OCCURRENCE OF AQUATIC MACROPHYTES IN RELATION TO pH, ALKALINITY, Ca^<++>, Cl^- AND CONDUCTIVITY

Abstract

The occurrence of aquatic macrophytes (excluding genus Potamogeton) was studied in relation to pH, alkalinity, Ca^<++>, Cl^- and conductivity of water, based on the samples collected from 500 sites throughout Japan. The results are presented regarding 20 species found in more than 10 sites. Most of the species showed more or less wide tolerance ranges as regards five chemical parameters, but some preferences were made clear by means of statistical procedures. The occurrence of many species had the significant correlations with pH, alkalinity and Ca^<++> of water. Cl^- appeared to be less important in the distribution of aquatic macrophytes.