Classification of Vegetation Communities of Maryland: First Iteration
A Subset of the International Classification of Ecological
Concept: This alliance includes woodland vegetation in the southern and central Appalachians, dominated or codominated by Pinus pungens, with or without some admixture of Pinus rigida and/or Pinus virginiana. This alliance also includes woodlands dominated by Pinus rigida that occur within the geographic area where Pinus pungens occurs as a canopy dominant. Common canopy and subcanopy associates include Quercus prinus, Quercus coccinea, Castanea dentata, Nyssa sylvatica, Acer rubrum, and Oxydendrum arboreum. Typical shrubs include Gaylussacia baccata, Vaccinium pallidum, Vaccinium stamineum, Vaccinium corymbosum, Vaccinium simulatum, Gaylussacia ursina, Rhododendron maximum, Kalmia latifolia, Rhododendron carolinianum, Rhododendron catawbiense, Leucothoe recurva, and Leiophyllum buxifolium. In the central Appalachians and in the Virginia portion of the Southern Blue Ridge, Quercus ilicifolia is a characteristic shrub. Herbaceous species composition will vary within the range of this alliance. Species commonly found in the sparse herb stratum include Galax urceolata, Pteridium aquilinum var. latiusculum, Xerophyllum asphodeloides, Fothergilla major, Comptonia peregrina, and the subshrubs Gaultheria procumbens, and Epigaea repens. These woodlands typically occur at elevations from 760-1220 m (2500-4000 feet), on xeric ridges and exposed, steep side-slopes over thin, excessively drained, nutrient-poor soils and are often associated with rock outcroppings. Without periodic fire, these woodlands will gradually succeed into forests dominated by Quercus prinus and Quercus coccinea, except on the most extreme sites, where this vegetation is self-perpetuating. The primary range of associations in this alliance is the Appalachian Mountains (within the range of Pinus pungens), although the nominal species, Pinus pungens, has insular occurrences in the Upper Piedmont.
Comments: Associations in this alliance generally have a woodland structure (open canopy), although locally vegetation may vary to a denser canopy.
Range: The primary range of associations in this alliance is the Appalachian Mountains (within the range of Pinus pungens), although the nominal species, Pinus pungens, has insular occurrences in the Upper Piedmont. This alliance is found in Georgia, North Carolina, South Carolina, Tennessee, Maryland, Pennsylvania, Virginia, and West Virginia.
States/Provinces: GA MD NC PA SC TN VA WV
TNC Ecoregions: 51:C, 52:C, 59:C, 61:C
USFS Ecoregions: 231Ak:CCC, 231Al:CCC, M221Aa:CCC, M221Ab:CCC, M221Ac:CCC, M221Ce:C??, M221Da:CCC, M221Db:CCC, M221Dc:CCC, M221Dd:CCC
Federal Lands: NPS (Carl Sandburg Home, Great Smoky Mountains, Shenandoah); USFS (Chattahoochee, Cherokee, George Washington, Jefferson, Nantahala, Pisgah, Sumter)
Synonymy: IA7b. Xeric Pitch Pine/Table Mountain Pine Ridge Forest, in part (Allard 1990); Pine--Oak/Heath, in part (Schafale and Weakley 1990); Pine--Oak/Heath, in part (Nelson 1986); Pinus pungens/Pinus rigida (Pyne 1994)
References: Allard 1990, Barden 1977, Golden 1981, McLeod 1988, Nelson 1986, Newell and Peet 1995, Pyne 1994, Racine 1966, Rawinski et al. 1996, Schafale and Weakley 1990, Sutherland et al. 1993, Thomas 1966, Turrill and Buckner 1995, Wharton 1978, Whittaker 1956, Williams 1991, Williams and Johnson 1990, Williams and Johnson 1992, Williams et al. 1990a, Zobel 1969
Authors: A.S. WEAKLEY, RW, Southeast Identifier: A.521
PINUS (PUNGENS, RIGIDA) / QUERCUS ILICIFOLIA / GAYLUSSACIA BACCATA WOODLAND
(Table Mountain Pine, Pitch Pine) / Bear Oak / Black Huckleberry Woodland
Central Appalachian Table Mountain Pine - Pitch Pine - Heath Woodland G4 (01-10-01)
Ecological Group (SCS;MCS): Appalachian Highlands Pitch and Table Mountain Pine Woodlands (401-80; n/a)
Concept: This association represents predominantly evergreen woodlands occupying xeric, convex, often rocky south- and west-facing slopes, ridge spurs, crests, and clifftops in the central Appalachians and peripherally in the Southern Blue Ridge. Stands occur at elevations from 450-1200 m (1500-4000 feet) on various substrates, but most commonly on acidic, sedimentary and metasedimentary substrates (e.g. quartzites, sandstones, and shales). Soils are very infertile, shallow, and droughty. A thick, poorly decomposed duff layer, along with dead wood and highly volatile ericaceous shrubs, create a strongly fire-prone habitat. Pinus pungens and Pinus rigida, individually or together, dominate the canopy, which can approach forest physiognomy in some situations as a result of fire suppression. Scattered canopy and subcanopy associates may include Quercus prinus, Quercus coccinea, Quercus rubra, Quercus marilandica, Pinus virginiana, Castanea dentata, Acer rubrum, Sassafras albidum, Nyssa sylvatica, and Amelanchier arborea. Quercus ilicifolia dominates a moderately open to very dense tall-shrub layer, while variable combinations of Kalmia latifolia, Gaylussacia baccata, Vaccinium pallidum, Vaccinium angustifolium, Vaccinium stamineum, Pieris floribunda, Rhododendron catawbiense, and other ericads form a generally dense low-shrub layer. Smilax rotundifolia and Smilax glauca may be prominent climbers among the shrubs. Herbaceous species, often very sparse, are rooted in small openings among the shrubs, on rocks, and in disturbed areas where mineral soil is exposed. Typical herbs and subshrubs include Epigaea repens, Gaultheria procumbens, Xerophyllum asphodeloides, Iris verna, Pteridium aquilinum var. latiusculum, Melampyrum lineare var. latifolium, Stenanthium gramineum var. micranthum, Uvularia puberula, Lycopodium tristachyum, Aralia hispida (usually on outcrops), and Carex tonsa. Periodic fire is an important ecological process which provides opportunities for the regeneration of both canopy pines and less competitive herbaceous species, while setting back successional encroachment of xeric oaks. On many sites (e.g. clifftops, quartzite ledges), the vegetation is self-perpetuating due to extreme edaphic conditions.
Comments: This community type is closely related to other associations classified in the II.A.4.N.a Pinus pungens - (Pinus rigida) Woodland Alliance (A.521). It is thought to differ in the shrub layer dominance of Quercus ilicifolia, a northern species which is absent in similar communities south of Virginia, as well as the absence of a number of characteristic southern species such as Gaylussacia ursina, Rhododendron carolinianum, Rhododendron minus, Leiophyllum buxifolium, and Fothergilla major. Long-term, widespread fire suppression is an ongoing problem which may be causing some stands to succeed to closed, mixed oak - pine forest. However, on many sites occupied by this community, edaphic conditions are so stressful that tree oaks are not or marginally competitive, and even long fire-return intervals (e.g., >25 years) are sufficient to maintain pine-dominated vegetation. Within the past ten years, much of this vegetation in Virginia has been devastated by infestations of Southern Pine Beetle (Dendroctonus frontalis). These outbreaks have resulted in extensive mortality of the dominant pines and changed physiognomies, at least temporarily, to a shrubland condition.
The recognition of global subtypes equivalent to two distinct state community types is well supported by quantitative analysis of compositional and environmental data. Further study may support the elevation of these subtypes to full association-level status in the USNVC.
Range: This community occurs in the Central Appalachian region of Virginia, West Virginia, Maryland, and Pennsylvania, with very local outliers in the western Piedmont of Virginia and Maryland (e.g., Sugarloaf Mountain). In Virginia, the type as a whole ranges through the Blue Ridge and Ridge and Valley provinces north of the New River. Outliers occur on Bull Run Mountain (Fauquier County), Willis Mountain (Buckingham County), and other Piedmont foothills. The Table-Mountain Subtype occurs throughout this range, while the Pitch Pine Subtype is more confined to the northern two-thirds of the state's mountain region.
States/Provinces: MD:S?, PA:S?, VA:S?, WV:S?
TNC Ecoregions: 51:C, 52:C, 59:C, 61:?
USFS Ecoregions: 231Ak:CCC, 231Al:CCC, M221Aa:CCC, M221Ab:CCC, M221Ce:C??, M221Da:CCC, M221Db:CCC, M221Dc:CCC, M221Dd:CCC
Federal Lands: NPS (Shenandoah); USFS (George Washington, Jefferson)
Synonymy: Pinus pungens / Quercus ilicifolia / Gaylussacia baccata - Pteridium aquilinum Woodland (Fleming and Moorhead 2000), Pinus pungens - Pinus rigida / Quercus ilicifolia / Gaylussacia baccata Association (Rawinski et al. 1996), Pinus rigida / Quercus ilicifolia / Gaylussacia baccata Association (Rawinski et al. 1994), Chestnut Oak: 44 (Eyre 1980) B. chestnut oak - pitch pine variant, pro parte., Pitch Pine: 45 (Eyre 1980) B. pitch pine - chestnut oak variant, pro parte., Pinus pungens - Quercus prinus - (Quercus coccinea) / Kalmia latifolia - Gaylussacia baccata Woodland (Fleming and Coulling 2001) F. VA Srank = S4, Quercus prinus - Pinus rigida / Quercus ilicifolia - Kalmia latifolia - Gaylussacia baccata / Gaultheria procumbens Woodland (Fleming and Coulling 2001) F. VA Srank = S3
References: Eyre 1980, Fleming and Coulling 2001, Fleming and Moorhead 2000, Fleming et al. 2001, Fleming pers. comm., Rawinski et al. 1994, Rawinski et al. 1996
Authors: G. Fleming and P. Coulling, SCS Confidence: 1 Identifier: CEGL004996
- Maryland Vegetation Classification Subset Report II. Woodland
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