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CEGL004145 Alnus maritima ssp. georgiensis - (Decodon verticillatus) / Hibiscus moscheutos - Sparganium americanum Spring-run Wet Shrubland

Type Concept Sentence: No Data Available


Common (Translated Scientific) Name: Georgia Alder - (Swamp-loosestrife) / Crimson-eyed Rosemallow - American Bur-reed Spring-run Wet Shrubland

Colloquial Name: Georgia Alder Spring-run Wet Shrubland

Hierarchy Level:  Association

Type Concept: This unusual permanently flooded shrubland is known to occur in only one location in northwestern Georgia, Drummond Swamp, in Bartow County. The hydrology of this site is not entirely known but is manifested as a spring-fed open wetland that appears to be very old. The geologic substrate is the Knox Group including Newala limestone. Possible theories for the persistence of this extensive shrub marsh through long geologic periods might include upwelling from an aquifer in karst geology leading to a very wet and open marshland which is normally too wet to be suitable for large wetland tree species. Beaver activity has also been suggested as an agent in the creation and maintenance of this wetland. In the deepest portions of this habitat, the local endemic Alnus maritima ssp. georgiensis may occur as a monotypic species and attain the stature of a small tree. In shallower areas, and along the edges of the wetland, an herbaceous zone occurs in patches, often dominated by Sparganium americanum, Sagittaria latifolia, Peltandra virginica, Leersia oryzoides, Carex lurida, Boehmeria cylindrica, Juncus effusus, and Saururus cernuus. Other woody shrubs that can occur include Decodon verticillatus, Acer rubrum var. trilobum, Fraxinus pennsylvanica, Itea virginica, Cornus amomum, and Cornus foemina. Additional herbaceous species observed within this association are Hibiscus moscheutos, Polygonum setaceum, Polygonum hydropiperoides, Panicum rigidulum var. elongatum, Carex crinita, Apios americana, Typha latifolia, and Impatiens capensis. The age of this wetland is suggested by the presence (dominance) of Alnus maritima ssp. georgiensis, one of three widely separated subspecies of Alnus maritima which have been isolated long enough in time to have developed distinct ecological and morphological characteristics. The Georgia subspecies is the tallest form of Alnus maritima, reaching a height of greater than 8 m and appears more adapted to open water conditions.

Diagnostic Characteristics: No Data Available

Rationale for Nominal Species or Physiognomic Features: No Data Available

Classification Comments: Alliance placement for this association is made difficult by the unusual permanently flooded condition of the habitat and strong dominance by a subspecies of Alnus maritima that is restricted to a solitary location.

Similar NVC Types: No Data Available
note: No Data Available

Physiognomy and Structure: No Data Available

Floristics: In the deepest portions of this habitat, Alnus maritima ssp. georgiensis may occur as a monotypic species and attain the stature of a small tree. In shallower areas, and along the edges of the wetland, an herbaceous zone occurs in patches, often dominated by Sparganium americanum, Sagittaria latifolia, Peltandra virginica, Leersia oryzoides, Carex lurida, Boehmeria cylindrica, Juncus effusus, and Saururus cernuus. Other woody shrubs that can occur include Decodon verticillatus, Acer rubrum var. trilobum, Fraxinus pennsylvanica, Itea virginica, Cornus amomum, and Cornus foemina. Additional herbaceous species observed within this association are Hibiscus moscheutos, Polygonum setaceum, Polygonum hydropiperoides, Panicum rigidulum var. elongatum, Carex crinita, Apios americana, Typha latifolia, and Impatiens capensis.

Dynamics:  No Data Available

Environmental Description:  The hydrology of this site is not entirely known but is manifested as a spring-fed open wetland that appears to be very old. The geologic substrate is the Knox Group including Newala limestone. Possible theories for the persistence of this extensive shrub marsh through long geologic time periods might include upwelling from an aquifer in karst geology leading to a very wet and open marshland which is normally too wet to be suitable for wetland tree species. Beaver activity has also been suggested as an agent in the creation and maintenance of this wetland. It seems clear from the dominance of this relictual species that has undergone enough change in morphology and ecological adaptation (Schrader and Graves 2002) to receive subspecies recognition, that this site must have maintained consistent habitat conditions for a very long extended period of time. Hydrologic and geomorphologic investigation of this site is warranted.

Geographic Range: This association is restricted to one occurrence in southwestern Bartow County, Georgia, in the Great Valley.

Nations: US

States/Provinces:  GA




Confidence Level: Low - Poorly Documented

Confidence Level Comments: No Data Available

Grank: G1

Greasons: No Data Available


Concept Lineage: No Data Available

Predecessors: No Data Available

Obsolete Names: No Data Available

Obsolete Parents: No Data Available

Synonomy: No Data Available

Concept Author(s): T. Govus and L. Chafin

Author of Description: T. Govus

Acknowledgements: No Data Available

Version Date: 05-16-11

  • Schrader, J. A., and W. R. Graves. 2002. Infraspecific systematics of Alnus maritima (Betulaceae) from three widely disjunct provenances. Castanea 67:380-401.
  • Southeastern Ecology Working Group of NatureServe. No date. International Ecological Classification Standard: International Vegetation Classification. Terrestrial Vegetation. NatureServe, Durham, NC.