Phosphorus sources for aquatic macrophytes in running waters: water or sediment?

Abstract

Summary In the Alsace Rhine floodplain, a good relation between the macrophyte communities and the nutrient concentrations in water was established, arguing the importance of the water column in the nutrition of aquatic plants. In this paper, we precise the relative importance of the water column and the sediment in the phosphorus nutrition of three aquatic macrophytes in running water system: Elodea nuttallii, Elodea canadensis, Callitriche obtusangula. We study the relation between the total phosphorus in plant, the phosphorus content in sediment and the phosphate concentrations in water. We show that the annual mean value of phosphorus content in plant is strongly correlated to the annual mean concentration of phosphate in water, for all the three species. In contrast, there is no definite relation between P-plant tissue and the concentration of total P in the sediment.