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Conservation Service
Ecological site F131AY312MS
Yazoo - Recent Wet Natural Levee and Meander Scroll Forest
Last updated: 6/10/2025
Accessed: 08/13/2026
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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): 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, 2006a).
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, 2006a).
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
There are no agency-approved and established Land Resource Units (LRUs) for MLRA 131A. However, the characteristics of each of the six subregions in this MLRA warrant noting and are presented here for each associated ecological site. This provisional ecological site is broadly mapped within the Yazoo Basin.
The Yazoo Basin is in northwest Mississippi and is the largest tributary basin within MLRA 131A. The MLRA boundary of the basin extends some 200 miles (north to south) from Memphis, Tennessee to Vicksburg, Mississippi; is about 60 miles wide (east to west) at its widest point; encompasses roughly 7,600 square miles; and is bounded by the Loess Hills to the east and the current Mississippi River channel to the west (Saucier, 1994; Klimas et al., 2011). Elevations range from 210 feet in the northern portions of the basin to about 85 feet in the south near Vicksburg (Kirchner et al., 1992).
The basin’s geomorphic features are dominated by abandoned Mississippi River meander belts and backswamp environments. The higher elevations of natural levees and point bar deposits (meander scrolls) form an alluvial ridge, which directs local drainage and floodwaters to the intervening flood basins or backswamps. Additional meander belt landforms that are quite common include abandoned channels (oxbow lakes) and courses (Saucier, 1994; Klimas et al., 2011). A minor feature of the Yazoo Basin is the Pleistocene-age valley train terraces, which comprise less than 5 percent of the total area (Saucier, 1994).
The movement of water through the Yazoo Basin is heavily influenced and controlled by the complex sequence of abandoned Mississippi River meander belts and distributary channels. Most surface water originates as precipitation (Berkowitz et al., 2020) or runoff from the uplands to the east, which are conveyed by the Coldwater, Yocona, Tallahatchie, and Yalobusha rivers in addition to several smaller streams. These systems, along with streams draining the interior portions of the basin (e.g., Big Sunflower River, Bogue Phalia, and the distributary Deer Creek), all flow to the only significant outlet for the basin, the Yazoo River, which enters the Mississippi River near Vicksburg (Saucier, 1994; Klimas et al., 2011).
Historically, large floods on the Mississippi River and in the Yazoo tributary system inundated most, if not all, of the Yazoo Basin (Moore, 1972). These periodic floods and the ponding aftereffects oftentimes lasted for very long durations (Berkowitz et al., 2020), delivering nutrient-rich sediments that are critical to the production and maintenance of the dominant natural vegetation, bottomland hardwood forests (Taylor et al., 1990; MMNS, 2015). Since settlement, the biophysical environment of the area has been vastly altered. Perhaps the most notable change entails extensive modification of the basin’s natural hydrology, which includes hundreds of miles of constructed levees along the mainstem of the Mississippi River and basin tributaries; channel modifications on many streams; water control structures; land leveled areas; and an extensive network of surface drainage systems (Kirchner et al., 1992). Even with these measures, widespread backwater flooding occurs in the southern portion of the area (Yazoo Backwater Area) when high stages are reached on the Mississippi River. The extensive modifications to the basin’s hydrology coupled with increased access (Hudson, 1979) set the stage for broadscale conversion of former forestland to a variety of land uses with agriculture production being dominant. Today, bottomland hardwood forests cover roughly 10 percent of the original forest area (Smith and Klimas, 2002).
The geographic distribution of all ecological sites within the Yazoo Basin is bounded to the west by an extensive, mainline levee system. Throughout its length, the constructed levee generally occurs within the current Mississippi River meander belt and is situated to the east of the active river channel. All lands between the river channel and the constructed levee are referred to as the Batture, and that subregion encapsulates its own complement of ecological sites due to significantly different hydrologic regimes (Smith and Klimas, 2002).Classification relationships
All or portions of the geographic range of this site fall within several ecological/land classifications including:
- NRCS Major Land Resource Area (MLRA) 131A – Southern Mississippi River Alluvium (USDA-NRCS, 2006a)
- National Hierarchical Framework of Ecological Units: 234 Lower Mississippi Riverine Forest Province; 234D White and Black River Alluvial Plains Section; 234Da North Mississippi River Alluvial Plain Subsection (Cleland et al., 2007)
- Environmental Protection Agency Level III Ecoregion: 8.5.2 Mississippi Alluvial Plain, 73; Level IV Ecoregion: Northern Holocene Meander Belt, 73a (Chapman et al., 2004; Wiken et al., 2011)
- Mississippi River Riparian Forest, CES203.190 (NatureServe, 2020)
- Riverfront Hardwoods (Putnam, 1951) or American Sycamore – Pecan – American Elm (Society of American Foresters, SAF, Type No. 94, variant) and Sugarberry – American Elm – Green Ash (SAF Type No. 93; Eyre, 1980)
- The following are hydrogeomorphic subclass, geomorphic setting, and potential natural vegetation association that dominantly coincides to or geometrically intersects the soil polygons of this ecological site (developed by Klimas et al., 2011): F4, Moderately drained lowlands, Sugarberry – Green Ash – American Elm; F5, Poorly drained Mississippi River sediments, Willow Oak – Cedar ElmEcological site concept
The distribution of this ecological site is largely confined to the more recent meander belt of the Mississippi River and its distributaries. Within the meander belt environment, the site occupies the low, wet toeslopes of recent natural levees and the level to nearly level areas of some meander scrolls. Of note, these features occur on abandoned Mississippi River segments that were naturally separated from the main river channel before construction of the mainline levee system. This is a “flood protected” ecological site occurring on the protected side of the constructed levee. In addition to meander belts, the soils of this site are broadly mapped along an important distributary of the Mississippi River and locally along the lower reaches of a few tributaries to the river. This site consists of deep, somewhat poorly to poorly drained soils that formed in loamy and clayey over loamy alluvium. Depending on horizon and local conditions, soil reaction ranges from medium acid to moderately alkaline. Slopes range from 0 to 5 percent. Natural vegetation of the site is generally on the wetter end of the riverfront association. Community components reportedly include American sycamore (Platanus occidentalis), pecan (Carya illinoinensis), American elm (Ulmus americana), sugarberry (Celtis laevigata), green ash (Fraxinus pennsylvanica), sweetgum (Liquidambar styraciflua), eastern cottonwood (Populus deltoides), silver maple (Acer saccharinum), red maple (A. rubrum), boxelder (A. negundo), red mulberry (Morus rubra), and persimmon (Diospyros virginiana). In some areas, several red oak species may be important associates such as water oak (Quercus nigra), willow oak (Q. phellos) and Nuttall oak (Q. texana). Dominance patterns are likely to vary tremendously with respect to location, and the prevailing forest type in some areas may be the sugarberry – American elm – green ash association. Former and current land use practices, local drainage patterns, and proximity to other community types, among other factors, will contribute to species variability on this site. Most areas, today, are cleared and under various forms of agriculture production.
Associated sites
F131AY302MS Yazoo - Wet Clayey Backswamp Flat Forest
This ecological site occupies the deep clayey backswamps, which adjoins F131AY312MS in some areas. Where this occurs, the heavy clay soils of the Sharkey series are typically the representative backswamp soils of site F131AY302MS.
F131AY301MS Yazoo - Frequently Flooded and Ponded Oxbow and Swale Forest
This site is characteristic of prominent depressions including oxbows, meander scroll swales, sloughs, and backswamp depressions. Locally, the deeper swales of F131AY301MS may adjoin the nearly level, poorly drained meander scroll environments of F131AY312MS.
F131AY311MS Yazoo - Recent Moderately Wet Natural Levee and Meander Scroll Ridge Forest
This ecological site occupies mid-slope positions that are intermediate to the higher, better drained loamy soils (F131AY310MS) and the lower, wetter toeslopes of F131AY312MS. Thus, F131AY311MS adjoins F131AY312MS on natural levees, meander scrolls, and riparian corridors of distributaries and tributaries.
F131AY304MS Yazoo - Wet Transitional Backswamp Forest
This ecological site occupies the transitional backswamp areas between the wet toeslopes of site F131AY312MS and the deep clayey backswamps of F131AY302MS.
Similar sites
F131AY214AR St. Francis - Recent Wet Natural Levee and Meander Scroll Forest
This site occupies similar positions and has similar drainage characteristics as the Recent Wet Natural Levee and Meander Scroll site (F131AY312MS). The principal difference is that F131AY214AR is situated in the St. Francis Basin.
F131AY403LA Tensas Basin - Poorly Drained Ridge and Swale Complex
This site occupies similar positions and has similar drainage characteristics as the Recent Wet Natural Levee and Meander Scroll site (F131AY312MS). The principal difference is that F131AY403LA is situated in the Tensas Basin.
F131AY503LA Delta Plain - Somewhat Poorly Drained Bottomland Hardwoods
This site occupies similar positions and has similar drainage characteristics as the Recent Wet Natural Levee and Meander Scroll site (F131AY312MS). The principal difference is that F131AY503LA is situated in the Delta Plain.
F131AY308MS Yazoo - Old Wet Natural Levee and Meander Scroll Forest
This site supports soils with similar drainage characteristics that occur on similar geomorphic features as site F131AY312MS, but the sites differ dramatically in their ages and time periods of deposition. The soils of F131AY312MS are of recent origin, whereas the soils of F131AY308MS are much older, more weathered, and have reactions that can be very strongly acid. Some locations have been abandoned by the parent stream for millennia. One characteristic that they have in common is that both occur on the protected side of the constructed levee system.
Figure 1. Distribution of site F131AY312MS
Table 2. Dominant plant species
Tree Not specified
Shrub Not specified
Herbaceous Not specified
Physiographic features
This ecological site is largely confined to the more recent meander belt of the Mississippi River. Within the meander belt environment, these deep, somewhat poorly and poorly drained soils occupy the wet toeslopes of natural levees and subtle rises and talfs (i.e., flats) of meander scrolls. These meander belt features occur on former Mississippi River segments that were naturally separated from the main river channel (via abandoned channels and courses) before construction of the extensive levee system along the east bank of the river. Therefore, the meander belt occurrences of this site are protected from flood influences and have been for nearly a century.
The soils of this site are also mapped locally along an important distributary, Deer Creek, and a few tributaries to the Mississippi River. These locations are subject to flooding and likely continue to receive sedimentation during flood events.
(In the block diagram below, this site is represented and characterized by the Mhoon soil series.)
Figure 1. The recent natural levee - backswamp catena. Mhoon soils are representative of site F131AY312MS.
Table 3. Representative physiographic features
Landforms (1) Meander belt > Natural levee > Toe
(2) Meander belt > Meander scroll > Swale
Runoff class Medium to very high Flooding duration Very brief (4 to 48 hours) Flooding frequency None to rare Ponding duration Brief (2 to 7 days) Ponding frequency None to occasional Elevation 95 – 205 ft Slope 0 – 3 % Water table depth 18 – 21 in Aspect Aspect is not a significant factor Climatic features
Climate of the Yazoo Basin is classified as Humid Subtropical (Koppen System), which is typified by mostly mild winters; long, hot and humid summers; and no routinely recurring wet or dry season (Smith and Klimas, 2002; NCDC, 2018). The average annual air temperature from 1980 through 2010 was 64 degrees F and the mean annual precipitation for the same period was 55 inches.
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. A potential hazard during late summer through early fall is the tropical cyclone. 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 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. From 1980 through 2010, August and September were the driest months with a characteristic average monthly low of 2.5 and 2.8 inches, respectively. The hottest months of the year were July and August with characteristic average highs of 91 to 92 degrees and lows of around 72 degrees F.
In the colder season, the area’s weather is dominated by the positions of the Polar and Subtropical Jet Streams, both of which exerts strong control over the passages of cold and warm fronts. These fronts alternately bring cold continental air and warm tropical air with periods of varying length. Particularly strong cold fronts can produce large and sudden drops in air temperature; however, cold spells seldom last over a week (NCDC, 2018). The coldest month of the year is typically January with an average monthly low and high of 33 and 52 degrees, respectively. The frost-free period from 1980 to 2010 averaged 207 days basin-wide and ranged from 200 days in the northern areas to 216 days in the south. Likewise, the freeze-free period averaged 241 days and ranged from 238 in the north to 246 days in the southern part of the basin.
Snow and/or sleet falls in the area in most years with the greatest frequency and accumulations occurring in the northern extent of the basin. Winter precipitation sometimes occurs as freezing rain and damaging ice storms hit some portion of the basin on occasion. However, these wintry events are generally the exception; they are typically brief and do not persist for very long. Rain is the characteristic form of winter precipitation, and the period of greatest rainfall generally occurs from November through June with March and April being the months of greatest frequency (NCDC, 2018). Precipitation for this period typically ranges from 4.5 to around 6.0 inches per month.Table 4 Representative climatic features
Frost-free period (characteristic range) 200-220 days Freeze-free period (characteristic range) 240-250 days Precipitation total (characteristic range) 50-60 in Frost-free period (actual range) 200-220 days Freeze-free period (actual range) 230-250 days Precipitation total (actual range) 50-60 in Frost-free period (average) 210 days Freeze-free period (average) 240 days Precipitation total (average) 60 in Characteristic rangeActual rangeBarLineFigure 2. Monthly precipitation range
Characteristic rangeActual rangeBarLineFigure 3. Monthly minimum temperature range
Characteristic rangeActual rangeBarLineFigure 4. Monthly maximum temperature range
BarLineFigure 5. Monthly average minimum and maximum temperature
Figure 6. Annual precipitation pattern
Figure 7 Annual average temperature pattern
Climate stations used
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(1) LAKE PROVIDENCE [USC00165090], Lake Providence, LA
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(2) CHARLESTON [USC00221606], Charleston, MS
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(3) CLARKSDALE [USC00221707], Clarksdale, MS
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(4) CLEVELAND 3 N [USC00221743], Cleveland, MS
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(5) MOORHEAD [USC00226009], Moorhead, MS
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(6) LAMBERT 1W [USC00224869], Lambert, MS
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(7) MINTER CITY [USC00225897], Minter City, MS
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(8) ROLLING FORK [USC00227560], Rolling Fork, MS
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(9) BELZONI [USC00220660], Belzoni, MS
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(10) CLEVELAND [USC00221738], Cleveland, MS
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(11) GREENVILLE [USC00223605], Greenville, MS
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(12) STONEVILLE EXP STA [USC00228445], Leland, MS
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(13) TUNICA 2 N [USC00228998], Tunica, MS
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(14) GREENWOOD LEFLORE AP [USW00013978], Carrollton, MS
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(15) YAZOO CITY 5 NNE [USC00229860], Yazoo City, MS
">Influencing water features
This site occurs in a variety of alluvial plain situations that are water receiving positions including wet toeslopes of recent natural levees, low ridges and “high flats” of meander scrolls, and the corridors of active tributaries to and a distributary of the Mississippi River. Today, this site occurs on the protected side of the extensive levee system and no longer receives overland flooding on the same scale that it may have experienced prior to levee construction. The locations that may continue to flood on any predictable basis are typically restricted to stream corridors and other low features (e.g., depressions) that may receive overland flow or backwater flooding. The seasonal high water table and poorly drained soils of this site provide suitable conditions for obligate and facultative wetland plants. This site is influenced by local hydrologic regimes.
Wetland description
Under the Cowardin et al. (1979) system, this site is classified as:<br />
System: Palustrine<br />
Class: Forested Wetland<br />
Subclass: Broad-leaved DeciduousSoil 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 General Information section of this description to determine if another site may be a better fit for your area of interest.
This site is characterized by deep, somewhat poorly drained and poorly drained soils that formed in recent loamy, and clayey over loamy Mississippi River alluvium. Slopes are dominantly 0 to 3 percent but may range upward to 5 percent. Depending on location, landuse history, and soil horizon, reactions generally range from moderately acid to moderately alkaline. The available water capacity is high; organic matter content is moderate; and natural fertility is high. A seasonal water table of 0 to 3 feet generally occurs during the wetter periods of winter into early spring, and all underlying layers are wet.
Two soil series are associated with the site: the Bowdre (clayey over loamy, smectitic, thermic Fluvaquentic Hapludolls) series and the Mhoon (fine-silty, mixed, superactive, nonacid, thermic Fluvaquentic Endoaquepts) series. Bowdre soils are somewhat poorly drained and formed in layered alluvium consisting of a thin clayey layer over loamy and sandy lower layers. Depth to the contrasting loamy layers ranges from 12 to 20 inches from the surface. Permeability is slow in the clayey surface layers but moderate in the underlying loamy material. Another distinction of Bowdre soils is the presence of a mollic epipedon that extends to a depth of approximately 16 inches from the surface.
Mhoon soils are poorly drained and formed in loamy sediments. They are fine-silty in the particle-size control section. The Bg horizon averages 25 to 35 percent clay and 10 to 30 percent sand that is dominantly very fine sand. The Cg horizon has similar characteristics as the Bg horizon except that in some pedons, it averages more than 35 percent clay. Permeability is slow throughout and some areas are subject to ponding.Table 5. Representative soil features
Parent material (1) Alluvium
Surface texture (1) Clay
(2) Silty clay
(3) Silty clay loam
Drainage class Poorly drained to somewhat poorly drained Permeability class Slow to moderate Soil depth 80 in Surface fragment cover <=3" Not specified Surface fragment cover >3" Not specified Available water capacity
(Depth not specified)5.9 – 7.9 in Calcium carbonate equivalent
(Depth not specified)0 – 3 % Electrical conductivity
(Depth not specified)Not specified Sodium adsorption ratio
(Depth not specified)Not specified Soil reaction (1:1 water)
(Depth not specified)6.5 – 7.3 Subsurface fragment volume <=3"
(40in)Not specified Subsurface fragment volume >3"
(40in)Not specified Ecological dynamics
Historically, this ecological site was part of a vast forested landscape with processes and functions directly connected to the highly dynamic nature of the Mississippi River (Gardiner and Oliver, 2005). Today, this site is effectively disconnected from the river via the vast network of constructed levees and, in many areas, local drainage controls. Widespread changes to the landscape occurred long before any intensive studies of the historic natural communities were conducted. Accordingly, reference conditions of this ecological site are still under review.
This site was primarily created by recent alluvial deposits on natural levees and meander scroll features of the Mississippi River and its tributaries. These younger deposits are distinguished from their much older counterparts of long abandoned meander belts (see site ID: F131AY308MS) in having weaker pedogenic horizon development and nonacid reactions.
Plant communities that develop on this site undergo dramatic changes over time. When these soils are first deposited, early colonizers primarily consist of black willow and eastern cottonwood (Eyre, 1980). The wetter soils and low landscape position of this site may favor black willow, especially in areas that are frequently flooded over extended growing season durations. Otherwise, eastern cottonwood is capable of exceptional growth on these moist soils and often rapidly dominates the developing stand (Williamson, 1913; Erye, 1980). Broadfoot (1960) indicated that eastern cottonwood can attain a height of 115 feet within 30 years of growth on this site. Stands can become very dense and the canopy nearly pure in composition, but the eastern cottonwood forest type (SAF Type No. 63; Eyre, 1980) is temporary on this site. The species does not tolerate competition from weeds, vines, and other woody species and cannot naturally regenerate itself due to extreme shade intolerance (Williamson, 1913; McKnight, 1969; Eyre, 1980; Hodges, 1995). Natural “break up” of cottonwood stands may begin as early as 35 years after establishing, and by year 85, stands are transitioning to the next successional community in the eastern riverfront forest association (Meadows and Nowacki, 1996).
Components of the succeeding riverfront community often begin filtering into the cottonwood stand by occupying canopy gaps and becoming established beneath the light to moderate shade cast by the cottonwood canopy (Williamson, 1913; Johnson and Shropshire, 1983). The succeeding association is generally comprised of American sycamore, pecan, American elm, sugarberry, green ash, silver maple, red maple, and boxelder and cottonwood may continue to persist as a minor component. Broadfoot and McKnight (1961) listed additional components of sweetgum, Nuttall oak, water oak, and willow oak as frequently to occasionally occurring on the soils of this site. The cover type generally recognized as representing the riverfront forest in the Mississippi River Valley is the American sycamore – pecan – American elm type, which is a variant of the American sycamore – sweetgum – American elm cover type (SAF Type No. 94; Eyre, 1980).
The eastern riverfront forest is reportedly an intermediate sere or successional stage between the pioneer eastern cottonwood type and a third succeeding forest type, the sweetgum – water oaks (water oak, willow oak, and Nuttall oak) type (Putnam et al., 1960). Sweetgum and water oaks begin to gradually invade the riverfront forest after about 80 years of it having replaced the initial cottonwood stand. Eventually, the sweetgum – water oaks type dominates and replaces the riverfront association in about 85 years after first initial invasion. In all, 250 years may be required for the succession and transition of the initial cottonwood – willow colonization to the replacement of the riverfront forest by the sweetgum – water oaks type (Shelford, 1954; Meadows and Nowacki, 1996). Hodges (1997), however, offers an alternate scenario regarding the succession of the riverfront community. After persisting for 75 to 125 years, the riverfront association may then be replaced by either the American elm – green ash – sugarberry association or the red oak (water, willow, and Nuttall) – sweetgum type. The pathway leading to either type ultimately depends on the occurrence and level of disturbance (e.g., a catastrophic stand replacing event) and the presence of advance regeneration within the stand prior to disturbance. In the absence of large-scale disturbances, the long-term trend favors the development of the American elm – green ash – sugarberry association, which is capable of self-replacement and can persist for 200 to 300 years (Hodges, 1997; Stanturf et al., 2001). It is unclear whether this level of succession has taken place on the recent soils of this site. Information from multiple sources suggest that the riverfront association may be the dominant forest type on this site (e.g., USDA-SCS, 1961a; USDA-SCS, 1961b; USDA-SCS, 1990; USDA-NRCS, 2004). Furthermore, repeated disturbances such as severe flooding and forest operations may promote persistence of the eastern riverfront association for many years (Sharitz and Mitsch, 1993; Meadows and Nowacki, 1996). Still, the reported occurrence of several important “water oak” species (i.e., Nuttall oak, water oak, and willow oak) on the soils of this site by Broadfoot and McKnight (1961) suggests that, at a minimum, this site is capable of supporting and producing one of the more desired forest associations in the MLRA, the sweetgum – water oaks forest complex (Oliver et al., 2005).
Overall, natural cover types on this site are minor compared to other uses. Most areas have been cleared and are used extensively for production, and many areas have been land leveled to meet irrigation needs. A secondary use on this site is pasturage.
Following this narrative, a “provisional” state and transition model is provided that includes the “perceived” reference state and several alternative (or altered) vegetation states that have been observed and/or projected for this ecological site. This model is based on limited inventories, literature, expert knowledge, and interpretations. Plant communities may differ from one location to the next depending on the severity of local land use activities and rates of deposition. Depending on objectives, the reference plant community may not necessarily be the management goal.
The environmental and biological characteristics of this site are complex and dynamic. As such, the following diagram suggests pathways that the vegetation on this site might take, given that the modal concepts of climate and soils are met within an area of interest. Specific locations with unique soils and disturbance histories may have alternate pathways that are not represented in the model. This information is intended to show the possibilities within a given set of circumstances and represents the initial steps toward developing a defensible description and model. The model and associated information are subject to change as knowledge increases and new information is garnered. This is an iterative process. Most importantly, local and/or state professional guidance should always be sought before pursuing a treatment scenario.State and transition model
Custom diagramStandard diagramMore interactive model formats are also available. View Interactive Models
Click on state and transition labels to scroll to the respective textEcosystem states
States 1, 5 and 2 (additional transitions)
States 3 and 7 (additional transitions)
T1A - Manipulate composition and manage for production (Community 2.1); heavy timber cutting or repeated partial harvests with no management (Community 2.2). T1B - Vegetation/stump removal (mechanical/chemical); preparation for cultivation. T1C - Vegetation/stump removal (mechanical/chemical); seedbed preparation; establishment of desired forage; manage for grazing. T2A - Reestablish missing species; control exotics (mechanical/chemical); timber stand improvement; natural stand dynamics. T2B - Vegetation/stump removal (mechanical/chemical); preparation for cultivation. T2C - Vegetation/stump removal (mechanical/chemical); seedbed preparation; establishment of desired forage; manage for grazing. T3A - Precision land leveling. T3B - Vegetation/stump removal (mechanical/chemical); seedbed preparation; establishment of desired forage; manage for grazing. T3C - Natural succession (Community 6.1) or prepare area (plow pan breakup, fertilizing, etc.) and plant species appropriate for site (Afforestation - Community 6.2). T3D - Establish select native species suitable for site; prepare for planting (herbicide and/or mechanical). T5A - Vegetation/stump removal (mechanical/chemical); preparation for cultivation. T5B - Natural succession (Community 6.1) or prepare area (plow pan breakup, fertilizing, etc.) and plant species appropriate for site (Afforestation - Community 6.2). T5C - Establish select native species suitable for site; prepare for planting (herbicide and/or mechanical). T6A - Vegetation/stump removal (mechanical/chemical); preparation for cultivation. T6B - Vegetation/stump removal (mechanical/chemical); seedbed preparation; establishment of desired forage; manage for grazing. T7A - Vegetation/stump removal (mechanical/chemical); preparation for cultivation. T7B - Vegetation/stump removal (mechanical/chemical); seedbed preparation; establishment of desired forage; manage for grazing. T7C - Natural succession (Community 6.1) or prepare area (plow pan breakup, fertilizing, etc.) and plant species appropriate for site (Afforestation - Community 6.2). State 1 submodel, plant communities
State 2 submodel, plant communities
2.1A - Cessation of management followed by heavy cutting or repeated partial harvests. 2.2A - Silvicultural treatments: removal of undesirable species; reestablish species favored in management; timber stand improvement; establish advance regeneration. State 3 submodel, plant communities
3.1A - Soil disturbance (tillage); reduction of soil health 3.1B - Conventional tillage, seeding, and fertility management for crops. 3.2A - No-till, cover crops, reduced till-soil health improvements. 3.2B - Conventional tillage, seeding, and fertility management for crops. 3.3A - Reduced till, no till, and cover crops with soil heath improvements as a goal. State 4 submodel, plant communities
State 5 submodel, plant communities
5.1A - Seeding and/or management for desired species composition. 5.1B - Species management without overseeding. 5.2A - Seeding, fertilizing, management/removal of undesirable species. 5.2B - Species management without overseeding. 5.3A - Seeding, fertilizing, management/removal of undesirable species. 5.3B - Seeding and/or management for desired species composition. 5.3C - Lack of disturbance; no (infrequent) mowing, herbivory, or brush management; natural succession of woody species. 5.4A - Brush management/removal of unwanted species. State 6 submodel, plant communities
6.1A - Remove undesirable competitors; final soil preparation; establish site-appropriate species (favored in management). State 7 submodel, plant communities
State 1
Reference: Wet Riverfront HardwoodsRemoval of the pre-settlement natural communities of this site occurred long before thorough studies and investigations were conducted. Modifications to the Yazoo Basin’s natural hydroperiod and drainage patterns coupled with location-specific land use histories have further complicated species-site relationships. Such complexity across the Yazoo Basin will likely be reflected in much variability in vegetation composition and structure of local forest stands (Stanturf et al., 2001). Accordingly, reference conditions for this site have yet to be confirmed, but they are perceived to consist of mature forest stands that support a diverse mix of southern bottomland hardwoods adapted to the somewhat poorly and poorly drained soils of this site. Once assigned or identified, the reference community will not represent the pre-settlement forest community, but it should identify an assemblage of naturally occurring species that reflects and contributes to regional biodiversity and local forest ecology. Implicated in the latter is that the “local” geomorphic features and drainage patterns of this soil-site environment should not have been drastically altered or removed (e.g., land leveled).
The return or transition pathway from the altered states (currently, only State 2) back to reference conditions is intended to represent the suite of hardwood species that, reportedly, frequently to occasionally occur and are favored in management on this site. Realistically, it may not always be possible to return to a “perceived” reference state from a former altered condition. While planting and establishing trees appropriate for a site may be possible, achieving restoration of the understory and other system functions are challenges that may never be realized (Stanturf et al., 2001; Flinn and Vellend, 2005).Community 1.1
Mixed Bottomland HardwoodsThe reference community of this site may vary depending on the local environment. This site mainly includes toeslopes on protected former natural levees and meander scrolls. Where the site occurs along active tributaries or stream systems, deposition may continue to occur during flood events. Plant composition and community structure along active stream systems may be strongly influenced by the amount of material deposited, when the last major deposition occurred, and pre-existing vegetation along the stream corridor or floodplain. Still, many of the same components of the abandoned meander belts will likely occur along stream corridors, although species composition and dominance patterns could vary locally.
Following initial deposition, colonizing vegetation may be predominantly comprised of black willow and eastern cottonwood (Eyre, 1980). The latter typically assumes dominance on these productive soils and can attain an average height of 115 feet in 30 years of growth (Broadfoot, 1960). Such rapid growth often leads to dense stands that are almost entirely comprised of eastern cottonwood (Johnson and Shropshire, 1983; Meadows and Nowacki, 1996). Shelford (1954) documented associates in young developing cottonwood stands to include black willow in lower elevations and occasional American sycamore and a ground cover of trumpet creeper (Campsis radicans) and grape vines (Vitis spp.) co-occurring with cottonwood trees.
As the cottonwood stand matures and natural break up begins, stands can become dense in the understory and midstory with components of the succeeding community, the American sycamore – pecan – American elm type. Associates of the latter may include sugarberry, green ash, silver maple, boxelder, river birch (Betula nigra), cedar elm (Ulmus crassifolia), sweetgum, and red maple with occasional cottonwood stems persisting into the succeeding stand. Additional components may include water oak, willow oak, and Nuttall oak, especially in older stands. Bald cypress (Taxodium distichum) and overcup oak (Quercus lyrata) may occasionally occur in the wettest locations, and the driest locations may support cherrybark oak (Q. pagoda) (Broadfoot, 1964a). Species characteristic of active stream corridors may include river birch, eastern cottonwood, black willow, American sycamore, boxelder, and American holly (Ilex opaca). Understory composition may be quite variable depending on the degree of canopy openings or overstory shade but may consist of seedlings and saplings of the preceding in addition to American hornbeam (Carpinus caroliniana), red mulberry, possumhaw (I. decidua), blackberry (Rubus sp.), and giant cane (Arundinaria gigantea). A dense woody vine cover is typically present and often represented by poison ivy (Toxicodendron radicans), grape (Vitis spp.), Virginia creeper (Parthenocissus quinquefolia), peppervine (Nekemias arborea), American buckwheat vine (Brunnichia ovata), greenbrier (Smilax spp.), and trumpet creeper (Campsis radicans) (Shelford, 1954; Eyre, 1980; Meadows and Nowacki, 1996; MMNS, 2015).
There is indication that a third community, the sweetgum – water oaks (Meadows and Nowacki, 1996) or American elm – green ash – sugarberry type, will eventually replace the American sycamore – pecan – American elm association (Eyre, 1980; Meadows and Nowacki, 1996; Hodges, 1997). This is a complex process that includes many different factors and many years to take place (Klimas et al., 2011). It is unclear and unknown whether the latter transition has occurred to any degree on this site.
Evaluations of the productive potential of this site were reported for several important forest components. The following are productivity estimates (site index or height at 50 years except cottonwood which is 30 years) of five select species that were generated on the two principal soil series of this site. These data were generated from dominant and codominant trees in well-stocked stands that had no modifying influence or manipulated treatments; information was gathered under natural conditions (Broadfoot, 1963).
Eastern cottonwood averaged 114 feet on Mhoon, level phase soils; 103 feet on Mhoon, sloping phase; 115 feet on Bowdre, level phase; and 94 feet on Bowdre, sloping phase units (Broadfoot, 1960).
Sweetgum averaged 100 feet on Mhoon, level phase and 97 feet on Bowdre, sloping phase (Broadfoot and Krinard, 1959).
Cherrybark oak heights are estimated to range from 90 to 99 feet on Mhoon soils (Broadfoot, 1961). This range suggests wetness issues on this site for cherrybark, and the species is likely unsuitable for establishing on most locations (Mike Oliver, Forester, personal communication).
Willow oak heights ranged from 105 to 114 feet on Bowdre, sloping phase soils (Broadfoot, 1964b).
Water oak heights ranged from 95 to 104 feet on Bowdre, level phase; 90 to 99 feet on Bowdre, sloping phase; and 85 to 94 feet on Mhoon, level phase soils (Broadfoot, 1963).Dominant plant species
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eastern cottonwood (Populus deltoides), tree
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American sycamore (Platanus occidentalis), tree
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American elm (Ulmus americana), tree
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green ash (Fraxinus pennsylvanica), tree
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sugarberry (Celtis laevigata), tree
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pecan (Carya illinoinensis), tree
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sweetgum (Liquidambar styraciflua), tree
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red maple (Acer rubrum), tree
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willow oak (Quercus phellos), tree
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Nuttall oak (Quercus texana), tree
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trumpet creeper (Campsis radicans), shrub
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grape (Vitis), shrub
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eastern poison ivy (Toxicodendron radicans), shrub
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Virginia creeper (Parthenocissus quinquefolia), shrub
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peppervine (Nekemias arborea), shrub
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American buckwheat vine (Brunnichia ovata), shrub
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greenbrier (Smilax), shrub
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possumhaw (Ilex decidua), shrub
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blackberry (Rubus), shrub
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giant cane (Arundinaria gigantea), shrub
State 2
Commercial ForestlandThis state consists of two very different community phases and management approaches. Community Phase 2.1 represents forest management and production on this site. A distinguishing feature of this phase is the level of management intensity designed to maximize merchantable goals. Various silvicultural methods are available for selection, and these are generally grouped into even-aged (e.g., clearcutting, seed-tree, and shelterwood) and uneven-aged (e.g., single tree, diameter-limit, basal area, and group selection) approaches (Meadows and Stanturf, 1997). Depending on the method selected, different structural and compositional characteristics of the stand may result. Removal and control of community associates are typically a critical element of production goals. These actions may result in different community or “management phases” (and possibly alternate states) depending on the methods used and desired results. Finding the appropriate approach for a given stand and environment necessitates close consultation with trained, experienced, and knowledgeable forestry professionals. If there is a desire to proceed with this state, it is strongly urged and advised that professional guidance be obtained and a well-designed silvicultural plan developed in advance of any work conducted.
Community Phase 2.2 represents conditions of many stands that have incurred indiscriminate timber harvests (e.g., heavy cutting or diameter-limit harvests of select species) and opportunistic regrowth following such harvests (i.e., no management at any period). Some stands may continue to support a few desirable species and quality stems, but in many instances, affected stands will be comprised of mostly shade tolerant species or trees of desirable species that are defective and fail to meet their maximum potential. (Because of the intensive management required to rehabilitate affected stands, this community phase may warrant elevation to a standalone state. This should be considered in future iterations of this site’s development.)
Although this site is well suited for forest production, seasonal wetness imposes moderate to severe limitations for some forest operations. The principal management concerns are equipment limitations, intense plant competition, and seedling mortality (USDA-SCS, 1990; USDA-NRCS, 2004). Seasonal wetness and periods of heavy precipitation can impose limitations on heavy equipment usage. If possible, equipment operations are best conducted during drier periods of the year, which minimizes soil damage, compaction, erosion, and helps to maintain productivity. A seasonal high water table can kill recently planted seedlings, especially if they are not suited to these wet soils.
An important caveat of this state is its representation of forest conditions that have retained full site production potential. Currently, transitional pathways to this state originate from another forested state (State 1), only. Former land uses (alternate states) that result in altered conditions of the soil environment (e.g., land leveling) may deleteriously affect predicting and planning for species site selection, tree productivity, and possibly survival of the targeted species. State 6 (Forest Recovery) is representative of forest establishment and growth on locations where soil compaction and reduction of nutrients have occurred due to former land practices. Once a previously affected location has recovered its site potential, transition to this state may be possible. That potential transition is still under review and is currently not shown or addressed in the state and transition model.Community 2.1
Forest ManagementPrescribing a silvicultural system for a given stand depends on species composition and long-term production and postproduction goals (Gardiner et al., 2002). The canopy trees listed in State 1 as “favored in management” are all production options on this site ranging from single species plantations to complex multi-species stands.
Two major forest types potentially suited for this site are the eastern cottonwood and the American sycamore – pecan – American elm types. Eastern cottonwood is the fastest growing commercial forest species in eastern North America (Cooper and Van Haverbeke, 1990), and because of this attribute, it has been utilized in short pulpwood rotations (Cao and Durand, 1991) and in sawtimber operations (Johnson and Shropshire, 1983). Challenges to eastern cottonwood production are its extreme shade intolerance and its inability to cast dense shade over the understory. Due to shade intolerance, it cannot succeed itself naturally and requires mechanical site preparation (or scarification) to expose the soil surface prior to reestablishing. The relatively “light shading” that its canopy produces permits invasion of shade tolerant species. Many such stands may have dense midstories and understories of American sycamore, pecan, green ash, sugarberry, American elm, boxelder, silver maple, and occasionally sweetgum (Johnson and Shropshire, 1983; Hodges, 1995; Meadows and Stanturf, 1997) – all associates of the American sycamore – pecan – American elm type. In general, mixed species stands of the latter will regenerate to the same canopy species with most any regeneration method. Uneven-aged approaches such as single-tree and small group selection harvests may favor proportionally more shade tolerant species (e.g., sugarberry and American elm), while even-aged methods such as seed-tree and clearcuts tend to benefit shade intolerant taxa like pecan, American sycamore, and sweetgum (Meadows and Stanturf, 1997).
Another option may be the establishment and production of one or more components of “water oaks” (i.e., Nuttall, willow, and water) on this site (see Community Phase 1.1 for site indices and general statements). Establishing and maintaining oaks on bottomland sites may be preferred given the multiple values they provide (e.g., timber and wildlife). However, Broadfoot (1976) cautioned against the planting of oaks if soil pH for a given location is around 7.5. Therefore, each targeted location should be carefully assessed and examined before costs are incurred and seedlings planted. If, however, a given location is suitable for planting oaks, then maintaining that component beyond a single rotation (or harvest) may be the most challenging. Creating conditions that promote oak persistence in future stands require a sufficient advance regeneration component. Ensuring that this future crop is established will require close adherence to a well-designed silvicultural plan, which requires programmatic intermediate operations (e.g., improvement cuttings, thinnings, and other partial cuttings). An even-aged silvicultural system that utilizes the clearcutting regeneration method along with brush management to reduce subsequent competition is typically the advocated approach when harvesting bottomland oak stands (Johnson and Shropshire, 1983; Clatterbuck and Meadows, 1993; Hodges, 1995; Meadows and Stanturf, 1997; Oliver et al., 2005).Dominant plant species
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eastern cottonwood (Populus deltoides), tree
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sweetgum (Liquidambar styraciflua), tree
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willow oak (Quercus phellos), tree
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water oak (Quercus nigra), tree
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Nuttall oak (Quercus texana), tree
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American sycamore (Platanus occidentalis), tree
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green ash (Fraxinus pennsylvanica), tree
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pecan (Carya illinoinensis), tree
Community 2.2
Non-managed/High-gradedThis forest community is directly influenced by former harvesting practices that include repeated single-tree selection or diameter-limit harvests with no additional management activities (i.e., brush management, competitor control, etc.). These practices typically target the highest quality trees of the most desirable species. The result is usually an expansion and in-filling of shade tolerant subcanopy trees. Over time, this practice will lead to a predominantly shade tolerant community that may be comprised of American elm, sugarberry, winged elm, boxelder, roughleaf dogwood, and possumhaw (Putnam et al., 1960).
Pathway 2.1A
Community 2.1 to 2.2Heavy cutting of the stand that removes the desired species (typically shade intolerant species) of sufficient diameters followed by no management of the residual stand. This pathway also includes repeated single-tree harvests (e.g., diameter-limit cuts) that removes the desired species followed by no management of the residual stand. The resulting stand is typically comprised of shade tolerant species with low commercial value.
Pathway 2.2A
Community 2.2 to 2.1Intensive management will be required to push a shade tolerant community into a more commercially desirable and viable system. Actions will likely require a complete clearcut of the stand followed by repeated brush and competitor control (chemical and mechanical). If there is a lack of seed source, artificial regeneration will likely be required to reintroduce heavy-seeded species (e.g., oaks). Continual competitor control will be needed.
State 3
CroplandThis state is representative of the dominant land use activity on this ecological site, agriculture production. Crops reportedly grown on this site include cotton (Gossypium hirsutum), corn (Zea mays), soybeans (Glycine max) and small grains such as wheat (Triticum aestivum) (USDA-SCS, 1961a; USDA-SCS, 1961b). Minor crops, such as some specialty crops (e.g., fruits, vegetables, and tree nuts such as pecans), may be grown locally.
The soils of this site are moderately to well suited to agriculture production depending on local hydrologic regimes and drainage patterns (USDA-SCS, 1990; USDA-NRCS, 2004). They have high available water capacity, natural fertility, and pH levels. Applications of fertilizer and lime may not be a necessity everywhere or in every circumstance. Soil tests should be conducted to determine fertilizer needs on a specific field and for a given crop (USDA-SCS, 1990). Management concerns are largely centered on seasonal high water tables, slow permeability and runoff, delayed plantings, soil compaction under equipment traffic, poor tilth, development of a plow pan, and low to moderate organic matter content (USDA-SCS, 1961a; USDA-SCS, 1961b; USDA-SCS, 1990). Areas that are prone to flooding or extended periods of wetness may not be suitable for small grain crops or to crops that require planting in April and May (USDA-SCS, 1990). Management measures to ameliorate some of these issues may include implementing a conservation tillage or management system; subsoiling to breakup plow pans; restricting tillage to appropriate soil moisture content; and establishing a drainage system or network in problematic areas (USDA-NRCS, 2004; USDA-NRCS, 2006b). Of caution, subsurface drainage systems (e.g., pipes or tiles) may not be effective in every situation due to slow permeability or localized flooding (USDA-SCS, 1990). Major components that producers generally develop and plan are proper selection of crop cultivar, pest control, cropping system, tillage methods, nutrient management, and water management (Snipes et al., 2005). Key practices of some cropping systems often include two or more crops grown in a multiyear rotation, which has been documented to disrupt pest cycles. Leaving crop residue on the surface can help to maintain tilth, fertility, and organic matter content – all critical elements of soil quality and health. For monoculture cropping systems, the implementation of well-designed pest and nutrient management systems are imperative (Pringle et al., 2017). (For assistance, interested parties are advised to visit their local NRCS Field Office.)
Three separate management phases comprise this state: Conservation Management (3.1), Transitional Conservation Management (3.2), and Conventional Management (3.3). The three phases consist of varying tillage methods and approaches to soil health management systems.Community 3.1
Conservation ManagementThis cropland phase utilizes long term, continuous conservation management systems that include reduced till and cover crops; no-till with cover crops; crop residue retention; and perennial cropping systems. The guiding principles of this system are minimizing soil disturbance and maximizing soil cover, biodiversity, and the presence of living roots. Implementing diverse crop rotations while maintaining these principles can lend to the development of an integrated pest management plan and contribute to overall system resilience.
Of caution, the above-ground crop growth or yields may not be the best tracking mechanism for assessing the efficacy or presence of this management phase. Indicators of these systems are generally determined via soil-site assessments with outcomes that may include enhanced soil aggregate stability, increased soil biological activity, higher organic matter content, and improved water holding capacity and infiltration rates while also alleviating soil compaction and reducing runoff and erosion (Chessman et al., 2019). Additional advantages to this system that have been noted by some producers are reductions in fuel and labor costs and less wear and tear on machinery and equipment.
There are challenges to this management system, especially in situations where tillage may be considered and/or needed to repair weather damage or other detrimental impacts. Implementation of conventional tillage even after long term conservation practices (e.g., no-till) can reset the affected area back to a conventional cropping system. However, those changes can be reversed and a return to a conservation management system is achievable.
Critical conservation practices associated with this phase include cover crops, no-till, and reduced till as the foundational practices. Additionally, this phase may include supporting and site-specific practices to address conservation needs for a given location.Community 3.2
Transitional Conservation ManagementThis cropland phase utilizes a hybrid approach that combines conventional methods with conservation practices at specific periods and under specific situations. Practices under this phase may include a combination of conventional till, reduced till, strip till, and the inclusion of cover crops. For instance, perennial crop species could be in a continuous transitional phase where conventional tillage is implemented at the time of planting followed by reduced tillage during the rotation. Planted forage crops could also be included in this phase, especially when part of a crop rotation that utilizes reduced tillage for one crop followed by conventional tillage for a succeeding crop.
The development, implementation, and refinement of nutrient and pest management plans throughout component operations are imperative. Additionally, this phase may include supporting and/or site-specific practices to address conservation needs for a given location.Community 3.3
Conventional ManagementThis management phase is representative of conventional cropland where tillage is implemented as an annual component of the production system. As crucial elements of the system, conservation practices such as nutrient and pest management are needed to address fertility requirements and pest concerns within the crop cycle. It is important to note that this phase may develop when tillage is implemented to address damage or for other purposes while under a conservation management system (Community Phase 3.1). There could also be associated, supporting, and site-specific practices that are needed to address specific conservation needs. Specific needs may include grade stabilization structures to control gully erosion, grassed waterways to trap sediment from sheet and rill erosion, or implementing reduced till.
Pathway 3.1A
Community 3.1 to 3.2Soil disturbance (tillage); reduction of soil health.
Pathway 3.1B
Community 3.1 to 3.3Conventional tillage, seeding, and fertility management for crops.
Pathway 3.2A
Community 3.2 to 3.1No-till, cover crops, reduced till-soil health improvements.
Pathway 3.2B
Community 3.2 to 3.3Conventional tillage, seeding, and fertility management for crops.
Pathway 3.3A
Community 3.3 to 3.2Reduced till, no-till, and cover crops with soil health improvements as a goal.
State 4
Land Formed CroplandThis level to nearly level ecological site oftentimes adjoins gently sloping to undulating landscapes. It is bordered by soils of varying textures and drainage characteristics. Accordingly, inconsistencies in wetness and dryness, ease of operation, and production or yields may occur across a cropped location. An increasingly common practice consists of land forming or leveling surface irregularities into a predetermined and engineered, uniform slope. This practice removes drier and higher features, which are then used to fill wetter and lower positions (e.g., depressions or swales) across the targeted area. Advantages of land leveling may include reduced hazards of erosion and runoff rates, improved surface drainage, and enhanced distribution and conservation of irrigation water. Disadvantages of the practice is a churning of various surface and subsurface materials (former soil horizons) that no longer occur in a predictable or regular pattern. Organic matter content in the surface layer is generally low, and the surface tends to crust and pack after heavy rains (USDA-NRCS, 2006b). One potential hazard that appears to be emerging in some areas is the need for managing surface water runoff. As both irrigated and stormwater runs off leveled fields at uniform rates, surface water tends to collect cumulatively and simultaneously, which places tremendous demands on local drainage systems. Without “in field” structures (natural or artificial) to stagger runoff, the downslope (or lower) ends of some fields tend to back flood thereby contributing to more flooding overall in local watersheds (personal observations).
Immediately following land leveling, the constituent elements of soil health are likely to be absent. In some areas, producers have initiated practices such as applying organic residues (e.g., poultry litter) or growing rice crops for one to two years to rapidly boost fertility and introduce organic matter (via rice biomass) in the surface layer. Over time, the full complement of the management (or community) phases of State 3 may be possible on land leveled fields. They are not repeated or indicated here.
Currently, this state serves as an endpoint in the state and transition model because the ability to predict vegetation response when transitioning to a different state is no longer possible without soil-site investigations for each area of interest. The former soils of this ecological site, including surface and subsurface horizons, will have been redistributed as particles among other former soils.Community 4.1
Land Leveled CroplandSome of the crop species and management practices indicated and discussed in State 3 (including all three management phases) may be suitable for establishing on land leveled areas that once supported the soils of this site. However, the type of crops suited for newly leveled areas may ultimately depend on the prevailing soil particle-size distribution and internal drainage characteristics. Former studies on precision leveled fields have noted variabilities and inconsistencies in soil particle-size distributions, bulk density, soil biological properties, and nutrients (Brye et al., 2003; Walker et al., 2003; Brye et al., 2006). Management concerns for this phase may consist of restricted permeability, low organic matter content, and crusting and packing (USDA-NRCS, 2006b). These impacts may be improved by implementing conservation tillage, cover crops, retaining crop residue, and nutrient and pest management strategies.
State 5
Pastureland/GrasslandThis state is representative of areas that have been converted to and maintained in pasture or grassland. In 1991, the soils of this site were placed in Pasture Suitability Groups 4a (Bowdre soils) and 5a (Mhoon soils) for the State of Mississippi. These groups consist of somewhat poorly and poorly drained nonacid clayey soils (Group 4a) and poorly drained loamy acid soils (Group 5a) with a root zone of 20 to 40 inches. (Although Mhoon soils were placed in Group 5a, a better fit may be Group 4a, or another group, due to its nonacid reaction class.) Limitations of this state are mainly associated with a seasonally high water table and the flooding of areas that are located along active tributaries. High water tables over long durations will restrict root growth and establishing plants in particularly wet locations may prove challenging. The soils of this site are suited to most commonly grown forage species except bahiagrass (Paspalum notatum), crimson clover (Trifolium incarnatum), and some cool season annual forage plants. Note that bahiagrass and crimson clover do not respond well where soil reactions are above 6.5 (Houck, 2009; Young-Mathews, 2013). Overall, forage production is considered moderate to high when adequately fertilized and properly managed. Lime may not be needed on these nonacid soils.
Given that this ecological site occurs on lower, wetter soils, some forage operations may experience multiple wetness events in a single year. Management concerns are mainly centered on soil compaction due to grazing (USDA-NRCS, 2006b), and overgrazing can lead to numerous bare spots and muddy conditions that effectively reduces or destroys plant establishment and productivity. Planning or prescribing the intensity, frequency, timing, and duration of grazing will be very important on these wetter soils. Of caution, some annual and perennial winter plants naturally growing in wet locations (e.g., sedges, rushes, and some forbs) may be an additional challenge as these are often unpalatable or toxic if consumed.
Flood-prone areas may limit the type of forage suited for this site. In areas that flood on a regular basis, implementing management actions such as planting or overseeding appropriate cool season forage varieties (e.g., ‘Marshall’ ryegrass, Lolium perenne ssp. multiflorum; also known as annual ryegrass) into established warm season grasses at heavy forage rates have been observed to help protect riparian areas from detrimental river or stream scouring (personal observations by Rachel Stout Evans, contributing author). Initiating such remedial actions aid in the recovery and reestablishment of preferred warm season forage following seasonal flooding. (Note that herbicide resistant varieties could be problematic and may warrant reconsideration. Please consult with local NRCS Field Offices for assistance.) Where permissible, a system of artificial drainage or water control structures may be in place to facilitate continued forage production and grazing during wetter periods. Additionally, adjacent higher elevation or protected areas may be needed for the storage of harvested forage or the holding of livestock when wet or flooded conditions occur.
Establishing an effective pasture management program can help minimize degradation of the site and assist in maintaining growth of desired forage. An effective pasture management program includes selecting well-adapted grass and/or legume species that will grow and establish rapidly; maintaining proper soil pH and fertility levels; using controlled grazing practices; mowing at proper timing and stage of maturity; allowing new seedings to become well established before use; and renovating pastures when needed (Rhodes et al., 2005; Green et al., 2006).
This state consists of four community phases that represent a range of forage management options and pasture and hayland condition scenarios. Options range from establishing a forage monoculture for haying to a broad mixture of forage species for production and grazing. It is strongly advised that consultation with local NRCS Service Centers be sought when assistance is needed in developing management recommendations or prescribed grazing practices.Community 5.1
Monoculture GrasslandThis phase is mainly characterized by planting forage species for hay production. Forage plantings generally consist of a single grass species. Native and/or non-native forage species can be seeded and is usually harvested as hay or haylage, although grazing may occur periodically. These environments are generally 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 and nutrient management.
Forage suited for this community phase include hybrid and common Bermudagrass (Cynodon dactylon), dallisgrass (Paspalum dilatatum), or possibly sorghum-Sudangrass hybrid (Sorghum bicolor ssp. drummondii) in drier locations. Tall fescue (Schedonorus arundinaceus) may be an option in the northern portions of the basin. The application of fertilizer is generally needed to establish and maintain improved desirable hayfields and pastures. An additional measure to aid production may include prescribed grazing. Implementing limited and monitored 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 potentially other site-specific practices.Dominant plant species
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Bermudagrass (Cynodon dactylon), grass
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dallisgrass (Paspalum dilatatum), grass
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tall fescue (Schedonorus arundinaceus), grass
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Sudangrass (Sorghum bicolor ssp. drummondii), grass
Community 5.2
Mixed Species SystemThis community is characterized by mixed species composition of grasses and legumes. Components of this forage system are either planted or they established naturally. Typically, perennial warm-season grasses are the foundation of the stand that are periodically overseeded with adapted cool-season forages. The latter creates an added benefit of extending 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 series 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 or forage heights, timing, and stocking rates. Supporting or facilitating practices such as fences, water lines, and watering facilities could be part of the system that maintains this phase.Dominant plant species
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Bermudagrass (Cynodon dactylon), grass
-
dallisgrass (Paspalum dilatatum), grass
-
tall fescue (Schedonorus arundinaceus), grass
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Sudangrass (Sorghum bicolor ssp. drummondii), grass
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white clover (Trifolium repens), other herbaceous
-
red clover (Trifolium pratense), other herbaceous
Community 5.3
Mixed Species, Non-seededThis community is characterized by a mixture of native and naturalized non-native species. Forage is usually grazed or harvested as stored forage, hay or haylage. Commonly established species may include Bermudagrass, dallisgrass, and potentially tall fescue in the north.
Stands are generally productive, and forage and grazing management can maintain the community. Healthy stands provide additional benefits by protecting soils from excessive runoff and erosion. However, a common peril associated with this phase is overgrazing, which lowers production and favors 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 develop deeper root systems and greater leaf area. Conversely, when plants are not allowed to adequately recover, root development will be restricted leading to lower forage and biomass production. Additionally, maintenance of grass stands requires implementing pest management practices to control unwanted weedy and woody species.Community 5.4
Early Woody SuccessionThis community is characterized by a diverse composition of grasses and forbs with an increasing presence of woody species (both native and non-native) that are immature and of low stature. Woody species grow quickly on this site and can be difficult and expensive to control. One potentially problematic species may be honeylocust (Gleditsia triacanthos). Putnam (1951) reported honeylocust as being common on old pastures, and the species can be difficult to remove once established. Management to transition this phase to other forage communities of this state is still possible without excessive inputs and effort, particularly if stem diameters remain below 2 inches and are widely scattered (e.g., a density of less than 100 stems per acre). However, if diameters become greater than 3 inches and densities exceed 300 stems per acre, far more investment, effort, and inputs will be required. If brush management measures are not undertaken, the plant community will transition to the Ruderal/Opportunistic Regrowth (Community Phase 6.1) of State 6.
Of note, this community phase is often very beneficial habitat for some wildlife species, especially a specific guild of resident and Neotropical migratory bird species that are habitat-specific on old field to young tree stand habitats.Dominant plant species
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honeylocust (Gleditsia triacanthos), tree
Pathway 5.1A
Community 5.1 to 5.2Seeding and/or management for desired species composition.
Pathway 5.1B
Community 5.1 to 5.3Species management without overseeding.
Pathway 5.2A
Community 5.2 to 5.1Seeding, fertilizing, management/removal of undesirable species.
Pathway 5.2B
Community 5.2 to 5.3Species management without overseeding.
Pathway 5.3A
Community 5.3 to 5.1Seeding, fertilizing, management/removal of undesirable species.
Pathway 5.3B
Community 5.3 to 5.2Seeding and/or management for desired species composition.
Pathway 5.3C
Community 5.3 to 5.4Lack of disturbance; no (or infrequent) mowing, herbivory, or brush management; natural succession of woody species.
Pathway 5.4A
Community 5.4 to 5.3Brush management/removal of unwanted species.
State 6
Forest RecoveryThis state is representative of forest recovery in areas that were once under former intensive land use such as long-term row crop cultivation. Characteristics that distinguish this state from other forest states on this site include a suite of soil-site properties that reportedly affect tree growth such as higher soil bulk density due to compaction, presence of a plow pan, lower organic matter content, and reduced fertility (Baker and Broadfoot, 1979; Groninger et al., 1999). Two community phases are provisionally recognized for this state. Community Phase 6.1 represents natural colonization of tree and shrub species without management. Community Phase 6.2 is representative of intentional forest establishment by artificial regeneration or planting.
For Community Phase 6.2, determining the objectives and goals of the future stand is imperative to increase the probability of successful establishment and production of the afforested area. These decisions will ultimately determine the species to be established, preparation requirements, planting density, and post-planting operations (e.g., competitor control, future improvement cuttings and thinnings, regeneration methods, and overall stand health). Since each area targeted for afforestation may have unique or different land use histories, having a clear understanding of the soil-site conditions is essential. Some areas may necessitate a series of soil improvement actions prior to planting. These actions may include subsoiling or deep plowing to breakup plow pans and fertilizing the targeted area. An additional option is to allow the area to undergo fallowing for a predetermined period (Community Phase 6.1) to potentially increase soil organic matter content, enhance soil aggregate stability, increase soil biological activity, and improve water holding capacity and infiltration rates. Controlling competing vegetation (chemical and/or mechanical treatment) will most likely be critical. Post-planting operations and maintenance of the stand can enhance survival, future development, and achieve goals and objectives (see Gardiner et al., 2002).
Finding the appropriate approach for a given environment necessitates close consultation with trained, experienced, and knowledgeable forestry professionals. If there is a desire to proceed with this state, it is strongly urged and advised that professional guidance be obtained and a well-designed afforestation and silvicultural plan developed in advance of any work conducted. For an exceptional review and summarization of the afforestation literature, techniques, and practices within the Southern Mississippi River Alluvium, interested parties are directed to Gardiner et al. (2002).Community 6.1
Ruderal/Opportunistic RegrowthThis community phase is representative of former working lands (e.g., cropland and possibly high concentration areas of former pastureland) that have fallowed and subsequently undergone natural colonization by vegetation. Depending on location, a profusion of growth may initiate within five to ten years of becoming idle - one that typically includes grasses, forbs, woody seedlings and shrubs, and an increasing presence and covering of vines. Initial colonization may be dominant in annuals followed by a shift to perennial vegetation. Shrubs and tree seedlings may appear very early following abandonment, however the rate of colonization and period to stand establishment likely depends on the proximity of established mature stands (Battaglia et al., 1995; Battaglia et al., 2002). If established stands consisting of light-seeded species adjoin fallow fields, colonizing tree species will likely be comprised of those taxa (e.g., elm, sycamore, and cottonwood) (Allen, 1990; Stanturf et al., 2001). Some areas may be far removed from established forest stands. Under this scenario, establishment of woody species (especially overstory tree species) may be very slow, and years may be required before stand establishment is reached (Battaglia et al., 1995; Allen, 1997). In fact, natural colonization by some species may be delayed indefinitely with some stands or areas being understocked (Allen, 1997; Battaglia et al., 2002; Groninger, 2005). Heavy-seeded species like pecan or oaks may not have an opportunity to colonize available areas due to distance and lack of a dependable dispersing agent (e.g., wildlife and water). Non-native invasive species may become part of the developing stand given the proliferation of exotic plant species over the past century.
It is extremely difficult, if not impossible, to predict the future composition and structure of an abandoned field on this site. Many different environmental factors will influence initial colonization and development trajectories. The following projections are simply based on native plant species reported to occur on the soils of this site. As the young stand matures and eventually enters the stem exclusion stage (crown or canopy closure), eastern cottonwood may be the dominant species if the stand began on bare mineral soils. Otherwise, the developing stand may be largely comprised of associates of the riverfront hardwoods including American sycamore, American elm, sugarberry, green ash, sweetgum, silver maple, boxelder, and eastern cottonwood as a secondary component. Problematic non-native species that may occur include Japanese honeysuckle (Lonicera japonica), Chinese privet (Ligustrum sinense), Chinese tallow (Triadica sebifera), and possibly Callery pear (Pyrus calleryana). Vines in the young, developing stand may include greenbrier (Smilax spp.), eastern poison ivy, trumpet creeper, grape, Virginia creeper, peppervine, and American buckwheat vine. As the stand matures decades into the future and the overstory stratifies (i.e., the understory reinitiation stage), shade tolerant species may dominate the stand.Dominant plant species
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American sycamore (Platanus occidentalis), tree
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American elm (Ulmus americana), tree
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sugarberry (Celtis laevigata), tree
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green ash (Fraxinus pennsylvanica), tree
-
silver maple (Acer saccharinum), tree
-
boxelder (Acer negundo), tree
-
eastern cottonwood (Populus deltoides), tree
-
sweetgum (Liquidambar styraciflua), tree
-
eastern poison ivy (Toxicodendron radicans), shrub
-
trumpet creeper (Campsis radicans), shrub
-
grape (Vitis), shrub
-
greenbrier (Smilax), shrub
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Virginia creeper (Parthenocissus quinquefolia), shrub
-
peppervine (Nekemias arborea), shrub
-
American buckwheat vine (Brunnichia ovata), shrub
Community 6.2
AfforestationThis community phase is representative of areas planted in tree species that are suited for and favored in management on this ecological site. Preparation of this phase may be initiated immediately following a former landuse activity (e.g., State 3) or it may be started following a fallow period (Community Phase 6.1). If afforestation is initiated immediately following years of conventional tillage without soil-site preparation and improvement efforts, potential productivity of the targeted area could be less than optimal (Baker and Broadfoot, 1979; Groninger et al., 1999; Gardiner et al., 2002).
Groninger et al. (1999) utilized the Baker and Broadfoot (1979) model for site evaluation to predict potential productivity of green ash, Nuttall oak, American sycamore, sweetgum, swamp chestnut oak, water oak, and cottonwood on what they termed “marginal soybean lands.” These are croplands occurring on frequently flooded areas that typically produce low soybean yields under conventional tillage. Soils associated with these areas are generally poorly drained, clayey, and typically classified as hydric. Two of the principal soil series of this site, Bowdre and Mhoon soils, were included for evaluation. Based on information presented in Groninger et al. (1999), site index predictions on Bowdre soils that had undergone extensive conventional tillage ranged 18 to 34 percent lower than what are generally reported in soil survey manuscripts for eastern cottonwood, sweetgum, and water oak. The estimated site index values for those species were listed as 73, 78, and 71 for cottonwood, sweetgum, and water oak, respectively. The same site index predictions on Mhoon soils indicated a 13 to 24 percent reduction for eastern cottonwood, green ash, and sweetgum. Estimated site index values on Mhoon soils were 92, 78, and 76 for cottonwood, green ash, and sweetgum, respectively. Comparing the Baker and Broadfoot (1979) estimated site index values of former conventional tilled cropland to the site index values generated from long established forestland are noteworthy (see Community Phase 1.1 for eastern cottonwood, sweetgum, and water oak). The site index predictions in Groninger et al. assumes that no soil-site improvement actions were undertaken. (Note that site index is the height in feet of select tree species at 50 years of growth except for eastern cottonwood which is height in 30 years of growth.)
Over the years, various afforestation innovations have increased the likelihood of success in addition to soil-site amelioration such as planting large, high-quality seedlings with well-developed root systems in an appropriate cover crop (Dey et al., 2010); interplanting seedlings within a fast-growing pioneer species nurse crop (e.g., cottonwood) (Gardiner et al., 2001); and planting companionable species combinations for mixed species stands (Lockhart et al., 2008). The cover crop and nurse crop approaches reportedly help to control rapid overtopping and crowding by competing vegetation and wildlife herbivory (Dey et al., 2010). A completely different approach must be taken if eastern cottonwood is the sole targeted species for planting. For eastern cottonwood, all potential competitors must be removed and the soil surface scarified via mechanical site preparation (Johnson and Shropshire, 1983; Hodges, 1995; Meadows and Stanturf, 1997). Finding the appropriate strategy for a given location requires matching the species to the local hydrologic and soil-site environment; determining short- and long-term objectives and goals; and implementing the appropriate management actions at the required intervals.
Several species that frequently occur and are favored in management are likely appropriate for planting on this ecological site. Broadfoot and McKnight (1961) listed eastern cottonwood, American sycamore, pecan, sweetgum, Nuttall oak, and water oak as species to favor on both Bowdre and Mhoon soils. The authors listed cherrybark oak, Shumard’s oak, and willow oak as additional species to favor on Bowdre soils whereas green ash was listed to favor on Mhoon soils. Of caution, the desirability and importance for establishing oaks have prompted many to attempt plantings on sites that were not conducive to oak production. Some of these former attempts likely targeted high pH soils (i.e., nonacid or alkaline) or species selections that were site incompatible (Mike Oliver, personal communication). Broadfoot (1976) warned against planting oaks on locations where soil reactions are pH 7.5 or higher. If oaks are planted on this site, intensive plant competition will likely dictate the need for scheduled competitor control efforts that cannot be delayed or postponed. If cherrybark oak is chosen to be planted, then targeted locations should be better drained than low-lying areas that remain wet for long periods, and even then, productivity may be lower than anticipated.Dominant plant species
-
eastern cottonwood (Populus deltoides), tree
-
American sycamore (Platanus occidentalis), tree
-
pecan (Carya illinoinensis), tree
-
sweetgum (Liquidambar styraciflua), tree
-
green ash (Fraxinus pennsylvanica), tree
-
Nuttall oak (Quercus texana), tree
-
willow oak (Quercus phellos), tree
-
water oak (Quercus nigra), tree
-
cherrybark oak (Quercus pagoda), tree
-
Shumard's oak (Quercus shumardii), tree
Pathway 6.1A
Community 6.1 to 6.2Remove undesirable competitors; final soil preparation; establish site-appropriate species (favored in management).
State 7
Conservation (Herbaceous)This state is representative of the range of conservation actions that may be implemented and established on this ecological site. Apart from planting trees and managing for forest, one may elect to establish native herbaceous species and manage for predominantly a native grassland; a complex mixture of native grasses and forbs; or a pollinator planting whereby native forbs dominate the mix. In each of these options, it is strongly advised (possibly a programmatic requirement) that the species comprising the planting or seed mix consist of spring, summer, and fall flowering species. Depending on goals and objectives, various conservation programs and practices may be available. For additional information and assistance, please contact or visit the local NRCS Field Office.
Community 7.1
Pollinator Planting/Native GrassesThis community phase represents the establishment of native forbs or wildflowers for pollinator habitat or native grasses. The seed mix for planting may be quite varied depending on objectives and goals. Ideally, the mix includes a wide range of species that flower at various times of the growing season (spring, summer, and fall). Plant species in some pollinator mixes may include but are not limited to beebalm (Monarda spp.), milkweeds (Asclepias spp.), beardtongue (Penstemon spp.), vervain (Verbena spp.), various legumes such as native lespedeza (Lespedeza spp.), Illinois bundleflower (Desmanthus illinoensis), partridge pea (Chamaecrista fasciculata), and a broad assortment of composites such as asters (Symphyotrichum spp.), tickseed (Coreopsis spp.), blazing star (Liatris spp.), coneflower (Rudbeckia spp.), sunflower (Helianthus spp.) among many others. If goals and objectives are to establish native grasses within a forb mix or in a grass-dominant stand, species suitable for planting may include switchgrass (Panicum virgatum), eastern gamagrass (Tripsacum dactyloides), big bluestem (Andropogon gerardii), little bluestem (Schizachyrium scoparium) and Indiangrass (Sorghastrum nutans). Of caution, if eastern gamagrass is chosen to be planted, soil pH must be below 8.0 as the species’ productivity falters under alkaline conditions (Henson, 2012).
Key to the establishment of this phase is initial preparation, seeding rate, planting period, follow-up treatment, and maintenance of the planting. The selection of species to establish on any given area may ultimately depend on size and conditions of the location where the planting will occur, landowner/manager goals and objectives, and the advice and knowledge of the conservation practitioner.Transition T1A
State 1 to 2Stand composition is heavily altered and managed to favor select species for production (Community 2.1). This transitional pathway also includes heavy timber cutting and/or repeated partial harvests (high-grading) leading to Community 2.2.
Transition T1B
State 1 to 3Actions include mechanical removal of vegetation and stumps; herbicide treatment of residual plants; and preparation for cultivation.
Transition T1C
State 1 to 5Actions include mechanical removal of vegetation and stumps; herbicide treatment of residual plants; seedbed preparation; and establishment of desired forage.
Transition T2A
State 2 to 1This transition represents a return to perceived reference conditions and involves the reestablishment of missing species; the control or removal of exotic species (herbicide and mechanical); stand improvement practices that favors a return of more shade intolerant components, although a return to the pioneer state of eastern cottonwood may not be feasible.
Transition T2B
State 2 to 3Actions include mechanical removal of vegetation and stumps; herbicide treatment of residual plants; and preparation for cultivation.
Transition T2C
State 2 to 5Actions include mechanical removal of vegetation and stumps; herbicide treatment of residual plants; seedbed preparation; and establishment of desired forage.
Transition T3A
State 3 to 4Precision land leveling.
Transition T3B
State 3 to 5Vegetation/stump removal (mechanical/chemical); seedbed preparation; establishment of desired forage; manage for grazing.
Transition T3C
State 3 to 6Natural succession (Community 6.1) or prep area (plow pan breakup, fertilizing, etc.); planting species appropriate for site (Community 6.2).
Transition T3D
State 3 to 7Establish select native species suitable for site; prep area for planting (herbicide and/or mechanical).
Transition T5A
State 5 to 3Actions include mechanical removal of vegetation; herbicide treatment of residual plants; and preparation for cultivation.
Transition T5B
State 5 to 6Natural succession (Community 6.1) or prepare area (e.g., plow pan breakup, fertilizing, etc.) for planting tree species appropriate for site (Afforestation - Community 6.2).
Transition T5C
State 5 to 7Establish select native species suitable for site and prepare area for planting (herbicide and/or mechanical).
Transition T6A
State 6 to 3Cropland establishment: vegetation removal (mechanical/chemical) and preparation for cultivation.
Transition T6B
State 6 to 5Mechanical removal of vegetation and stumps; herbicide treatment of residual plants; establish desired forage species and manage for grazing.
Transition T7A
State 7 to 3Cropland establishment: vegetation removal (mechanical/chemical) and preparation for cultivation.
Transition T7B
State 7 to 5Establish desired forage species and manage for grazing.
Restoration pathway T7C
State 7 to 6Natural succession (Community 6.1) or prepare area (e.g., plow pan breakup, fertilizing, etc.) for planting tree species appropriate for site (Afforestation - Community 6.2).
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 2.2 plant community composition
Group Common name Symbol Scientific name Annual production () Foliar cover (%) Table 9. Community 3.1 plant community composition
Group Common name Symbol Scientific name Annual production () Foliar cover (%) Table 10. Community 3.2 plant community composition
Group Common name Symbol Scientific name Annual production () Foliar cover (%) Table 11. Community 3.3 plant community composition
Group Common name Symbol Scientific name Annual production () Foliar cover (%) Table 12. Community 4.1 plant community composition
Group Common name Symbol Scientific name Annual production () Foliar cover (%) Table 13. Community 5.1 plant community composition
Group Common name Symbol Scientific name Annual production () Foliar cover (%) Table 14. Community 5.2 plant community composition
Group Common name Symbol Scientific name Annual production () Foliar cover (%) Table 15. Community 5.3 plant community composition
Group Common name Symbol Scientific name Annual production () Foliar cover (%) Table 16. Community 5.4 plant community composition
Group Common name Symbol Scientific name Annual production () Foliar cover (%) Table 17. Community 6.1 plant community composition
Group Common name Symbol Scientific name Annual production () Foliar cover (%) Table 18. Community 6.2 plant community composition
Group Common name Symbol Scientific name Annual production () Foliar cover (%) Table 19. Community 7.1 plant community composition
Group Common name Symbol Scientific name Annual production () Foliar cover (%) Interpretations
Supporting information
Inventory data references
The information provided on the states and community phases in this provisional description report were generated from literature reviews, conversations with technical specialists, and limited personal observations and experience on this soil-site environment. Intensive vegetation inventories were not conducted during the development of this provisional report. Those tasks will occur during future phases of ecological site development.
Other references
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Barry Hart
Rachel Stout EvansApproval
Charles Stemmans, 6/10/2025
Acknowledgments
We would like to express our sincere appreciation to the MLRA 131A Technical Team for their assistance and input in the development of this report. Special recognition is owed to Tom Foti (Ecologist, Arkansas Natural Heritage Commission, Retired) and Henry Langston (Wetland Ecologist, Arkansas Department of Transportation, Retired) for their time, personal travel expenses, and willingness to share their vast knowledge of the region. Their assistance with field reconnaissance, identifying sites and locations for investigating, and verifying ecological factors across multiple Mississippi River basins has led to a deeper understanding of the ecological sites and their associated states and community phases in the Southern Mississippi River Alluvium.
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 08/13/2026 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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PrintThe Ecosystem Dynamics Interpretive Tool is an information system framework developed by the USDA-ARS Jornada Experimental Range, USDA Natural Resources Conservation Service, and New Mexico State University.
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