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CEGL003819 Rhododendron maximum Montane Ruderal Thicket
Type Concept Sentence: No Data Available
Common (Translated Scientific) Name: Great Laurel Montane Ruderal Thicket
Colloquial Name: Ruderal Montane Rhododendron Thicket
Hierarchy Level: Association
Type Concept: This community occurs along streams and on protected slopes in the mountains of North Carolina, Tennessee, South Carolina, Georgia, and possibly Virginia. It can also occur on xeric ridges and sideslopes, or sites which have been subjected to extreme crown fires or other catastrophic disturbance that has removed the canopy. It is a broad-leaved, evergreen shrubland, dominated by Rhododendron maximum which forms a continuous, dense shrub canopy up to 5 m tall. Kalmia latifolia, Rhododendron minus, and Rhododendron catawbiense may also occur as components of the shrub stratum. Shrub vegetation beneath the upper shrub canopy may be open to dense depending on the stand''s age and topographic setting. The ground layer is dominated by leaf litter or bare soil, although scattered herbs and woody seedlings do occur. Seedlings and saplings of Rhododendron maximum, Acer rubrum, Betula lenta, Betula alleghaniensis, and Tsuga canadensis are common and typical herbs include Dryopteris intermedia, Heuchera villosa, Viola spp., Thelypteris noveboracensis, Listera smallii, and Galax urceolata. This shrubland is typical along streams and on mesic, unexposed, often north-facing slopes at elevations of approximately 300-1100 m (1000-3000 feet), but can also occur on steep slopes and ridges where natural disturbances have removed the canopy. Soils supporting this community are typically acidic. Occurrences at edges of streams may flood during rainy seasons. This community can occur as the result of disturbance and will succeed to forest with an ericaceous understory without some form of disturbance. This community may have scattered woody species that are greater than 5 m tall but with generally less than 10% total cover.
Diagnostic Characteristics: No Data Available
Rationale for Nominal Species or Physiognomic Features: No Data Available
Classification Comments: This Rhododendron maximum shrubland frequently occurs adjacent to wet herbaceous cliff vegetation, riparian shrublands, or within forests dominated by Tsuga canadensis, Quercus rubra, Liriodendron tulipifera, Pinus strobus, Quercus montana, Picea rubens, or Abies fraseri. Similar ericaceous shrublands occur at higher elevations, over 1100 m (3500 feet), in the southern Appalachian Mountains. These high-elevation "heath balds" are distinguished from Rhododendron maximum Upland Shrubland by the dominance of Rhododendron catawbiense or by the occurrence of ericaceous shrubs typical of high-elevation environments such as Leiophyllum buxifolium, Menziesia pilosa, and Aronia melanocarpa. Disjunct populations of Rhododendron maximum are found in Maine and New Hampshire, but these populations may represent a different community (Hodgdon and Pike 1961). Similar vegetation has been observed at 1400 m (4600 feet) elevation on Beartown Mountain (Tazewell County, Virginia), where historical logging and subsequent fires burned Picea / Rhododendron forests, consuming the organic soil and exposing bare rock. Today this site has large areas of dense Rhododendron maximum on ridgecrests and upper slopes, with an occasional spruce tree growing above the shrubs and some shrub-sized spruce regeneration intermixed. These areas are currently treated as a disturbance stage of ~Picea rubens - (Betula alleghaniensis, Aesculus flava) / Rhododendron (maximum, catawbiense) Forest (CEGL004983)$$.
Similar NVC Types: No Data Available
note: No Data Available
Physiognomy and Structure: No Data Available
Floristics: This evergreen, sclerophyllous shrubland is dominated by Rhododendron maximum which forms a continuous, dense shrub canopy up to 5 m tall. Kalmia latifolia, Rhododendron minus, and Rhododendron catawbiense may also occur as components of the shrub stratum. Shrub vegetation beneath the upper shrub canopy may be open to dense depending on the stand''s age and topographic setting. Species such as Tsuga canadensis, Pinus strobus, Acer rubrum, Betula lenta, and Liriodendron tulipifera in the tree canopy stratum make up less than 10% cover. The ground layer is dominated by leaf litter or bare soil although scattered herbs and woody seedlings do occur. Seedlings and saplings of Rhododendron maximum, Acer rubrum, Betula lenta, Betula alleghaniensis, and Tsuga canadensis are common, and typical herbs include Dryopteris intermedia, Heuchera villosa, Viola spp., Thelypteris noveboracensis, Listera smallii, and Galax urceolata.
Dynamics: Rhododendron maximum sprouts vigorously after disturbance, and this community often results from logging, fire, chestnut blight, death of canopy trees, or cessation of grazing. Stems greater than 4 cm in diameter survive hot fires, and fire generally stimulates basal sprouting, although intense annual fires may suppress reestablishment (Core 1966). Drastic overstory removal, heavy shading, and disease have been found to decrease the density of or kill Rhododendron (Hodgdon and Pike 1961).
This shrubland will become established by invading disturbed or cleared lands if there is adequate moisture and lack of direct sunlight. This community can also result from secondary succession when a forest''s canopy is removed (by logging, disease, etc.) and the Rhododendron understory closes, forming a dense shrubland. The reestablishment of woody competitors is inhibited by the shade of the dense shrub canopy as well as by phytotoxins in the litter and soil (Gant 1978). Rhododendron maximum Shrubland may persist for over 60 years on a site (Plocher and Carvell 1987) but will succeed to a forested community as trees that become established in thicket openings mature.
This shrubland will become established by invading disturbed or cleared lands if there is adequate moisture and lack of direct sunlight. This community can also result from secondary succession when a forest''s canopy is removed (by logging, disease, etc.) and the Rhododendron understory closes, forming a dense shrubland. The reestablishment of woody competitors is inhibited by the shade of the dense shrub canopy as well as by phytotoxins in the litter and soil (Gant 1978). Rhododendron maximum Shrubland may persist for over 60 years on a site (Plocher and Carvell 1987) but will succeed to a forested community as trees that become established in thicket openings mature.
Environmental Description: This community occurs along streams and on mesic, unexposed, often north-facing slopes at elevations of approximately 300-1100 m (1000-3000 feet). Soils supporting this community are typically acidic. Occurrences at edges of streams may flood during rainy seasons. It can occur at higher elevations on steep slopes and ridges where extreme crown fires or other catastrophic disturbance have removed the canopy.
Geographic Range: This community occurs in the Southern Blue Ridge, but may be possible throughout the range of Rhododendron maximum.
Nations: US
States/Provinces: GA, NC, SC, TN, VA?
Plot Analysis Summary:
http://vegbank.org/natureserve/ELEMENT_GLOBAL.2.687995
Confidence Level: Low - Poorly Documented
Confidence Level Comments: No Data Available
Grank: GNA
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.90 Orchardgrass - Canada Goldenrod - Multiflora Rose Eastern North American Ruderal Grassland & Shrubland | M123 | 2.B.2.Nc.90 |
| Group | 2.B.2.Nc.90.a Tall goldenrod - Kentucky Bluegrass - Stiff Dogwood Ruderal Meadow & Shrubland Group | G059 | 2.B.2.Nc.90.a |
| Alliance | A4246 Great Laurel Ruderal Shrubland Alliance | A4246 | 2.B.2.Nc.90.a |
| Association | CEGL003819 Great Laurel Montane Ruderal Thicket | CEGL003819 | 2.B.2.Nc.90.a |
Concept Lineage: No Data Available
Predecessors: No Data Available
Obsolete Names: No Data Available
Obsolete Parents: No Data Available
Synonomy: ? IC4b. Montane Rhododendron Thicket (Allard 1990)
? Submesotrophic Scrub (Rawinski 1992)
? Submesotrophic Scrub (Rawinski 1992)
- Allard, D. J. 1990. Southeastern United States ecological community classification. Interim report, Version 1.2. The Nature Conservancy, Southeast Regional Office, Chapel Hill, NC. 96 pp.
- Core, E. L. 1966. Vegetation of West Virginia. McClain Printing, Parsons, WV. 217 pp.
- Fleming, G. P., and K. D. Patterson. 2009a. A vegetation classification for the Appalachian Trail: Virginia south to Georgia. Virginia Department of Conservation and Recreation, Division of Natural Heritage. In-house analysis, March 2009.
- Gant, R. E. 1978. The role of allelopathic interference in the maintenance of Southern Appalachian heath balds. Ph.D. dissertation, University of Tennessee, Knoxville. 123 pp.
- Hodgdon, A. R., and R. Pike. 1961. An ecological interpretation of Rhododendron colonies in Maine and New Hampshire. Rhodora 63:61-70.
- McGee, C. E., and R. Smith. 1967. Undisturbed Rhododendron thickets are not spreading. Journal of Forestry 65:334-335.
- Monk, C. D., D. T. McGinty, and F. P. Day, Jr. 1985. The ecological importance of Kalmia latifolia and Rhododendron maximum in the deciduous forest of the Southern Appalachians. Bulletin of the Torrey Botanical Club 112:187-193.
- Nelson, J. B. 1986. The natural communities of South Carolina: Initial classification and description. South Carolina Wildlife and Marine Resources Department, Division of Wildlife and Freshwater Fisheries, Columbia, SC. 55 pp.
- Phillips, D. L., and W. Murdy. 1985. Effects of Rhododendron on regeneration of Southern Appalachian hardwoods. Forest Science 31:226-233.
- Plocher, A. E., and K. L. Carvell. 1987. Population dynamics of rosebay rhododendron thickets in the Southern Appalachians. Bulletin of the Torrey Botanical Club 114:121-126.
- Rawinski, T. J. 1992. A classification of Virginia''s indigenous biotic communities: Vegetated terrestrial, palustrine, and estuarine community classes. Unpublished document. Virginia Department of Conservation and Recreation, Division of Natural Heritage. Natural Heritage Technical Report No. 92-21. Richmond, VA. 25 pp.
- Southeastern Ecology Working Group of NatureServe. No date. International Ecological Classification Standard: International Vegetation Classification. Terrestrial Vegetation. NatureServe, Durham, NC.