The aquatic microphytes and macrophytes of the transvase Tajo-Segura irrigation system, southeastern Spain

The aquatic plant communities of the irrigation channels of the Transvase Tajo-Segura project are described in order to assess the various options for the control of nuisance vegetation. The low flow rate permits relatively complex planktonic assemblages in addition to epipelic cyanophytes, diatoms and chlorophyes. The only macrophytes to establish themselves in the bottom sediment and form well developed mats were Cladophora glomerata and Potamogeton pectinatus. The water quality of these channels is characterised by high temperature, pH, conductivity and sulphate and chloride concentrations. Moreover? the channels may remain dry for several months.