Effects of freezing and thawing on water environment and soil nutrient in typical wetlands from northeast China high latitudes

In order to make clear the effect of freezing and thawing on the northeast of China high latitude forest wetland and shrub swamp soil nutrient and overlying water indicators, through field monitoring and laboratory analysis, with the China Wuyiling National Wetland as experimental subjects, an analysis is made of the change of wetland overlying water indicators and soil elements after a complete freeze thaw cycle. The experimental result shows that the concentration of the wetland water indicators and nutrient in wetland soil has changed substantially after being influenced by freezing and thawing. In forest wetland water, the concentrations of NH₄⁺-N, TP and TN increased by 20.2%, 38%, 29.4% and shrub swamp increased by 27.6%, 38.4%, 34%; In forest wetland litter layer, the concentrations of TN, TP decreased by 11.02%, 11.5% and organic matter increased 25.23%, indicating that freezing and thawing can provide nutrients for plant growth and contribute to maintain the balance of ecosystem.