Vegetation zonation and management in the Damietta estuary of the River Nile

The zonation of the vegetation along the saline and freshwater marshes of the Damietta estuary of the Nile River was studied from near the river mouth to 20 km upstream. Downstream, the estuarine water is almost stagnant and highly saline with high concentrations of nutrients. This makes the habitat unsuitable for euhydrophytes. Upstream, the vegetation consists mostly of freshwater macrophytes. 75 sampling plots were established in representative stands of the upshore and upstream vegetation zones. Classification and ordination of the data revealed seven vegetation types, indicated A - G. The dominant species of the saline marshes were Phragmites australis, Tamarix nilotica and Arthrocnemum macrostachyum (A), Zygophyllum aegyptium and Polygonum equisetiforme (B), Cynodon dactylon and Suaeda vera (C). In the freshwater marshes the dominants were: Ludwigia stolonifera, Persicaria lapathifolia (D), Typha domingensis (E), Eichhornia crassipes (F) and Ceratophyllum demersum (G). The first axis of the ordination axis obtained with Detrended Correspondence Analysis can be associated with the upstream gradient. It separates the salt marsh vegetation groups from those of the freshwater marshes. Plant species richness increased upshore along both saline and freshwater marshes. The concentration of dominance increased upstream. Some aspects of proper management of estuarine vegetation are mentioned.