Common (Translated Scientific) Name: Shrubby Fivefingers - Rock Polypody / Cup Lichen species Eastern North American Cliff & Rock Vegetation Macrogroup
Colloquial Name: Eastern North American Cliff & Rock Vegetation
Hierarchy Level: Macrogroup
Type Concept: This type encompasses vegetation of eastern temperate and boreal North American cliffs, talus slopes and erosional bluffs characterized by often sparse and patchy vascular vegetation and often high nonvascular cover. It ranges from the East Coast west to the Ouachitas and upper Great Lakes and through central and eastern boreal Canada. Vegetation structure varies widely, and may include scattered small trees such as Betula papyrifera, Juniperus virginiana, Picea glauca, Pinus banksiana, Pinus strobus, Thuja occidentalis, and Quercus spp. Other commonly encountered species may include Asplenium spp., Cystopteris fragilis, Danthonia spicata, Dasiphora fruticosa ssp. floribunda, Deschampsia cespitosa, Dryopteris marginalis, Hydrangea arborescens, Parthenocissus quinquefolia, Polypodium virginianum, Ribes spp., Rubus pubescens, Sibbaldiopsis tridentata, and Toxicodendron radicans. Characteristic foliose and fruticose macrolichen genera include Cladonia, Lasallia, Stereocaulon, and Umbilicaria. Crustose lichens are also common. Substrates include all lithologies from acidic granites to circumneutral basalts to calcareous limestones, with concomitant floristic variation. These cliffs are prone to harsh climatic conditions; frequent disturbances include drought stress and wind and storm damage. Most of the substrate is dry and exposed, but small (occasionally large) areas of seepage are often present. The vegetation is patchy and sparse overall, except in some wet, or seepy, areas where the rocks are often densely or moderately covered with bryophytes or algae. Outside of the glaciated regions and the Appalachian Mountains, this vegetation is primarily limited to river gorges and bluffs. A specialized habitat within this macrogroup is the vertical walls of limestone sinkholes. Vegetation occurring on shoreline examples seems to be mostly restricted to areas protected from wave action, ice-scour, and wind.
Diagnostic Characteristics: This type has sparse vascular vegetation and variable cryptogam (bryophyte, lichen and ferns) cover found on some to strongly vertical cliffs, talus slopes, and erosional bluffs of eastern temperate and central to eastern boreal North America. Cliffs and other rock vegetation with >10% vascular cover of trees, shrubs and herbs are placed elsewhere.
Rationale for Nominal Species or Physiognomic Features: Nominals for this group are challenging due to its wide geographic and ecological range.
Classification Comments: This is a large and "bulky" macrogroup which is geographically broad and floristically heterogeneous. More sampling is needed to determine how best to divide it, either at the group or alliance level, and whether the boreal group should be moved with other boreal rock groups to a separate boreal macrogroup or even division. Rocky outcrop vegetation, typically on flat, more vascular-vegetated habitats, is placed elsewhere in a number of shrub and grassland macrogroups in 2.B.2.Nc Eastern North American Grassland & Shrubland Division (D024). Cliffs with sufficient cover of vascular plants (>10% cover) are placed with forest and woodland, shrubland and grassland types. There may be some degree of floristic overlap between rock outcrops and cliff and talus, and the distinction may be strongest when based on overall physiognomy (i.e., <10% vascular cover, cryptogam cover variable).
Similar NVC Types:
M116 Great Plains Cliff, Scree & Rock Vegetation, note: is similarly sparsely vegetated but geographically separated.
M880 Eastern North American Wet Shoreline Vegetation, note: "occupies open rocky shorelines on rivers and beaches, if wet enough."
Physiognomy and Structure: Vascular vegetation is sparse, patchy, and widely variable in structure, with scattered trees, shrubs, and herbs. The nonvascular and fern component varies from sparse to dense cover. Physiognomy is variable.
Floristics: Floristics vary with geography, substrate, and moisture availability. Taxa include Aquilegia canadensis, Asplenium spp., Arabis spp., Betula spp., Corydalis sempervirens, Cystopteris bulbifera, Cystopteris fragilis, Danthonia spicata, Dasiphora fruticosa ssp. floribunda, Deschampsia cespitosa, Dryopteris marginalis, Hydrangea arborescens, Juniperus virginiana, Parthenocissus quinquefolia, Pellaea atropurpurea, Phlox subulata, Picea glauca, Pinus banksiana, Pinus strobus, Polypodium spp., Quercus spp., Sibbaldiopsis tridentata (= Potentilla tridentata), Saxifraga michauxii, Saxifraga virginiensis, Schizachyrium scoparium, Thuja occidentalis, Toxicodendron radicans, and Woodsia obtusa. Characteristic foliose and fruticose lichen genera include Cladonia, Flavoparmelia, Lasallia, Stereocaulon, and Umbilicaria. Characteristic crustose lichen genera include Caloplaca, Dimelaena, Fuscidea, Lepraria, Physcia, and Porpidia. Bryophytes are also common.
Dynamics: On cliffs, plants that are rooted in crevices or ledges are subject to erosion or slumping. Severe drought can also limit woody encroachment on sites with dry aspects.
Environmental Description: Climate: Climate is primarily north temperate and boreal, but this type spans a wide area. Soil/substrate/hydrology: Substrate includes rocky cliffs, talus, and unconsolidated to mineral materials (bluffs) that are somewhat to strongly vertical. Consolidated rock substrates comprise various lithologies, including basalt-diabase, granite-metamorphic, limestone-dolostone, shale, or sandstone. Landforms include cliffs, erosional slopes, talus slopes, riverside outcrops and gorges, and shorelines of waterbodies. Cliffs range from overhanging to vertical to nearly vertical, with the physical structure usually irregular, with some ledges and crevices. Moisture levels vary drastically over short distances. Seepage of groundwater from adjacent soils or through rock fractures often creates permanently or seasonally flooded microsites, while lack of soil makes other portions extremely dry. In less sheltered topography, slope and aspect affect overall moisture levels to some degree. Rock chemistry and moisture appear to be the most important factors affecting different associations on cliff sites. On talus, small pockets among the rocks provide rooting substrates; on bluffs, plants have more rooting sites available, but they are subject to erosion or slumping.
Geographic Range: This type ranges in the boreal region from eastern to central Canada, and in the temperate region from New England and adjacent Canada west to the Great Lakes and northern Minnesota, south through the Appalachians and Piedmont (occasional in the Atlantic Coastal Plain), and west across the Cumberland Plateau and Interior Low Plateau to the Ozarks.
Nations: CA, MX?, US
States/Provinces: AB?, AL, AR, CT, FL, GA, IA, IL, IN, KY, LA, MA, MB, MD, ME, MI, MN, MO, MS, NB, NC, NH, NJ, NS, NY, OH, OK, ON, PA, QC, RI, SC, SK?, TN, TX, VA, VT, WI, WV
|US Forest Service Ecoregions (2007)|
Prairie Parkland (Temperate) Province
Confident or certain
Confident or certain
Confidence Level: Low
Confidence Level Comments:
Concept Author(s): S. Gawler, D. Faber-Langendoen, and S. Menard, in Faber-Langendoen et al. (2014)
Author of Description: S. Gawler, S. Menard, L. Sneddon, D. Faber-Langendoen
Version Date: 08Jan2016
- Albert, D. A., P. J. Comer, R. A. Corner, D. Cuthrell, M. Penskar, and M. Rabe. 1995. Bedrock shoreline survey of the Niagaran Escarpment in Michigan's Upper Peninsula: Mackinac County to Delta County. Michigan Natural Features Inventory for Land and Water Management Division (grant # CD-0.02).
- Clark, P. W. 2012. Cliff ecology: Extent, biota, and recreation of cliff environments in the New River Gorge, WV. M.S. thesis, Department of Geology and Geography, West Virginia University, Morgantown. 106 pp.
- Faber-Langendoen, D., J. Drake, S. Gawler, M. Hall, C. Josse, G. Kittel, S. Menard, C. Nordman, M. Pyne, M. Reid, L. Sneddon, K. Schulz, J. Teague, M. Russo, K. Snow, and P. Comer, editors. 2010-2019a. Divisions, Macrogroups and Groups for the Revised U.S. National Vegetation Classification. NatureServe, Arlington, VA. plus appendices. [in preparation]
- Larson, D. W., U. Matthes, and P. E. Kelly. 2000b. Cliff ecology: Patterns and processes in cliff ecosystems. Cambridge University Press, Cambridge, MA.