The Response Characteristic Of Rice Yields In Jiangsu Province To Climate Change

The climate change impact on the natural, ecological, economic and social has become a global problem and was concerned by government and society. Climate change has adverse impact on the agriculture, especially the extreme weather events. Based on the data in1980-2008from the county level agricultural statistics and the rice data in1981-2009from the seven agro-meteorological stations of Jiangsu Province and the climate data in1980-2009from the seven agro-meteorological stations of Jiangsu Province, using the cumulative anomaly, Mann-Kendall test and wavelet analysis method to explore the climate change characteristics during the past30years of Jiangsu. To analyse the trend of the meteorological factors and the correlation between meteorological factors and rice yield, authors investigated the effects of climate change on rice yields in Jiangsu province by the basic equation of mean temperature and precipitation influence on the rice yield by using county and station data, and analysed the characteristics of the heat injury. The main results were as follows:(1) During the past30years, the cumulative anomalies of the mean temperature is negative and experienced a significant fluctuation, the cumulative anomalies of the mean temperature had a decreasing trend prior to the1993s while had an increasing trend after1993s. According to the M-K test result, the mean temperature had an increasing trend during the past three decades, especially after1993s the warming trend became more significant. Precipitation fluctuations reach a maximum around the1990s, and less volatile in the past ten years. During the whole rice growing stage, the trend of temperature(including maximum temperature, minimum temperature, and mean temperature)is warming, the growth trend of minimum temperature higher than the maximum temperature and the growth trend in the southern Jiangsu significant than in northern Jiangsu, the trend of precipitation is not significant in Jiangsu Province. The characteristic of climate change is different during the different growth period. The trend of temperature in S1(emergence-panicle initiation)stage is significant than S2(panicle initiation-anthesis), S3stage(anthesis-maturity). The trend of mean temperature is increasing and the increasing trend is significant in southern Jiangsu during the S1stage. The trend of temperature is not significant during the S2stage. The mean temperature trend is quite different in northern and southern Jiangsu during the S3stage, the trend is decreasing in northern Jiangsu, Precipitation trend is not obvious in each growth stage.(2) Generally, the trends of mean temperature and precipitation are beneficial for the rice production during the rice growing stage in Jiangsu Province. According to county data the effect of the mean temperature trend on the rice yield is0.33%and the effect of the precipitation trend on the rice yield is0.03%while according to station data the effect of the mean temperature trend on the rice yield is1.21%and the effect of the precipitation trend on the rice yield is0.14%. The influence of mean temperature to rice yield in S1, S3stage is more significant than in S2stage, while the influence of precipitation to rice yield in S2stage is more significant than in S1, S3stage. Climate change makes rice transplanting trend advanced but the flowering and maturing trend postponed. The transplanting period is advanced5.30d/10a(P<0.01) in Yixing station and1.96d/10a(P<0.01) in Kunshan station. The flowering period is postponed4.48d/10a(P<0.01) in Huaian station and3.66d/10a(P<0.05) in Xinghua station while advanced3.10d/10a(P<0.01) in Kunshan station. The maturing period is postponed4.19d/10a(P<0.01) in Xuzhou station and8.30d/10a(P<0.01) in Huaian station while advanced2.60d/10a(P<0.01)in Kunshan station.(3) The occurrence frequency of heat injury during the rice booting season and flowering period have increased, mainly for mild heat injury. The heat injury occurred mainly in the southern region, whereas occurred less in the northern area and mainly for mild heat injury.