Date of Award

Summer 1973

Document Type


Degree Name

Master of Science (MS)


Biological Sciences



Committee Director

Harold G. Marshall

Committee Member

Gerald F. Levy

Committee Member

Ray S. Birdsong

Call Number for Print

Special Collections LD4331.B46 R62


Four different plant communities occur on the Southern Branch of the Elizabeth River, Virginia, 1. Spartina alterniflora, 2. Distichlis spicata - Spartina patens - Juncus roemerianus, J. Baccharis halimifolia - Iva frutescens and 4. Spartina cynosuroides. The cordgrasses s. alterniflora and S. cynosuroides dominate the marsh.

Based-on standing crop estimates S. alterniflora produced 1218.6 grams dry wt/m2 and S.cynosuroides 1681.3 grams dry wt/m2, which is much higher than generally assumed for Virginia marshes. Evidence for the presence of two crops of S. alterniflora on the marsh during the growing season is-presented.

Two animal associations, composed of typically marsh associated invertebrates, were defined. The low marsh association was dominated by Uca minax, Modiolus demissus, Sesarma reticulatum, Uca pugnax, Littorina irrorata and Polymesoda caroliniana, and the high marsh by Uca minax. Sesarma cinereum and Melampus bidentatus. Uca minax was the major dominant throughout the marsh.

Frequency of tidal inundation was thought to be the principal factor delineating plant and animal communities. This factor and salinity appeared to be the primary regulator of the density of marsh invertebrates.

Comment is made on communities present in the adjacent river and the influence of the marsh on these waters.


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