Effect of Some Environmental Properties on Distribution of Aquatic Macrophyte in Majnoon Marsh, Southern Iraq

The macrophyte distribution of Majnoon Marsh is described in relation to water depth, light penetration, turbidity, air temperature, water temperature, pH, electrical conductivity, salinity, dissolved oxygen, chloride, reactive phosphate, reactive nitrate, and reactive nitrite. Changes in species composition of macrophytes are visualized by means of multivariate analysis. CANOCO ordination programs (CCA) were used to analyze the data set. The classification of 100 stands revealed nine aquatic macrophyte communities, which have 15 aquatic macrophyte species can be recognized in the marsh. These macrophytes species belong to three categories: Submerged species, representing by Ceratophyllum demersum, Myriophyllum spicatum, Najas armata, Najas minor, Potamogeton crispus, Potamogeton lucens, Potamogeton perfoliatus, Potamogeton pectinatus, Hydrilla verticillata, Chara sp.,; free-floating hydrophytes, Lemna minor, Salvinia natans; and the dominant emergent species, Phragmites australis, Typha domingensis, and Schoenoplectus litoralis. Species diversity increases with decreasing salinity and water depth; also, increasing water nutrient and light penetration play important role in increasing species diversity. Free-floating macrophytes (Lemna minor and Salvinia natans) have significant relationship with water nutrient.