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CEGL003818 Rhododendron catawbiense Shrubland

Type Concept Sentence: No Data Available

Common (Translated Scientific) Name: Catawba Rosebay Shrubland

Colloquial Name: Southern Appalachian Catawba Rosebay Heath Bald

Hierarchy Level:  Association

Type Concept: This evergreen shrubland occurs at the highest elevations, typically 1500-1980 m (5000-6500 feet), in the southern Appalachian Mountains on steep, exposed slopes, ridges, and rock outcrops. It occurs primarily in the northern portion of the Southern Appalachians, north of the Asheville Basin, in mountain ranges lacking Pieris floribunda and Rhododendron carolinianum. Greater than 75% of the shrub cover is composed of evergreen species, and the predominant shrub is Rhododendron catawbiense. Scattered trees contribute less than 1% cover, typically Aronia melanocarpa, Abies fraseri, and Picea rubens. Small openings in the shrub canopy are dominated by rock or herbs. Herb cover beneath the shrub canopy is absent or very sparse (<5%) and may include Gaultheria procumbens, Galax urceolata, Epigaea repens, Medeola virginiana, Trillium undulatum, Melampyrum lineare, Dryopteris campyloptera, Houstonia serpyllifolia, Viola spp., and Carex debilis var. rudgei. Mosses may be locally dominant at the base of Rhododendron clumps, often Polytrichum commune or bryophytes from adjacent Picea - Abies communities. This community can result from secondary succession after fire or logging or can occur as a topo-edaphic climax on steep, exposed sites. Occurrences may range in size from 0.5-200 hectares. This community can grade into or occur adjacent to high-elevation rock outcrop communities, montane grass-dominated communities, or forests dominated by Picea rubens, Abies fraseri, and northern hardwood species such as Fagus grandifolia, Acer saccharum, and Betula alleghaniensis.

Diagnostic Characteristics: No Data Available

Rationale for Nominal Species or Physiognomic Features: No Data Available

Classification Comments: This community can grade into or occur adjacent to high-elevation rock outcrop communities, montane grass-dominated communities, or forests dominated by Picea rubens, Abies fraseri, and northern hardwood species such as Fagus grandifolia, Acer saccharum, and Betula alleghaniensis. A more open, low-growing, evergreen shrubland, ~Leiophyllum buxifolium Dwarf-shrubland (CEGL003951)$$, is restricted to areas where Leiophyllum buxifolium dominates areas greater than 0.1 hectare. However, the species may be locally dominant as inclusions in this shrubland. Similar, but floristically different, ericaceous shrublands occur in the Mahoosuc Mountains of Maine (Fahey 1976). Exemplary occurrences are known from the Roan Mountain Massif, North Carolina and Tennessee, and Mount Rogers, Virginia.

Similar NVC Types: No Data Available
note: No Data Available
Physiognomy and Structure: No Data Available

Floristics: Greater than 75% of the shrub cover is composed of evergreen species, and the predominant shrub is Rhododendron catawbiense, which forms a continuous, dense shrub canopy from 1-4 m tall. On the most rugged, windswept sites, shrubs are stunted and gnarled. The occurrence and relative abundance of associated shrub species vary with elevation and adjacent vegetation. Scattered trees contribute less than 1% cover, typically Aronia melanocarpa, Abies fraseri, and Picea rubens. Small openings in the shrub canopy are dominated by rock or herbs. Herb cover beneath the shrub canopy is absent or very sparse (<5%) and may include Gaultheria procumbens, Galax urceolata, Epigaea repens, Medeola virginiana, Trillium undulatum, Melampyrum lineare, Dryopteris campyloptera, Houstonia serpyllifolia, Viola spp., and Carex debilis var. rudgei. Mosses may be locally dominant at the base of Rhododendron clumps, often Polytrichum commune or bryophytes from adjacent Picea - Abies communities. This community contains species endemic to the southern Appalachian Mountains, including Abies fraseri, Fothergilla major, Galax urceolata, Geum radiatum, Houstonia purpurea var. montana, Houstonia serpyllifolia, Hudsonia montana, Hypericum buckleii, Liatris helleri, Lilium grayi, Menziesia pilosa, Pieris floribunda, Prenanthes roanensis, Rhododendron vaseyi, Rhododendron carolinianum, Aronia melanocarpa, and Vaccinium erythrocarpum. Species occurring disjunct from their typical northern distributions include Alnus viridis ssp. crispa, Dryopteris campyloptera, Picea rubens, and Vaccinium corymbosum.

Dynamics:  Windfall, landslides, and small, localized and lightning-caused fires are important in the establishment and maintenance of this community. This community can result from secondary succession after fire or logging, in which case it is unstable and will eventually succeed to a forest community with a Rhododendron understory (e.g., ~Picea rubens - (Abies fraseri) / (Rhododendron catawbiense, Rhododendron maximum) Forest (CEGL007130)$$). When this community occurs on steep, exposed sites, where wind exposure, soil infertility, and drought maintain a scrubby shrub community, it is a topo-edaphic climax. According to Gant (1978) Rhododendron catawbiense heath balds represent stable communities that employ allelopathic interference to arrest succession and maintain themselves.
Environmental Description:  This evergreen shrubland occurs at the highest elevations, typically 1500-1980 m (5000-6500 feet), in the southern Appalachian Mountains on steep, exposed slopes, ridges, and rock outcrops. It occurs primarily in the northern portion of the Southern Appalachians, north of the Asheville Basin, in mountain ranges lacking Pieris floribunda and Rhododendron carolinianum. This community can result from secondary succession after fire or logging or can occur as a topo-edaphic climax on steep, exposed sites. Occurrences may range in size from 0.5-200 hectares. This community can grade into or occur adjacent to high-elevation rock outcrop communities, montane grass-dominated communities, or forests dominated by Picea rubens, Abies fraseri, and northern hardwood species such as Fagus grandifolia, Acer saccharum, and Betula alleghaniensis.
Geographic Range: This community occurs primarily in the northern portion of the Southern Appalachians, north of the Asheville Basin, in North Carolina, Tennessee, and Virginia.

Nations: US

States/Provinces:  GA?, NC, TN, VA


Confidence Level: Moderate

Confidence Level Comments: No Data Available
Grank: G2

Greasons: No Data Available
Type Name Database Code Classification Code
Class 2 Shrub & Herb Vegetation Class C02 2
Subclass 2.B Temperate & Boreal Grassland & Shrubland Subclass S18 2.B
Formation 2.B.2 Temperate Grassland & Shrubland Formation F012 2.B.2
Division 2.B.2.Nc Eastern North American Grassland & Shrubland Division D024 2.B.2.Nc
Macrogroup 2.B.2.Nc.1 Catawba Rosebay / Michaux''s Saxifrage - Flattened Oatgrass Felsic & Mafic Scrub & Grassland Macrogroup M506 2.B.2.Nc.1
Group 2.B.2.Nc.1.a Catawba Rosebay - Mountain Fetterbush - Mountain Alder Southern Appalachian Shrub Bald Group G658 2.B.2.Nc.1.a
Alliance A0744 Catawba Rosebay - Carolina Azalea - Mountain Laurel Shrub Bald Alliance A0744 2.B.2.Nc.1.a
Association CEGL003818 Catawba Rosebay Shrubland CEGL003818 2.B.2.Nc.1.a
Concept Lineage: No Data Available

Predecessors: No Data Available

Obsolete Names: No Data Available

Obsolete Parents: No Data Available
Synonomy: > Rhododendron catawbiense - Menziesia pilosa Subtype (Fleming and Coulling 2001)
> Sorbus americana / Menziesia pilosa - Vaccinium erythrocarpum - Rubus canadensis Subtype (Fleming and Coulling 2001)
< IC4a. Heath Bald Shrubland (Allard 1990)
Concept Author(s): K.D. Patterson

Author of Description: K.D. Patterson

Acknowledgements: No Data Available

Version Date: 09-09-94
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