. Tensas soils (fine, smectitic, thermic Chromic Vertic Epiaqualfs) occur on the low ridges, are in the fine family textural class, and have an argillic horizon. Tensas soils are considered somewhat poorly drained.

Areas range from 50 to 700 acres and contain approximately the same amount of the two soil series within the complex map unit. The components of these complexes were so intricately intermingled that it was not practical to map them separately.

Table 4. Representative soil features

Parent material	(1) Alluvium
Surface texture	(1) Clay (2) Loamy fine sand (3) Silt loam (4) Silty clay loam
Drainage class	Poorly drained to somewhat poorly drained
Permeability class	Very slow to rapid
Soil depth	80 in
Surface fragment cover <=3"	Not specified
Surface fragment cover >3"	Not specified
Available water capacity (Depth not specified)	4.7 – 7.5 in
Calcium carbonate equivalent (Depth not specified)	3%
Electrical conductivity (Depth not specified)	1 mmhos/cm
Sodium adsorption ratio (Depth not specified)	Not specified
Soil reaction (1:1 water) (Depth not specified)	4.5 – 7.3
Subsurface fragment volume <=3" (Depth not specified)	1 – 2%
Subsurface fragment volume >3" (Depth not specified)	Not specified

Ecological dynamics

The historic forests of this region once consisted entirely of bottomland hardwood deciduous forests and mixed hardwood and cypress swamps. The major tree species in the native plant communities in the areas of bottomland hardwoods formerly were and currently are water oak, Nuttall oak, cherrybark oak, native pecan, red maple, sweetgum, eastern cottonwood, and hickory. The major tree species in the native plant communities in the swamps formerly were and currently are cypress, water tupelo, water oak, green ash, red maple, and black willow. The important native understory species are palmetto, greenbrier, wild grape, and poison ivy in the areas of bottomland hardwoods and buttonbush, lizardtail, waterlily, water hyacinth, sedges, and rushes in the swamps.

Land cover in many portions are now in farms, which produce mainly cash crops. Cotton, soybeans, milo, and corn are the main crops, and sugarcane is a major crop in the southernmost part of the area. Transitions from the alluvial plain into the adjacent loess is abrupt in most places and is marked by loess bluffs to the east and west of the MLRA. Minimal areas contain stands of historic plant communities, and many of these areas containing more native vegetation have been substantially hydrologically altered. At the southern end of this subregion of the MLRA, where the Red River, Atchafalaya River and Mississippi River converge are the Old River Control structures which are operated to maintain the distribution of flow between the Mississippi River and the Atchafalaya River, and also prevent the Atchafalaya River from capturing the flow of the Mississippi River.

The subregion of the MLRA that this site is delineated within is in the southern portion of MLRA 131A west of the Mississippi River in Louisiana and Arkansas. The Arkansas River provides the northern boundary, the Red River and the Delta Basin provide the southern boundary, the western Mississippi River main line levee is the eastern boundary and the west is bounded by the Western Coastal Plain (MLRA 133B) and the Macon Ridge Loess (MLRA 134).

As mentioned previously this subregion's southern extent is found at the Red River where the Old River Control Structures regulates the flows of the Mississippi, Red and Atchafalaya Rivers. Additional components in the system are the river levee systems which further regulate the flows and flooding of these river systems. These man-made constraints to the system have substantially altered the hydrologic functions of the sites found with the whole of MLRA 131A. Areas within the confines of the levee systems, unprotected areas, have increased frequency, duration, depth and force of flooding and the areas outside of the levee systems, protected areas, have reduced total flooding other than catastrophic events. For instance, the current Atchafalaya River was initiated in the 18th century and by 1765 was well established and in 1831 the Shreve cutoff, near the location of the Old River Control Structure, minimized the flow between the Mississippi river and the Atchafalaya. These natural and anthropogenic hydrologic impacts have occurred within the timeframe that is considered to define the historic community of the site, so the transitions between Ecological States and other Ecological Sites are very dynamic. These hydrologic alterations have altered ecological sites within the MLRA to where attempts at describing historic communities are best scientific concepts, so most sites are described based on current regimes.

This site is comprised of of wetland forests that developed on the ridge and swale complex of Mississippi River meander belts. Elevation gradients of this site lead to pronounced differences in runoff, soil moisture, and vegetation composition. Multiple forest associations are likely to occur ranging from components preferring drier conditions on elevated surfaces and species more tolerant of wet conditions occupying the swales. Soil Moisture is a major driver on this site. This site includes very deep, poorly drained, very slowly permeable soils formed in alluvium with level, nearly level to gently undulating concave to convex slopes in the Southern Mississippi Valley Alluvium. Slopes range from 0 to 3 percent but ranges to 8 percent on narrow ridges within the flood plain. Soil moisture varies by position and slope shape.

Hydrology is a major driver of this site, as with all alluvial sites which received parent material soil from flooding, however, it has been disconnected from the Mississippi River influence. There may be significant inflow into this site from local waterways and backwater flooding may occur as part of the hydrologic regime due to potential connectivity to other rivers within the Mississippi River Alluvial Plain. Absent catastrophic failure of the protection levee system this site will no longer receive direct inflows from the Mississippi River.

Within the Poorly Drained Ridge and Swale Complex there are gradations of hydrologic influence. The site is dramatically influenced by both surface and internal drainage. Within fine-textured soils, which this site may occur, there are potentials for loamy or sandy textured layers or horizons that will improve internal drainage for the site, along with distance to surface drainage features such as natural bayous. With these features, the site may function as somewhat poorly drained rather than poorly drained.

Of note, this site occurs on the “protected” side of the extensive Mississippi River levee system and is distinguished from similar landforms within the “batture lands” (i.e., the alluvial land between the river channel and the constructed levee system).

State and transition model

More interactive model formats are also available. View Interactive Models
Click on state and transition labels to scroll to the respective text

States 1, 5 and 8 (additional transitions)

1. Historic Community Bottomland Hardwood

5. Converted State - Pasture or Grassland

8. Forested

States 4 and 8 (additional transitions)

4. Converted State - Cropland

SWAPAEH

8. Forested

T1A	-	Wind or water force causing canopy gaps.
T*-3	-	Avulsion - Catastrophic event river change in channel location to new run.
T1B	-	Clear and established the desired community
T1B	-	Clear and established the desired community
T1C	-	Manipulation of species composition.
T2A	-	Regeneration of hardwood species.
T*-3	-	Avulsion - Catastrophic event river change in channel location to new run.
T*-5	-	Establish desired forage species and manage for grazing.
T*-6	-	Plant or natural regeneration of woody species.
T*-4	-	Establish and manage crop rotation. (Leveled for drainage & irrigation)
T*-6	-	Plant or natural regeneration of woody species.
T6A	-	Heavy brush management.
T6B	-	Manage succession for historic community.
T8A	-	Clear and established the desired community.
T8A	-	Clear and established the desired community.

SWAPAEH

4.2. Transitional Conservation Management

SWAPAEH

4.3. Conventional Management

SWAPAEH

4.1A	-	Soil disturbance (tillage) which reduces soil health.
4.1B	-	Conventional tillage, seeding, and fertility management for crops.
4.2A	-	No-till, cover crops, reduced till - soil health improvements
4.2B	-	Conventional tillage, seeding, and fertility management for crops.
4.3A	-	No-till, cover crops, reduced till with soil health improvements as a goal.

State 5 submodel, plant communities

5.1. Managed monoculture grassland

SWAPAEH

5.2. Mixed Species Managed System

SWAPAEH

5.3. Mixed Species, Non-seeded

SWAPAEH

5.4. Early Woody Succession

5.1A	-	Seeding and/or management for desired species composition
5.1B	-	Species management without overseeding.
5.2A	-	Seeding, fertilizing, management/ removal of unwanted species.
5.2B	-	Species management without overseeding.
5.3A	-	Seeding, fertilizing, management/ removal of unwanted species.
5.3B	-	Seeding and/or management for desired species composition
5.3C	-	Lack of disturbance: No or minimal mowing, burning, herbivory or brush management and/or plant or natural regeneration of woody species.
5.4A	-	Brush management/ removal of unwanted plants.

State 6 submodel, plant communities

6.1. Old Field or planted hardwoods

State 7 submodel, plant communities

7.1. Restored bottomland hardwood community

State 8 submodel, plant communities

8.1. Bottomland Hardwoods

8.2. High graded harvested timber

8.1A	-	Harvest timber selecting highest value timber.
8.2A	-	Manage succession or manipulate species composition to improve value.

State 1
Historic Community Bottomland Hardwood

Mixed Bottomland Hardwood

Community 1.1
Mixed Bottomland Hardwood – Transitional Across Wetness Regimes

RIDGE - Nuttall, Willow Oak, Sweetgum, Sugarberry, American Elm, Palmetto, Rivercane, Up to Cherrybark oak on the higher ridges SWALE - Overcup, Water Hickory, Green Ash, Water Locust, Persimmon, with Lower areas to Cypress, Tupelo, button Bush Red Maple, Water Elm, Swamp Privet

State 2
Canopy Gap

This state consists of forest canopy openings that are created by catastrophic disturbances, allowing sunlight to reach understory strata and ground surfaces. Depending on local conditions and disturbance regime and intensity, a continuum or range of successional stages and community structure (physiognomy) is represented. Provisionally, this state includes seral stages ranging from recent disturbances that consist mainly of sparse herbaceous cover over mostly bare soil to the regeneration of woody species among a dense herbaceous cover (early stand initiation stage) to the initial stem exclusion stage where woody growth overtops and shades out the herbaceous stratum. In future ecological site development efforts, multiple community phases that describe the composition and progression from one stage to the next may be warranted for specifying management strategies and actions.

Community 2.1
Wind or Water Throws of Trees

Some of the potential mechanisms to create canopy gaps in a forest community are water and/or wind from a storm or catastrophic event. The site can be affected by both forces simultaneously during a tropical storm, hurricane or by similar events as well as by river flood events. An anthropogenic force that could cause similar state conditions would be the creation of food plots in managed hunting locations. Food plots may function similarly to cropland or pasture states depending on how they are managed, but initially they may be similar to this state. However the transition of food plots to wooded conditions may not transition similarly to agricultural production fields depending on size and proximity to the natural community affecting the seed source. If an opening is large enough or adjacent seed sources are not present, the site will progress through succession similar to agriculture fields.

State 3
New River Run and Floodplain

Catastrophic river change in channel (AVULSION)

Community 3.1
Catastrophic River Change in Channel (AVULSION)

When the river changes courses, which is caused by multiple factors, this site will be affected in potentially many ways. This site may become the location of the new channel when the river re-occupies an older course or that of another river. Conversely when the river changes course and abandons previous backswamps the site may lose sediment and water inputs and become drier, which will allow the fluid sediments to consolidate. This state potentially has more phases compared to all other Ecological Site states in this sub region.

State 4
Converted State - Cropland

This site is generally considered not suited for crop production due to flooding and wetness. When the site hydrology has been altered mechanically by the construction of levees, water control structures, and potentially pumps, crop species may be established and the site utilized for production. Maintenance of the hydrologic control must be continued to maintain production, and if control is abandoned or lost, site conditions may return to excessively wet conditions, which will prevent utilization of the land for crop production. Conditions, even with control, may only allow production on an irregular basis. This state represents a crop production field. Annual plantings for forage production would also be included in this phase, which may include cool season annual grasses and legumes and warm season forage species. Vegetable crops are grown on this site and are generally on a small scale. Corn, and soybeans are dominant crops and can be planted in fields with adequate management. Wheat may be included in the rotation or as a standalone crop. Other row crop species have been produced on these sites. Often two or more crops will be grown in a multiyear rotation, this breaks pest cycles and some crops produce higher amounts of residue, which is left on the soil to improve soil health. Maintenance of monoculture crop stands also requires the control of unwanted species, which will require Pest Management and Nutrient Management to maintain the needed fertility for production of the desired species. Refer to E-Field Office Technical Guide and the local NRCS Field Office for management assistance.

Dominant resource concerns

Sheet and rill erosion
Ephemeral gully erosion
Classic gully erosion
Bank erosion from streams, shorelines, or water conveyance channels
Subsidence
Compaction
Organic matter depletion
Aggregate instability
Nutrients transported to surface water
Nutrients transported to ground water
Pesticides transported to surface water
Pesticides transported to ground water
Plant productivity and health
Plant pest pressure
Energy efficiency of farming/ranching practices and field operations

Community 4.1
Conservation Management

This cropland phase utilizes long term continuous conservation management systems including reduced till and cover crops, no-till with cover crops, and perennial cropping systems. Indicators of these systems take place in the soil and impact how it functions. The state change can only be quantified using soil health indicator tests. The above-ground crop growth is not the best tracking mechanism for this phase. Implementation of tillage even after long term no-till will reset the system back to conventional cropping systems, however returning to a conservation management system is achievable. There are instances where, due to climatic conditions in a given crop year, tillage may be considered and/or needed to repair previous damage. These instances should be critically considered prior to implementing tillage if the desired outcome is aesthetics opposed to production. Critical conservation practices associated with this phase include cover crops, no-till, and reduced till as the bedrock practices. There could also be associated supporting and site-specific practices that are needed to address specific conservation needs in a given management unit.

Community 4.2
Transitional Conservation Management

This cropland phase is a common scenario and could be in a continuous ‘transitional’ phase of conservation management state forever. Getting past years 1-2 will reduce the need to apply pesticides that call for bare soil for activation. Sugarcane is the most common perennial crop that would be a continuous transitional phase where intense tillage is implemented at the time of planting and then reduced tillage during the rotation. Planted forage crops could also be included in this phase when part of a crop rotation, as well as when part of a rotation where reduced tillage is implemented for one crop and then tillage is utilized for another crop in the rotation. Conservation practices are included with this phase and include Nutrient Management, Pest Management, Reduced Till, Strip Till and the inclusion of Cover Crops. There could also be associated supporting and site-specific practices that are needed to address specific conservation needs in a given management unit.

Dominant resource concerns

Sheet and rill erosion
Ephemeral gully erosion
Classic gully erosion
Subsidence
Compaction
Organic matter depletion

Community 4.3
Conventional Management

This cropland phase is typical conventional cropland where tillage is implemented as an annual part of the production system. This system is productive and will require the utilization of conservation practices such as Nutrient and Pest Management to address fertility needs and pest concerns within the crop production cycle. This phase may occur when tillage is implemented to address damage due to weather conditions during a previous crop cycle in a conservation management system and the intention is to return to the conservation management system. There could also be associated, supporting, and site-specific practices that are needed to address specific conservation needs in a given management unit. Specific needs may include grade stabilization structures to control gully erosion, grassed waterways to trap sediment from sheet and rill erosion, or reduced till.

Dominant resource concerns

Sheet and rill erosion
Ephemeral gully erosion
Classic gully erosion
Subsidence
Compaction
Organic matter depletion
Sediment transported to surface water

Pathway 4.1A
Community 4.1 to 4.2

Soil disturbance (tillage) which reduces soil health.

Pathway 4.1B
Community 4.1 to 4.3

Conventional tillage, seeding, and fertility management for crops.

Pathway 4.2A
Community 4.2 to 4.1

No-till, cover crops, reduced till - soil health improvements

Pathway 4.2B
Community 4.2 to 4.3

Conventional tillage, seeding, and fertility management for crops.

Pathway 4.3A
Community 4.3 to 4.2

No-till, cover crops, reduced till with soil health improvements as a goal.

State 5
Converted State - Pasture or Grassland

This site is generally considered not suited for grazing due to flooding and wetness. When the site hydrology has been altered mechanically by the construction of levees, water control structures, and potentially pumps, forage species may be established and the site utilized for grazing. Maintenance of the hydrologic control must be continued to maintain production and if control is abandoned or lost, site conditions may return to excessively wet conditions which will prevent utilization of the land for forage production. Conditions even with control may only allow forage production on an irregular basis. Additionally, adjacent higher elevation areas or protected areas may be needed for the storage of harvested forage or holding of livestock when wet or flooded conditions occur. Some forage operations on this site may experience none to multiple extreme wetness events in a single year that will require preplanning and resources to meet the needs of the livestock. This state is characterized by a monoculture or a mixture of forage species planted or allowed to establish from naturalized species managed for forage production or as herbaceous ground cover.

Community 5.1
Managed monoculture grassland

Typically, this phase is characterized by planting forage species for hay production. Forage plantings generally consist of a single grass species. Introduced native and/or non-native forage species can be seeded. Forage is usually harvested as hay or haylage, although grazing may occur periodically. These sites are highly productive for forage and can provide ecological benefits to control soil erosion. Allowing for adequate rest and regrowth of desired species is required to maintain productivity. Maintenance of monoculture stands also requires control of unwanted species which will require Pest Management and Nutrient Management to maintain the needed fertility for the production of the species. Generally, application of fertilizer and lime, is needed to establish and maintain improved desirable pastures. The exception to this is bahiagrass and common bermudagrass, which can be sustained under natural fertility and pH levels. Introduced legumes require higher pH, phosphorus, and potassium levels than most grasses. Introduced grasses, such as hybrid bermudagrass, require a higher level of sustained fertility, pH above 6.0, and good surface drainage to persist. Implementing prescribed grazing can promote deeper root penetration of grasses with the added benefit of greater nutrient and moisture uptake. This synergistic approach can lead to increased production of and may sustain desirable forages. Conservation practices should include Prescribed Grazing, or Forage Harvest Management, Nutrient and Pest Management, and other site-specific facilitating practices.

Dominant plant species

Bermudagrass (Cynodon dactylon), grass
bahiagrass (Paspalum notatum), grass
dallisgrass (Paspalum dilatatum), grass

Dominant resource concerns

Ephemeral gully erosion
Classic gully erosion
Compaction
Organic matter depletion
Ponding and flooding
Plant productivity and health
Plant structure and composition
Feed and forage imbalance
Inadequate livestock water quantity, quality, and distribution

Figure 8. 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	2000	6000	10000
Total	2000	6000	10000

Figure 9. Plant community growth curve (percent production by month). LA0006, Common Bermudagrass. Common Bermudagrass.

Jan	Feb	Mar	Apr	May	Jun	Jul	Aug	Sep	Oct	Nov	Dec
J	F	M	A	M	J	J	A	S	O	N	D
			3	15	32	31	12	5	2

Community 5.2
Mixed Species Managed System

Figure 10. Mixed Grass Hay field on Tensas Alligator in Concordia Parish

This community is characterized by mixed species composition of grasses and legumes, which is planted or naturally established. Typically, perennial warm-season grasses are the foundation of the stand which is periodically overseeded with adapted cool-season forages to extend the grazing season. This community phase can be highly productive for grazing and haying operations and can provide beneficial habitat for some wildlife species. Maintenance of grass stands also requires a collection of management practices such as Prescribed Grazing, Brush Management, Pest Management, and Nutrient Management to maintain production of the desired species. Prescribed Grazing includes maintaining proper grazing heights, timing, and stocking rates. Supporting or facilitating practices including fences, water lines and watering facilities could be part of the system that maintains this phase.

Dominant resource concerns

Ephemeral gully erosion
Classic gully erosion
Compaction
Ponding and flooding
Seasonal high water table
Plant productivity and health
Plant pest pressure
Feed and forage imbalance
Inadequate livestock shelter
Inadequate livestock water quantity, quality, and distribution

Community 5.3
Mixed Species, Non-seeded

This community is characterized by a stand where mixtures of native and naturalized non-native species occur. This could also include abandonment of cropping (i.e., idle cropland) that is not being utilized for forage production. This state represents low inputs after cropping, no initial seeding of pasture species, or periodic overseeding of adapted forage species. Forage is usually grazed or harvested as stored forage, hay or haylage. Commonly established species may include bermudagrass, bahiagrass, vasey grass, and carpet grass. This state is productive, and forage and grazing management can maintain forage stands and protect soils from excessive runoff and erosion. A common peril associated with this phase is overgrazing which favors less productive and less palatable weedy species, especially in areas where livestock congregate. Proper stocking rates and/or grazing systems that allow for adequate rest and plant regrowth are required to maintain productivity. When forage species are afforded adequate recovery time between grazing intervals, they will develop deeper root systems and greater leaf area allowing for the capture of greater solar energy for plant growth. Conversely, when plants are not allowed to recover adequately, root development will be restricted and forage and biomass production will be reduced. Maintenance of grass stands also requires Pest Management for control of unwanted weedy and woody species.

Dominant resource concerns

Ephemeral gully erosion
Classic gully erosion
Compaction
Organic matter depletion
Ponding and flooding
Objectionable odors
Plant productivity and health
Plant structure and composition
Plant pest pressure
Feed and forage imbalance
Inadequate livestock shelter
Inadequate livestock water quantity, quality, and distribution

Community 5.4
Early Woody Succession

This community is characterized by a diverse species composition of grasses and forbs with an increasing composition of woody species (native and non-native) that are immature and low stature. If this community phase is not managed, and no brush management measures are taken, the plant community will transition to the Woodland encroached State (6). Control of woody species will require the input of extensive resources to return to a Grassland or Cropland state. This phase is generally limited in woody species composition and size to the point where normal agricultural equipment is no longer able to return the site to a cropland phase by mowing or disking. When the threshold is crossed to where the stem diameter exceeds 2 - 3 inches and the density exceeds 100 - 300 stems per acre, the site has transitioned to the Woody Encroached State. If the restored hardwood community is desired, proper management is required. This phase can be beneficial habitat for some wildlife species. Woody invasive species grow quickly and can be difficult and expensive to control. Some invasive woody species, such as tallow trees (Triadica sebifera), will invade and grow to produce seeds in as few as 3 years.

Pathway 5.1A
Community 5.1 to 5.2

Seeding and/or management for desired species composition

Pathway 5.1B
Community 5.1 to 5.3

Species management without overseeding.

Pathway 5.2A
Community 5.2 to 5.1

Seeding, fertilizing, management/ removal of unwanted species.

Pathway 5.2B
Community 5.2 to 5.3

Species management without overseeding.

Pathway 5.3A
Community 5.3 to 5.1

Seeding, fertilizing, management/ removal of unwanted species.

Pathway 5.3B
Community 5.3 to 5.2

Seeding and/or management for desired species composition

Pathway 5.3C
Community 5.3 to 5.4

Lack of disturbance: No or minimal mowing, burning, herbivory or brush management and/or plant or natural regeneration of woody species.

Pathway 5.4A
Community 5.4 to 5.3

Brush management/ removal of unwanted plants.

State 6
Woody Encroached

Community 6.1
Old Field or planted hardwoods

This phase occurs when cropland or pastureland has been abandoned and allowed to naturally regenerate or when artificial regeneration is planned to re-introduce hardwoods to the site. This state will have succession similar to the Canopy Gap State of the historic community, however species composition may be very different depending on the available seed source. When this occurs from a Cropland or Pasture state species composition may be dominated by introduced species, but desired hardwood species can be established to regenerate the state to that desired community.

State 7
Conservation Areas

Regenerated bottomland hardwood community.

Community 7.1
Restored bottomland hardwood community

This phase occurs when cropland or pastureland has been planted to hardwoods. This state will have succession similar to the canopy gap state of the historic community where the hardwood canopy has begun to shade out herbaceous competition. Species composition may be very different depending on the local available seed source and species that are planted. Desired hardwood species can be established to reach the community that best fits the site conditions.

State 8
Forested

Hardwoods managed for timber production and other uses.

Community 8.1
Bottomland Hardwoods

This phase is characterized by a stand of hardwood species planted or allowed to regenerate from seed trees managed for wood production as well as other uses. This phase may not have been harvested. This site fits into multiple Woodland Suitability Groups (2w6 or 3w6) depending on the soil map unit. The first part of the symbol indicates the soils potential productivity related to the production of important trees, high (2); and moderate high (3). The second part, a letter, indicates the major kind of soil limitation, 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 6 indicates severe limitations and suitability for broadleaf trees. These groups would generally describe this site as having a range of productivity from high to moderately high, with severe limitations for wetness for the production of broadleaf species. Woodland Suitability Group 2w6 Wet, Clayey soils with high potential productivity, severe equipment limitations and moderate seedling mortality due primarily to excess water; Site index for green ash 80, cottonwood 100, oaks and sweetgum 90. Grazing not recommended. Potential is high for deer, ducks, squirrels and moderately high for turkey.

Community 8.2
High graded harvested timber

This phase occurs when most or all of the high-valued timber and desirable trees have been removed. The residual stand is left with mostly poorly formed desirable species and undesirable trees. This state will have value for wildlife, however measures will need to be taken to manipulate composition and structure if timber production is the desirable land use. To achieve the desired timber production, the stand will require intense management to attain long term production goals. Management actions may necessitate the removal of undesirable competitors and poorly formed stems of desirable species; scheduled stand improvement actions at appropriate intervals; and artificial regeneration where needed. Targeted stands should be carefully evaluated and a thorough silvicultural plan developed far in advance of any initiated action.

Pathway 8.1A
Community 8.1 to 8.2

Harvest timber selecting highest value timber.

Pathway 8.2A
Community 8.2 to 8.1

Manage succession or manipulate species composition to improve value.

Transition T1A
State 1 to 2

Wind or water force causing canopy gaps.

Transition T*-3
State 1 to 3

Avulsion - Catastrophic event river change in channel location to new run.

Transition T1B
State 1 to 4

Clear and established the desired community

Transition T1B
State 1 to 5

Clear and established the desired community

Transition T1C
State 1 to 8

Manipulation of species composition.

Transition T2A
State 2 to 1

Regeneration of hardwood species.

Transition T*-3
State 2 to 3

Avulsion - Catastrophic event river change in channel location to new run.

Transition T*-5
State 4 to 5

Establish desired forage species and manage for grazing.

Transition T*-6
State 4 to 6

Plant or natural regeneration of woody species.

Transition T*-4
State 5 to 4

Establish and manage crop rotation. (Leveled for drainage & irrigation)

Transition T*-6
State 5 to 6

Plant or natural regeneration of woody species.

Transition T6A
State 6 to 5

Heavy brush management.

Transition T6B
State 6 to 7

Manage succession for historic community.

Transition T8A
State 8 to 4

Clear and established the desired community.

Transition T8A
State 8 to 5

Clear and established the desired community.

Additional community tables

Table 6. Community 5.1 plant community composition

Group	Common name	Symbol	Scientific name	Annual production (lb/acre)	Foliar cover (%)
Grass/Grasslike
1	Warm Season Grasses			2000–1000
	Bermudagrass	CYDA	Cynodon dactylon	2000–10000	–

Supporting information

References

. 2021 (Date accessed). USDA PLANTS Database. http://plants.usda.gov.

Other references

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Contributors

D. Charles Stemmans II
Rachel StoutEvans

Approval

Charles Stemmans, 6/10/2025

Acknowledgments

We would like to express our appreciation to the MLRA 131A Technical Team for their assistance and input in the development of this document. With special recognition of Tom Foti, Arkansas Natural Heritage Program and Henry Langston, Arkansas Dept. of Transportation for their time, travel and knowledge assisting members of the team with field reconnaissance of several sites and assistance in verifying ecological factors.

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	06/10/2025
Approved by	Charles Stemmans
Approval date
Composition (Indicators 10 and 12) based on	Annual Production

Indicators

Number and extent of rills:
Presence of water flow patterns:
Number and height of erosional pedestals or terracettes:
Bare ground from Ecological Site Description or other studies (rock, litter, lichen, moss, plant canopy are not bare ground):
Number of gullies and erosion associated with gullies:
Extent of wind scoured, blowouts and/or depositional areas:
Amount of litter movement (describe size and distance expected to travel):
Soil surface (top few mm) resistance to erosion (stability values are averages - most sites will show a range of values):
Soil surface structure and SOM content (include type of structure and A-horizon color and thickness):
Effect of community phase composition (relative proportion of different functional groups) and spatial distribution on infiltration and runoff:
Presence and thickness of compaction layer (usually none; describe soil profile features which may be mistaken for compaction on this site):
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:
Amount of plant mortality and decadence (include which functional groups are expected to show mortality or decadence):
Average percent litter cover (%) and depth ( in):
Expected annual annual-production (this is TOTAL above-ground annual-production, not just forage annual-production):
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:
Perennial plant reproductive capability:

Download reference sheet

Click on box and path labels to scroll to the respective text.

States 1, 5 and 8 (additional transitions)

1. Historic Community Bottomland Hardwood

5. Converted State - Pasture or Grassland

8. Forested