Through 4 years continuous field original place observation in the freshwater marsh wetland of Sanjiang Plain, the results showd that marsh wetland was N2O source in winter; but from the view of while year, it was still the source of N2O emission.

Using the methods of sampling in winter and the dividing soil layers in soil profiles, the characteristics of TN, NH + 4 N and NO - 3 N concentration distribution in peat sediments of river bed flood land and valley depression land in Sanjiang Plain where is the most extensive freshwater marsh wetland in China were systematically studied.

Analysis of wetland landscape pattern change and its driving mechanism in Jilin western part;

Effect of paddy field drainage on Carex lasiocarpa mire wetland;

N 2O concentration and its flux were measured in Sanjiang Plain wetland,from August to September in 2001,by using in situ closed chamber technique.

Effects of exogenous nitrogen input on the CH_4 and N_2O fluxes in freshwater marshes;

The ecosystem respiration was constrained by temperature,nutrient(particularly N) availability and plant growing-status in freshwater marshes.

To understand the influence of nitrogen fertilization on the carbon balance in the freshwater marshes,we measured the CO_2 and CH_4 emissions as well as net ecosystem exchange(NEE) of CO_2 using the static chamber and gas chromatogram technique in situ over Deyeuxia angustifolia wetland in Sanjiang Plain.

Dynamic changes of mire landscape in Northeast China;

N_2O flux from the mire in Ruoergai Plateau;

CO_2 fluxes in mire and grassland on Ruoergai plateau;