Print Report

A0329 Quercus palustris - Quercus bicolor Flatwoods & Swamp Forest Alliance

Type Concept Sentence: These are "flatwoods" and poorly drained floodplain communities found in the central midwestern and northeastern United States and dominated by Quercus bicolor and/or Quercus palustris, as well as Acer rubrum, Carya ovata, Liquidambar styraciflua, Nyssa sylvatica, Quercus alba, Quercus coccinea, and others.

Common (Translated Scientific) Name: Pin Oak - Swamp White Oak Flatwoods & Swamp Forest Alliance

Colloquial Name: North-Central Wet Oak Flatwoods & Swamp Forest

Hierarchy Level:  Alliance

Type Concept: This alliance, found in the central midwestern and northeastern United States, contains "flatwoods" and poorly drained floodplain communities. Stands are characterized by a closed to partially open canopy dominated by Quercus bicolor and/or Quercus palustris, as well as Acer rubrum, Carya ovata, Liquidambar styraciflua, Nyssa sylvatica, Quercus alba, Quercus coccinea, and others. Many stands are seasonally wet (mostly during winter and early spring) with a shallow, perched water table that tend to be dry in late summer and early fall. This situation promotes vegetation often called "flatwoods." Although flatwoods are best developed on soils with massive, brittle fragipans, they are also well-represented on relatively impermeable clay soils that are found on poorly drained uplands or in depressions on level glacial lakeplains or outwash plains. Fragipans (or hardpans) are usually developed from glacial till of Illinoisan age in the Midwest. During the rainy season, water slowly permeates these soils and may remain standing in depressions. The soil dries rapidly in the summer or during drought, and herbaceous vegetation wilts in response to this stress. The penetration of tree roots in the subsoil and burrowing by animals are limited by the hardpan, and tree species may appear somewhat stunted. Some stands are found on seasonally saturated sites that receive groundwater seepage. This water, combined with rainwater, keeps the soils saturated during wet periods and moist during dry periods. The soils have a pH below 5.5. The parent material is sand, gravelly or sandy alluvium, muck, or peat.

Diagnostic Characteristics: These are flatwoods and depression forests typically dominated by Quercus palustris and Quercus bicolor.

Rationale for Nominal Species or Physiognomic Features: No Data Available

Classification Comments: Bryant (1978) reports forests on "flat, poorly drained land" in an abandoned Pliocene channel of the Kentucky River in the Inner Bluegrass Subsection (222Fb of Keys et al 1995; 223Fb of Cleland et al. 2005). This vegetation seems to pertain to this alliance and is reported to be dominated by Quercus palustris and Acer rubrum, with Fagus grandifolia, Fraxinus americana, Liquidambar styraciflua, Nyssa sylvatica, Quercus alba, Quercus bicolor, and Quercus velutina.

Similar NVC Types: No Data Available
note: No Data Available
Physiognomy and Structure: Stands are generally characterized by a closed canopy of trees, but the canopy may also be partially open. The shrub layer is often poorly developed, and the herbaceous layer is generally not well-developed.

Floristics: Stands are characterized by a closed to partially open canopy dominated by Quercus bicolor and/or Quercus palustris. Other tree species associates include Acer rubrum, Carya ovata, Liquidambar styraciflua, Nyssa sylvatica, Quercus alba, Quercus coccinea, and others. Throughout much of its range, this alliance is dominated by Quercus palustris. Quercus bicolor can occur in pure stands, or in association with Acer rubrum, Quercus alba, Quercus coccinea, and Quercus palustris. In addition, Quercus macrocarpa occurs more commonly in the Great Lakes lakeplain and Quercus pagoda in the Interior Plateau. Shrub and herb layers are generally sparse, containing such species as Carex stipata, Gaylussacia baccata, Glyceria striata, Isoetes spp., Scirpus cyperinus, Thelypteris palustris, and Vaccinium corymbosum. Stands found in seepage areas have a more hydrophytic flora, including species such as Alnus serrulata, Carex crinita, Cephalanthus occidentalis, Onoclea sensibilis, and Osmunda regalis.

Dynamics:  No Data Available
Environmental Description:  Many stands are seasonally wet (mostly during winter and early spring) with a shallow, perched water table, but tend to be dry in late summer and early fall, a condition often leading to vegetation called "flatwoods." Although flatwoods are best developed on soils with massive, brittle fragipans, they are also well-represented on relatively impermeable clay soils that are found on poorly drained uplands or in depressions on level glacial lakeplains or outwash plains. Fragipans (or hardpans) are usually developed from glacial till of Illinoisan age in the Midwest (White and Madany 1978). During the rainy season, water slowly permeates these soils and ponds in depressions. The soil dries rapidly in the summer or during drought, and herbaceous vegetation wilts in response to this stress. The penetration of tree roots in the subsoil and burrowing by animals is limited by the hardpan (White and Madany 1978, Nelson 1985), and tree species may appear somewhat stunted. Some stands are found on seasonally saturated sites that receive groundwater seepage. This water, combined with rainwater, keeps the soils saturated during wet periods and moist during dry periods. The soils have a pH below 5.5. The parent material is sand, gravelly or sandy alluvium, muck, or peat (Nelson 1985).
Geographic Range: This alliance is found in the eastern U.S. from New Hampshire to Virginia and west and south to Arkansas, Illinois, Kentucky and (possibly) Tennessee, and in Canada in Ontario.

Nations: CA,US

States/Provinces:  AR, CT, DC?, DE, IA, IL, IN, KY, MA, MD, MI, MO, NH, NJ, NY, OH, ON, PA, TN?, VA, WV


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.g <i>Quercus palustris - Quercus bicolor - Fagus grandifolia</i> Flatwoods & Swamp Forest Group G917 1.B.3.Na.2.g
Alliance A0329 Pin Oak - Swamp White Oak Flatwoods & Swamp Forest Alliance A0329 1.B.3.Na.2.g
Concept Lineage: Most (10/14) members of the old A.329 go into this alliance (one of the others is a floodplain and is elsewhere in G597; one other is in G034, one in G171).

Predecessors: No Data Available

Obsolete Names: No Data Available

Obsolete Parents: No Data Available
Synonomy: ? Quercus palustris forest alliance (Hoagland 1998a)
? P1B3cVI. Quercus palustris (Foti et al. 1994)
>< Pin Oak - Sweetgum: 65 (Eyre 1980)
>< perched swamp white oak swamp (Reschke 1990)
Concept Author(s): D.J. Allard and D. Faber-Langendoen, in Faber-Langendoen et al. (2013)

Author of Description: M. Pyne and L. A. Sneddon

Acknowledgements: We have incorporated information compiled by D.J. Allard and D. Faber-Langendoen.

Version Date: 12-18-14
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