Home/Ecosystems/ Central Appalachian River Floodplain

Central Appalachian River Floodplain

EVT 9059Central Appalachian River Floodplain Forest

CES202.608GNRTreeRiparian

Summary

This system encompasses floodplains of medium to large rivers in Atlantic drainages from southern New England to Virginia. This system can include a complex of wetland and upland vegetation on deep alluvial deposits and scoured vegetation on depositional bars and on bedrock where rivers cut through resistant geology. This complex includes floodplain forests in which Acer saccharinum, Populus deltoides, and Platanus occidentalis are characteristic, as well as herbaceous sloughs, shrub wetlands, riverside prairies and woodlands. Microtopography and soil texture determine how long the various habitats are inundated. Depositional and erosional features may both be present depending on the particular floodplain.

Source: NatureServe Explorer

Vegetation

This complex includes floodplain forests in which Acer saccharinum, Platanus occidentalis, and Populus deltoides are characteristic, as well as herbaceous sloughs, shrub wetlands, riverside prairies and woodlands. Other trees may include Acer rubrum, Acer negundo, Betula nigra, Carpinus caroliniana, Fraxinus pennsylvanica, Liriodendron tulipifera, Platanus occidentalis, Populus deltoides, and Ulmus americana. Herbs and shrubs may include Ageratina altissima, Boehmeria cylindrica, Carex trichocarpa, Carex torta, Cyperus squarrosus, Elymus virginicus, Eragrostis hypnoides, Hypericum prolificum, Ionactis linariifolius, Laportea canadensis, Eubotrys racemosa (= Leucothoe racemosa), Lindera benzoin, Lindernia dubia, Ludwigia palustris, Matteuccia struthiopteris, Onoclea sensibilis, Peltandra virginica, Physocarpus opulifolius, Schizachyrium scoparium, and Solidago simplex var. racemosa.

Source: NatureServe Explorer

Environment

This system forms on broad, relatively flat floodplains along medium-sized to large rivers. Rivershores often exhibit development of one or more terraces formed in relation to hydroperiod and height from river channel. Backswamps may occur in poorly drained depressions behind the main river channel, where substrate is deep muck. Soils range from sandy and silty on point bars to deep muck in backswamps.

Source: NatureServe Explorer

Dynamics

Spring and summer flooding brings large amounts of sediment carried from tributaries, as well as other debris that is deposited on the floodplain as flood waters recede. Floodplain canopy trees often topple as a result of prolonged saturation of sediments; vegetation structure is highly variable and dynamic as a result. Dynamic disturbance regime and high fertility make this system highly susceptible to invasions of non-native plants.

Source: NatureServe Explorer

Threats

The high nutrient content of soils and the level topography of the floodplain have attracted a high degree of conversion to agriculture. Pesticides from crops and nutrients from fertilizer and farm animals often flow unimpeded into rivers, altering water quality and increasing the incidence of invasive species. Historic use of rivers as dumping areas of industrial waste leads to concentrations of toxic chemicals in the sediments. Dams convert natural flooding regimes, diminishing the dynamic quality of these systems as a result of controlled water releases. Dams also inhibit fish movement, altering movement of invertebrates such as freshwater mussels. Riprap or hardening of shorelines changes the flow regime. Vegetation on terraces and higher elevations above the river formerly maintained by flooding undergoes succession to other community types. Invasive plant species, easily spread by waterflow, inhibit growth of native plants.

Source: NatureServe Explorer

Distribution

Southern New England west to Lake Erie and south to Virginia. The James River in Virginia marks the southern extent of this system.

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

Acer saccharinum, Fraxinus pennsylvanica, Platanus occidentalis, Populus deltoides

Tree subcanopy

Carpinus caroliniana

Shrub/sapling (tall & short)

Diervilla rivularis, Rhamnus alnifolia, Rhododendron arborescens, Spiraea tomentosa, Spiraea virginiana

Short shrub/sapling

Rosa obtusiuscula

Herb (field)

Arabis georgiana, Arnoglossum reniforme, Carex scabrata, Dryopteris carthusiana, Dryopteris cristata, Eleocharis compressa var. compressa, Hasteola suaveolens, Laportea canadensis, Listera smallii, Lorinseria areolata, Lysimachia fraseri, Lysimachia terrestris, Maianthemum stellatum, Marshallia grandiflora, Menispermum canadense, Sagittaria secundifolia, Symplocarpus foetidus, Toxicodendron radicans

Nonvascular

Anthoceros lamellatus, Cetradonia linearis, Fissidens appalachensis, Hygrohypnum closteri, Lejeunea blomquistii, Peltigera hydrothyria

Submerged aquatic

Myriophyllum pinnatum, Orontium aquaticum, Podostemum ceratophyllum, Potamogeton amplifolius, Potamogeton epihydrus

Source: NatureServe Ecological System assessment

Ecologically Associated Animals (25)

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 (4)

Common Name	Scientific Name	G-Rank
Red Wolf	Canis rufus	G1
North American River Otter	Lontra canadensis	G5
Least Weasel	Mustela nivalis	G5
Southeastern Myotis	Myotis austroriparius	G4

Birds (1)

Common Name	Scientific Name	G-Rank
Northern Waterthrush	Parkesia noveboracensis	G5

Reptiles (4)

Common Name	Scientific Name	G-Rank
Green Anole	Anolis carolinensis	G5
Common Watersnake	Nerodia sipedon	G5
Eastern Ribbonsnake	Thamnophis saurita	G5
Common Ribbonsnake	Thamnophis saurita saurita	G5T5

Amphibians (7)

Common Name	Scientific Name	G-Rank
Mole Salamander	Ambystoma talpoideum	G4G5
American Toad	Anaxyrus americanus	G5
Junaluska Salamander	Eurycea junaluska	G2G3
Longtail Salamander	Eurycea longicauda	G5
Green Frog	Lithobates clamitans	G5
Tellico Salamander	Plethodon aureolus	G2G3
Mud Salamander	Pseudotriton montanus	G5

Butterflies & Moths (3)

Common Name	Scientific Name	G-Rank
Marbled Underwing	Catocala marmorata	G3?
Chestnut Clearwing Moth	Synanthedon castaneae	G3G5
Golden-banded Skipper	Telegonus cellus	G5

Insects (1)

Common Name	Scientific Name	G-Rank
Appalachian Tiger Beetle	Cicindela ancocisconensis	G3

Other Invertebrates (2)

Common Name	Scientific Name	G-Rank
Northern Spiny Softshell Turtle	Apalone spinifera spinifera	G5T5
Wood Turtle	Glyptemys insculpta	G2G3

Other (3)

Common Name	Scientific Name	G-Rank
Eastern Cougar	Puma concolor couguar	G5TXQ
Southern Water Shrew	Sorex palustris punctulatus	G5T3
Loggerhead Musk Turtle	Sternotherus minor	G5

Source: NatureServe Ecological System assessment

At-Risk Species Associated with this Ecosystem (17)

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 Name	Scientific Name	G-Rank	ESA Status
Georgia Rockcress	Arabis georgiana	G1	Threatened
Red Wolf	Canis rufus	G1	Endangered; Experimental population, non-essential
Marbled Underwing	Catocala marmorata	G3?	--
Rock Gnome Lichen	Cetradonia linearis	G3	Endangered
Appalachian Tiger Beetle	Cicindela ancocisconensis	G3	--
Mountain Bush-honeysuckle	Diervilla rivularis	G3	--
Junaluska Salamander	Eurycea junaluska	G2G3	--
Appalachian Pocket Moss	Fissidens appalachensis	G2G3	--
Wood Turtle	Glyptemys insculpta	G2G3	Under Review
Closter's Brook Moss	Hygrohypnum closteri	G3	--
Blomquist Leafy Liverwort	Lejeunea blomquistii	G3	--
Fraser's Loosestrife	Lysimachia fraseri	G3	--
Tellico Salamander	Plethodon aureolus	G2G3	--
Eastern Cougar	Puma concolor couguar	G5TXQ	Delisted
Little River Arrowhead	Sagittaria secundifolia	G1	Threatened
Southern Water Shrew	Sorex palustris punctulatus	G5T3	--
Virginia Spiraea	Spiraea virginiana	G2?	Threatened

Source: NatureServe Ecological System assessment

Component Associations (53)

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.

Name	G-Rank
Acer negundo Ruderal Floodplain Forest		NatureServe
Acer (rubrum, saccharinum) - Fraxinus pennsylvanica - Ulmus americana / Boehmeria cylindrica Floodplain Forest		NatureServe
Acer saccharinum - Acer negundo / Ageratina altissima - Laportea canadensis - (Elymus virginicus) Floodplain Forest		NatureServe
Acer saccharinum / Onoclea sensibilis - Boehmeria cylindrica Floodplain Forest		NatureServe
Acer saccharinum - (Populus deltoides) / Matteuccia struthiopteris - Laportea canadensis Floodplain Forest		NatureServe
Acer saccharinum - Ulmus americana / Onoclea sensibilis Floodplain Forest		NatureServe
Acer saccharinum - Ulmus americana / Physocarpus opulifolius Floodplain Forest		NatureServe
Acer saccharum - Fraxinus americana / Carpinus caroliniana / Podophyllum peltatum Forest		NatureServe
Acer saccharum - Fraxinus spp. - Tilia americana / Matteuccia struthiopteris - Ageratina altissima Floodplain Forest		NatureServe
Acer saccharum - Liriodendron tulipifera / Galium concinnum - Carex laxiculmis Forest		NatureServe
Alnus incana - Viburnum recognitum / Calamagrostis canadensis Shrub Swamp		NatureServe
Alnus serrulata / Calamagrostis canadensis Shrub Swamp		NatureServe
Alnus serrulata - Physocarpus opulifolius Wet Shrubland		NatureServe
Andropogon gerardii - Panicum virgatum - Baptisia australis Riverscour Wet Meadow		NatureServe
Betula nigra - Platanus occidentalis Floodplain Forest		NatureServe
Betula nigra - Platanus occidentalis / Impatiens capensis Floodplain Forest		NatureServe
Calamagrostis canadensis North-Central Wet Meadow	G4	NatureServe
Carex torta - Apocynum cannabinum - Cyperus spp. Riverbed		NatureServe
Carex torta Riverbed		NatureServe
Carex trichocarpa Rivershore Wet Meadow		NatureServe
Carpinus caroliniana - Ilex decidua Wet Shrubland		NatureServe
Carya cordiformis - Prunus serotina / Ageratina altissima Forest		NatureServe
Cephalanthus occidentalis - Decodon verticillatus Shrub Swamp		NatureServe
Eragrostis hypnoides - Ludwigia palustris - Lindernia dubia - Cyperus squarrosus Riverbar Wet Meadow		NatureServe
Eupatorium serotinum - Polygonum (lapathifolium, punctatum, pensylvanicum) Riverbar Wet Meadow		NatureServe
Fagus grandifolia - Quercus spp. - Acer rubrum - Juglans nigra Floodplain Forest		NatureServe
Fraxinus americana / Andropogon gerardii - Sorghastrum nutans - Schizachyrium scoparium - Pycnanthemum tenuifolium Riverscour Wet Meadow		NatureServe
Fraxinus pennsylvanica - (Juglans nigra, Platanus occidentalis) Floodplain Forest		NatureServe
Fraxinus pennsylvanica - Ulmus spp. - Celtis occidentalis Floodplain Forest		NatureServe
(Hypericum prolificum, Eubotrys racemosa) / Schizachyrium scoparium - Solidago simplex var. racemosa - Ionactis linariifolius Riverscour Wet Meadow		NatureServe
Juglans nigra / Verbesina alternifolia Ruderal Forest	GNA	NatureServe
Justicia americana Riverbed		NatureServe
Liriodendron tulipifera - Pinus strobus - (Tsuga canadensis) / Carpinus caroliniana / Amphicarpaea bracteata Forest		NatureServe
Liriodendron tulipifera - Platanus occidentalis - Betula lenta / Lindera benzoin / Circaea lutetiana ssp. canadensis Floodplain Forest		NatureServe
Peltandra virginica - Polygonum amphibium var. emersum - Carex stricta - Impatiens capensis Marsh		NatureServe
Peltandra virginica - Saururus cernuus - Boehmeria cylindrica / Climacium americanum Marsh		NatureServe
Pinus virginiana - Quercus stellata / Amelanchier stolonifera / Danthonia spicata / Leucobryum glaucum Woodland		NatureServe
Platanus occidentalis - Acer negundo - Juglans nigra / Asimina triloba / Mertensia virginica Floodplain Forest		NatureServe
Platanus occidentalis - Acer saccharinum - Fraxinus pennsylvanica / Boehmeria cylindrica - Carex emoryi Floodplain Forest		NatureServe
Platanus occidentalis / Aesculus flava Floodplain Forest		NatureServe
Platanus occidentalis - Betula nigra - Salix (caroliniana, nigra) Floodplain Forest		NatureServe
Platanus occidentalis - Fraxinus pennsylvanica Floodplain Forest		NatureServe
Prunus pumila / Andropogon gerardii - Sorghastrum nutans Riverscour Wet Meadow		NatureServe
Quercus bicolor - Acer rubrum / Carpinus caroliniana Wet Forest		NatureServe
Quercus bicolor - Fraxinus pennsylvanica - (Platanus occidentalis) / Chasmanthium latifolium - Zizia aurea Floodplain Forest		NatureServe
Quercus palustris - Acer rubrum / Carex grayi - Geum canadense Wet Forest		NatureServe
Quercus palustris - Quercus bicolor / Carex tribuloides - Carex radiata - (Carex squarrosa) Wet Forest		NatureServe
Quercus rubra - Quercus shumardii / Cercis canadensis Floodplain Forest		NatureServe
Salix nigra - Betula nigra / Schoenoplectus pungens Riverscour Shrubland		NatureServe
Salix sericea Shrub Swamp		NatureServe
Spiraea alba Wet Shrubland		NatureServe
Tilia americana - Acer saccharum - Acer nigrum / Laportea canadensis Floodplain Forest		NatureServe
Verbesina alternifolia - Elymus riparius - Solidago gigantea - (Teucrium canadense) Riverbar Wet Meadow		NatureServe

State Conservation Ranks (10)

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.

State	S-Rank
CT	SNR
MA	SNR
MD	SNR
NH	SNR
NY	SNR
OH	SNR
PA	SNR
VA	SNR
VT	SNR
WV	SNR

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.

Pennsylvania (1)

Area	Forest	Coverage	Hectares
Verbeck Island	Allegheny National Forest	45.3%	2.61

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.