Abstract: From May to October in 1997, the plant,soil and logging water in the wetlands were sampled monthly,and their P and K concentrations were measured.With the method of one-factor non-linear regression analysis,the seasonal dynamics of P and K in two types of wetland i.e.,in Carex lasiocarpa-Glyceria spiculosa wetland and in Deyeuxia angustifolia wetland were studied.The concentrations of P and K varied with different species of wetland plant and different organs of the same plant species.But their common property was that the concentration of K was higher than that of P,which shows that the mire-wetland plants had the property of enriching K element.The concentrations of P and K had an obvious seasonal dynamics in plant,soil and logging water,but the patterns were not the same.Some simulation models were obtained,which could be used to forecast the seasonal dynamics of P and K contents.

Key words: Wetland ecosystem, Distribution characteristics of phosphorus and potassium, Seasonal dynamics, Sanjiang Plain