AN EXPERIMENTAL STUDY ON THE GROWTH AND PHYSIOLOGICAL RESPONSES OF CAREX SCHMIDTII TO EXCESS NITROGEN AND PHOSPHORUS

Wastewater from agricultural source carries excess nitrogen and phosphorous into wetlands and causes eutrophication in waterbody. Enrichment of nitrogen and phosphorous affects the natural nutrient removal and plant growth in wetlands. We conducted a greenhouse experience to explore the effects of excess N and P on the growth of Carex schmidtii, so as to provide evidence for wetland phytoremediation. The results showed that high concentration of N had negative effects on the plant height and growth rate of C. schmidtii. Excess N and P significantly reduced the leaf morphology and mass per plant or leaf but increased the length and the ratio of withered leaf. Furthermore, the chlorophyll content and lid peroxidation indicated that high concentrations of N and P exerted much injury to the blades of C. schmidtii. These results help in understanding the responses of C. schmidtii to agricultural wastewater and suggest the limited capacity of C. schmidtii tussock for the phytoremediation of agricultural wastewater in wetlands.