Observations and Modeling of ANPP Dynamics for Wushengzhao Town In Inner Mongolia Grassland and Its Responses to Global Climate Change Based on CENTURY Model
In order to explore the effect of climatic factors on the annual aboveground net primary production (ANPP) and provide theoretical support for rational management and sustainable utilization of grassland,Dynamic changes of ANPP were simulated by CENTURY model for Wushengzhao Town in Inner Mongolia grassland from 1963 to 2010, and correlations of simulated values of ANPP and 26 meteorological factors were analyzed. The results suggested that CENRUTY model can successfully simulate the seasonal and interannual dynamics of aboveground net primary productivity in Wushengzhao Town of Inner Mongolia grassland. In growing season, temperature increased, precipitation decreased and ANPP were on the downward trend in the past 48 years, and ANPP decline rate was more significant than the precipitation. With changes of temperature and precipitation, simulated ANPP using meteorological data showed significant changing patterns, and above ground biomass of growing season is very sensitive to temperature and precipitation seasonal distribution. Model correction and validation results showed that the r~2 for the comparison of observed and simulated values varied from 0.41 to 0.62 and root mean square error of ANPP varied from 57.29 to 87.17 g?m~(-2) and the ratio of the absolute mean error of ANPP varied from 33.76% to 63.39%. Correlation analysis showed that precipitation in different time interval obviously effected on ANPP, focus growing season, winter and spring rainfall. Extreme high temperature had very significant negative impact on ANPP, effects of other meteorological factors on ANPP was not significant, just as low temperature, evaporation, sunshine duration, wind speed, and annual max snow cover depth. It was precipitation decreasing and extreme high temperature events increasing that leaded to ANPP declining in the study area.