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CEGL003801 Avicennia germinans / Spartina alterniflora Saline Shrubland

Type Concept Sentence: No Data Available

Common (Translated Scientific) Name: Black Mangrove / Smooth Cordgrass Saline Shrubland

Colloquial Name: Black Mangrove Shrubland

Hierarchy Level:  Association

Type Concept: This distinctive salt marsh/shrubland community of coastal Louisiana, Texas, and Florida occurs in Gulf-fringing areas, mostly flanking large bays, on the protected sides of barrier islands, and on a few islands on the northern edge of the bays. In Louisiana this type reaches its northern range in limited areas in the Deltaic Plain where occasional hard freezes prevent Avicennia from ever attaining the stature of forests or swamps as it does at more southerly latitudes. This type is also very rare in north Florida for the same reason. This community type oscillates over time between an herbaceous-dominated marsh and tidal low shrubland in direct relationship to hard freezes in the coastal salt marsh, and possibly also due to effects of hurricanes. Although freezes top-kill Avicennia, it resprouts and, within a few freeze-free years, it comes to dominate substantial acreages in salt marsh, particularly on some coastal barrier islands (e.g., Raccoon Island) and in far southern salt marshes immediately adjacent to the Gulf or coastal bays. It may attain heights of 3 m (10 feet) or more during long freeze-free intervals. Species richness is characteristically quite low. Common species in addition to the nominal species include Batis maritima, Salicornia depressa, Iva frutescens, Borrichia frutescens, and Distichlis spicata.

Diagnostic Characteristics: No Data Available

Rationale for Nominal Species or Physiognomic Features: No Data Available

Classification Comments: This community occurs in northern Florida (Panhandle coast) on Dog Island and Shell Island, where they are "essentially curiosities" (A. Johnson pers. comm.). Hurricane Opal may have destroyed the stand on Shell Island. In Texas, this community exists at Harbor Island and other sites on the landward side of barrier islands north of Corpus Christi Bay (L. Elliott pers. comm.). In Louisiana, this type oscillates between an herbaceous-dominated marsh and tidal shrubland in direct relationship to hard freezes in the coastal salt marsh. In Texas, this community occurs north of the hypersaline lagoons region.

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

Floristics: This community is dominated by Avicennia germinans. It may attain heights of 3 m (10 feet) or more during long freeze-free intervals. Species richness is characteristically quite low, but other species may include Batis maritima, Salicornia depressa (= Salicornia virginica), Iva frutescens, Borrichia frutescens, and Distichlis spicata.

Dynamics:  Environmental factors such as periodic freezing maintain the structure of this vegetation as a shrubland. The amount of Avicennia in this type oscillates over time in direct relationship to hard freezes, which it can not survive and possibly also due to effects of hurricanes. Although freezes top-kill Avicennia, it resprouts and, within a few freeze-free years, it may come to dominate substantial acreages in salt marshes, particularly on some coastal barrier islands in Louisiana (e.g., Raccoon Island) (C. Sasser pers. comm.) and in far southern salt marshes immediately adjacent to the Gulf or coastal bays.
Environmental Description:  This community occurs in Gulf-fringing areas, mostly flanking large bays, on the protected sides of barrier islands, and on a few islands on the northern edge of the bays.
Geographic Range: This community occurs in Florida (entirely or primarily on the Gulf Coast), Louisiana, and Texas. It may also occur in Tamaulipas, Mexico.

Nations: MX?,US

States/Provinces:  FL, LA, MXTAM?, TX


Confidence Level: Low - Poorly Documented

Confidence Level Comments: No Data Available
Grank: G2?

Greasons: No Data Available
Type Name Database Code Classification Code
Class 2 Shrub & Herb Vegetation Class C02 2
Subclass 2.C Shrub & Herb Wetland Subclass S44 2.C
Formation 2.C.5 Salt Marsh Formation F035 2.C.5
Division 2.C.5.Nb North American Atlantic & Gulf Coastal Salt Marsh Division D034 2.C.5.Nb
Macrogroup 2.C.5.Nb.1 North American Atlantic & Gulf Coastal Salt Marsh Macrogroup M079 2.C.5.Nb.1
Group 2.C.5.Nb.1.a Smooth Cordgrass Low Salt Marsh Group G122 2.C.5.Nb.1.a
Alliance A4497 Smooth Cordgrass South Atlantic-Gulf Low Salt Marsh Alliance A4497 2.C.5.Nb.1.a
Association CEGL003801 Black Mangrove / Smooth Cordgrass Saline Shrubland CEGL003801 2.C.5.Nb.1.a
Concept Lineage: No Data Available

Predecessors: No Data Available

Obsolete Names: No Data Available

Obsolete Parents: No Data Available
Synonomy: = Spartina alterniflora - Avicennia germinans Tidal Herbaceous / Shrubland Vegetation (Smith 1999)
? Polyhaline Mangrove Marsh/Shrubland (Visser and Sasser 1998)
Concept Author(s): L.M. Smith (1999)

Author of Description: L.M. Smith

Acknowledgements: No Data Available

Version Date: 03-01-97
  • Diamond, D. D. 1993. Classification of the plant communities of Texas (series level). Unpublished document. Texas Natural Heritage Program, Austin. 25 pp.
  • Johnson, Ann F. Personal communication. Florida Natural Areas Inventory, Tallahassee.
  • LNHP [Louisiana Natural Heritage Program]. 2009. Natural communities of Louisiana. Louisiana Natural Heritage Program, Louisiana Department of Wildlife & Fisheries, Baton Rouge. 46 pp. [http://www.wlf.louisiana.gov/sites/default/files/pdf/page_wildlife/6776-Rare%20Natural%20Communities/LA_NAT_COM.pdf]
  • Sasser, Charles E. Personal communication. Associate Professor Research. Louisiana State University, Baton Rouge.
  • Smith, L. 1999. Coastal marsh types currently recognized in Louisiana and relationships with existing types in ICEC-TNC. Draft report. Louisiana Department of Wildlife and Fisheries, Natural Heritage Program, Baton Rouge. 20 pp.
  • Southeastern Ecology Working Group of NatureServe. No date. International Ecological Classification Standard: International Vegetation Classification. Terrestrial Vegetation. NatureServe, Durham, NC.
  • Visser, J. M., C. E. Sasser, R. H. Chabreck, and R. G. Linscombe. 1998. Marsh vegetation types of the Mississippi River Deltaic Plain. Estuaries 21(48):818-828.
  • Visser, J. M., and C. E. Sasser. 1998. 1997 Coastal vegetation analysis. Unpublished report to Greg Steyer, Louisiana Department of Natural Resources, Baton Rouge, LA. Draft report November 20, 1998. 47 pp.