Invalid Unit Specified
CEGL004643 Quercus palustris - Quercus bicolor / Viburnum prunifolium / Leersia virginica - Impatiens capensis Wet Forest

The U.S. National
Vegetation Classification
Type Concept Sentence: This wetland forest or open woodland community is nearly endemic to hardpan soils of the Culpeper Basin in northern Virginia, Maryland, and West Virginia, and dominated by Quercus palustris and Quercus bicolor.
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Common (Translated Scientific) Name: Pin Oak - Swamp White Oak / Blackhaw / Whitegrass - Orange Jewelweed Wet Forest
Colloquial Name: Pin Oak - Swamp White Oak Seasonal Pond
Hierarchy Level: Association
Type Concept: This wetland forest community is nearly endemic to hardpan soils of the Culpeper Basin in northern Virginia and Montgomery County, Maryland, with a few known outliers elsewhere in the Piedmont and the Ridge and Valley of Maryland, Virginia, and West Virginia. Habitats are shallow, seasonally flooded upland basins and wet, elongated bottoms along sluggish small streams with little or no active alluvial deposition. These habitats are characterized by shallow seasonal flooding induced by perched groundwater. Moderate hummock-and-hollow microtopography is often present, and maximum flooding depth is usually <25 cm (10 inches). A-horizon soils are dark brown to blackish, loamy clays which typically exhibit pronounced orange and white mottling and have moderate base status. This type is most common on areas underlain by diabase but also occurs on some soils weathered from siltstone and other metasedimentary substrates. The vegetation is an open forest or woodland dominated by Quercus palustris, mixtures of Quercus palustris and Quercus bicolor, or less frequently Quercus bicolor alone. Fraxinus pennsylvanica and Acer rubrum are the most frequent subcanopy trees. Viburnum prunifolium is the sole shrub dominant, while Smilax rotundifolia, Toxicodendron radicans, and Parthenocissus quinquefolia are common climbing and scrambling vines. The herb layer is usually open or sparse. The most constant and characteristic herbs are Leersia virginica, Cinna arundinacea, Impatiens capensis, Arisaema triphyllum, Symphyotrichum lateriflorum, Galium obtusum, Lycopus virginicus, and Juncus tenuis. Less constant herbs that can be locally common or abundant include Carex pellita, Carex festucacea, Dichanthelium acuminatum var. lindheimeri, Eleocharis tenuis var. tenuis, Glyceria striata, Scirpus georgianus, and Stachys pilosa var. arenicola. The invasive exotic Microstegium vimineum can be problematic on the drier edges and hummocks.
Diagnostic Characteristics: No Data Available
Rationale for Nominal Species or Physiognomic Features:
Classification Comments: Classification of this association is supported by analysis of a 1250-plot regional dataset assembled for the NCR vegetation mapping project. In that analysis, this type was represented by 16 Virginia and Maryland plots. Field-collected qualitative data also exist for additional Virginia sites. This association is similar to the partly sympatric Quercus palustris - Quercus bicolor / Carex tribuloides - Carex radiata - (Carex squarrosa) Wet Forest (CEGL006497), which occurs in backswamps, sloughs, wet flats, and depressions of large-stream and small-river floodplains in the same region. The relationship between these types is somewhat problematic. In their typical floristic expressions and habitats (i.e., floodplain backswamps vs. isolated upland basins), the two types are quite distinct. However, because of very low topographic relief in the Culpeper Basin, there is considerable ambiguity between alluvial and non-alluvial landforms, and composition of stands can be a continuous gradient between the typical expressions. The two groups do not separate well in cluster analysis, but do separate convincingly in ordinations studies. Ultimately, very intensive head-to-head analytical comparisons support the recognition of two types. However, some individual stands will be hard to assign by subjective field assessment. One stand located around a sinkhole depression pond in the Ridge and Valley of West Virginia is attributed to this association based on similar composition and non-alluvial landform. Atypical species at the West Virginia site include Cephalanthus occidentalisand Scirpus ancistrochaetus.
Similar NVC Types:
Quercus phellos / Carex (albolutescens, intumescens, joorii) / Climacium americanum Wet Forest, note: upland depression swamp of the southern Piedmont, but sympatric in the Potomac valley region; dominated by Quercus phellos.
Quercus palustris - (Quercus bicolor) - Acer rubrum / Vaccinium corymbosum / Osmunda cinnamomea Wet Forest, note: acidic pin oak swamp of the northeastern states, occurring just east of the range of CEGL004643 in VA and MD; exceedingly species-poor with shrub dominance by Vaccinium corymbosum and other acidophiles.
Quercus palustris - Quercus bicolor / Carex tribuloides - Carex radiata - (Carex squarrosa) Wet Forest, note: alluvial swamp forest of the same region; differs in the composition of understory and herb layers.
Physiognomy and Structure: No Data Available
Floristics: The vegetation is an open forest or woodland dominated by Quercus palustris, mixtures of Quercus palustris and Quercus bicolor, or less frequently Quercus bicolor alone. Disturbed examples are often dominated by Acer rubrum. Fraxinus pennsylvanica is a frequent overstory associate and often prevalent in a subcanopy layer. Additional understory tree associates include Acer rubrum, Diospyros virginiana, and Ulmus americana. Carya spp. often grow along the margins of the wetland habitats. Viburnum prunifolium is the sole shrub dominant, with densities up to 850 stems/ha recorded in some plots. Minor shrubs include Carpinus caroliniana, Cephalanthus occidentalis, Ilex verticillata, Rosa palustris, and Zanthoxylum americanum. Small individuals of Juniperus virginiana var. virginiana usually grow on wetland edges and hummocks, while Smilax rotundifolia, Toxicodendron radicans, and Parthenocissus quinquefolia are common climbing and scrambling vines. The herb layer is usually open or sparse. The most constant and characteristic herbs are Leersia virginica, Cinna arundinacea, Impatiens capensis, Arisaema triphyllum, Symphyotrichum lateriflorum (= Aster lateriflorus), Galium obtusum, Lycopus virginicus, and Juncus tenuis. Less constant herbs that can be locally common or abundant include Carex lupulina, Carex pellita, Carex festucacea, Dichanthelium acuminatum var. lindheimeri, Eleocharis tenuis var. tenuis, Glyceria striata, Scirpus georgianus, Boehmeria cylindrica, Polygonum hydropiperoides, Scirpus ancistrochaetus, and Stachys pilosa var. arenicola. The invasive exotic Microstegium vimineum can be problematic on the drier edges and hummocks. Mean species richness of 16 Virginia and Maryland plot samples was 46 taxa per 400 m2, significantly higher than that of other forested depression wetlands in the region.
Dynamics: No Data Available
Environmental Description: This community occupies shallow, seasonally flooded upland basins and wet, elongated bottoms along small streams. Most of the known occurrences are in the Culpeper (Mesozoic) Basin of northern Virginia and adjacent Montgomery County, Maryland. Because of the basin's low relief, headwater drainages are very diffuse, with sluggish, usually intermittent flows and little or no active alluvial deposition. Within this physiographic context, it can be difficult to distinguish true isolated wetlands from small stream bottoms. Hydrologically, these habitats are comparable, with shallow seasonal flooding induced by perched water tables during the winter and spring months. Hydroperiods, however, can apparently be irregular and unpredictable. Moderate hummock-and-hollow microtopography is often present, and maximum flooding depth is usually <25 cm (10 inches). A-horizon soils are dark brown to blackish, loamy clays which typically exhibit pronounced orange and white mottling. Samples collected from plot-sampling sites varied from extremely to moderately acidic, with moderate to high calcium, magnesium, and aluminum levels but only moderate total base saturation. This type is most common on areas underlain by diabase but also occurs on some soils weathered from siltstone and other metasedimentary substrates. One stand located around a sinkhole depression pond on a sandstone ridge in West Virginia is attributed to this association based on similar non-alluvial landform.
Geographic Range: This community type is nearly endemic to hardpan soils of the Culpeper Basin in northern Virginia and Montgomery County, Maryland, with a few known outliers elsewhere in the Piedmont and the Ridge and Valley of Maryland, Virginia, and West Virginia.
Nations: US
States/Provinces: MD, VA, WV
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 Appalachian Piedmont Section
Section Code: 231A     Occurrence Status: Confident or certain
US Forest Service Ecoregions (2007)
Domain Name:
Division Name:
Province Name: Southeastern Mixed Forest Province
Province Code: 231    Occurrence Status: Confident or certain
Section Name: Northern Ridge and Valley Section
Section Code: M221A     Occurrence Status: Confident or certain
Omernik Ecoregions:
Confidence Level: Moderate
Confidence Level Comments:
Grank: G2
Greasons: In evaluating the global status of this unit, six ranking criteria of approximately equal weight were used: (1) Estimated number of occurrences: <300; (2) Area of Occupancy: 1000 to 10,000 acres; (3) Long-Term Decline: moderate (26-75% of original area remaining); (4) Environmental Specificity: highly specific abiotic and biotic factors required for community to persist; (5) Global Range: regional endemic (100 to 10,000 square miles); and (6) Condition of Remaining Occurrences: few high-quality EOs. This community type has a very limited geographic range and is restricted to wetland habitats with special edaphic conditions. Although there are probably hundreds of occurrences, these tend to be small and degraded to some degree by invasive weeds, agricultural impacts such as grazing and ditching, and poor landscape context. A "large" patch of this association is 10 acres, and most are much smaller (historically, however, stands may have been much more extensive). A significant part of this community's range is situated in the greater Washington, DC, metropolitan area; many occurrences have been destroyed outright by development, and many others are imminently threatened with destruction or severe alteration.
Concept Lineage:
Predecessors:
Obsolete Names:
Obsolete Parents:
Quercus palustris - Quercus bicolor Flatwoods & Swamp Forest Alliance
Synonomy: = Quercus bicolor - Quercus palustris / Viburnum prunifolium / Cinna arundinacea Woodland (Fleming and Patterson 2004)
= Quercus bicolor - Quercus palustris / Viburnum prunifolium / Glyceria striata - Scirpus atrovirens Woodland (Fleming 2002a)
= Quercus bicolor - Quercus palustris / Viburnum prunifolium / Glyceria striata - Scirpus atrovirens Woodland (Fleming 2002b)
= Quercus bicolor - Quercus palustris / Viburnum prunifolium / Impatiens capensis - Scirpus atrovirens Woodland (Fleming and Patterson 2003)
= Quercus bicolor - Quercus palustris / Viburnum prunifolium / Scirpus atrovirens Woodland (Fleming and Weber 2003)
= Quercus palustris - Quercus bicolor / Viburnum prunifolium / Leersia virginica - Impatiens capensis Forest (Fleming et al. 2007b)
> Quercus palustris / Carex lupulina Sinkhole Swamp [Sinkhole Pond Oak Swamp] (Vanderhorst 2016b)
Concept Author(s): G.P. Fleming and A.S. Weakley
Author of Description: G.P. Fleming and A.S. Weakley
Acknowledgements:
Version Date: 20Dec2018
References:
  • Fleming, G. P. 2002a. Ecological communities of the Bull Run Mountains, Virginia: Baseline vegetation and floristic data for conservation planning and natural area stewardship. Natural Heritage Technical Report 02-12. Virginia Department of Conservation and Recreation, Division of Natural Heritage, Richmond. 274 pp. plus appendices.
  • Fleming, G. P. 2002b. Preliminary classification of Piedmont & Inner Coastal Plain vegetation types in Virginia. Natural Heritage Technical Report 02-14. Virginia Department of Conservation and Recreation, Division of Natural Heritage, Richmond. 29 pp.
  • Fleming, G. P., and J. T. Weber. 2003. Inventory, classification, and map of forested ecological communities at Manassas National Battlefield Park, Virginia. Unpublished report submitted to the National Park Service. Natural Heritage Technical Report 03-07. Virginia Department of Conservation and Recreation, Division of Natural Heritage, Richmond. 101 pp. plus appendix.
  • Fleming, G. P., and K. D. Patterson. 2003. Preliminary vegetation classification for the National Capitol Region parks. Regional (VA-WVA-MD-DC) analysis prepared for NatureServe and USGS-NPS Vegetation Mapping Program, March 2003. Virginia Department of Conservation and Recreation, Division of Natural Heritage, Richmond.
  • Fleming, G. P., and K. D. Patterson. 2004. Natural community inventory of selected areas in the Northern Virginia Culpeper Basin, Fairfax, Loudoun, Prince William, Fauquier, and Culpeper counties. Unpublished report submitted to the Virginia Native Plant Society, Potowmack Chapter. Natural Heritage Technical Report 04-07. Virginia Department of Conservation and Recreation, Division of Natural Heritage, Richmond. 21 pp. plus appendices.
  • Fleming, G. P., and K. D. Patterson. 2011b. Analysis of Coastal Plain / Outer Piedmont bottomlands and non-alluvial wetlands in Virginia, 400 plots. In-house analysis, January 2011. Virginia Department of Conservation and Recreation, Division of Natural Heritage, Richmond.
  • Fleming, G. P., K. D. Patterson, and K. Taverna. 2017. The natural communities of Virginia: A classification of ecological community groups and community types. Third approximation. Version 3.0. Virginia Department of Conservation and Recreation, Division of Natural Heritage, Richmond, VA. [http://www.dcr.virginia.gov/natural-heritage/natural-communities/]
  • Fleming, G. P., K. Taverna, and P. P. Coulling. 2007b. Vegetation classification for the National Capitol Region parks, eastern region. Regional (VA-MD-DC) analysis prepared for NatureServe and USGS-NPS Vegetation Mapping Program, March 2007. Virginia Department of Conservation and Recreation, Division of Natural Heritage, Richmond.
  • Harrison, J. W. 2011. The natural communities of Maryland: 2011 working list of ecological community groups and community types. Unpublished report. Maryland Department of Natural Resources, Wildlife and Heritage Service, Natural Heritage Program, Annapolis. 33 pp.
  • Harrison, J. W., compiler. 2004. Classification of vegetation communities of Maryland: First iteration. A subset of the International Classification of Ecological Communities: Terrestrial Vegetation of the United States, NatureServe. Maryland Natural Heritage Program, Maryland Department of Natural Resources, Annapolis. 243 pp.
  • Southeastern Ecology Working Group of NatureServe. No date. International Ecological Classification Standard: International Vegetation Classification. Terrestrial Vegetation. NatureServe, Durham, NC.
  • Vanderhorst, J. 2016b. Wild vegetation of West Virginia: Bottomland oak swamps. West Virginia Division of Natural Resources, Natural Heritage Program. [http://wvdnr.gov/Wildlife/Factsheets/OakSwamps.shtm]
  • WVNHP [West Virginia Natural Heritage Program]. No date. Unpublished data. West Virginia Natural Heritage Program, Elkins.