Ecological site F131AY011MO

Tree	(1) Celtis occidentalis (2) Ulmus americana
Shrub	(1) Cephalanthus occidentalis
Herbaceous	(1) Leersia oryzoides

Landforms	(1) Flood plain (2) Meander scroll (3) Backswamp
Flooding duration	Brief (2 to 7 days) to long (7 to 30 days)
Flooding frequency	Occasional to frequent
Ponding frequency	None
Slope	0 – 3 %
Water table depth	6 – 24 in
Aspect	Aspect is not a significant factor

Surface texture	(1) Silty clay loam (2) Silty clay (3) Clay
Family particle size	(1) Clayey
Drainage class	Poorly drained to somewhat poorly drained
Permeability class	Very slow
Surface fragment cover <=3"	Not specified
Surface fragment cover >3"	Not specified
Available water capacity (0-40in)	5 – 8 in
Calcium carbonate equivalent (0-40in)	0 – 5 %
Electrical conductivity (0-40in)	0 – 2 mmhos/cm
Sodium adsorption ratio (0-40in)	Not specified
Soil reaction (1:1 water) (0-40in)	5.6 – 8.2
Subsurface fragment volume <=3" (Depth not specified)	Not specified
Subsurface fragment volume >3" (Depth not specified)	Not specified

Ecological dynamics

Information contained in this section was developed using historical data, professional experience, field reviews, and scientific studies. The information presented is representative of very complex vegetation communities. Key indicator plants, animals and ecological processes are described to help inform land management decisions. Plant communities will differ across the MLRA because of the naturally occurring variability in weather, soils, and aspect. The Reference Plant Community is not necessarily the management goal. The species lists are representative and are not botanical descriptions of all species occurring, or potentially occurring, on this site. They are not intended to cover every situation or the full range of conditions, species, and responses for the site.

Historically, the Mississippi River was a very dynamic system with frequent flooding and multiple braided channels that shifted back and forth across the floodplain. Gravelly, sandy, loamy, and clayey deposits of sediment sorted themselves out on the floodplain depending on the speed, volume and duration of the waters carrying them. Clayey deposits occurred in areas of slower moving water, such as in isolated, concave meander scars or backwater areas between the natural levees formed nearer the channel. Current management of the river has drastically altered this dynamic process although the clayey soil texture and seasonally high water table still influences the development of these floodplain forest communities. Vegetation is subject to debris deposition and scouring.

Clayey Floodplain Forests resembles the adjacent Loamy Floodplain Forests, except that it lacks species of oak, sugar maple, and walnut that do not tolerate extended periods of wetness that can occur in these units. In addition, the ground flora is often barren because of inundation and occasional ponding. Historic flooding of Clayey Floodplain Forest occurred annually in this region or at least once every 3 years. Flooding would have been a combination of headwater and backwater events, with periods of slower moving water distinguishing it from adjacent forest types.

Succession in Clayey Floodplain Forests appears to be similar to that of the Loamy Floodplain Forests, except that periods of inundation and ponding exclude later successional hardwood species. Hackberry, elm, ash, eastern cottonwood and sycamore form a tall canopy (80 to 100 feet) that is uneven and has frequent holes. Catastrophic floods will often partially or completely knock down trees; consequently, this ecological site is often made up of a mosaic of early to late successional floodplain forests.

Today most of these ecological sites have been cleared and converted to intensive agriculture. While some cleared fields have retained a narrow strip of forest along the stream, many of these ecological sites are often cleared right up to the bank. In such cases, severe flooding may cause stream bank erosion and complete loss of this ecological site. Uncontrolled grazing by domestic livestock in the remaining strips of forest can also kill trees and remove the ground cover, resulting in de-stabilization and degradation of this ecological site as well.

The remaining remnants that still exist along un-leveed areas, within levees and on islands play an important role as a source of food and shelter for migrating birds. In addition, large floodplain trees that extend above the canopy are important nesting sites for bald eagles and herons. Carefully planned timber harvests can be tolerated in this system, but high grading of the timber will eventually degrade the ecological site. Re-establishment of these riparian forests is important for stream quality and health, as well as for migratory birds. Planting of appropriate species has proven to be quite successful.

State and transition model

Additional community tables

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
Approved by
Approval date
Composition (Indicators 10 and 12) based on	Annual Production

Indicators

Number and extent of rills:
Presence of water flow patterns:
Number and height of erosional pedestals or terracettes:
Bare ground from Ecological Site Description or other studies (rock, litter, lichen, moss, plant canopy are not bare ground):
Number of gullies and erosion associated with gullies:
Extent of wind scoured, blowouts and/or depositional areas:
Amount of litter movement (describe size and distance expected to travel):
Soil surface (top few mm) resistance to erosion (stability values are averages - most sites will show a range of values):
Soil surface structure and SOM content (include type of structure and A-horizon color and thickness):
Effect of community phase composition (relative proportion of different functional groups) and spatial distribution on infiltration and runoff:
Presence and thickness of compaction layer (usually none; describe soil profile features which may be mistaken for compaction on this site):
Functional/Structural Groups (list in order of descending dominance by above-ground annual-production or live foliar cover using symbols: >>, >, = to indicate much greater than, greater than, and equal to):

Dominant:

Sub-dominant:

Other:

Additional:
Amount of plant mortality and decadence (include which functional groups are expected to show mortality or decadence):
Average percent litter cover (%) and depth ( in):
Expected annual annual-production (this is TOTAL above-ground annual-production, not just forage annual-production):
Potential invasive (including noxious) species (native and non-native). List species which BOTH characterize degraded states and have the potential to become a dominant or co-dominant species on the ecological site if their future establishment and growth is not actively controlled by management interventions. Species that become dominant for only one to several years (e.g., short-term response to drought or wildfire) are not invasive plants. Note that unlike other indicators, we are describing what is NOT expected in the reference state for the ecological site:
Perennial plant reproductive capability:

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Ecological site F131AY011MO

Clayey Floodplain Forest

Accessed: 09/23/2026

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General information

MLRA notes

Classification relationships

Ecological site concept

Table 1. Dominant plant species

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