Southern Coastal Plain Wetland Hammock

EVT 9248Southern Coastal Plain Hydric Hammock
CES203.501GNRTreeRiparian
Summary
This ecological system occupies flat lowlands along the southern and outermost portions of the Coastal Plain of the southeastern United States, usually over limestone substrates. The vegetation of this system is characterized by mixed hardwood species, often with hydric oak species common. In Florida, examples of this system are often found adjacent to the floodplain of spring-fed rivers with relatively constant flows. In some areas, such as the Big Bend region of Florida, they occupy large areas of broad, shallow, mucky or seepy wetlands but generally do not receive overbank flooding. In Alabama, this system is apparently confined to floodplains of the Mobile-Tensaw, where examples are topographically higher than the surrounding floodplains.
Source: NatureServe Explorer
Vegetation
The vegetation of this system is characterized by mixed hardwood species, often with hydric oak species common (FNAI 2010a, A. Johnson pers. comm.). Stands may be dominated by a variety of wetland and upland tree species, including Chamaecyparis thyoides, Sabal palmetto, and Quercus laurifolia, as well as Quercus virginiana, Magnolia virginiana, and Ulmus americana. Some shrubs and understory trees include Ilex cassine and Morella cerifera.
Source: NatureServe Explorer
Environment
Examples of this system are associated with limestone-rich sites. Soils may range from sand to clay to organic (FNAI 2010a). In Florida, examples of this system are often found adjacent to the floodplain of spring-fed rivers with relatively constant flows. In some areas, such as the Big Bend region of Florida, they occupy large areas of broad, shallow, mucky or seepy wetlands but generally do not receive overbank flooding (A. Johnson pers. comm.). In Alabama, this system is apparently confined to floodplains of the Mobile-Tensaw, where examples are topographically higher than the surrounding floodplains (A. Schotz pers. comm.).
Source: NatureServe Explorer
Dynamics
Saturation, but usually not inundation, is characteristic of the hydrology of some hydric hammocks; lower areas generally are prone to more flooding. The distributions of trees within hydric hammocks are influenced by the timing and depth of flooding (Vince et al. 1989). These are sites which are only occasionally subject to wildland fire (FNAI 2010a) and are dominated by mixed evergreen and deciduous forest, often with Sabal palmetto which is fire-tolerant.
Source: NatureServe Explorer
Threats
Conversion of hydric hammock to pine plantations has been a threat, especially damage to the soil from logging and forestry site preparation (FNAI 2010a). Drainage and other hydrological alteration are threats. Feral hogs (Sus scrofa) are a real threat; hydric hammock is a preferred habitat for them. Soil disturbance and canopy openings allow the spread of exotic invasive plants, particularly Cinnamomum camphora, Imperata cylindrica, Lygodium japonicum, Lygodium microphyllum, Nephrolepis cordifolia, Paederia foetida, Schinus terebinthifolius, Tradescantia fluminensis, and Urena lobata (FNAI 2010a). Threats to coastal hydric hammocks also include sea-level rise over the next century (FNAI 2010a).
Source: NatureServe Explorer
Distribution
As currently documented, this system occurs in Florida, Georgia and rarely in southern Alabama. In Alabama, this system is apparently confined to floodplains of the Mobile-Tensaw (A. Schotz pers. comm.).
Source: NatureServe Explorer
Ecologically Associated Plant Species

Plant species that characterize this ecosystem type, organized by vegetation stratum. These are species ecologically associated with the ecosystem, not confirmed present in any specific area.

Tree canopy

Chamaecyparis thyoides, Magnolia virginiana, Quercus laurifolia, Quercus virginiana, Sabal palmetto, Taxus floridana, Ulmus americana

Tree subcanopy

Magnolia ashei

Shrub/sapling (tall & short)

Elliottia racemosa, Forestiera godfreyi, Ilex cassine, Illicium parviflorum, Leitneria floridana, Morella cerifera, Pieris phillyreifolia, Salix floridana, Sideroxylon alachuense, Sideroxylon thornei

Herb (field)

Arnoglossum diversifolium, Asclepias viridula, Baptisia megacarpa, Coreopsis integrifolia, Cuphea aspera, Fimbristylis perpusilla, Hartwrightia floridana, Hymenocallis henryae, Lythrum curtissii, Macbridea caroliniana, Matelea alabamensis, Matelea floridana, Phyllanthus liebmannianus ssp. platylepis, Ruellia noctiflora, Schwalbea americana, Scutellaria ocmulgee, Silene polypetala, Symphyotrichum racemosum var. 2, Thalictrum macrostylum, Tiedemannia canbyi, Verbesina heterophylla

Nonvascular

Acroporium smallii, Fissidens amoenus, Lejeunea floridana, Plagiochila floridana, Plagiochila sullivantii, Sphaerocarpos donnellii

Submerged aquatic

Najas filifolia
Source: NatureServe Ecological System assessment
Ecologically Associated Animals (18)

Animal species ecologically associated with this ecosystem type based on NatureServe assessment. These are species whose habitat requirements overlap with this ecosystem, not confirmed present in any specific roadless area.

Mammals (2)

Common NameScientific NameG-Rank
Florida PantherPuma concolor coryiG5T1
Florida Black BearUrsus americanus floridanusG5T4

Birds (1)

Common NameScientific NameG-Rank
Florida Sandhill CraneAntigone canadensis pratensisG5T2

Reptiles (4)

Common NameScientific NameG-Rank
Northern CottonmouthAgkistrodon piscivorusG5
Southern Hog-nosed SnakeHeterodon simusG2G3
Rough GreensnakeOpheodrys aestivusG5
Eastern RibbonsnakeThamnophis sauritaG5

Amphibians (2)

Common NameScientific NameG-Rank
Striped NewtNotophthalmus perstriatusG2
Broad-striped Dwarf SirenPseudobranchus striatus striatusG5T1T3

Fish (2)

Common NameScientific NameG-Rank
Dougherty Burrowing CrayfishCambarus doughertyensisG1
Hobbs's Cave AmphipodCrangonyx hobbsiG2G3

Butterflies & Moths (2)

Common NameScientific NameG-Rank
Dukes' SkipperEuphyes dukesi calhouniG3G4T2T3
Okefenokee Zale MothZale percultaG2?

Insects (4)

Common NameScientific NameG-Rank
Logan's Agarodes CaddisflyAgarodes loganiG1
Gold Head Branch CaddisflyOxyethira chrysocaraG1
Large-Jawed Cebrionid BeetleSelonodon mandibularisG2G4
Say's SpiketailZoraena sayiG3

Molluscs (1)

Common NameScientific NameG-Rank
Delicate SpikeElliptio arctataG2G3
Source: NatureServe Ecological System assessment
At-Risk Species Associated with this Ecosystem (51)

Species with conservation concern that are ecologically associated with this ecosystem type. G-Rank indicates global conservation status: G1 (critically imperiled) through G5 (secure). ESA status indicates U.S. Endangered Species Act listing.

Common NameScientific NameG-RankESA Status
Small's Acroporium MossAcroporium smalliiG1?--
Logan's Agarodes CaddisflyAgarodes loganiG1Under Review
Florida Sandhill CraneAntigone canadensis pratensisG5T2--
Variableleaf Indian-plantainArnoglossum diversifoliumG3--
Southern MilkweedAsclepias viridulaG2--
Apalachicola Wild IndigoBaptisia megacarpaG1G2--
Dougherty Burrowing CrayfishCambarus doughertyensisG1--
Ciliate-leaf TickseedCoreopsis integrifoliaG2Under Review
Hobbs's Cave AmphipodCrangonyx hobbsiG2G3Under Review
Tropical WaxweedCuphea asperaG2--
Georgia PlumeElliottia racemosaG2?--
Delicate SpikeElliptio arctataG2G3Under Review
Dukes' SkipperEuphyes dukesi calhouniG3G4T2T3Under Review
Harper's FimbryFimbristylis perpusillaG2Under Review
Hall's Pocket MossFissidens amoenusG3--
Godfrey's Swamp-privetForestiera godfreyiG2--
Florida HartwrightiaHartwrightia floridanaG2G3Under Review
Southern Hog-nosed SnakeHeterodon simusG2G3Proposed threatened
Henry's Spider-lilyHymenocallis henryaeG2Under Review
Yellow AnisetreeIllicium parviflorumG2G3--
CorkwoodLeitneria floridanaG3--
a liverwortLejeunea floridanaG2G3--
Curtiss' LoosestrifeLythrum curtissiiG2Under Review
Carolina Birds-in-a-nestMacbridea carolinianaG3--
Ashe's MagnoliaMagnolia asheiG3--
Alabama AnglepodMatelea alabamensisG2--
Florida MilkvineMatelea floridanaG2G3--
Narrowleaf NaiadNajas filifoliaG3Under Review
Striped NewtNotophthalmus perstriatusG2--
Gold Head Branch CaddisflyOxyethira chrysocaraG1--
Florida Leaf-flowerPhyllanthus liebmannianus ssp. platylepisG4T2--
Florida Leafy LiverwortPlagiochila floridanaG2?--
Sullivant's Leafy LiverwortPlagiochila sullivantiiG3G4--
Broad-striped Dwarf SirenPseudobranchus striatus striatusG5T1T3--
Florida PantherPuma concolor coryiG5T1Endangered
Night-flowering Wild PetuniaRuellia noctifloraG3?--
Florida WillowSalix floridanaG2G3Under Review
American ChaffseedSchwalbea americanaG2Endangered
Ocmulgee SkullcapScutellaria ocmulgeeG2Endangered
Large-Jawed Cebrionid BeetleSelonodon mandibularisG2G4--
Alachua Sink BuckthornSideroxylon alachuenseG1--
Swamp BuckthornSideroxylon thorneiG3--
Fringed CampionSilene polypetalaG2Endangered
a liverwortSphaerocarpos donnelliiG2G3--
Apalachicola River AsterSymphyotrichum racemosum var. 2G5T1Q--
Florida YewTaxus floridanaG2--
Small-leaf MeadowrueThalictrum macrostylumG3G4--
Canby's DropwortTiedemannia canbyiG2Endangered
Diverseleaf CrownbeardVerbesina heterophyllaG2--
Okefenokee Zale MothZale percultaG2?--
Say's SpiketailZoraena sayiG3--
Source: NatureServe Ecological System assessment
Component Associations (6)

Plant community associations that occur within this ecological system. Associations are the finest level of the U.S. National Vegetation Classification (USNVC) and describe specific, repeating assemblages of plant species. Each association represents a distinct community type that may be found where this ecosystem occurs.

NameG-Rank
Chamaecyparis thyoides - Sabal palmetto Swamp NatureServe
Fagus grandifolia - Pinus glabra - Magnolia grandiflora / Serenoa repens Forest NatureServe
Fraxinus caroliniana - Sabal palmetto - Ulmus americana / Cephalanthus occidentalis Forest NatureServe
Sabal palmetto / Ilex cassine - Morella cerifera Swamp Woodland NatureServe
Sabal palmetto - Quercus laurifolia - Quercus virginiana - Magnolia virginiana - Ulmus americana Swamp NatureServe
Sabal palmetto - Quercus virginiana Swamp NatureServe
State Conservation Ranks (3)

Subnational conservation status ranks (S-ranks) assigned by Natural Heritage Programs in each state where this ecosystem occurs. S1 indicates critically imperiled at the state level, S2 imperiled, S3 vulnerable, S4 apparently secure, and S5 secure. An ecosystem may be globally secure but imperiled in specific states at the edge of its range.

StateS-Rank
ALSNR
FLSNR
GASNR
Roadless Areas (1)

Inventoried Roadless Areas where this ecosystem is present, identified from LANDFIRE 2024 Existing Vegetation Type spatial analysis. Coverage indicates the proportion of each area occupied by this ecosystem type.

Florida (1)

AreaForestCoverageHectares
Alexander Springs CreekOcala National Forest8.0%96.21
Methodology and Data Sources

Ecosystem classification: Ecosystems are classified using the LANDFIRE 2024 Existing Vegetation Type (EVT) layer, mapped to NatureServe Terrestrial Ecological Systems via a curated crosswalk. Each EVT is linked to the USNVC (U.S. National Vegetation Classification) hierarchy through pixel-level co-occurrence analysis of LANDFIRE EVT and NatureServe IVC Group rasters across all roadless areas.

Vegetation coverage: Coverage percentages and hectares are derived from zonal statistics of the LANDFIRE 2024 EVT raster intersected with roadless area boundaries.

Ecosystem narratives and community species: Sourced from the NatureServe Explorer API, representing professional ecological assessments of vegetation composition, environmental setting, dynamics, threats, and characteristic species assemblages.

IVC hierarchy: The International Vegetation Classification hierarchy is sourced from the USNVC v3.0 Catalog, providing the full classification from Biome through Association levels.

Component associations: Plant community associations listed as components of each NatureServe Ecological System. Association data from the NatureServe Explorer API.

State ranks: Conservation status ranks assigned by NatureServe member programs in each state where the ecosystem occurs.