The Effects of Climate Change on the Planting Boundary and Potential Yield for Different Rice Cropping Systems in Southern China

Based on climate data from 254 meteorological stations,this study estimated the effects of climate change on rice planting boundaries and potential yields in the southern China during 1951-2010.The results indicated a significant northward shift and westward expansion of northern boundaries for rice planting in the southern China.Compared with the period of 1951-1980,the average temperature during rice growing season in the period of 1981-2010 increased by 0.4°C,and the northern planting boundaries for single rice cropping system(SRCS),early triple cropping rice system(ETCRS),medium triple cropping rice system(MTCRS),and late triple cropping rice system(LTCRS)moved northward by 10,30,52 and 66 km,respectively.In addition,compared with the period of 1951-1980,the suitable planting area for SRCS was reduced by 11%during the period of1981-2010.However,the suitable planting areas for other rice cropping systems increased,with the increasing amplitude of 3,8,and 10%for ETCRS,MTCRS and LTCRS,respectively.In general,the light and temperature potential productivity of rice decreased by 2.5%.Without considering the change of rice cultivars,the northern planting boundaries for different rice cropping systems showed a northward shift tendency.Climate change resulted in decrease of per unit area yield for SRCS and the annual average yields of ETCRS and LTCRS.Nevertheless,the overall rice production in the entire research area showed a decreasing trend even with the increasing trend of annual average yield for MTCRS.