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A3430 Quercus phellos Piedmont-Cumberland Wet Depression Forest Alliance

Type Concept Sentence: These are wet depressions in the Piedmont, Cumberland, and Interior Plateau regions of the southeastern United States with Quercus phellos, primarily a coastal plain species, as an indicator and typically dominant canopy component.

Common (Translated Scientific) Name: Willow Oak Piedmont-Cumberland Wet Depression Forest Alliance

Colloquial Name: Piedmont-Cumberland Willow Oak Wet Depression Forest

Hierarchy Level:  Alliance

Type Concept: This alliance includes vegetation of wet depressions and related habitats in the Piedmont, Cumberland, and Interior Plateau regions of the southeastern United States from Alabama north to Kentucky and Maryland. Examples have Quercus phellos as an indicator and typically dominant to codominant component of the canopy. It is noteworthy as an indicator in these regions as it is primarily a species of the coastal plains. The associated species vary across this range. Additional canopy trees include Liquidambar styraciflua, Quercus alba, Quercus lyrata, Quercus michauxii, Quercus nigra, Quercus shumardii, and Quercus stellata. Some other canopy and subcanopy trees include Acer floridanum, Carya carolinae-septentrionalis, Celtis laevigata, Fraxinus americana, Juglans nigra, Morus rubra, Nyssa biflora, and Ulmus americana. The small understory trees Cercis canadensis, Cornus florida, Cornus foemina, Crataegus viridis, Quercus oglethorpensis, and Sideroxylon lycioides may also occur. Some herbs that are found in component associations include Carex albolutescens, Carex intumescens, Carex joorii, Chasmanthium laxum, Chasmanthium sessiliflorum, Dichanthelium boscii, Dulichium arundinaceum, Glyceria striata, Hymenocallis occidentalis, Podophyllum peltatum, and Zephyranthes atamasca. This alliance occurs in upland depressions and swales in flatwoods that do not receive overbank flooding, including gently sloped upper drainages in flat Piedmont terrain with dense clay hardpan soils that have restricted internal drainage; shallow depressions in ridgetop or plateau-top sandstone of the Cumberland Plateau or on limestones and dolostones in the Southern Ridge and Valley; sloping terrain or shallowly depressed upland flats over gabbro-derived clays in the Piedmont of Georgia and South Carolina; as well as depression swamps found in the Piedmont and in limited areas of the adjacent Inner Coastal Plain.

Diagnostic Characteristics: Examples of this group are distinctive for being dominated by Quercus phellos and being found in the Piedmont and Cumberland regions of the southeastern United States. Quercus phellos is primarily a species of the coastal plains.

Rationale for Nominal Species or Physiognomic Features: No Data Available

Classification Comments: No Data Available

Similar NVC Types: No Data Available
note: No Data Available
Physiognomy and Structure: Stands of this alliance are dominated by broad-leaved deciduous trees and have sparse to well-developed shrub and herbaceous strata.

Floristics: Examples of this alliance have Quercus phellos as an indicator and typically dominant to codominant component of the canopy. It is noteworthy as an indicator in these interior regions as it is primarily a species of the coastal plains. The associated species vary across the alliance''s range. Additional canopy trees include Liquidambar styraciflua, Quercus alba, Quercus lyrata, Quercus michauxii, Quercus nigra, Quercus shumardii, and Quercus stellata. Some other canopy and subcanopy trees include Acer floridanum (= Acer barbatum), Carya carolinae-septentrionalis, Celtis laevigata, Fraxinus americana, Juglans nigra, Morus rubra, Nyssa biflora, and Ulmus americana. The small understory trees Cercis canadensis, Cornus florida, Cornus foemina, Crataegus viridis, Quercus oglethorpensis, and Sideroxylon lycioides may also occur. Vines are abundant and diverse. They may include Berchemia scandens, Bignonia capreolata, Campsis radicans, Cocculus carolinus, Lonicera sempervirens, Matelea carolinensis, Parthenocissus quinquefolia, Passiflora lutea, Smilax bona-nox, Smilax glauca, Smilax rotundifolia, Toxicodendron radicans, Trachelospermum difforme, and Vitis rotundifolia. Some herbs that are found in component associations include Carex albolutescens, Carex intumescens, Carex joorii, Chasmanthium laxum, Chasmanthium sessiliflorum, Dichanthelium boscii, Dulichium arundinaceum, Glyceria striata, Hymenocallis occidentalis, Podophyllum peltatum, and Zephyranthes atamasca.

Dynamics:  Community dynamics are not well-known. These communities probably exist naturally as uneven-aged, old-growth forests. However, wetness and shallow rooting depth may make them more susceptible to windthrow than most upland forests, and subject to larger canopy gaps. Both extreme wet and extreme dry periods would stress some component species and might cause tree mortality. Floods, if any, have little flow, and flood disturbance is correspondingly low, but the clearing of ground by flowing water is likely important to the establishment of some herbaceous species. In examples on gabbro in Piedmont Georgia, the water table is never far from the surface because of the very subdued topography, and the ground may be saturated for extended periods of time during the growing season. In winter and early spring, large areas of standing water are typically found, helping create the unusual habitat conditions. In summer and fall, as the water table drops, the Iredell soil shrinks and becomes almost pavement-like, even though the water table may be only a foot or two below the soil surface (Clark 1978).
Environmental Description:  This vegetation is confined to a variety of upland wet depressions and swales in flatwoods that do not receive overbank flooding, found in the Piedmont, Cumberland, and Interior Plateau regions of the southeastern United States. These environments include upland depressions, including gently sloped upper drainages in flat Piedmont terrain with dense clay hardpan soils that have restricted internal drainage; shallow depressions in ridgetop or plateau-top sandstone of the Cumberland Plateau or on limestones and dolostones in the Southern Ridge and Valley; sloping terrain or shallowly depressed upland flats over gabbro-derived clays in the Piedmont of Georgia and South Carolina; as well as depression swamps found in the Piedmont and in limited areas of the adjacent Inner Coastal Plain.
Geographic Range: This alliance is primarily found in the Piedmont, southern Ridge and Valley/Cumberlands, and Interior Low Plateau of the southeastern United States from Maryland, Virginia, and Kentucky south to Georgia and Alabama. One southern Piedmont association is peripheral to the adjacent Atlantic Coastal Plain and northern Piedmont.

Nations: US

States/Provinces:  AL, GA, KY, MD, NC, SC, TN, VA


Confidence Level: Low

Confidence Level Comments: No Data Available
Grank: GNR

Greasons: No Data Available
Type Name Database Code Classification Code
Class 1 Forest & Woodland Class C01 1
Subclass 1.B Temperate & Boreal Forest & Woodland Subclass S15 1.B
Formation 1.B.3 Temperate Flooded & Swamp Forest Formation F026 1.B.3
Division 1.B.3.Na Eastern North American-Great Plains Flooded & Swamp Forest Division D011 1.B.3.Na
Macrogroup 1.B.3.Na.2 Pin Oak - Green Ash - Blackgum Swamp Forest Macrogroup M503 1.B.3.Na.2
Group 1.B.3.Na.2.b Overcup Oak - Post Oak - Blackgum Flatwoods & Pond Forest Group G654 1.B.3.Na.2.b
Alliance A3430 Willow Oak Piedmont-Cumberland Wet Depression Forest Alliance A3430 1.B.3.Na.2.b
Association CEGL003880 (Cherrybark Oak, Shumard Oak) / Stiff Dogwood / Mayapple - Woodland Spiderlily Flatwoods Forest CEGL003880 1.B.3.Na.2.b
Association CEGL004042 Willow Oak - White Oak - (Swamp Chestnut Oak) - Southern Shagbark Hickory Wet Forest CEGL004042 1.B.3.Na.2.b
Association CEGL004116 Swamp Tupelo / Common Buttonbush - Shining Fetterbush Sagpond Forest CEGL004116 1.B.3.Na.2.b
Association CEGL004550 Swamp Tupelo / Common Buttonbush - Swamp Doghobble Swamp Forest CEGL004550 1.B.3.Na.2.b
Association CEGL007403 Willow Oak / (Green-white Sedge, Greater Bladder Sedge, Cypress Swamp Sedge) / American Tree Moss Wet Forest CEGL007403 1.B.3.Na.2.b
Association CEGL007405 Willow Oak - Water Oak - (Swamp Tupelo) Wet Forest CEGL007405 1.B.3.Na.2.b
Association CEGL008441 Willow Oak - Sweetgum / Slender Woodoats Cumberland / Southern Ridge & Valley Wet Forest CEGL008441 1.B.3.Na.2.b
Association CEGL008484 Willow Oak - (Swamp Chestnut Oak, Shumard Oak) / (Oglethorpe Oak) / Atamasco Lily Gabbro Wet Forest CEGL008484 1.B.3.Na.2.b
Concept Lineage: This alliance contains associations from two old alliances; A.292 (2/21) and A.330 (5/19) [proto-alliance A2052?].

Predecessors: No Data Available

Obsolete Names: No Data Available

Obsolete Parents: No Data Available
Synonomy: >< IIA10d. Upland Depression Swamp (Allard 1990)
>< Sweetgum - Willow Oak: 92 (Eyre 1980)
>< Willow Oak - Water Oak - Diamondleaf (Laurel) Oak: 88 (Eyre 1980)
Concept Author(s): M. Pyne, in Faber-Langendoen et al. (2013)

Author of Description: M. Pyne

Acknowledgements: No Data Available

Version Date: 01-08-14
  • Allard, D. J. 1990. Southeastern United States ecological community classification. Interim report, Version 1.2. The Nature Conservancy, Southeast Regional Office, Chapel Hill, NC. 96 pp.
  • Clark, R. C. 1978. Natural landmark site evaluation: Georgia. Monticello Bottomland Woods, Jasper County. Unpublished document.
  • Evans, M., B. Yahn, and M. Hines. 2009. Natural communities of Kentucky 2009. Kentucky Nature Preserves Commission, Frankfort, KY. 22 pp.
  • Eyre, F. H., editor. 1980. Forest cover types of the United States and Canada. Society of American Foresters, Washington, DC. 148 pp.
  • Faber-Langendoen, D., J. Drake, M. Hall, G. Kittel, S. Menard, C. Nordman, M. Pyne, M. Reid, M. Russo, K. Schulz, L. Sneddon, K. Snow, and J. Teague. 2013-2019b. Screening alliances for induction into the U.S. National Vegetation Classification: Part 1 - Alliance concept review. NatureServe, Arlington, VA.
  • Gemborys, S. R., and E. J. Hodgkins. 1971. Forests of small stream bottoms in the coastal plain of southwestern Alabama. Ecology 52:70-84.
  • Glascock, S., and S. Ware. 1979. Forests of small stream bottoms in the peninsula of Virginia. Virginia Journal of Science 30:17-21.
  • Golden, M. S. 1979. Forest vegetation of the lower Alabama Piedmont. Ecology 60:770-782.
  • Klimas, C. V. 1988b. Forest vegetation of the leveed floodplain of the lower Mississippi River. U.S. Army Corps of Engineers, Waterways Experimental Station, Lower Mississippi River Environmental Program. Report No. 11. Vicksburg, MS. 281 pp.
  • Schafale, M. P., and A. S. Weakley. 1990. Classification of the natural communities of North Carolina. Third approximation. North Carolina Department of Environment, Health, and Natural Resources, Division of Parks and Recreation, Natural Heritage Program, Raleigh. 325 pp.