Print Report
A2069 Andropogon gerardii - Sorghastrum nutans Appalachian Gravel Riverscour Alliance
Type Concept Sentence: This alliance includes scoured riverbank "prairies" of the Central Appalachian regions of the United States. These grasslands may be called "riverside prairies," "linear prairies," "rivershore grasslands," "scoured riverine prairies," or other local names, and are typically associated with dry cobble or gravel riverbanks, as well as flood-scoured, acidic or calcareous bedrock exposures associated with major rivers. Examples typically contain Andropogon gerardii, Chasmanthium latifolium, Panicum virgatum, Schizachyrium scoparium, and/or Sorghastrum nutans, any of which could be locally dominant.
Common (Translated Scientific) Name: Big Bluestem - Indiangrass Appalachian Gravel Riverscour Alliance
Colloquial Name: Appalachian Riverine Gravel Wash Prairie
Hierarchy Level: Alliance
Type Concept: This alliance includes scoured riverbank "prairies" of the Central Appalachian regions of the United States, including the Allegheny Plateau, Cumberland Plateau, and the adjacent Ridge and Valley. These may be called "riverside prairies," "linear prairies," "rivershore grasslands," "scoured riverine prairies," or other local names. These grasslands may be associated with dry cobble or gravel riverbanks, as well as flood-scoured, acidic or calcareous bedrock exposures associated with major rivers. This includes riverine gravel/cobble bar "prairies" along the upper Cumberland River in Kentucky and Tennessee, as well as scour areas along high-gradient sections of major rivers, such as in gorges in Virginia, Maryland, Ohio, Pennsylvania, West Virginia, and possibly farther west. In addition to Panicum virgatum, Andropogon gerardii, and/or Sorghastrum nutans, examples may also contain Schizachyrium scoparium and Chasmanthium latifolium, any of which could be locally dominant. Examples of this alliance have mixed shrub and herbaceous physiognomy and may include a few taller trees. Trees are characteristically less than 5 m tall (but scattered individuals may approach 10 m), and canopy cover characteristically ranges from 0 to 10% (but in intervals between flood events may locally approach 30%).
Diagnostic Characteristics: This alliance contains riverine riverwash and riverscour patch prairies and related vegetation from the Appalachian regions of the eastern United States.
Rationale for Nominal Species or Physiognomic Features: No Data Available
Classification Comments: A regional review of this vegetation from the Potomac to western Pennsylvania and south to the Cumberlands would be instructive to clarify the differences and confirm the correct circumscription of associations.
Similar NVC Types: No Data Available
note: No Data Available
Physiognomy and Structure: Examples of this alliance have mixed shrub and herbaceous physiognomy and may include a few taller trees. Trees are characteristically less than 5 m tall (but scattered individuals may approach 10 m) and canopy cover characteristically ranges from 0 to 10% (but in intervals between flood events may locally approach 30%).
Floristics: Stands are typically dominated by some combination of Andropogon gerardii, Panicum virgatum, and/or Sorghastrum nutans; examples may also contain Chasmanthium latifolium and/or Schizachyrium scoparium, any of which could be locally dominant. Other graminoids include Aristida purpurascens and Eleocharis compressa. Many of the forbs are also typical of prairies. Characteristic species include Allium cernuum, Baptisia australis, Bidens frondosa, Clematis viorna, Conoclinium coelestinum (= Eupatorium coelestinum), Eupatorium serotinum, Lespedeza violacea, Packera aurea, Physostegia virginiana, Pycnanthemum virginianum, Solidago rupestris, Teucrium canadense, Veronicastrum virginicum, Zizia trifoliata, and Zizia aurea. Low-growing vines include Campsis radicans, Toxicodendron radicans, and Vitis rupestris. In the Potomac River drainage, Ceanothus herbaceus, Cerastium arvense var. velutinum, Helianthus occidentalis, and Solidago simplex var. racemosa are noteworthy components (Lea 2000). In the James River drainage, Orbexilum pedunculatum var. psoralioides, Silphium trifoliatum, Solidago speciosa, and Vicia americana are associated. The federally listed threatened shrub Spiraea virginiana and the Virginia state-rare shrub Prunus pumila both have been occasionally found in some associations of this alliance.
Dynamics: Examples of this alliance occur in riparian zones subject to very frequent, high-energy flooding. Flooding maintains an open physiognomy by removing or damaging trees before they become large enough to provide significant shade. Examples are prone to flooding in the upper regions and deposition in the topographically lower areas. They are also prone to severe drought periods that may stress or kill some vegetation. flood-scouring may become a powerful and ecologically important abrasive force along the riverbanks.
Environmental Description: Examples of this alliance occur in small patches and linear zones in positions along rivershores subject to very frequent, high-energy flooding. Flooding disturbance maintains an open physiognomy by removing or damaging trees before they become large enough to provide significant shade. The largest, best developed occurrences are located along rapids created by constrictions in the river channel (bedrock outcrops, point bars, bends, islands, alluvial fans).
Geographic Range: This alliance is found in the Appalachian regions of the United States, including the Alleghenies, Cumberlands, and adjacent Ridge and Valley. States of distribution include Georgia, Kentucky, Maryland, Pennsylvania, Tennessee, Virginia, West Virginia, and Ohio.
Nations: US
States/Provinces: GA, KY, MD, OH, PA, TN, VA, WV
Plot Analysis Summary:
http://vegbank.org/natureserve/ELEMENT_GLOBAL.2.878775
Confidence Level: Moderate
Confidence Level Comments: No Data Available
Grank: GNR
Greasons: No Data Available
Concept Lineage: A2069 and A2070 represent a split-up and reconfiguration of parts of A.1337, A.1343, and A.1843 (MP 9-12). Adopted proto-alliance with minor edits. This alliance (A2069) has members from A.1337 (4/10) & A.1843 (1/21); Protoalliance A2069 in part.
Predecessors: No Data Available
Obsolete Names: No Data Available
Obsolete Parents: No Data Available
Synonomy: No Data Available
- Bailey, C. J., Jr., and F. G. Coe. 2001. The vascular flora of the riparian zones of the Clear Fork River and the New River in the Big South Fork National River and Recreation Area (BSFNRRA). Castanea 66(3):252-274.
- Evans, Marc. Personal communication. Ecologist. Kentucky Natural Heritage Program, Kentucky State Nature Preserves Commission, Frankfort.
- 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. 2013-2019b. Screening alliances for induction into the U.S. National Vegetation Classification: Part 1 - Alliance concept review. NatureServe, Arlington, VA.
- Faber-Langendoen, D., and Midwest State Natural Heritage Program Ecologists. 1996. Terrestrial vegetation of the midwest United States. International classification of ecological communities: Terrestrial vegetation of the United States. The Nature Conservancy, Arlington, VA.
- 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.
- 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. 2004. Draft vegetation types in National Capital Region Parks. Edited by S.C. Gawler and J. Teague. Working draft for review by NatureServe, Virginia Natural Heritage, West Virginia Natural Heritage, Maryland Natural Heritage, and National Park Service. July 2004. 157 pp.
- Schmalzer, P. A., and H. R. DeSelm. 1982. Vegetation, endangered and threatened plants, critical plant habitats and vascular flora of the Obed Wild and Scenic River. Unpublished report. USDI National Park Service, Obed Wild and Scenic River. 2 volumes. 369 pp.
- Smith, T. L. 1991. Natural ecological communities of Pennsylvania. First revision. Unpublished report. Pennsylvania Science Office of The Nature Conservancy, Middletown, PA. 111 pp.
- Vanderhorst, J. 2001a. Plant community classification and mapping of the Camp Dawson Collective Training Area, Preston County, West Virginia. West Virginia Natural Heritage Program, West Virginia Division of Natural Resources, Elkins. 101 pp.
- Vanderhorst, J. 2017b. Wild vegetation of West Virginia: Riverscour prairies. West Virginia Division of Natural Resources, Natural Heritage Program. [http://wvdnr.gov/Wildlife/Factsheets/Riverscour.shtm]
- Vanderhorst, J., and B. P. Streets. 2006. Vegetation classification and mapping of Camp Dawson Army Training Site, West Virginia: Second approximation. Natural Heritage Program, West Virginia Division of Natural Resources, Elkins. 83 pp.
- Walton, D., and M. Anderson. 1997. Critical habitats and associated communities in the riparian zone of the Gauley River. West Virginia Division of Natural Resources, Natural Heritage Program, Elkins.