Net primary productivity of Leymus chinensis steppe in Xilin River basin of Inner Mongolia and its responses to global climate change

CENTURY model was utilized to simulate the annual aboveground net primary production (ANPP) of Leymus chinensis steppe, a dominant community type in Xilin River basin of Inner Mongolia steppe region. The results showed that the model performed reasonably well in predicting the dynamics of the ANPP. The scenario-based simulations indicated that though the variations of air temperature and precipitation due to global climate change as well as the elevated CO₂ would significantly affect the dynamics of the ANPP, precipitation was the key affecting factor. Several GCM models had predicted that the precipitation in this region would decrease in the future, and consequently, it was likely that the ANPP would also decrease. Nevertheless, the simulation results showed that while the ANPP decreased in most climate change scenarios, it might also increase in the following climate change scenarios: 1) if the atmospheric CO₂ concentration was doubled, air temperature was increased by 2 °C, and precipitation was kept unchanged or increased by 10%-20%, and 2) if the atmospheric CO₂ concentration was kept unchanged, air temperature was increased by 2 °C, and precipitation was increased by 20%. Overall, it was evident that climate change would have significant effects on the steppe in Xilin River basin of Inner Mongolia.