Parameter optimization of BEPS model based on the flux data of the temperate deciduous broad-leaved forest in Northeast China.

Abstract

Keeping other parameters as empirical constants, different numerical combinations of the main photosynthetic parameters Vc max and Jmax were conducted to estimate daily GPP by using the iteration method in this paper. To optimize Vc max and Jmax in BEPSHourly model at hourly time steps, simulated daily GPP using different numerical combinations of the parameters were compared with the flux tower data obtained from the temperate deciduous broad-leaved forest of the Maoershan Forest Farm in Northeast China. Comparing the simulated daily GPP with the observed flux data in 2011, the results showed that optimal Vc max and Jmax for the deciduous broad-leaved forest in Northeast China were 41.1 μmol·m-2·s-1 and 82.8 μmol·m-2·s-1 respectively with the minimal RMSE and the maximum R2 of 1.10 g C·m-2·d-1 and 0.95. After Vc max and Jmax optimization, BEPSHourly model simulated the seasonal variation of GPP better.