Content of tissue nitrogen and phosphor-us of aquatic plant is affected by trophic statue of the waters and the plant growth condition. Nitrogen and phosphorus contents(N and P) of aquatic plants of eighteen investigated lakes in the middle reaches of Changjiang River were comparative studied. The results showed that, among all life forms of aquatic plants, the submersed mainly distributed in mesotrophic to meso-eutrophic lakes, while the floating-leaved and emergent in lake's littoral zone of different trophic levels. N and P contents were highest in the submersed and lowest in the emergent, intermediate in floating leaved plants. All aquatic plants reached or exceeded their least requirements of N and P content for maximum growth N and P contents of the major submersed and floating-leaved plants changed relative to increased trophic levels of the lakes. N and P content of 5 aquatic plants showed significant correlations with different N and P species in different growth season. Among the plants of different life form, P content of Trapa natans was related significantly to total phosphorus (TP) and total dissolved phosphorus (TDP) in water in the spring and the summer, its N content related to the ammonia (NH4-N) in the spring. P content of Potamogeton maackianus was related to TP in the spring and to TDP in the summer. N contents of P. maakianus and Myriophyllum spicatum were positive related to total nitrogen (TN) and total dissolved nitrogen (TDN) in the water both in the spring and the summer, and were negative related in autumn. P contents in shoot and root of Phragmites communis were significantly related to TP and TDP of the water in the summer; N contents in the shoot of P. communis and in Typha latiorlia in spring were related to ammonia (NH4-N) and nitrite (NO2-N). Sumersed and floating leaved plants are more correlatived with the nutrition level of lakes than emergent Plants are, so it is better to choose the formers as the indicative species of the pollution degree of water quality.
Wu Ai-Ping; Wu Shi-Kai; Ni Le-Yi (email@example.com).Study of macrophytes nitrogen and phosphorus contents of the shallow lakes in the middle reaches of Changrang River,Acta Hydrobiologica Sinica,2005,29(4):406-412