未来气候变化对华中地区中稻产量影响的模拟

Impacts of future climate change on middle-season rice yield in Central China:A simulation study

按照政府间气候变化专业委员会(IPCC)排放情景特别报告(SRES)中的A2和B2情景,将基于区域气候模式PRECIS构建的气候变化情景与水稻生长模型ORYZA2000相结合,在多年试验数据和模型适宜性验证的基础上,模拟基准时段(1961—1990年)和2011—2050年时段A2、B2情景下的中稻发育期和产量,分析未来气候变化对华中地区中稻的影响。结果表明:1)相对于基准年,未来40年华中地区中稻生育期缩短,A2情景下中稻生育期平均缩短3.5d,B2情景下生育期平均缩短1.3d。其中,生育期缩短4d以上的区域集中在鄂西。2)不考虑CO2肥效作用时,未来40年华中地区中稻产量下降:A2情景下,雨养中稻产量平均减少17.8%,灌溉中稻产量平均减少14.2%;B2情景下,雨养中稻产量平均减少16.4%,灌溉中稻产量平均减少12.7%。A2情景比B2情景减产幅度大,说明升温幅度越大,对中稻负面影响越大。同一情景下,灌溉中稻比雨养中稻减产幅度小,说明灌溉一定程度上能抵消升温的不利影响。3)考虑CO2肥效作用后,未来40年华中地区中稻产量变化趋势不一致:A2情景下,雨养中稻产量平均减少4.3%,灌溉中稻产量平均增加4.3%;B2情景下,雨养中稻和灌溉中稻产量分别增加3.6%、11.8%。4)与不考虑CO2肥效相比,考虑CO2肥效时,A2情景下雨养中稻减产幅度缩小,A2情景灌溉中稻、B2情景雨养中稻、B2情景灌溉中稻均为增产,但增产幅度小于相同情景下的减产幅度,说明CO2肥效一定程度上可提高中稻产量,但不足以抵消升温的负面影响。5)无论是否考虑CO2肥效,雨养还是灌溉,未来气候变化将增加中稻产量的不稳定性,华中地区中稻生产风险加大;灌溉中稻稳定性大于雨养中稻,CO2肥效下稳定性大于无CO2肥效,因此灌溉、CO2肥效是提高区域中稻产量稳定性的有效措施。

According to the scenarios A2 and B2 in IPCC Special Report on Emissions Scenarios（SRES）,the climate change scenarios based on regional climate model PRECIS were combined with rice growth model ORYZA2000,and,on the basis of many years experimental data and of model suitability verification,the growth period and yield of middle-season rice in base period（1961-1990） and in 2011-2050 under scenarios A2 and B2 were simulated,aimed to analyze the impacts of future climate change on the growth and yield of middle-season rice in Central China.In the next 40 years,the growth period of middle-season rice in Central China would be shortened,with an average of 3.5 days under scenario A2 and of 1.3 days under scenario B2,as compared with that in 1961-1990.The areas where the growth period would be shortened by more than 4 days would be in west Hubei.Without considering the effect of CO2 fertilization,the yield of middle-season rice in Central China would be decreased in the next 40 years.Under scenario A2,the yield reduction of rain-fed middle-season rice would be averagely 17.8%,and that of irrigated middle-season rice would be 14.2%;under scenario B2,the yield reduction of rain-fed middle-season rice would be averagely 16.4%,and that of irrigated middle-season rice would be 12.7%.The more yield reduction under scenario A2 than under scenario B2 indicated that the greater the increment of air temperature,the greater the negative effect of the increment on middle-season rice.Under the same scenarios,the yield reduction of irrigated middle-season rice would be smaller than that of rain-fed middle-season rice,indicating that irrigation could offset the adverse effect of rising temperature to some extent.Considering the effect of CO2 fertilization,the variation trend of the middle-season rice yield in Central China would be inconsistent in the next 40 years.Under scenario A2,the yield reduction of rain-fed middle season rice would be averagely 4.3%,but irrigated middle season rice yield would be increased by 4.3%;while under scenario B2,the yield would be increased by 3.6% and 11.8%,respectively.As compared to without considering the effect of CO2 fertilization,under the consideration of the effect of CO2 fertilization,the yield reduction of rain-fed middle-season rice under scenario A2 would be decreased while the yield of irrigated middle season rice under scenario A2 and that of rain-fed middle-season rice and irrigated middle season rice under scenario B2 would be increased,but the yield increment would be smaller than the yield reduction under the same scenarios,which indicated that CO2 fertilization could increase the yield of middle-season rice to some extent,but be not enough to offset the adverse effects of rising temperature.Whether considering the effect of CO2 fertilization or not,and rain-fed or irrigated,the future climate change would increase the instability of middle-season rice yield,and thus,increase the risk of middle-season rice production in Central China.The stability of irrigated middle-season rice would be greater than that of rain-fed rice,and the stability of rice yield with CO2 fertilization would be greater than that without CO2 fertilization.Therefore,irrigation and adequate CO2 fertilization would be the effective measures to improve the stability of middle-rice yield.