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CEGL006476 Platanus occidentalis - Acer saccharinum - Fraxinus pennsylvanica / Boehmeria cylindrica - Carex emoryi Floodplain Forest
Type Concept Sentence: This bedrock floodplain forest is restricted to the Ridge and Valley and Piedmont sections of the Potomac River floodplain, where it occurs on floodplains where bedrock is at or very near the surface; examples are dominated by a combination of trees, including Platanus occidentalis, Acer saccharinum, Betula nigra, and/or Fraxinus pennsylvanica.
Common (Translated Scientific) Name: American Sycamore - Silver Maple - Green Ash / Small-spike False Nettle - Emory''s Sedge Floodplain Forest
Colloquial Name: Central Appalachian-Piedmont Bedrock Floodplain Forest
Hierarchy Level: Association
Type Concept: This community is restricted to the Ridge and Valley and Piedmont sections of the Potomac River floodplain, where it occurs on scoured shorelines in high-gradient reaches where there is a combination of control by bedrock and alluvial processes. Stands are usually on the active channel shelf but have some aspects of depositional bars. Sites are flooded annually and inundated about 3 to 7% of the year, mostly during the dormant season, and often but probably irregularly in the early growing season. Surface substrate is variable, averaging >10% cover of bedrock and boulders in 14 plot samples. Two intergrading phases have been recognized and are described according to perceived differences in net rates of sediment erosion/accretion. In the eroding phase, the channel shelf surface is actively eroding along low channels often filled with cobbles and other coarse material, with finer soil being retained around tree bases. In the stable phase, vegetation holds finer sediments in place and provides an equilibrium between erosion and accretion. Stand physiognomy ranges from wooded herbaceous vegetation to nearly closed-canopy forest. In all expressions, some combination of Platanus occidentalis, Acer saccharinum, Betula nigra, and/or Fraxinus pennsylvanica dominate as the uppermost woody layer, which tends to be a woodland to open forest in the species-rich eroding phase and woodland or wooded herbaceous vegetation in the stable phase. Less constant species include Ulmus americana, Diospyros virginiana, Juglans nigra, Quercus bicolor, Populus deltoides, and Salix nigra. The shrub layer is absent to poorly developed, with battered individuals of Cornus amomum, Cephalanthus occidentalis, and Salix caroliniana the most frequent true shrubs. Woody vines, including Toxicodendron radicans, Campsis radicans, and Vitis riparia, are frequent. The herb layer is diverse and variable. The most constant and characteristic herbs in 14 plot samples are Verbesina alternifolia, Boehmeria cylindrica, Polygonum punctatum, Eupatorium serotinum, Leersia virginica, Dichanthelium clandestinum, Carex emoryi (locally abundant in large clones), Ambrosia artemisiifolia, Polygonum virginianum, Teucrium canadense, Polygonum pensylvanicum, Symphyotrichum lanceolatum var. lanceolatum, Pilea pumila, Chasmanthium latifolium, and Conoclinium coelestinum.
Diagnostic Characteristics: No Data Available
Rationale for Nominal Species or Physiognomic Features: No Data Available
Classification Comments: In the Delaware variant of this community, Platanus occidentalis, Acer negundo, and Fraxinus pennsylvanica dominate the low canopy. Populus deltoides, Salix nigra, Betula nigra, Acer saccharinum, and Cephalanthus occidentalis are found in the lower "understory." Amorpha fruticosa dominates the shrub layer and is associated by Sambucus nigra ssp. canadensis with lesser amounts of Ilex verticillata and Viburnum prunifolium. Vines are fairly common and include exotics Lonicera japonica, Celastrus orbiculatus, and Wisteria sinensis. Many herbs are present but some of the more common ones are Dichanthelium clandestinum, Elymus riparius, Elymus virginicus, Perilla frutescens, Rudbeckia laciniata, and Eleocharis erythropoda on rocks.
Similar NVC Types: No Data Available
note: No Data Available
Physiognomy and Structure: No Data Available
Floristics: Physiognomic and floristic expressions of this type are variable, with physiognomy ranging from wooded herbaceous vegetation to nearly closed-canopy forest. In all expressions, some combination of Platanus occidentalis, Acer saccharinum, Betula nigra, and/or Fraxinus pennsylvanica dominates the uppermost woody layer, which tends to be a woodland to open forest in the eroding phase and woodland or wooded herbaceous vegetation in the stable phase. Less constant species include Ulmus americana, Diospyros virginiana, Juglans nigra, Quercus bicolor, Populus deltoides, and Salix nigra. The shrub layer is absent to poorly developed, with battered individuals of Cornus amomum, Cephalanthus occidentalis, and Salix caroliniana the most frequent true shrubs. Woody vines, including Toxicodendron radicans, Campsis radicans, and Vitis riparia, are frequent. The herb layer is diverse and variable. Characteristic herbs, in descending order of constancy in plot samples, include Verbesina alternifolia, Boehmeria cylindrica, Polygonum punctatum, Eupatorium serotinum, Leersia virginica, Dichanthelium clandestinum, Carex emoryi (locally abundant in large clones), Ambrosia artemisiifolia, Polygonum virginianum, Teucrium canadense, Polygonum pensylvanicum, Symphyotrichum lanceolatum var. lanceolatum (= Aster lanceolatus var. simplex), Pilea pumila, Chasmanthium latifolium, Conoclinium coelestinum (= Eupatorium coelestinum), Elymus riparius, Solidago gigantea, Eupatorium perfoliatum var. perfoliatum, Eutrochium fistulosum (= Eupatorium fistulosum), and Apocynum cannabinum. In drier expressions, Panicum virgatum, Andropogon gerardii, and other prairie species may be present. In the stable phase, rhizomatous species, primarily Carex emoryi but also Onoclea sensibilis, Boehmeria cylindrica, Dichanthelium clandestinum, and inconstantly Spartina pectinata, exhibit patch dominance; in the eroding phase these species are less prominent, evidently because of higher rates of substrate disturbance which may select for fast-growing but less strongly rhizomatous species. Species richness is dramatically higher in the eroding phase (mean in 14 plots = 102 taxa vs. 44 taxa). Although relatively well-defined, the two "phases" nevertheless have a high degree of floristic similarity and should be considered variants of a single association. This type is prone to invasion by the exotics Microstegium vimineum, Fallopia japonica var. japonica, Lysimachia nummularia, and Phalaris arundinacea.
Dynamics: No Data Available
Environmental Description: This association occurs on scoured shorelines of high-gradient, large-river reaches where there is a combination of control by bedrock and alluvial processes. Stands are usually on the active channel shelf but have some aspects of depositional bars. Sites are flooded annually and inundated from 3 to 7% of the year, mostly during the dormant season, and often but probably irregularly in the early growing season. Surface substrate is variable, averaging >10% cover of bedrock and boulders in 14 plot samples. Two intergrading phases have been recognized and are described according to perceived differences in net rates of sediment erosion/accretion. In the eroding phase, the channel shelf surface is actively eroding along low channels often filled with cobbles and other coarse material, with finer soil being retained around tree bases. In the stable phase, vegetation holds finer sediments in place and provides an equilibrium between erosion and accretion. Soils are sandy loams to sands, with coarser textures prevailing in the eroding phase, which also often has a surface layer of cobbles.
Geographic Range: The type is known from the higher gradient sections of the Potomac River, with well-documented stands concentrated in the fall-line (Potomac Gorge) and Ridge and Valley provinces. It may occur along the Shenandoah River but is unlikely to occur on the Monocacy River and other smaller tributaries. There is an unverified report of similar vegetation on the Susquehanna River below Conowingo Dam (C. Lea pers. comm. 2006).
Nations: US
States/Provinces: DC, DE, MD, VA, WV?
Plot Analysis Summary:
http://vegbank.org/natureserve/ELEMENT_GLOBAL.2.795520
Confidence Level: Moderate
Confidence Level Comments: No Data Available
Grank: G2?
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.1 Silver Maple - American Sycamore - Hackberry species Floodplain Forest Macrogroup | M029 | 1.B.3.Na.1 |
| Group | 1.B.3.Na.1.b <i>Acer saccharinum - Platanus occidentalis - Liquidambar styraciflua</i> Floodplain Forest Group | G673 | 1.B.3.Na.1.b |
| Alliance | A3701 American Sycamore - Green Ash - Tuliptree Central Appalachian-Piedmont Floodplain Forest Alliance | A3701 | 1.B.3.Na.1.b |
| Association | CEGL006476 American Sycamore - Silver Maple - Green Ash / Small-spike False Nettle - Emory''s Sedge Floodplain Forest | CEGL006476 | 1.B.3.Na.1.b |
Concept Lineage: No Data Available
Predecessors: No Data Available
Obsolete Names: No Data Available
Obsolete Parents: No Data Available
Synonomy: > Betula nigra / Andropogon gerardii - Panicum virgatum - Carex emoryi Woodland (Lea 2000)
= Platanus occidentalis - Acer saccharinum - Betula nigra - Fraxinus pennsylvanica / Eupatorium fistulosum - (Carex emoryi) Woodland (Lea 2003)
> Ulmus americana - Betula nigra - Quercus bicolor / Eupatorium coelestinum Woodland (Lea 2000)
= Platanus occidentalis - Acer saccharinum - Betula nigra - Fraxinus pennsylvanica / Eupatorium fistulosum - (Carex emoryi) Woodland (Lea 2003)
> Ulmus americana - Betula nigra - Quercus bicolor / Eupatorium coelestinum Woodland (Lea 2000)
- Coxe, R. 2009. Guide to Delaware vegetation communities. Spring 2009 edition. State of Delaware, Division of Fish and Wildlife, Delaware Natural Heritage Program, Smyrna.
- Eastern Ecology Working Group of NatureServe. No date. International Ecological Classification Standard: International Vegetation Classification. Terrestrial Vegetation. NatureServe, Boston, MA.
- Fleming, G. P. 2007. Ecological communities of the Potomac Gorge in Virginia: Composition, floristics, and environmental dynamics. Natural Heritage Technical Report 07-12. Unpublished report submitted to the National Park Service. Virginia Department of Conservation and Recreation, Division of Natural Heritage, Richmond. 341 pp. plus appendices.
- 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., and K. Taverna. 2006. Vegetation classification for the National Capitol Region parks, western region. Regional (VA-WVA-MD-DC) analysis prepared for NatureServe and USGS-NPS Vegetation Mapping Program, March 2006. 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.
- Lea, C. 2000. Plant communities of the Potomac Gorge and their relationship to fluvial factors. M.S. thesis, George Mason University. Fairfax, VA. 219 pp.
- Lea, C. 2003. Vegetation types in the National Capital Region Parks. Draft for review by NatureServe, Virginia Natural Heritage, West Virginia Natural Heritage, Maryland Natural Heritage, and National Park Service. March 2003. 140 pp.