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A1199 Uniola paniculata - Panicum amarum Dune Grassland Alliance

Type Concept Sentence: This dune grassland vegetation is dominated by Uniola paniculata, possibly with Panicum amarum and typically with scattered shrubs and forbs, and occurs on the Southeastern Coastal Plain from Virginia to Texas.

Common (Translated Scientific) Name: Sea-oats - Bitter Panicgrass Dune Grassland Alliance

Colloquial Name: Sea-oats Dune Grassland

Hierarchy Level:  Alliance

Type Concept: This dune grassland vegetation of the Southeastern Coastal Plain typically contains Uniola paniculata as dominant or codominant with Panicum amarum. Other typical species of this alliance include Andropogon spp., Cakile spp., Cenchrus spp., Chamaecrista fasciculata, Chamaesyce spp., Croton punctatus, Heterotheca subaxillaris, Hydrocotyle bonariensis, Iva imbricata, Physalis walteri, Spartina patens, and Strophostyles helvola. In the southern part of the range, additional forbs and vines include Helianthus debilis, Ipomoea pes-caprae, Ipomoea imperati, and Sesuvium spp. On the Chandeleurs and related islands of coastal Louisiana, Spartina patens replaces Uniola paniculata (which is present in small amounts) as the dominant grass. In the northern portion of the distribution of this alliance (northern North Carolina and Virginia), Ammophila breviligulata may be present. This is primarily dune grassland vegetation, typically with scattered shrubs and forbs. The vegetative cover varies from sparse on foredunes and on actively moving sand areas to fairly dense on more stable dunes. This dune grassland is found in the Southeastern Coastal Plain from Virginia to Texas, exclusive of subtropical Florida, and occurs almost exclusively on sandy, unstable, droughty substrates (Typic Quartzipsamments) with no soil profile development. Eolian processes cause active sand deposition and erosion. The sand substrate is usually visible, and litter accumulation from plant debris is nearly absent. This community generally occurs on foredunes that receive the force of wind and salt spray but is beyond the influence of most storm tides. The effects of nearly continuous salt spray exclude most other species and maintain the vegetation type.

Diagnostic Characteristics: This alliance contains temperate coastal grasslands dominated or codominated by Uniola paniculata.

Rationale for Nominal Species or Physiognomic Features: No Data Available

Classification Comments: Uniola paniculata-dominated vegetation from southern Florida is found in ~Uniola paniculata - Muhlenbergia filipes - Ernodea littoralis Subtropical Dune Grassland Alliance (A3693)$$. ~Smilax auriculata / Heterotheca subaxillaris - Strophostyles helvola - (Uniola paniculata) Grassland (CEGL004234)$$ may be transitional to vegetation of ~Smilax auriculata - Toxicodendron radicans Dune Vine Alliance (A3691)$$.

Similar NVC Types: No Data Available
note: No Data Available
Physiognomy and Structure: The perennial graminoid cover varies from sparse on foredunes and on actively moving sand areas to fairly dense on more stable dunes.

Floristics: In examples of this vegetation, Uniola paniculata is dominant or codominant with Panicum amarum. Other typical species of this alliance include Andropogon spp., Cakile spp., Cenchrus spp., Chamaecrista fasciculata, Chamaesyce spp., Croton punctatus, Heterotheca subaxillaris, Hydrocotyle bonariensis, Iva imbricata, Physalis walteri, Spartina patens, and Strophostyles helvola. In the southern part of the range, additional forbs and vines include Helianthus debilis, Ipomoea pes-caprae, Ipomoea imperati (= Ipomoea stolonifera), and Sesuvium spp. On the Chandeleurs and related islands of coastal Louisiana, Spartina patens replaces Uniola paniculata (which is present in small amounts) as the dominant grass. In the northern portion of the distribution of this alliance (northern North Carolina and Virginia), Ammophila breviligulata may be present. Oceanwards are the annual-dominated, unstable, upper beach communities, often with trailing vines. Landwards are shrub-dominated communities or grasslands dominated by species other than Uniola, such as Spartina patens or Muhlenbergia filipes.

Dynamics:  Eolian processes cause active sand deposition and erosion. The sand substrate is usually visible, and litter accumulation from plant debris is nearly absent. This community generally occurs on foredunes that receive the force of wind and salt spray but is beyond the influence of most storm tides. The effects of nearly continuous salt spray exclude most other species and maintain the vegetation type. On Padre Island, Texas, this vegetation is also found on dunes along the Laguna Madre.
Environmental Description:  This dune grassland community occurs almost exclusively on sandy, unstable, droughty substrates (Typic Quartzipsamments) with no soil profile development. Eolian processes cause active sand deposition and erosion. The sand substrate is usually visible, and litter accumulation from plant debris is nearly absent. This community generally occurs on foredunes that receive the force of wind and salt spray but is beyond the influence of most storm tides.
Geographic Range: This alliance is found in the Southeastern Coastal Plain of the United States from Virginia to Texas.

Nations: US

States/Provinces:  AL, FL, GA, MS, NC, SC, TX, VA


Confidence Level: Moderate

Confidence Level Comments: No Data Available
Grank: GNR

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.4 Temperate to Polar Scrub & Herb Coastal Vegetation Formation F005 2.B.4
Division 2.B.4.Na Eastern North American Coastal Scrub & Herb Vegetation Division D026 2.B.4.Na
Macrogroup 2.B.4.Na.2 American Beachgrass - Sea-oats - Seaside Goldenrod Dune & Grassland Macrogroup M057 2.B.4.Na.2
Group 2.B.4.Na.2.a Wax-myrtle - Sea-oats - Shore Little Bluestem Dune & Grassland Group G494 2.B.4.Na.2.a
Alliance A1199 Sea-oats - Bitter Panicgrass Dune Grassland Alliance A1199 2.B.4.Na.2.a
Association CEGL002218 Sea-oats - (Bitter Panicgrass) - Gulf Croton Grassland CEGL002218 2.B.4.Na.2.a
Association CEGL003885 Earleaf Greenbrier - Eastern Poison-ivy Vine-Shrubland CEGL003885 2.B.4.Na.2.a
Association CEGL004039 Sea-oats - Shore Little Bluestem - Bitter Panicgrass Grassland CEGL004039 2.B.4.Na.2.a
Association CEGL004040 Sea-oats - Beach Marsh-pennywort Grassland CEGL004040 2.B.4.Na.2.a
Association CEGL004041 Sea-oats - Coastal Panicgrass - Seacoast Marsh-elder Grassland CEGL004041 2.B.4.Na.2.a
Association CEGL004234 Earleaf Greenbrier / Camphorweed - Trailing Fuzzy-bean - (Sea-oats) Grassland CEGL004234 2.B.4.Na.2.a
Association CEGL004397 Muscadine / Purple Sandgrass - Bitter Panicgrass - Shore Little Bluestem Mid-Atlantic Coastal Medaño Sparse Vegetation CEGL004397 2.B.4.Na.2.a
Concept Lineage: This new alliance is equivalent to old alliance A.1199 (6/6).

Predecessors: No Data Available

Obsolete Names: No Data Available

Obsolete Parents: No Data Available
Synonomy: ? Beach Dune (FNAI 1990)
? Beach Dune (FNAI 1992a)
Concept Author(s): A.S. Weakley, in Faber-Langendoen et al. (2013)

Author of Description: M. Pyne and J. Teague

Acknowledgements: We have incorporated significant descriptive information previously compiled by A.S. Weakley.

Version Date: 10-06-14
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