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A3991 Appalachian Lichen Boulderfield Alliance

Type Concept Sentence: This alliance consists of large, dry, lichen-dominated boulderfields with little or no vascular vegetation, occurring in the eastern U.S. It occurs on a variety of sedimentary, metasedimentary and metamorphic substrates, including quartzite, sandstone and metabasalt. The dominant taxa vary across the range of the alliance but common combinations of lichens include Lasallia papulosa and Lasallia pensylvanica (either singly or together), Lasallia papulosa and Lasallia caroliniana, and Umbilicaria mammulata.

Common (Translated Scientific) Name: Appalachian Lichen Boulderfield Alliance

Colloquial Name: Appalachian Lichen Boulderfield

Hierarchy Level:  Alliance

Type Concept: This alliance consists of large, dry, lichen-dominated boulderfields with little or no vascular vegetation, occurring in the eastern U.S. It occurs on a variety of sedimentary, metasedimentary and metamorphic substrates, including quartzite, sandstone and metabasalt. The dominant taxa vary across the range of the alliance. Some common combinations of lichens include Lasallia papulosa and Lasallia pensylvanica (either singly or together), Lasallia papulosa and Lasallia caroliniana, and Umbilicaria mammulata. Some other examples are dominated by Umbilicaria muhlenbergii, Lasallia papulosa, and Melanelia stygia. These are some of the most abundant and conspicuous lichens found in examples. Individual occurrences can be as large as an acre. Vascular plants are generally sparse or absent. In moister examples, trees of adjacent forest communities often shade the outcrop community for much of the day.

Diagnostic Characteristics: Large boulder talus lacking vascular plants and dominated by lichens.

Rationale for Nominal Species or Physiognomic Features: No Data Available

Classification Comments: This alliance is likely of much broader distribution but currently reflects the limited geographic scope of study. Considerably more data are needed on lichen-dominated vegetation rangewide.

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

Floristics: This alliance consists of consolidated cliffs or unconsolidated bouldery talus dominated by Umbilicaria muhlenbergii, in combination with other lichens. Some common combinations of lichens include Lasallia papulosa and Lasallia pensylvanica (either singly or together), Lasallia papulosa and Lasallia caroliniana (= Umbilicaria caroliniana), and Umbilicaria mammulata. The only association currently defined is dominated by Umbilicaria muhlenbergii, Lasallia papulosa, and Melanelia stygia. The highly acidic, extremely quartzitic rocks support numerous crustose lichens. Crevices with slight soil development have Cladonia rangiferina (= Cladina rangiferina), and very scattered vascular plants, such as Vaccinium angustifolium, Menziesia pilosa, Kalmia latifolia, and Sorbus americana, are established.

Dynamics:  No Data Available
Environmental Description:  This alliance consists of consolidated cliffs or unconsolidated bouldery talus. The only association currently defined in this alliance occurs on talus and exposed outcrops of Tuscarora quartzite and sandstone, at 1050-1450 m (3500-4800 feet) elevation in the Central Appalachians. The highly acidic rocks support numerous crustose lichens.
Geographic Range: This alliance ranges from Lower New England south through the Southern Blue Ridge.

Nations: US

States/Provinces:  CT, GA, KY, MD, NC, NJ, PA, SC, TN, VA, WV


Confidence Level: Moderate

Confidence Level Comments: No Data Available
Grank: GNR

Greasons: No Data Available
Type Name Database Code Classification Code
Class 6 Open Rock Vegetation Class C06 6
Subclass 6.B Temperate & Boreal Open Rock Vegetation Subclass S04 6.B
Formation 6.B.1 Temperate & Boreal Cliff, Scree & Other Rock Vegetation Formation F034 6.B.1
Division 6.B.1.Na Eastern North American Temperate Cliff, Scree & Rock Vegetation Division D051 6.B.1.Na
Macrogroup 6.B.1.Na.1 Shrubby Fivefingers - Rock Polypody / Cup Lichen species Eastern North American Cliff & Rock Vegetation Macrogroup M111 6.B.1.Na.1
Group 6.B.1.Na.1.c Appalachian Cliff & Rock Vegetation Group G840 6.B.1.Na.1.c
Alliance A3991 Appalachian Lichen Boulderfield Alliance A3991 6.B.1.Na.1.c
Association CEGL004142 (Common Toadskin Lichen, Pennsylvania Toadskin Lichen) - Golden Moonglow Lichen - Culberson''s Black-parmelia Nonvascular Vegetation CEGL004142 6.B.1.Na.1.c
Association CEGL004143 Common Toadskin Lichen - Snow Lichen - Sulphur Dust Lichen Nonvascular Vegetation CEGL004143 6.B.1.Na.1.c
Association CEGL004385 Common Toadskin Lichen - Pennsylvania Toadskin Lichen Nonvascular Vegetation CEGL004385 6.B.1.Na.1.c
Association CEGL004389 Plated Rocktripe Lichen - Common Toadskin Lichen - (Stygian Black-parmelia) Nonvascular Vegetation CEGL004389 6.B.1.Na.1.c
Concept Lineage: Nonvascular portion of A2079, in part

Predecessors: No Data Available

Obsolete Names: No Data Available

Obsolete Parents: No Data Available
Synonomy: No Data Available
Concept Author(s): A.S. Weakley, in Faber-Langendoen et al. (2013)

Author of Description: A.S. Weakley, G.P. Fleming and L.A. Sneddon

Acknowledgements: No Data Available

Version Date: 12-18-14
  • Faber-Langendoen, D., J. Drake, M. Hall, G. Kittel, S. Menard, C. Nordman, M. Pyne, M. Reid, M. Russo, K. Schulz, L. Sneddon, K. Snow, and J. Teague. 2013-2019b. Screening alliances for induction into the U.S. National Vegetation Classification: Part 1 - Alliance concept review. NatureServe, Arlington, VA.