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CEGL006598 Rhododendron arborescens / Marshallia grandiflora - Triantha glutinosa - Platanthera flava var. herbiola Riverscour Wet Meadow

The U.S. National
Vegetation Classification
Type Concept Sentence:
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Common (Translated Scientific) Name: Smooth Azalea / Monongahela Barbara's-buttons - Sticky Bog-asphodel - Pale-green Orchid Riverscour Wet Meadow
Colloquial Name: Barbara's-buttons Riverscour Wet Meadow
Hierarchy Level: Association
Type Concept: This herbaceous riverscour prairie occurs on temporarily flooded sand and cobbles in the Allegheny Mountains region of West Virginia, at elevations between 1060 and 1100 m. It is a small-patch type that occupies flat to gently sloping islands, cobble bars, and shorelines along high-gradient streams. Ice-scour and flood deposition/scour keep this community open and prevent accumulation of organic material in the substrate. Flooding can occur at any time of year. The community is characterized by a remarkable profusion of showy, flowering forbs, which share a tolerance for high-energy flooding and ice-scour. The shrub layer, kept at low stature and cover by frequent ice-scour, averages 12% cover and includes Rhododendron arborescens, Hypericum densiflorum, and Alnus incana ssp. rugosa. The herbaceous layer, averaging 60% cover, includes a large number of species with high constancy, including Marshallia grandiflora, Euthamia graminifolia var. graminifolia, Carex stricta, Eleocharis tenuis, Sanguisorba canadensis, Triantha glutinosa, Hypericum ellipticum, Solidago rugosa, Calamagrostis canadensis var. canadensis, Trautvetteria caroliniensis var. caroliniensis, Juncus dudleyi, Potentilla simplex, Houstonia serpyllifolia, Phlox maculata, Deschampsia caespitosa, Lycopus uniflorus var. uniflorus, and Platanthera flava var. herbiola. Exotic weeds washed in by the river typically include Prunella vulgaris, Anthoxanthum odoratum ssp. odoratum, and Daucus carota. Cover by nonvascular plants is insignificant. Indicator species that help to distinguish this community from others within the herbaceous physiognomy for high-elevation wetlands of the Allegheny Mountains region include Marshallia grandiflora, Juncus dudleyi, Krigia biflora var. biflora, Lysimachia quadrifolia, Phlox maculata, Platanthera flava var. herbiola, Rhododendron arborescens, Sanguisorba canadensis, Triantha glutinosa, and Trautvetteria caroliniensis var. caroliniensis. Mean species richness of vascular plants is 37 taxa per 400 square meters.
Diagnostic Characteristics: No Data Available
Rationale for Nominal Species or Physiognomic Features:
Classification Comments: Four plots (1 occurrence) represent this type, which was classified as part of a 2004-2006 study of high-elevation wetlands in West Virginia's Allegheny Mountains region. (Byers et al. 2007).
Similar NVC Types:
Physiognomy and Structure: No Data Available
Floristics: This herbaceous riverscour prairie occurs in the Allegheny Mountains region of West Virginia. The community is characterized by a remarkable profusion of showy, flowering forbs, which share a tolerance for high-energy flooding and ice-scour. The shrub layer, kept at low stature and cover by frequent ice-scour, averages 12% cover and includes Rhododendron arborescens, Hypericum densiflorum, and Alnus incana ssp. rugosa. The herbaceous layer, averaging 60% cover, includes a large number of species with high constancy, including Marshallia grandiflora, Euthamia graminifolia var. graminifolia, Carex stricta, Eleocharis tenuis, Sanguisorba canadensis, Triantha glutinosa, Hypericum ellipticum, Solidago rugosa, Calamagrostis canadensis var. canadensis, Trautvetteria caroliniensis var. caroliniensis, Juncus dudleyi, Potentilla simplex, Houstonia serpyllifolia, Phlox maculata, Deschampsia caespitosa, Lycopus uniflorus var. uniflorus, and Platanthera flava var. herbiola. Exotic weeds washed in by the river typically include Prunella vulgaris, Anthoxanthum odoratum ssp. odoratum, and Daucus carota. Cover by nonvascular plants is insignificant. Indicator species that help to distinguish this community from others within the herbaceous physiognomy for high-elevation wetlands of the Allegheny Mountains region include Marshallia grandiflora, Juncus dudleyi, Krigia biflora var. biflora, Lysimachia quadrifolia, Phlox maculata, Platanthera flava var. herbiola, Rhododendron arborescens, Sanguisorba canadensis, Triantha glutinosa, and Trautvetteria caroliniensis var. caroliniensis. Mean species richness of vascular plants is 37 taxa per 400 square meters (Byers et al. 2007).
Dynamics: This is a small-patch herbaceous riverscour community. Nutrient cycling occurs primarily from ice-scour, flood scour, and flood deposition.
Environmental Description: This herbaceous riverscour prairie occurs on temporarily flooded sand and cobbles in the Allegheny Mountains region of West Virginia, at elevations between 1060 and 1100 m. It is a small-patch type that occupies flat to gently sloping islands, cobble bars, and shorelines along high-gradient streams. Ice-scour and flood deposition/scour keep this community open and prevent accumulation of organic material in the substrate. Flooding can occur at any time of year. Shoreline locations probably receive seepage from the adjacent upland forest. Bedrock may be shale or sandstone. The unvegetated surface averages 40% large rocks, 25% small rocks, 20% sand, and 15% bare soil, with a trace amount of litter and woody debris (Byers et al. 2007).
Geographic Range: This community is known from the Allegheny Mountains region of West Virginia at elevations between 1060 and 1100 m. The single known occurrence is on the Upper Shavers Fork of the Cheat River. This type may possibly occur in a similar setting in the headwaters of the Gauley River.
Nations: US
States/Provinces: PA?, WV
US Forest Service Ecoregions (1994/1995)
Domain Name:
Division Name:
Province Name: Central Appalachian Broadleaf Forest - Coniferous Forest - Meadow Province
Province Code: M221    Occurrence Status: Confident or certain
Section Name: Allegheny Mountains Section
Section Code: M221B     Occurrence Status: Confident or certain
Omernik Ecoregions:
Confidence Level: Low
Confidence Level Comments:
Grank: G1
Greasons: This community is restricted to very small patches on the Upper Shavers Fork of the Cheat River, at elevations between 1060 and 1100 m in the Allegheny Mountains region of West Virginia. It may occur on one other river in a similar setting in West Virginia; beyond this, additional occurrences are unlikely to be found. The type is characterized by a rare central Appalachian endemic (Marshallia grandiflora) in co-occurrence with a northern species at the southern edge of its range (Triantha glutinosa). It has a very narrow environmental specificity along high-elevation, high-gradient streams with intact ice-scour and flood hydrology.
Concept Lineage:
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Obsolete Names:
Obsolete Parents:
Synonomy: = Rhododendron arborescens / Marshallia grandiflora - Triantha glutinosa - Platanthera flava var. herbiola Riverscour Prairie (Byers et al. 2007)
Concept Author(s): E.A. Byers et al. (2007)
Author of Description: E.A. Byers
Acknowledgements:
Version Date: 03Apr2007
References:
  • Byers, E. A., J. P. Vanderhorst, and B. P. Streets. 2007. Classification and conservation assessment of high elevation wetland communities in the Allegheny Mountains of West Virginia. West Virginia Natural Heritage Program, West Virginia Division of Natural Resources, Elkins.
  • Eastern Ecology Working Group of NatureServe. No date. International Ecological Classification Standard: International Vegetation Classification. Terrestrial Vegetation. NatureServe, Boston, MA.
  • Fike, J. 1999. Terrestrial and palustrine plant communities of Pennsylvania. Pennsylvania Natural Diversity Inventory. Pennsylvania Department of Conservation and Recreation, Bureau of Forestry, Harrisburg, PA. 86 pp.
  • Zimmerman, E. A. 2011u. Pennsylvania Natural Heritage Program. Floodplain Scour Community Factsheet. [http://www.naturalheritage.state.pa.us/Community.aspx?=16011[ (accessed February 14, 2012)
  • Zimmerman, E. A., T. Davis, M. A. Furedi, B. Eichelberger, J. McPherson, S. Seymour, G. Podniesinski, N. Dewar, and J. Wagner, editors. 2012. Terrestrial and palustrine plant communities of Pennsylvania. Pennsylvania Natural Heritage Program, Pennsylvania Department of Conservation and Natural Resources, Harrisburg. [http://www.naturalheritage.state.pa.us/Communities.aspx]