Print Report
CEGL006479 Hydrangea arborescens / Sedum ternatum - Polypodium virginianum Cliff Shrubland
Type Concept Sentence: This subcalcareous cliff and rock outcrop association is found on rocky cliffs, typically facing north and overlooking large rivers, in the Piedmont and Central Appalachian regions; characteristic shrubs include Hydrangea arborescens, Toxicodendron radicans, Parthenocissus quinquefolia, and Physocarpus opulifolius, and may be overtopped by fringing Quercus montana, Fraxinus americana, Ostrya virginiana, and other trees.
Common (Translated Scientific) Name: Wild Hydrangea / Woodland Stonecrop - Rock Polypody Cliff Shrubland
Colloquial Name: Piedmont-Central Appalachian Subcalcareous Cliff & Rock Outcrop
Hierarchy Level: Association
Type Concept: This association is currently known only from the Potomac River drainage in the Piedmont Triassic Basin of Virginia and Maryland and the adjacent Blue Ridge of Virginia. It occupies cliff-faces weathered from siltstone, shale, calcareous sandstone, and metabasalt. Sites are next to rivers and large streams, where progressive stream incision through resistant strata has formed escarpments of exposed bedrock. All of the documented cliffs have northerly aspects and are partly to heavily shaded by overhanging trees or trees growing in the cliff-base floodplains. Microhabitat conditions are characterized by vertical to very steep faces, with much exposed bedrock, numerous fissures and shelves, and considerable local deposition of organic-rich, colluvial soil material. Vegetation cover ranges from sparse or somewhat sparse (5-20% vascular cover) on the most massive cliffs, to moderately dense (20-50% vascular cover) on other examples. Saplings and stunted trees of Fraxinus americana, Ostrya virginiana, Tsuga canadensis, Ulmus rubra, Ulmus americana, Acer saccharum, Acer nigrum, Tilia americana, Juniperus virginiana var. virginiana, Carpinus caroliniana, Quercus rubra, and Quercus montana may occur on the cliff-faces. Hydrangea arborescens is a characteristic and sometimes abundant shrub, while Toxicodendron radicans and Parthenocissus quinquefolia are constant vines. Less constant shrubs include Physocarpus opulifolius, Ptelea trifoliata, Hamamelis virginiana, and Viburnum acerifolium. Characteristic herbaceous species include Polypodium virginianum (locally abundant), Sedum ternatum (locally abundant), Symphyotrichum cordifolium (locally abundant), Dryopteris marginalis, Pilea pumila, Asplenium trichomanes, Woodsia obtusa ssp. obtusa, Aquilegia canadensis, Saxifraga virginiensis, Eurybia divaricata, Asplenium rhizophyllum, Ageratina altissima, Carex communis, Carex platyphylla, Heuchera americana, Arabis laevigata var. laevigata, Polymnia canadensis, Polystichum acrostichoides, and Solidago caesia. Exotic weeds, including Stellaria media, Lonicera japonica, Alliaria petiolata, and Microstegium vimineum, are problematic invaders at most sites.
Diagnostic Characteristics: No Data Available
Rationale for Nominal Species or Physiognomic Features: No Data Available
Classification Comments: The classification is supported by quantitative data from three plots.
Similar NVC Types: No Data Available
note: No Data Available
Physiognomy and Structure: No Data Available
Floristics: Vegetation cover ranges from sparse or somewhat sparse (5-20% vascular cover) on massive cliffs at Red Rock Wilderness Regional Park and Chilton Woods (C&O Canal), to moderately dense (20-50% vascular cover) on the other examples along the Potomac River and Bull Run. Saplings and stunted trees of Fraxinus americana, Ostrya virginiana, Tsuga canadensis, Ulmus rubra, Ulmus americana, Acer saccharum, Acer nigrum, Tilia americana, Juniperus virginiana var. virginiana, Carpinus caroliniana, Quercus rubra, and Quercus montana (= Quercus prinus) may occur on the cliff-faces. Hydrangea arborescens is a characteristic and sometimes abundant shrub, while Toxicodendron radicans and Parthenocissus quinquefolia are constant vines. Less constant shrubs include Physocarpus opulifolius, Ptelea trifoliata, Hamamelis virginiana, and Viburnum acerifolium. Characteristic herbaceous species include Polypodium virginianum (locally abundant), Sedum ternatum (locally abundant), Symphyotrichum cordifolium (= Aster cordifolius) (locally abundant), Dryopteris marginalis, Pilea pumila, Asplenium trichomanes, Woodsia obtusa ssp. obtusa, Aquilegia canadensis, Saxifraga virginiensis, Eurybia divaricata (= Aster divaricatus), Asplenium rhizophyllum, Ageratina altissima, Carex communis, Carex platyphylla, Heuchera americana, Arabis laevigata var. laevigata, Polymnia canadensis, Polystichum acrostichoides, and Solidago caesia. Species that may be confined to the large, exposed cliff at Red Rock Wilderness Regional Park include Cerastium arvense, Hylotelephium telephioides (= Sedum telephioides), and Solidago arguta var. harrisii. Exotic weeds, including Stellaria media, Lonicera japonica, Alliaria petiolata, and Microstegium vimineum, are problematic invaders at most sites.
Dynamics: The known substrates of this type (siltstone, shale, calcareous sandstone, metabasalt) could be characterized as "subcalcareous" or moderately calcareous, at least compared to carbonate parent material. The vegetation composition is thus somewhat intermediate between that of strongly calcareous rock habitats and that of more acidic habitats. With a few rare exceptions, it lacks many of the obligate calciphiles (Thuja occidentalis, Cystopteris bulbifera, Asplenium ruta-muraria, Asplenium resiliens, Pellaea atropurpurea, Carex eburnea, etc.) of limestone and dolomite cliffs, and contains species of more acidic rock outcrops that are generally absent on limestone (e.g., Polypodium virginianum, Polystichum acrostichoides, Dryopteris marginalis, Hamamelis virginiana). Many of the characteristic species (Hydrangea arborescens, Sedum ternatum, Polypodium virginianum, Asplenium trichomanes, Woodsia obtusa, etc.) occur on a fairly wide range of substrates but prefer at least subacidic or somewhat calcareous conditions.
Environmental Description: This association is currently known from cliff-faces weathered from siltstone, shale, calcareous sandstone, and metabasalt. Sites subtend rivers and large streams, where progressive stream incision through resistant strata has formed escarpments of exposed bedrock. All of the documented cliffs have northerly aspects and are partly to heavily shaded by overhanging trees or trees growing in the cliff-base floodplains. Microhabitat conditions are characterized by vertical to very steep faces, with much exposed bedrock, numerous fissures and shelves, and considerable local deposition of organic-rich, colluvial soil material. Examples on siltstone readily erode along horizontal, slab-forming fissures, forming loose, fissile channery. There is some variation in the microtopographic character of these cliffs, with the larger, more exposed examples having a more massive, less weathered character. Soil samples collected from plots had moderate calcium concentrations (900 to 1000 ppm).
Geographic Range: This association is currently known only from the Potomac River drainage in Maryland and Virginia, in the Piedmont Triassic Basin and the adjacent Blue Ridge. Depending on the extent of bedrock types that might support the type, this range could be potentially much larger. A tentative report (Lea 2003) of comparable vegetation on Devonian shales of the Ridge and Valley province needs additional investigation.
Nations: US
States/Provinces: MD, VA, WV?
Plot Analysis Summary:
http://vegbank.org/natureserve/ELEMENT_GLOBAL.2.795484
Confidence Level: Low
Confidence Level Comments: No Data Available
Grank: G3
Greasons: No Data Available
| Type | Name | Database Code | Classification Code |
|---|---|---|---|
| Class | 6 Open Rock Vegetation Class | C06 | 6 |
| Subclass | 6.B Temperate & Boreal Open Rock Vegetation Subclass | S04 | 6.B |
| Formation | 6.B.1 Temperate & Boreal Cliff, Scree & Other Rock Vegetation Formation | F034 | 6.B.1 |
| Division | 6.B.1.Na Eastern North American Temperate Cliff, Scree & Rock Vegetation Division | D051 | 6.B.1.Na |
| Macrogroup | 6.B.1.Na.1 Shrubby Fivefingers - Rock Polypody / Cup Lichen species Eastern North American Cliff & Rock Vegetation Macrogroup | M111 | 6.B.1.Na.1 |
| Group | 6.B.1.Na.1.c Appalachian Cliff & Rock Vegetation Group | G840 | 6.B.1.Na.1.c |
| Alliance | A2072 Wild Hydrangea / Hairy Alumroot Appalachian Circumneutral Cliff Alliance | A2072 | 6.B.1.Na.1.c |
| Association | CEGL006479 Wild Hydrangea / Woodland Stonecrop - Rock Polypody Cliff Shrubland | CEGL006479 | 6.B.1.Na.1.c |
Concept Lineage: No Data Available
Predecessors: No Data Available
Obsolete Names: No Data Available
Obsolete Parents: No Data Available
Synonomy: >< Hydrangea arborescens / Arabis laevigata - Sedum ternatum Sparse Vegetation (Lea 2003)
= Hydrangea arborescens / Sedum ternatum - Polypodium virginianum Shrubland (Fleming and Taverna 2006)
= Hydrangea arborescens / Sedum ternatum - Polypodium virginianum Shrubland (Fleming and Taverna 2006)
- Davis, C. A. 2014. Survey of rare, threatened, and endangered plants of the Maryland Heights Cliff, Harpers Ferry National Historical Park, Harpers Ferry, West Virginia. Report to National Park Service. Charles A. Davis, Ecologist. Lutherville, Maryland. 29 pp. plus appendices.
- Eastern Ecology Working Group of NatureServe. No date. International Ecological Classification Standard: International Vegetation Classification. Terrestrial Vegetation. NatureServe, Boston, MA.
- 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. 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.