Spatiotemporal Characteristics of Grain Potential Productivity Change Under the Background of Climate Change over the Past 50 Years in the Sanjiang Plain
As an important commodity grain base in China,the Sanjiang Plain is also the significant global warming area. This study estimated the grain potential productivity in Sanjiang Plain from 1961 to 2010 by using the Global Agro-Ecological Zones (GAEZ) model. The spatiotemporal pattern of grain potential productivity caused by climate change in recent 50 years was analyzed from several aspects,such as changes of the whole Sanjiang Plain, annual variation,and differences between counties. The study aimed to provide scientific information for crop pattern optimization and grain production capacity protection. The results indicated that: (1) the average grain potential productivity showed a growth trend during the past 50 years in the Sanjiang Plain, and the grain potential productivity increased by 140.39 kg/(hm~2 · 10 a),with an average annual growth rate of 0.60%; the grain potential productivity was increasing, but the stability was low, the fluctuation was frequent and the magnitude was large from 1991 to 2010; (2) the spatiotemporal changes of potential grain productivity in different counties showed the great differences, which was caused by the special geographical environment of the Sanjiang Plain; the northern region of the Sanjiang Plain including Youyi County, Fujin City and other counties had the higher potential grain productivity, while southern region of the Sanjiang Plain such as Muling City and Boli County had a lower potential grain productivity; meanwhile, Jixian County, Mishan City,Hulin City had higher average annual growth rate of potential grain productivity than the other counties, and their growth rates were more than 0.70%; however,Mulin City had the lowest growth rate which was 0.24%; (3) the grain potential productivity of the Sanjiang Plain had the positive growth trend except for the negative growth trend in the western and southern parts of this region, the positive growth of each region was different, and the positive growth of some areas in the southeastern part was higher, and it was lower in the central part.