Invalid Unit Specified
A3692 Spartina patens - Schoenoplectus pungens Coastal Marsh Alliance

The U.S. National
Vegetation Classification
Type Concept Sentence: This vegetation of dune swales and low dunes is typically dominated by Fimbristylis caroliniana, Fimbristylis castanea, Hydrocotyle bonariensis, Panicum virgatum, and Spartina patens. It is found in seasonally and periodically flooded to saturated interdune swales and depressions on barrier islands, as well as from low flats and overwash areas and low dunes in the maritime coastal plains from Texas and Louisiana east through Florida and Alabama to (possibly) South Carolina and Georgia, as well as possibly in Mexico.
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Common (Translated Scientific) Name: Saltmeadow Cordgrass - Common Threesquare Coastal Marsh Alliance
Colloquial Name: Low Dune Coastal Marsh
Hierarchy Level: Alliance
Type Concept: Dominant herbs in Texas examples of this dune swale and low dune alliance can include Fimbristylis caroliniana, Fimbristylis castanea, Hydrocotyle bonariensis, Panicum virgatum, and Spartina patens. Other species typically include Andropogon glomeratus, Andropogon virginicus, Centella erecta, Eleocharis spp., Eragrostis sp., Juncus sp., Paspalum monostachyum, Phyla nodiflora, Pluchea foetida, Rhynchospora colorata (= Dichromena colorata), Rhynchospora spp., Samolus ebracteatus, and Schoenoplectus pungens. In one Florida association, Sporobolus virginicus is usually the most common species, with patches of Iva imbricata, Paspalum distichum, Sesuvium portulacastrum, and Spartina patens. In Louisiana, on the Chandeleurs and related islands, Spartina patens replaces Uniola paniculata (which is present only in small amounts) as the dominant grass along the upper beach and primary dune. This alliance is found in the maritime coastal plains from Texas and Louisiana east through Florida and Alabama to (possibly) South Carolina and Georgia. It may also occur in Mexico. This vegetation is found in seasonally and periodically flooded to saturated interdune swales and depressions on barrier islands, as well as from low flats and overwash areas and low dunes.
Diagnostic Characteristics: This alliance is restricted to dune swales and low dunes in the maritime coastal plains from Texas and Louisiana east through Florida and Alabama. Stands are typically dominated by Andropogon glomeratus, Andropogon virginicus, Fimbristylis caroliniana, Fimbristylis castanea, Panicum virgatum, Paspalum monostachyum, and Spartina patens. This combination of geography and species composition is diagnostic.
Rationale for Nominal Species or Physiognomic Features:
Classification Comments: This alliance unifies associations that were classified as uplands and some that were classified as seasonally flooded, with similar floristic composition.
Similar NVC Types:
Physiognomy and Structure: This alliance is dominated by perennial graminoids.
Floristics: Dominant herbs in Texas examples can include Fimbristylis caroliniana, Fimbristylis castanea, Hydrocotyle bonariensis, Panicum virgatum, Schoenoplectus pungens, and Spartina patens. Other species typically include Andropogon glomeratus, Andropogon virginicus, Centella erecta, Eragrostis sp., Juncus sp., Paspalum monostachyum, Phyla nodiflora, Pluchea foetida, Rhynchospora colorata (= Dichromena colorata), Rhynchospora spp., and Samolus ebracteatus. In one Florida association, Sporobolus virginicus is usually the most common species, with patches of Iva imbricata, Paspalum distichum, Sesuvium portulacastrum, and Spartina patens. In Louisiana, on the Chandeleurs and related islands, Spartina patens replaces Uniola paniculata (which is present only in small amounts) as the dominant grass along the upper beach and primary dune.
Dynamics: This vegetation receives the force of wind and salt spray but is beyond the influence of most storm tides. It is periodically strongly altered by hurricanes and other storm events.
Environmental Description: This alliance is found in seasonally and periodically flooded to saturated interdune swales and depressions on barrier islands, as well as from low flats and overwash areas and low dunes. One component association from Florida occupies low, newly colonized beaches with low dunes, along the outer shore side of barrier islands and also occurs as a narrow ridge along inner bayshores with little wave action. This vegetation also occurs on low dunes of barrier islands along the Louisiana and Texas coasts. The substrate is almost exclusively sandy, unstable, and droughty (Typic Quartzipsamments) with no soil profile development. An Alabama association is known from low sand deposits particularly on back sides of barrier islands or on low grassy barrier spits.
Geographic Range: This dune swale alliance is found in the maritime coastal plains from Texas and Louisiana east through Alabama and Florida, and north to (possibly) South Carolina and Georgia. It may also occur in Tamaulipas, Mexico.
Nations: MX?, US
States/Provinces: AL, FL, GA?, LA, MS?, MXTM?, SC?, TX
US Forest Service Ecoregions (1994/1995)
Domain Name:
Division Name:
Province Name: Southeastern Mixed Forest Province
Province Code: 231    Occurrence Status: Confident or certain
Section Name: Louisiana Coast Prairies and Marshes Section
Section Code: 232E     Occurrence Status: Confident or certain
Omernik Ecoregions: 34:C, 34i:C
Confidence Level: Low
Confidence Level Comments:
Grank: GNR
Greasons:
Concept Lineage: Three members of this new alliance are from the old alliance A.1274, and two from A.1390.
Predecessors:
Obsolete Names:
Obsolete Parents:
Synonomy:
Concept Author(s): M. Pyne, in Faber-Langendoen et al. (2013)
Author of Description: M. Pyne
Acknowledgements:
Version Date: 06Oct2014
References:
  • 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. 2013-2017b. Screening alliances for induction into the U.S. National Vegetation Classification: Part 1 - Alliance concept review. NatureServe, Arlington, VA.