Name:
Alnus maritima ssp. georgiensis - (Decodon verticillatus) / Hibiscus moscheutos - Sparganium americanum Spring-run Marsh Shrubland
Reference:
Southeastern Ecology Working Gro...
Description:
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 <i>Alnus maritima ssp. georgiensis</i> 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 <i>Sparganium americanum, Sagittaria latifolia, Peltandra virginica, Leersia oryzoides, Carex lurida, Boehmeria cylindrica, Juncus effusus</i>, and <i>Saururus cernuus</i>. Other woody shrubs that can occur include <i>Decodon verticillatus, Acer rubrum var. trilobum, Fraxinus pennsylvanica, Itea virginica, Cornus amomum</i>, and <i>Cornus foemina</i>. Additional herbaceous species observed within this association are <i>Hibiscus moscheutos, Polygonum setaceum, Polygonum hydropiperoides, Panicum rigidulum var. elongatum, Carex crinita, Apios americana, Typha latifolia</i>, and <i>Impatiens capensis</i>. The age of this wetland is suggested by the presence (dominance) of <i>Alnus maritima ssp. georgiensis</i>, one of three widely separated subspecies of <i>Alnus maritima</i> which have been isolated long enough in time to have developed distinct ecological and morphological characteristics. The Georgia subspecies is the tallest form of <i>Alnus maritima</i>, reaching a height of greater than 8 m and appears more adapted to open water conditions.
Accession Code:
VB.CC.34765.CEGL004145
Plot-observations of this Community Concept:
0
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