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Ecological site F153AY070NC

Wet Spodosol Flats and Depressions

Last updated: 2/12/2025
Accessed: 03/30/2025

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General information

Provisional. A provisional ecological site description has undergone quality control and quality assurance review. It contains a working state and transition model and enough information to identify the ecological site.

MLRA notes

Major Land Resource Area (MLRA): 153A–Atlantic Coast Flatwoods

The MLRA notes section provides a brief description of the entire MLRA. This brief description of the entire MLRA is intended to provide some context about the MLRA that this ecological site resides within. A more complete description of the MLRA can be found in Ag Handbook 296 (USDA-NRCS, 2022).

This MLRA is found on the lower coastal plain and is known as the Atlantic Coast Flatwoods. This flat terrain is formed from marine terraces and fluviomarine sediments of Tertiary and Quaternary age. These marine terraces are younger to the east and are progressively older and higher inland to the west. Post formation these terraces have been crossed by widely meandering river and stream channels producing broad shallow valleys with many high order interfluves. All these factors combine to produce relatively flat landscapes that favor high water tables.

Many rivers and streams that flow through this area have headwaters that originate to the west in the upper coastal plain (MLRA 133A, Southern Coastal Plain) and piedmont (MLRA 136, Southern Piedmont) regions. Large river valleys are extremely flat and of great extent. Most surface water that originates from within the MLRA starts as blackwater in very low energy and subtle low-order channels. Most surface water emerges first as broad, very low energy, very low velocity sheet flow before accumulating in these very subtle channels. Local relief is generally less than 35 feet (10 meters), although some short, steep slopes border the stream valleys.

The dominant soil orders in MLRA 153A are Ultisols and Spodosols. The soils in this MLRA have a thermic temperature regime, an aquic or udic moisture regime, and generally have siliceous mineralogy. They are generally very deep, well drained to very poorly drained, and loamy or clayey. The major soil suborders of the MLRA include: 1) Alaquods, which formed in marine sediments on flats and terraces and in depressions, 2) Albaquults, which formed in mixed alluvium and marine sediments on flats and terraces, 3) Haplosaprists, which formed in organic deposits over mixed marine and fluvial deposits, 4) Paleaquults, which formed in marine sediments on flats and in depressions, and 5) Paleudults, which formed in marine sediments on uplands.

MLRA 153A has a lengthy north-south extent. It runs parallel to the Atlantic coast and has a width of approximately 10 to 30 miles. The MLRA extends from the northeastern corner of Florida to southern Virginia. Five states are intersected by the MLRA, including Georgia (30 percent), South Carolina (28 percent), North Carolina (28 percent), Florida (10 percent), and Virginia (4 percent). The MLRA extent makes up about 30,319 square miles (78,527 square kilometers).

Because of climatic differences between the northern and southern reaches of the MLRA, vegetative communities vary with latitude. Overall, the MLRA is dominated by pine-oak forest vegetation. Loblolly pine, longleaf pine, slash pine, sweetgum, red maple, red oak, and white oak are dominant in the uplands. Water tupelo, pond pine, swamp blackgum, laurel oak, swamp chestnut oak, bald cypress, and red maple are dominant on the bottomland. Herbaceous understory species common to the MLRA include cutover muhly, toothache grass, little bluestem, and various panicums.

Major wildlife species of the MLRA include alligator, white-tailed deer, black bear, gray fox, red fox, bobcat, raccoon, skunk, opossum, otter, rabbit, squirrel, turkey, and bobwhite quail. The threatened and endangered gopher tortoise inhabits the southern portion of this MLRA. This area provides crucial habitat for neotropical migrants, migratory waterfowl, and wading birds along the Atlantic Flyway.

(USDA-NRCS, 2022)

LRU notes

Currently, Ecological Site Descriptions (ESDs) for MLRA 153A cover the full north-south range of the MLRA. However, climate variation across the north-south extent warrants the future development of Land Resource Unit (LRU) classifications to support more precise Ecological Site Descriptions.

Classification relationships

MLRA 153A overlaps with two level III EPA ecoregion concepts: 63) the Middle Atlantic Coastal Plain and 75) the Southern Coastal Plain. Under ecoregions 63 and 75 are a number of level IV concepts, of which several apply to MLRA 153A. These include: 63c) Swamps and Peatlands, 63e) Mid-Atlantic Flatwoods, 63h) Carolina Flatwoods, 63n) Mid-Atlantic Floodplains and Low Terraces, 75e) Okefenokee Plains, 75f) Sea Island Flatwoods, 75g) Okefenokee Swamp, and 75i) Floodplains and Low Terraces. (U.S. EPA, 2013)

MLRA 153A overlaps portions of the US Forest Service Outer Coastal Plain Mixed Forest province (232). The MLRA 153A concept roughly corresponds to the western portion of the Atlantic Coastal Flatwoods (232C) and the southcentral portion of the Northern Atlantic Coastal Flatwoods (232I) sections. In combination with MLRA 153B, these two MLRAs correspond very closely to the full extent of sections 232C and 232I. (Cleland et al., 2007)

Based on the USGS physiographic classification system, most of MLRA 153A is in the Sea Island section of the Coastal Plain province, in the Atlantic Plain division. The northern quarter is in the Embayed section of the same province and division. The embayed barrier islands extend from the eastern shore of the Chesapeake Bay in Virginia to north of Charleston, South Carolina (Fenneman et al., 1946). The portion in North Carolina is referred to as the Outer Banks. Large bodies of brackish water, such as Pamlico and Albemarle Sounds, are on the inland side of the barrier islands. The Sea Islands extend from north of Charleston, South Carolina, to Jacksonville, Florida.

The reference community for this particularly site is approximately aligned with Wet Pine Flatwoods (Schafale and Weakely, 1990) and Wet Flatwoods (FNAI, 2010).

Ecological site concept

This site is characterized by poorly drained and very poorly drained Spodosol soils (dominantly acidic and sandy) with long hydroperiods on coastal plain flats and depressions. Long hydroperiod refers to relatively long periods of soil saturation and/or inundation. Depressions may be either open or closed.

This concept represents locations where the soils meet hydric field criteria, meaning that some periods of soil saturation and/or inundation happen during the growing season, but some locations will also periodically dry out during the growing season. On this site, the water table is near the surface during a portion of the growing season for a period sufficiently long to produce anaerobic conditions. This site is wet but mostly free from flood plain processes. This wet site is often associated with moist sites that do not meet hydric criteria, and the transition can be exceptionally subtle. This distinction is especially subtle for Spodosols, because they are characterized by relatively high rates of infiltration and a fluctuating water table. These soils are often associated with relict sandy shoreline features.

The acidic nature of spodic soils typically favors conifers and broadleaf evergreen tree species. Due to the acidity, the relatively poor nutrient status of the Spodosol soils, and long hydroperiods, much of this site remains in a forested state. This site supports a variety of vegetation communities including wet flatwoods and freshwater graminoid marsh. This ecological site includes some locations associated with Carolina bay landforms.

Ecological dynamics on this site are largely driven by precipitation, artificial drainage, and fire. Although it is regulated today, artificial drainage has been extensively applied to manage this site. Once applied, the effects of drainage are persistent. Historically, the use of fire by indigenous civilizations may have also been extensive. Some limited wildfire and prescribed fire occur today, but fire suppression has been the norm since the 20th century. Both fire and drainage can impact the thickness of organic surface soil accumulation. Persistent and prolonged saturation slows decomposition and allows for the accumulation of organic surface soil material. Hurricanes produce winds and rain that can have significant impact. Saturated soils decrease the rooting strength of trees and make them more susceptible to windfall. Extreme precipitation can increase and prolong inundation and saturation.

Table 1 very briefly lists some of the most dominant vegetation on this site today. More detailed descriptions of community compositions are available in the State and Transition Model.

Associated sites

TX153AX010	Dry Sands Dry sands often comprise a Carolina bay rim adjacent to, and higher on the landscape than a wet Spodosol flats and depressions.
F153AY020NC	Moist Sands Moist sands often comprise a Carolina bay rim adjacent to, and higher on the landscape than a wet Spodosol flats and depressions.
F153AY050NC	Moist Spodosol Rises and Flats A moist Spodosol soil flat is often associated with and difficult to distinguish from a wet Spodosol soil flat. Much of the difference between moist and wet sites is driven by variations in subsurface drainage patterns, which are difficult to see at the surface, but these sites can be distinguished by soil moisture.

TX153AX010

Dry Sands

Dry sands often comprise a Carolina bay rim adjacent to, and higher on the landscape than a wet Spodosol flats and depressions.

F153AY020NC

Moist Sands

Moist sands often comprise a Carolina bay rim adjacent to, and higher on the landscape than a wet Spodosol flats and depressions.

F153AY050NC

Moist Spodosol Rises and Flats

A moist Spodosol soil flat is often associated with and difficult to distinguish from a wet Spodosol soil flat. Much of the difference between moist and wet sites is driven by variations in subsurface drainage patterns, which are difficult to see at the surface, but these sites can be distinguished by soil moisture.

Similar sites

F153AY065NC	Wet Clay Flats and Depressions This site occupies similar landforms and is poorly and very poorly drained, but is comprised of clayey Ultisols.
F153BY070NC	Wet Spodosol Flats and Depressions This site is on very similar landforms but in an adjacent MLRA where the marine terrace surfaces are younger, less dissected, and more prone to tidal impacts.
F153AY060NC	Wet Loamy Flats and Depressions This site occupies similar landforms and is poorly and very poorly drained, but is comprised of loamy Ultisols.
F153AY080NC	Wet Organic Soil Flats and Depressions This site occupies similar landforms and is very poorly drained, but is comprised of Histosols (deep organic soils). The wet Spodosol flats and depressions includes soils with histic epipedons, mineral soils with an organic surface horizon that is significant but not deep enough to classify as a Histosol.

Table 1. Dominant plant species

Tree	(1) Pinus taeda (2) Pinus elliottii
Shrub	(1) Serenoa repens (2) Morella cerifera
Herbaceous	(1) Aristida beyrichiana (2) Muhlenbergia expansa

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Physiographic features

This ecological site represents flats and depressions of acidic sandy mineral soils (Spodosols) that are mostly isolated from most flood plain processes. Ponding is the most common inundation process on this ecological site. The water table fluctuates, but is persistently shallow on this site. In general, these flat landforms developed by marine deposition, or ancient fluvial reworking and redeposition. Many Spodosols are associated specifically with sandy relict shoreline features.

This ecological site includes some locations associated with Carolina bay landforms. Many of the soils mapped on Carolina bay interiors are also mapped on open depressions and marine terrace or interfluve flats which do not have any bay characteristics, so not all locations represented by this ecological site are Carolina bays.

A Carolina bay is a type of closed depression (USDA-NRCS, 2017). Carolina bay depressions are oval or elliptical and have a long-axis orientated northwest to southeast (figure 1). The most recognizable landform of a Carolina bay is the sand rim, which is often well pronounced on the south and east sides of the depression. While highly recognizable, not all Carolina bays have a sand rim. Furthermore, the mere presence of a sand rim is not sufficient to diagnose current local hydrology, which is essential for determining the type of ecosystem. The most diagnostic landform of a Carolina bay is the oval or elliptical depression below the surrounding landscape surface. While the interior depression is typically shallow, it is lower than the general elevational surface of the surrounding flat, not just lower than the rim. The interior of a Carolina bay can vary significantly from flat to slightly concave, mineral soil to organic soil, and open water to raised peatland. (Ross 2003)

Within geologic time, head cutting headwaters (nick points) may intersect a Carolina bay rim, and the depression may eventually become open (figures 1, 2, and 3). As surface waters begin to flow out of a bay, it becomes an open depression, and it is hydrologically different than a closed depression (figure 2). This is especially true where surface waters flow into and through the landform, and the interior experiences flood plain dynamics (figure 3). Open depressions and flood plain systems within a bay rim may be more appropriately referred to as relict Carolina bays. In large relict Carolina bay interiors, flat topography and distance from an outlet can enable portions of the area to function much like a closed depression, so precise classification of hydrology might be challenging in some locations.

The interiors of some Carolina bays are occupied by lakes, while others are occupied by domed forested peatlands that rarely pond (Ross, 2003). Some bay interiors are dominated by mineral soils that are seasonally saturated, while others support deep muck and are saturated at or near the soil surface for significant portions of the year (Caldwell et al. 2011). Carolina bays are more defined by landform than vegetation. Vegetation communities well suited to a Carolina bay are determined mostly by soil characteristics and hydroperiod. For Carolina bay interiors with multiple different soil types and hydrologic regimes, see also the similar ESDs with descriptions of Carolina bay site types including: Wet Loamy Flats and Depressions (F153AY060NC and F153BY060NC), Wet Clay Flats and Depressions (F153AY065NC and F153BY065NC), Wet Spodosol Flats and Depressions (F153AY070NC and F153BY070NC), and Wet Histosol Flat and Depressions (F153AY080NC and F153BY080NC). At locations where the Carolina bay landform is now open to both inflow and outflow of surface water, you should examine the following ESDs: Flooded Mineral Soil Flood plains and Terraces (F153AY090NC and F153BY090NC), and Flooded Organic Soil Flood plains and Terraces (F153AY100NC and F153BY100NC).

The Carolina bay rim is typically non-hydric and comprised of sandy soils that create a distinct transition to upland conditions at the bay rim. For information about the vegetation communities on Carolina bay rims, see the following associated ecological sites: Dry Sands (F153AY010NC and F153BY010NC) and Moist Sands (F153AY020NC and F153BY020NC).

Table 2 summarizes physiography of the modal soil concepts. Table 3 summarizes physiography of all soils included in this description.

Figure 1. Numerous intact undissected closed depressional Carolina bay landforms in Bladen County, NC of MLRA 153A. The numerous oval and elliptical shaped depressions are all Carolina bay landforms.

Figure 2. Carolina bay landforms that have been dissected sufficiently to deliver surface water outflows in Bladen County, NC of MLRA 153A. This system now functions as an open depression.

Figure 3. A relict Carolina bay landform in Pender County, NC, of MLRA 153A. This depression is dissected by surface water and now classifies as an open riverine depression. This landform does not fit this site concept. It fits a riparian zone landscape concept.

Table 2. Representative physiographic features

Landforms	(1) Coastal plain > Marine terrace (2) Flat (3) Flatwoods (4) Depression
Runoff class	Negligible
Flooding frequency	None
Ponding duration	Not specified
Ponding frequency	None
Elevation	25 – 295 ft
Slope	2%
Ponding depth	Not specified
Water table depth	18 in
Aspect	Aspect is not a significant factor

Table 3. Representative physiographic features (actual ranges)

Runoff class	Negligible
Flooding frequency	None
Ponding duration	Long (7 to 30 days)
Ponding frequency	None to frequent
Elevation	25 – 295 ft
Slope	2%
Ponding depth	24 in
Water table depth	18 in

Climatic features

The climate across MLRA 153A is generally warm, temperate, and humid with some maritime influences near the coast. The maximum precipitation occurs during summer. Rainfall is usually of moderate intensity. Occasionally, extreme weather events (e.g., northeasters, tropical storms, and hurricanes) produce large amounts of precipitation and destructive winds. On rare occasions snowfall occurs in the northern third of the area. The average annual temperature is 59 to 70 degrees F (15 to 21 degrees C), increasing to the south. (USDA-NRCS, 2022)

Table 4. Representative climatic features

Frost-free period (characteristic range)	222-237 days
Freeze-free period (characteristic range)	257-306 days
Precipitation total (characteristic range)	49-52 in
Frost-free period (actual range)	211-241 days
Freeze-free period (actual range)	250-350 days
Precipitation total (actual range)	46-53 in
Frost-free period (average)	229 days
Freeze-free period (average)	286 days
Precipitation total (average)	50 in

Characteristic range

Actual range

Bar

Line

Figure 4. Monthly precipitation range

Characteristic range

Actual range

Bar

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Figure 5. Monthly minimum temperature range

Characteristic range

Actual range

Bar

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Figure 6. Monthly maximum temperature range

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Figure 7. Monthly average minimum and maximum temperature

Figure 8. Annual precipitation pattern

Figure 9. Annual average temperature pattern

Climate stations used

(1) NEWPORT NEWS INTL AP [USW00093741], Newport News, VA
(2) NEW BERN CRAVEN CO AP [USW00093719], New Bern, NC
(3) CHARLESTON INTL AP [USW00013880], Charleston AFB, SC
(4) FT STEWART [USC00093538], Fort Stewart, GA
(5) JACKSONVILLE CECIL FLD NAS [USW00093832], Jacksonville, FL

Influencing water features

This MLRA is dominated by a persistent high water table. On this site, the water table is near the surface during a portion of the growing season for a period sufficiently long to produce anaerobic conditions. This ecological site is mostly isolated from flood plain processes, so water inputs are mostly precipitation and ground water.

Wetland description

This site represents locations where the soils meet hydric field criteria, but, in order to classify as a wetland, a location must meet soils, hydrology, and vegetation criteria. Furthermore, field verification of hydric soils criteria is necessary at any individual location. This site represents locations where the soil is seasonally saturated and/or ponded, is not typically flooded, and is not exposed to tidal influences, so any wetlands that occur on this site are palustrine in nature. Any location where the soils are not hydric is covered by a different ESD.

Soil features

The soils of this site are acidic sandy Spodosols, which are often formed on sandy relict shoreline features. Spodosols are developed under conditions of a fluctuating water table. Organic material is stripped from the surface horizon(s) and deposited in the subsoil by the movement of water through the soil profile. A spodic horizon is developed where the organic material is redeposited. This site concept applies where the soils meet hydric criteria, meaning that they are saturated near the surface during a portion of the growing season for a period sufficiently long to produce anaerobic conditions. This ecological site is correlated with hydric soils. It is often spatially associated with moist, non-hydric soils correlated to a different ecological site. The ecotonal transition between these ecological sites can be exceptionally subtle. This distinction is especially subtle for Spodosols, because they are characterized by relatively high rates of infiltration and a fluctuating water table. The soils on this site are poorly and very poorly drained, and the water table is typically at or near the surface 6 to 12 months out of the year. These soils are very deep, but they are subject to repeated wetting and drying cycles and some soils on this site may develop a root restricting layer.

Soil series on this site include: Allanton, Boulogne, Chaires, Evergreen, Kingsferry, Leon, Lynn Haven, Mascotte, Murville, Olustee, Pottsburg, Sapelo, St. Johns, and Wesconnett.

Leon and Mascotte are modal.

Table 5. Representative soil features

Parent material	(1) Marine deposits (2) Eolian sands
Surface texture	(1) Fine sand (2) Sand
Drainage class	Poorly drained
Permeability class	Moderately rapid
Soil depth	80 in
Surface fragment cover <=3"	Not specified
Surface fragment cover >3"	Not specified
Available water capacity (0-40in)	2.6 – 5.5 in
Soil reaction (1:1 water) (0-10in)	3.5 – 5.5
Subsurface fragment volume <=3" (0-40in)	Not specified
Subsurface fragment volume >3" (0-40in)	Not specified

Table 6. Representative soil features (actual values)

Drainage class	Very poorly drained to poorly drained
Permeability class	Moderately rapid to rapid
Soil depth	80 in
Surface fragment cover <=3"	3%
Surface fragment cover >3"	Not specified
Available water capacity (0-40in)	1.2 – 7.8 in
Soil reaction (1:1 water) (0-10in)	3.5 – 6.5
Subsurface fragment volume <=3" (0-40in)	3%
Subsurface fragment volume >3" (0-40in)	Not specified

Ecological dynamics

The most dominant ecological drivers on this site are hydrology, fire, and extreme weather. Although it is regulated today, artificial drainage has been extensively applied to manage this site. Once applied, the effects of drainage are persistent. Historically, the use of fire by indigenous civilizations may have also been extensive. Some limited wildfire and prescribed fire occur today, but fire suppression has been the norm since the 20th century. Both fire and drainage can impact the thickness of organic surface soil accumulation. Persistent and prolonged saturation slows decomposition and allows for the accumulation of organic surface soil material. Hurricanes produce winds and rain that can have significant impact. Saturated soils decrease the rooting strength of trees and make them more susceptible to windfall. Extreme precipitation can increase and prolong inundation and saturation.

The variety of vegetation communities that occur on this site are representative of a variety of strategies to adapt to fire return intervals. For example, longleaf pine flatwoods are well adapted to periodic low intensity surface fires on short return intervals, whereas bottomland hardwoods are well suited to thrive only in the prolonged absence of fire. Pond pine woodlands are maintained by intense stand replacement fire. In this ESD, longleaf pine dominated wet flatwoods are the reference community, because they represent the dominant precolonial forest community. It is probable that wet Longleaf pine flatwoods were a cultural state maintained by indigenous civilizations, and, in most locations, they no longer dominate the landscape.

In the State and Transition Model below for this site where soils meet hydric criteria, hydrologically driven transitions represent both changes in conditions across space as well as changes in conditions over time. Ideally, transitions would represent only changes over time. As updates to the soil survey allow, individual states within this site may be split into individual distinct sites.

Peet and Allard, 1993

State and transition model

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

Ecosystem states

1. Wet Pine Flatwoods

2. Nonriverine Swamp Woodlands

3. Wet Grassland

4. Drained

5. Restored

T1A	-	Historical replacement of Longleaf pine
T1B	-	Loss of tree canopy
T1C	-	Drainage
T2A	-	Re-establishment of Longleaf pine
T2B	-	Significantly increased inundation
T2C	-	Drainage
T3A	-	Establishment of tree cover
T3B	-	Decreased inundation
T3C	-	Drainage
T4A	-	Restoration of hydrology, vegetation, and fire

State 1 submodel, plant communities

1.1. Wet Longleaf Pine Savanna

1.2. Shrubby Wet Flatwoods

1.1.2	-	Decreasing fire return interval
1.2.1	-	Increasing fire return interval

State 2 submodel, plant communities

2.1. Pond Pine Woodland

2.2. Bay Woodland (Baygall)

2.1.2	-	Loss of periodic fire
2.2.1	-	Periodic fire

State 3 submodel, plant communities

3.1. Wet Prairie

3.2. Graminoid Marsh

3.1.2	-	Increased inundation
3.2.1	-	Decreased inundation

State 4 submodel, plant communities

4.1. Drained Forest

4.2. Cultivated Agriculture

4.3. Managed Grassland

4.4. Urban Development

4.1.2	-	Land clearing and cultivation
4.1.3	-	Land clearing and establishment of grassland
4.1.4	-	Land clearing and urban development
4.2.1	-	Establishment of trees
4.2.3	-	Establishment of grassland
4.2.4	-	Urban development
4.3.1	-	Establishment of trees
4.3.2	-	Establishment of cultivation
4.3.4	-	Urban development

State 1
Wet Pine Flatwoods

Wet pine flatwoods often occur on the landscape as an ecotone between Wet Organic Soil Flats and Depressions and moist flats and depressions. The distinction between wet flats and depressions from moist flats and depressions can be exceptionally subtle with many sites supporting an even mix of facultative wetland, facultative, and facultative upland species. This reference state presents as two relatively distinct community phases: a pine savanna community and a shrubby flatwoods community. The relationship between the two community phases seems poorly understood. The relationship between the two community phases will tend to reflect slight changes in fire return intervals and lengths in hydroperiod. Nonetheless, across the MLRA it is consistently understood that the pine savanna community occurs where fire intervals are more frequent (every 1-3 years), and the shrubby flatwoods are more common where fire is less frequent (every 5-10 years). Extreme fluctuations in these drivers may warrant a state change with changes in dynamic soil properties, shifting Wet Pine Flatwoods to Pond Pine Woodlands. (FNAI, 2010; Peet and Allard, 1993; Schafale et al., 1990)

Community 1.1
Wet Longleaf Pine Savanna

The wet longleaf pine savanna community is characterized by a moderate to sparse overstory pine cover with sparse to absent woody midstory or understory and a dense groundcover of graminoids and other herbs. A low shrub cover is often present. (FNAI, 2010; Peet and Allard, 1993; Schafale et al., 1990)

Resilience management. The wet longleaf pine savanna community persists at locations where low intensity ground fires occur nearly every 1 to 3 years.

Dominant plant species

longleaf pine (Pinus palustris), tree
wax myrtle (Morella cerifera), shrub
inkberry (Ilex glabra), shrub
saw palmetto (Serenoa repens), shrub
pineland threeawn (Aristida stricta), grass
Beyrich threeawn (Aristida beyrichiana), grass
cutover muhly (Muhlenbergia expansa), grass
toothache grass (Ctenium aromaticum), grass

Community 1.2
Shrubby Wet Flatwoods

The shrubby wet flatwoods community is characterized by a moderate to sparse overstory pine cover with a dense shrubby understory. Shrubby wet flatwoods may also support a woody midstory, while graminoid ground cover tends to be sparse to absent. (FNAI, 2010; Peet and Allard, 1993; Schafale et al., 1990)

Resilience management. The shrubby wet flatwoods persist where fire return intervals are longer or where cool season fires predominate. Fire return intervals on the order of 5 to 7 years or 5 to 10 years are believed to support the shrubby wet flatwoods community.

Dominant plant species

longleaf pine (Pinus palustris), tree
pond pine (Pinus serotina), tree
sweetbay (Magnolia virginiana), tree
swamp bay (Persea palustris), tree
wax myrtle (Morella cerifera), shrub
fetterbush lyonia (Lyonia lucida), shrub
saw palmetto (Serenoa repens), shrub
pineland threeawn (Aristida stricta), grass
Beyrich threeawn (Aristida beyrichiana), grass

Pathway 1.1.2
Community 1.1 to 1.2

Fire return interval decreasing from 1 to 3 years to roughly 5 to 10 years.

Pathway 1.2.1
Community 1.2 to 1.1

Fire return interval increasing from roughly 5 to 10 years to approximately 1 to 3 years.

State 2
Nonriverine Swamp Woodlands

Community 2.1
Pond Pine Woodland

Pond pine woodlands tend to occur on the outer perimeter of a raised bog or domed pocosin. Pond pine woodlands persist well and increasingly dominate this site type in the presence of periodic fire. Bay woodlands and pond pine woodlands are believed to be hydrologically very similar with fire dynamics driving the difference. Pond pine withstands low intensity fire well as it sprouts from epicormic buds. The serotinous cones of pond pine also enable it to reoccupy a site quickly after catastrophic fire. (FNAI, 2010; Nelson, 1986; Schafale et al., 1990; Sharitz et al., 1982)

Dominant plant species

pond pine (Pinus serotina), tree
loblolly bay (Gordonia lasianthus), tree
sweetbay (Magnolia virginiana), tree
red maple (Acer rubrum), tree
swamp bay (Persea palustris), tree
swamp titi (Cyrilla racemiflora), shrub
fetterbush lyonia (Lyonia lucida), shrub
maleberry (Lyonia ligustrina), shrub
large gallberry (Ilex coriacea), shrub
inkberry (Ilex glabra), shrub
coastal sweetpepperbush (Clethra alnifolia), shrub
laurel greenbrier (Smilax laurifolia), shrub
wax myrtle (Morella cerifera), shrub
giant cane (Arundinaria gigantea), grass
Virginia chainfern (Woodwardia virginica), other herbaceous
sphagnum (Sphagnum), other herbaceous

Community 2.2
Bay Woodland (Baygall)

Bay woodland communities tend to occur on the outer perimeter of a raised bog or domed pocosin. Bay woodlands persist well and increasingly dominate this site type in the long term absence of fire. Bay woodlands and pond pine woodlands are believed to be hydrologically very similar with fire dynamics driving the difference. Bay species sprout after low-intensity surface fire, but increasing bay abundance will increase fire intensity. Fires can be expected to be intense in the dense vegetation of a bay woodland, and bay trees do not typically survive high intensity fire. (FNAI, 2010; Nelson, 1986; Schafale et al., 1990; Sharitz et al., 1982)

Dominant plant species

loblolly bay (Gordonia lasianthus), tree
sweetbay (Magnolia virginiana), tree
swamp bay (Persea palustris), tree
red maple (Acer rubrum), tree
fetterbush lyonia (Lyonia lucida), shrub
large gallberry (Ilex coriacea), shrub
swamp titi (Cyrilla racemiflora), shrub
wax myrtle (Morella cerifera), shrub
coastal doghobble (Leucothoe axillaris), shrub
swamp doghobble (Eubotrys racemosus), shrub
dahoon (Ilex cassine), shrub
Virginia sweetspire (Itea virginica), shrub
laurel greenbrier (Smilax laurifolia), shrub
coral greenbrier (Smilax walteri), shrub
sphagnum (Sphagnum), other herbaceous

Pathway 2.1.2
Community 2.1 to 2.2

Fire suppression

Pathway 2.2.1
Community 2.2 to 2.1

Periodic fire

State 3
Wet Grassland

Community 3.1
Wet Prairie

Wet prairie typically occupies locations that are wet but not inundated. These communities are characterized by high species diversity. (FNAI, 2010; Schafale et al., 1990)

Resilience management. These communities are supported by a fire return interval of 2 to 4 years.

Dominant plant species

pineland threeawn (Aristida stricta), grass
cutover muhly (Muhlenbergia expansa), grass
pitcherplant (Sarracenia), grass
sundew (Drosera), grass
toothache grass (Ctenium aromaticum), grass

Community 3.2
Graminoid Marsh

Much of this community is commonly found occurring in shallow depressions containing standing water during most of the year. Some depressions are formed by fires that consume organic soil to depths that expose the water table. Most marsh is mucky and is dominated by dense stands of sedges, and they may succeed to shrub bog. (Florida SWCD, 1989; Sharitz et al., 1982)

Dominant plant species

beaksedge (Rhynchospora), grass
maidencane (Amphicarpum), grass
threeawn (Aristida), grass
bulrush (Scirpus), grass
sedge (Carex), grass
reed (Phragmites), grass
flatsedge (Cyperus), grass
rush (Juncus), grass
spikerush (Eleocharis), grass
umbrella-sedge (Fuirena), grass
tenangle pipewort (Eriocaulon decangulare), other herbaceous
clubmoss (Lycopodium), other herbaceous
St. Peterswort (Hypericum crux-andreae), other herbaceous
sandbog deathcamas (Zigadenus glaberrimus), other herbaceous
cinnamon fern (Osmunda cinnamomea), other herbaceous
arrowhead (Sagittaria), other herbaceous
cattail (Typha), other herbaceous
knotweed (Polygonum), other herbaceous

Pathway 3.1.2
Community 3.1 to 3.2

Any mechanism that increases inundation.

Pathway 3.2.1
Community 3.2 to 3.1

Any mechanism that decreases inundation.

State 4
Drained

Historically, these sites have been drained frequently to support a variety of land uses including forestry, agriculture, and development. This drained state is included in this STM because this state exists widely today across the landscape. Drainage of wetlands today is significantly regulated. NRCS is required to consider impacts to wetlands according to Federal laws including, but not limited to, the Clean Water Act, the Wetland Conservation provisions of the Food Security Act of 1985, and State, Tribal, and local laws. It is the policy of NRCS to protect and promote wetland functions and values in all NRCS assistance (National Environmental Compliance Handbook (NECH) 610.36).

Community 4.1
Drained Forest

Forests are typically drained to facilitate timber production, especially artificial regeneration. The timber industry in the Southeast has artificially expanded the ecological footprint of slash pine and loblolly pine in particular.

Community 4.2
Cultivated Agriculture

Drainage is typically necessary on this site in order to successfully maintain cultivated agriculture.

Community 4.3
Managed Grassland

Lands drained in order to support pasture and/or hayland management.

Community 4.4
Urban Development

Lands developed to urban land use conditions.

Pathway 4.1.2
Community 4.1 to 4.2

Land clearing and cultivation

Pathway 4.1.3
Community 4.1 to 4.3

Land clearing and establishment of grassland

Pathway 4.1.4
Community 4.1 to 4.4

Land clearing and urban development

Pathway 4.2.1
Community 4.2 to 4.1

Establishment of trees. The timber industry in the Southeast has artificially expanded the ecological footprint of slash pine and loblolly pine in particular, mostly through significant site preparation during stand establishment.

Pathway 4.2.3
Community 4.2 to 4.3

Establishment of grassland

Pathway 4.2.4
Community 4.2 to 4.4

Urban development

Pathway 4.3.1
Community 4.3 to 4.1

Establishment of trees

Pathway 4.3.2
Community 4.3 to 4.2

Establishment of cultivation

Pathway 4.3.4
Community 4.3 to 4.4

Urban development

State 5
Restored

After land on this site has been drained, it is impossible to return fully to reference conditions that existed at that location prior to drainage, especially at locations that remained under active drainage management for long periods of time. Restoration efforts might include blocking and removing drainage structures, revegetation, and reintroduction of periodic fire.

Transition T1A
State 1 to 2

A variety of industrial exploitations cycles, loss of periodic fire cycles, and industrial removal of longleaf pine.

Transition T1B
State 1 to 3

Any mechanism that causes widespread mortality of overstory trees including insects, diseases, weather, and/or increased inundation. These systems are well adapted to fire, so fire would not likely trigger this transition.

Transition T1C
State 1 to 4

The drained state is included in this STM because this state exists widely today across the landscape. This transition is included to show how we got to where we are today. Drainage of wetlands today is significantly regulated. NRCS is required to consider impacts to wetlands according to Federal laws including, but not limited to, the Clean Water Act, the Wetland Conservation provisions of the Food Security Act of 1985, and State, Tribal, and local laws. It is the policy of NRCS to protect and promote wetland functions and values in all NRCS assistance (National Environmental Compliance Handbook (NECH) 610.36).

Transition T2A
State 2 to 1

Renewed planting of longleaf pine as well as expanded application of low-intensity, frequent prescribed fire

Transition T2B
State 2 to 3

Significantly increased inundation

Transition T2C
State 2 to 4

Transition T3A
State 3 to 1

Planting or natural volunteer seeding

Transition T3B
State 3 to 2

Decreased inundation

Transition T3C
State 3 to 4

Transition T4A
State 4 to 5

Remove, plug, or otherwise restore drainage, revegetate, and reintroduce periodic fire.

Additional community tables

Supporting information

Inventory data references

Data collection and analysis of field data will be performed during the Verification Stage of ESD development.

Other references

Ash, A., E. McDonald, E. Kane, and C. Pories. 1983. Natural and modified pocosins: Literature synthesis and management options. U.S. Fish and Wildlife Services, Dept. Biol., Tech. Rep. FWS/OBS-83/04. U.S. Fish and Wildlife Services, Washington, D.C.

Caldwell, P., M. Vepraskas, J.D. Gregory, R.W. Skaggs, and R.L. Huffman. 2011. Linking Plant Ecology and Long-Term Hydrology to Improve Wetland Restoration Success. Transactions of the ASABE. 54: 2129-2137. DOI: 10.13031/2013.40662

Cleland, D.T., J.A. Freeouf, J.E. Keys, G.J. Nowacki, C.A. Carpenter, W.H. McNab. 2007. Ecological Subregions: Sections and Subsections for the conterminous United States. General Technical Report WO-76D. U.S. Department of Agriculture, Forest Service. Washington, D.C.

Dimick, B. P., J. Stucky, W. Wall, M. Vepraskas, T. Wentworth, and C. Arellana. 2010. Plant‐soil‐ hydrology relationships in three Carolina bays in Bladen County, North Carolina, USA. Castanaea 75(4): 407‐420

Fenneman, N.M., and D.W. Johnson. 1946. Physical divisions of the United States. U.S. Geological Survey, Physiographic Committee. Scale 1:700,000.

Florida Chapter, Soil and Water Conservation Society. 1989. 26 Ecological Communities of Florida. 147 pp.

Florida Natural Areas Inventory (FNAI). 2010. Guide to the natural communities of Florida: 2010 edition. Florida Natural Areas Inventory, Tallahassee, FL.

McNab, W.H.; D.T. Cleland, J.A Freeouf, J.E. Keys Jr., G.J. Nowacki, C.A. Carpenter, comps. 2007. Description of ecological subregions: sections of the conterminous United States [CD-ROM]. Gen. Tech. Report WO-76B. Washington, DC: U.S. Department of Agriculture, Forest Service. 80 pp.

Moritz, C. 2021. Evaluating mitigation sites in Carolina bay wetlands that were previously converted to agriculture. Institutional Repository at North Carolina State University, North Carolina State University, Raleigh, NC, 1–323.

Moritz C., M. Vepraskas, and M. Ricker. 2022. Hydrology and Vegetation Relationships in a Carolina Bay Wetland 15 Years after Restoration. Wetlands. 42. DOI: 10.1007/s13157-022-01530-0.

Nelson, J.B. 1986. The Natural Communities of South Carolina Initial Classification and Description, South Carolina Wildlife and Marine Resources Department, Division of Wildlife and Freshwater Fisheries.

Peet, R.K., and D.J. Allard. 1993. Longleaf Pine Vegetation of the Southern Atlantic and Eastern Gulf Coast Regions: A Preliminary Classification. In Proceedings of the Tall Timbers Fire Ecology Conference, No. 18, The Longleaf Pine Ecosystem: ecology, restoration and management, edited by Sharon M. Hermann, Tall Timbers Research Station, Tallahassee, FL, 1993.

Ross, T.E. 2003. Pocosins and Carolina Bays Compared, The North Carolina Geographer, Volume 11: 22-32

Schafale, M.P., and A.S. Weakley. 1990. Classification of the Natural Communities of North Carolina Third Approximation. North Carolina Natural Heritage Program. 321 pp.

Sharitz R.R., and J.W. Gibbons. 1982. The ecology of southeastern shrub bogs (pocosins) and Carolina bays: a community profile. U.S. Fish and Wildlife Service, Division of Biological Services, Washington, D.C. FWS/OBS-82/04. 93 pp.

Soil Survey Staff. 2023. Web Soil Survey. USDA Natural Resources Conservation Service. http://websoilsurvey.sc.egov.usda.gov/ (accessed 16 February 2023).

U.S. Department of Agriculture, Natural Resources Conservation Service. 2017. Geomorphic Description System, Version 5.0. Schoeneberger, P.J., and D.A. (eds). USDA-NRCS, National Soil Survey Center, Lincoln, NE.

U.S. Department of Agriculture, Natural Resources Conservation Service. 2022. Land resource regions and major land resource areas of the United States, the Caribbean, and the Pacific Basin. Agriculture Handbook 296.

U.S. Environmental Protection Agency. 2013. Level III and IV ecoregions of the continental United States: Corvallis, Oregon, U.S. EPA, National Health and Environmental Effects Research Laboratory, map scale 1:3,000,000, https://www.epa.gov/eco-research/level-iii-and-iv-ecoregions-continental-united-states.

Contributors

Matthew D. Duvall

Approval

Charles Stemmans, 2/12/2025

Rangeland health reference sheet

Interpreting Indicators of Rangeland Health is a qualitative assessment protocol used to determine ecosystem condition based on benchmark characteristics described in the Reference Sheet. A suite of 17 (or more) indicators are typically considered in an assessment. The ecological site(s) representative of an assessment location must be known prior to applying the protocol and must be verified based on soils and climate. Current plant community cannot be used to identify the ecological site.

Author(s)/participant(s)
Contact for lead author
Date	02/12/2025
Approved by	Charles Stemmans
Approval date
Composition (Indicators 10 and 12) based on	Annual Production