• This association includes high-elevation boulderfield forests of the southern Appalachians, strongly dominated by Betula alleghaniensis, with few or no other species in the canopy, and with other species indicative of high elevations.
  • This community occurs in a cool, humid climate, on steep, rocky, northwest- to northeast-facing, middle to upper concave slopes, or in saddles between ridges, at elevations of 1,370-1,615 m (4,500-5,300 feet).
  • It is known from the high elevations of the Blue Ridge from West Virginia south to eastern Tennessee and western North Carolina.
  • This forest is distinguished by a closed to somewhat open canopy dominated by Betula alleghaniensis, occurring over angular rocks (0.25-1 m diameter) covered by thin soil, lichens, mosses or vines.
    
    
• This association is distinguished by being strongly dominated by Betula alleghaniensis, with few or no other species in the canopy, and with other species indicative of high elevations (e.g., Abies fraseri, Dryopteris campyloptera, Ribes glandulosum, Rugelia nudicaulis, Streptopus amplexifolius, Prunus pensylvanica, and Sorbus americana.
  • On less extreme sites, generally at lower elevations in the Blue Ridge and adjacent montane ecoregions, a similar boulderfield forest is ~Betula alleghaniensis - Tilia americana var. heterophylla / Acer spicatum / Ribes cynosbati / Dryopteris marginalis Forest (CEGL004982).
  • Similar Betula alleghaniensis-dominated forests occur on glaciated rocky slopes in the upper mid-Atlantic and in the northeastern United States.
  • The Betula alleghaniensis-dominated periglacial boulderfields of the southern Appalachian Mountains are distinguished from the northern forests by the occurrence of southern Appalachian endemic species, better developed shrub layers and slightly less species diversity.



• Betula alleghaniensis in the canopy are often stunted and gnarled, with roots that may have grown to encircle the boulders.
  • Tree density is typically less than that of the surrounding forests.
  • Other species that may form a minor canopy component include Aesculus flava, Prunus pensylvanica, Sorbus americana, Acer spicatum, Picea rubens, Tilia americana var. heterophylla, Sambucus racemosa var. pubens, or Quercus rubra.
  • Tree windthrow is common, leaving patches of exposed mineral soil and gaps in the canopy.
    
    
• The shrub density is typically high but may vary between occurrences.
  • Characteristic species include, Acer pensylvanicum, Acer spicatum, Amelanchier arborea var. austromontana, Diervilla sessilifolia, Hydrangea arborescens, Ilex montana, Lonicera canadensis, Ribes glandulosum, Ribes rotundifolium, Rubus canadensis, Sambucus racemosa var. pubens, Vaccinium erythrocarpum, and Viburnum lantanoides.
    
    
• Herbaceous cover is generally sparse because of thin, rocky soil, but herbs and mosses may cover the rocks and boulders.
  • Characteristic species include, Oclemena acuminata, Eurybia chlorolepis, Aconitum reclinatum, Cardamine clematitis, Carex aestivalis, Actaea podocarpa, Claytonia caroliniana, Clintonia borealis, Dryopteris campyloptera, Dryopteris marginalis, Huperzia lucidula, Oxalis montana, Polypodium appalachianum, Streptopus amplexifolius.
    
    
• Seepage areas are common, producing wet microhabitats with unique species assemblages (Chelone lyonii, Chrysosplenium americanum, Circaea alpina, Rudbeckia laciniata, Impatiens pallida, and Monarda didyma).
  
  
• The rocks may be almost totally covered by moss.

• This forest has a canopy strongly dominated by Betula alleghaniensis.
  • Canopy trees are often stunted and gnarled, with roots that may have grown to encircle the boulders.
  • Tree windthrow is common, leaving patches of exposed mineral soil and gaps in the canopy.
• Other species in the canopy and subcanopy can include Aesculus flava, Prunus pensylvanica, Sorbus americana, Acer spicatum , and Picea rubens.
  
  
• The tall shrub/sapling stratum is dominated by Acer spicatum, Hydrangea arborescens, and Viburnum lantanoides.
• The short shrub/sapling stratum is dominated by Ribes glandulosum.
  • Other shrubs include Sambucus racemosa var. pubens, Diervilla sessilifolia, Lonicera canadensis, Vaccinium erythrocarpum, Ribes rotundifolium, and Rubus canadensis.
    
    
• Herbs and mosses cover the rocks and boulders.
  • Characteristic herbaceous species include Eurybia chlorolepis, and Dryopteris campyloptera.
  • Other species include Actaea podocarpa, Clintonia borealis, Cystopteris protrusa, Cardamine clematitis, Huperzia lucidula, Rugelia nudicaulis, Streptopus amplexifolius, and Polypodium appalachianum.

• This community type ranges at high elevations of the Blue Ridge from eastern Tennessee and western North Carolina north to southwestern Virginia.
  • In the southern Virginia Blue Ridge, it occurs frequently on steep, north-facing slopes of Mount Rogers, Whitetop, and Pine Mountain.
  • Small, highly localized outliers also occur at the highest elevations of Clinch Mountain in the adjacent Ridge and Valley province.

• This community was sampled on the Mount Le Conte quadrangle and Clingman's Dome quadrangle and was not found on the Cades Cove quadrangle.
  • It is likely in other areas of the park and should be sought on steep slopes and boulderfields at elevations over 5,000 feet, particularly in areas adjacent to spruce (Picea rubens) and fir (Abies fraseri) forests.
    
    
• On the Mount Le Conte quadrangle, this community was sampled on the north slope of Mount Le Conte, on the Rainbow Falls Trail, at 5,300 feet elevation.
  
  
• On the Clingman's Dome quadrangle, it was sampled off of Forney Ridge Trail south of Andrews Bald at an elevation of approximately 5,200 feet.

• Global Conservation Status Rank: G2G3 (Last reviewed: 10 27 2003).
  
  
• This community is scattered throughout the high elevations of the Southern Blue Ridge with highly localized outliers also found at the highest elevations of Clinch Mountain in the adjacent Ridge and Valley province.
  • Examples are further confined to boulder strewn substrates which are relatively uncommon.
  • Unlike many other forest types in the southern Appalachians, this community has been less impacted by logging due to the stunted nature of the trees and the relative inaccessibility of these boulderfield sites.
  • As of 2003, North Carolina has 12 (principal) Element Occurrences, and given their proportion of the total occurrences and their protection status, a rank of G2G3 is probably justified (M. Schafale pers. comm.).

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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.

Ambrose, J. 1990a. Georgia's natural communities--A preliminary list. Unpublished document. Georgia Natural Heritage Inventory. 5 pp.

CAP [Central Appalachian Forest Working Group]. 1998. Central Appalachian Working group discussions. The Nature Conservancy, Boston, MA.

Chafin, L. G., and S. B. Jones, Jr. 1989. Community structure of two southern Appalachian boulderfields. Castanea 54:230-237.

NatureServe Ecology - Southeastern United States. No date. Unpublished data. NatureServe, Durham, NC.

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Pittillo, J. D., and G. A. Smathers. 1979. Phytogeography of the Balsam Mountains and Pisgah Ridge, southern Appalachian Mountains. Pages 206-245 in: H. Lieth and E. Landolt, editors. Proceedings of the 16th International phytogeographic excursion. Veroff. Geobot. Inst., Stiftung Rubel, Zurich.

Pyne, M. 1994. Tennessee natural communities. Unpublished document. Tennessee Department of Conservation, Ecology Service Division, Nashville. 7 pp.

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.

Rheinhardt, R. D., and S. A. Ware. 1984. The vegetation of the Balsam Mountains of southwestern Virginia: A phytosociological study. Buletin of the Torrey Botanical Club 111:287-300.

Schafale, M. 1998b. Fourth approximation guide. High mountain communities. March 1998 draft. North Carolina Natural Heritage Program, Raleigh.

Schafale, M. P., and A. S. Weakley. 1990. Classification of the natural communities of North Carolina. Third approximation. North Carolina Department of Environment, Health, and Natural Resources, Division of Parks and Recreation, Natural Heritage Program, Raleigh. 325 pp.

Schafale, Mike P. Personal communication. Ecologist, North Carolina Department of Environment, Health, and Natural Resources, Division of Parks and Recreation, Natural Heritage Program, Raleigh.

Southeastern Ecology Working Group of NatureServe. No date. International Ecological Classification Standard: International Vegetation Classification. Terrestrial Vegetation. NatureServe, Durham, NC.

Stamper. 1976. Vegetation of Beech Mountain, North Carolina. M.S. thesis, University of Tennessee, Knoxville. 185 pp.

Wharton, C. H. 1978. The natural environments of Georgia. Georgia Department of Natural Resources, Atlanta. 227 pp.

Wood, E. W. 1975. A comparison of mature, yellow birch-dominated forests in northern and southern Appalachian regions. Unpublished document. University of Georgia Herbarium Library, Athens. 67 pp.