Agricultural ecosystems in Monsoon Asia region, home of the 60% of world’s population, have played a key role for food production. However, large-scale climate extreme disturbances such as severe flooding and droughts have caused major impacts on the structure and functioning of agriculture ecosystems through changing the water, carbon and nitrogen dynamics, and therefore been threatening the food security. To investigate the variations of the crop production and yield in response to climate extreme disturbances, an integrated approach was used in this study. We applied the process-based ecosystem model DLEM-Ag (the agricultural module of Dynamic Land Ecosystem Model) driven by regional database including historical changes in climate, land use/ land cover, agronomic practices (e.g. fertilizer, irrigation), atmosphere components (tropospheric ozone, nitrogen deposition) etc. We firstly investigated the variations of crop production and yield in response to the long-term climate variability/change combined with other environmental factors during the period 1948-2007. We further examined the spatiotemporal patterns of crop production and yield in the years containing climate extreme disturbance.
Results/Conclusions
The preliminary results indicate that in Monsoon Asia region historical climate variability/change controlled the annual variations of crop production and yield; and climate extreme disturbances (flooding and droughts) significantly reduced crop production and yield, while the fertilizer application and ozone pollution continuously increased or reduced the crop production and yield since 1948. Analysis on national level shows large spatial variations of crop production and yield in climate-extreme years, for instant, in China, the reduction rates of crop yield varied from 0.8%-47.6% in drought years and 0.4%-30.9% in flooding years in recent two decades, which is either smaller or larger than those in other countries during the same period. Our simulation results indicate that air quality and optimized land management could be an adaption strategy for future climate variability/change and frequent extreme disturbance although environmental problems and agronomic practices varied in different regions or countries, which could enhance the sustainability of agricultural ecosystems and food security in Monsoon Asia region.
