Invalid Unit Specified
A1996 Quercus alba - Nyssa sylvatica Wet Depression Forest Alliance

The U.S. National
Vegetation Classification
Type Concept Sentence: These are depressional wetlands with an open to nearly closed canopy dominated by various mixtures of Quercus alba, Nyssa sylvatica, and sometimes other trees, with documented examples in Alabama, Virginia, and Kentucky.
Collapse All::Expand All
Common (Translated Scientific) Name: White Oak - Blackgum Wet Depression Forest Alliance
Colloquial Name: White Oak Wet Depression & Pond Forest
Hierarchy Level: Alliance
Type Concept: This alliance includes depressional wetlands with an open to nearly closed canopy dominated by various mixtures of Quercus alba, Nyssa sylvatica, and sometimes other trees. In upland depressions on sandstone on ridgetops in the Cumberland Plateau of Alabama, Quercus alba and Nyssa sylvatica form an open canopy. Other canopy species are Carya glabra and Quercus falcata. Other woody species include Acer rubrum var. rubrum, Diospyros virginiana, and Pinus taeda, In Virginia, Malus coronaria and Nyssa sylvatica dominate the very open understory and shrub layers. Typically, flooding is for several months in the late winter into early spring. There are documented examples in Alabama, Virginia, and Kentucky.
Diagnostic Characteristics: These are depressional wetlands with an open to nearly closed canopy dominated by various mixtures of Quercus alba and Nyssa sylvatica.
Rationale for Nominal Species or Physiognomic Features: Quercus alba and Nyssa sylvatica dominate these depressional wetlands.
Classification Comments: This alliance needs additional assessment from a broader area. Its old alliance predecessor (A.1996) was established because studies in a variety of areas have suggested that Quercus alba ponds are a reality. Quercus phellos - Quercus alba / Vaccinium fuscatum - (Viburnum nudum) / Carex barrattii Wet Forest (CEGL007364) from Arnold Air Force Base has been moved to this alliance.
Similar NVC Types:
Physiognomy and Structure: The canopy can be open to nearly closed. Sometimes, the deepest part of the depression is wet enough that the canopy is locally absent or sparse.
Floristics: In upland depressions on sandstone on ridgetops in the Cumberland Plateau of Alabama, Quercus alba and Nyssa sylvatica form an open canopy. Other canopy species are Carya glabra and Quercus falcata. Other woody species include Acer rubrum var. rubrum, Diospyros virginiana, and Pinus taeda. Prominent vines are Smilax rotundifolia and Smilax glauca. Some typical herbaceous species are Andropogon virginicus, Chamaecrista nictitans, Dichanthelium dichotomum var. dichotomum, and Hypericum hypericoides. The long hydroperiod prevents many herbs from growing. In Virginia, Malus coronaria and Nyssa sylvatica dominate the very open understory and shrub layers. The most characteristic herbaceous species are Agrostis perennans, Carex annectens, Dichanthelium villosissimum, Hypoxis hirsuta, Lysimachia lanceolata, Oxalis grandis, Polygonum hydropiperoides, Smilax glauca, and Viola hirsutula.
Dynamics: These depressions are flooded continuously for a relatively short period of time in the late winter and early spring, and probably also refill after heavy rain events in other seasons.
Environmental Description: In the Cumberland Plateau of Alabama, this vegetation occurs in upland depressions on sandstone on ridgetops. The flooding regime is seasonal, though with a shorter duration than related vegetation in the coastal plains, such as depressions dominated by Quercus phellos, Quercus lyrata, Carya aquatica, Quercus palustris, Quercus bicolor, Nyssa aquatica, Nyssa biflora, and Nyssa ogeche.
Geographic Range: This alliance is currently reported for locations in the Ridge and Valley province of Virginia (Frozen Knob on Peters Mountain, Alleghany County) and the Cumberland Plateau of northern Alabama (Bankhead National Forest, Sipsey Wilderness). Its distribution is likely to be more widespread.
Nations: US
States/Provinces: AL, KY, TN?, VA
US Forest Service Ecoregions (1994/1995)
Domain Name:
Division Name:
Province Name: Southeastern Mixed Forest Province
Province Code: 231    Occurrence Status: Confident or certain
Section Name: Southern Cumberland Plateau Section
Section Code: 231C     Occurrence Status: Confident or certain
Omernik Ecoregions:
Confidence Level: Low
Confidence Level Comments:
Grank: GNR
Greasons:
Concept Lineage: Both of the two associations in A.1996 are here (2/2; one-to-one relationship).
Predecessors:
Obsolete Names:
Obsolete Parents:
Synonomy:
Concept Author(s): A.S. Weakley, in Faber-Langendoen et al. (2013)
Author of Description: M. Pyne
Acknowledgements: We have incorporated significant descriptive information previously compiled by Alan Weakley.
Version Date: 08Jan2014
References:
  • 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. 2013-2017b. Screening alliances for induction into the U.S. National Vegetation Classification: Part 1 - Alliance concept review. NatureServe, Arlington, VA.
  • Fleming, G. P., and W. H. Moorhead, III. 2000. Plant communities and ecological land units of the Peter's Mountain area, James River Ranger District, George Washington and Jefferson national forests, Virginia. Natural Heritage Technical Report 00-07. Virginia Department of Conservation and Recreation, Division of Natural Heritage, Richmond. Unpublished report submitted to the USDA Forest Service. 195 pp. plus appendices.
  • NatureServe Ecology - Southeastern United States. No date. Unpublished data. NatureServe, Durham, NC.