THE AQUATIC MICROPHYTES AND MACROPHYTES OF THE TRANSVASE TAJO-SEGURA IRRIGATION SYSTEM, SOUTHEASTERN SPAIN

The aquatic plant communities of the irrigation channels of the Transv ase Tajo-Segura project are described in order to assess the various o ptions for the control of nuisance vegetation. The low flow rate permi ts relatively complex planktonic assemblages in addition to epipelic c yanophytes, diatoms and chlorophyes. The only macrophytes to establish themselves in the bottom sediment and form well developed mats were C ladophora glomerata and Potamogeton pectinatus. The water quality of t hese channels is characterised by high temperature, pH, conductivity a nd sulphate and chloride concentrations. Moreover? the channels may re main dry for several months.