Abstract: Based on meteorological gradient observation data during 2003-2008, the net ecosystem productivity (NEP) was simulated using multi-layer model under different canopy layered numbers of mixed broadleaf-conifer forest of Changbai Mountain. By comparing the modeled NEP with those measured by eddy covariance system, the influence of different layered numbers on simulated NEP accuracy was analyzed with the criteria of the maximum coefficient of the determination (R²) and the minimum rootmeansquare error (RMSE). The results showed that: (1) The model built in this study had good reappearance ability of diurnal NEP variation under different canopy layered numbers, but showing a tendency to undervaluing NEP when the layered number was small and a tendency to overestimating NEP when the layered number was large. (2) The ability to simulate diurnal variation of NEP increased with the increase of layered number when the layered number was small, while the ability to simulate diurnal variation of NEP was relatively stable with the increase of layered number when the layered number exceeded by a certain value. (3) It was advisable to divide the canopy into 4-7 layers when NEP was estimated by multilayer model at mixed broadleaf-conifer forest ecosystem of Changbai Mountain. The results can provide reference for the study of the NEP simulation of forest ecosystem.

Key words: pothole, habitat, model system, mountain river.