Impact of Submerged Macrophytes on Behavior of Organic Carbon and Nutrients: An Experimental Study

Abstract

The aim of this study was to survey the behavior of water quality and surface sediment during the growth period of submerged macrophytes. Their dynamics were investigated by a microcosm experiment. In midsummer, the nitrogen and phosphorus concentration of the column with vegetation (Column A) was kept low and the inorganic nitrogen loading in the first 15 days was about 3 times lower than that of the column without vegetation (Column B). The vegetated column prevented algal blooms in midsummer and was checked to see zooplankton and zoobenthos during the biological active period. The rate of change of masses of carbon and nutrients in the sediment before and after the column experiment were calculated on the basis of the contents of each and sediment thickness (0 to 5 cm). Masses of organic carbon in Column A and Column B in the sediment after 100 days were estimated to decrease by 14 and 23%, respectively. Masses of nitrogen in Column A and Column B in the sediment after 100 days were estimated to decrease by 11 and 26%, respectively. Thus, the mass reduction rate of the vegetated column was 10 to 16% less than that of the column without vegetation.

Keywords

• submerged macrophytes
• organic carbon
• nitrogen
• phosphorus
• water quality management