Study On Transformation Of Carbon, Nitrogen And Phosphorus In Soil-water-plant System In Wetland Of Liangzi Lake

Wetland is important ecosesytem and exist environment in globe. Transformations of carbon, nitrogen and phosphorus were content of biogeochemical circulation. Because of the present of Liangzi lake wetland, studies on transformation of carbon, nitrogen, phosphorus in soil-water-plant system at wetland of Liangzi lake, E zhou, Hubei were conducted by a serial of field investigation and simulating experiment. The results were smmmarized as follows:1 The content of organic carbon, total nitrogen, total phosphorus were 24.2g/kg -56.8g/kg, 1.39g/kg-2.91g/kg, 0.41g/kg-0.52g/kg respectively. The organic carbon, total nitrogen, total phosphorus increased with drop of topographical location (gone up of ground-water level) in the plow layer of five typical paddy soils. The organic carbon, total nitrogen, total phosphorus was decreased form plow layer to subsoil in five paddy soil profile. The organic carbon, total nitrogen, total phosphorus had significantly correlated each other in plow layer.2 Soil properties varied sharply, with available phosphorus showing the highest coefficient of vaeiation and soil total phosphorus the lowest coefficient of vaeiation, their values were 50.4% and 13.7% respectively. Theoertical semivariogram models of soil organic matter, total nitrogen, total phosphorus, available nitrogen and available P were spherical model with a sill. Soil organic matter, total nitrogen, total phosphorus, available nitrogen had middle spatial correlation patterns. No significant differences in ranges of soil organic matter and nitrogen, phosphorus were found. The map of Kringing interpolation indicated that the spatial distribution of soil organic matter and nitrogen, phosphorus were similarity.3 The concentrations of total nitrogen, total phosphorus, NO₃^--N and NH₄⁺-N were 0. 71mg/L, 0.046mg/L, 0. 257mg/L, 0. 065mg/L respectively in the water of liangzi lake. The concentrations of total nitrogen, total phosphorus, NO₃^--N and NH₄⁺-N show significantly various with seasons. The concentrations of total nitrogen was high in spring, low in winter in lake centre and exit, but in entrance was high in summer, low in winter; The concentrations of NO₃^--N was high in spring, low in winter; The concentrations of NH₄⁺-N was high in spring, low in summer; The concentrations of total phosphorus was high in winter, low in summer. The loading of nitrogen and phosphorus was 493.2t and 122.2t respectively. The results of prediction for phosphorus concentration in the water using different models were significant difference.4 The temperature and pH play an important role in nitrogen, phosphorus release. High temperature promoted the nitrogen, phosphorus released from sediment. Changing of pH in water body increased the amount of nitrogen, phosphorus released from sediment. The amount of nitrogen, phosphorus released from sediment in entrance and exit was higher than that in centre of lake.5 The forms of inorganic phosphorus insurface sediments were Ca-P 55%-61%, Fe-P 26%-33%, O-P about 10%, Al-P 3%-5% respectively. Ca-P was found to be the major...