This paper was aimed to assess the potential impacts of rising temperature and CO2 concentration on the production of different rice cultivars in the cold region of China, Heilongjiang Province. Total three representative rice varieties with different maturity types were selected to conduct the simulation experiments according to the required accumulated temperature. Daily weather data and open top chamber (OTC) test yield data for year 2013 were used to initialize CERES-Rice model parameters. CERES-Rice model was executed to simulate the influence of climate change on early-mature, mid-mature and late-mature rice production under fixed weather scenarios, which consisted of three CO2 concentrations (i.e. 390, 450 and 550 μmol·mol-1) and four temperature rise levels (i.e. 1, 2, 3 and 4 ℃). Results showed that with the increase in concentration of CO2, the rice yield would increase. With the rise in temperature, early-mature rice yield would decline significantly. However, mid-mature and late-mature rice yield would increase at first and then gra-dually decline. Without considering the effect of CO2 fertilization, except that the medium and late varieties under 1 ℃ warming would slightly increase the yield by 3.1% and 0.27% respectively, yield under the other treatments would reduce. The most serious reduction occurred to early-mature rice, which decreased up to 57.7% when the temperature increased by 4 ℃, while mid-mature rice and late-mature rice yields decreased about 10%. Considering the effect of CO2 fertilization, mid-mature and late-mature rice yields would even increase by 0.75% and 3.2% at 450 μmol·mol-1 CO2 under 2 ℃ warming, respectively. Mid-mature rice yield would still increase 4.5% under 3 ℃ warming and late-mature rice yield would also increase 0.39% under 4 ℃ warming at 550 μmol·mol-1 CO2. However, it was identified that early-mature rice yield would always sharply decrease with temperature increasing regardless of the effect of CO2 fertilization. Similarly, CO2 fertilization effects could improve rice yield to certain extent with temperature increasing. However, the diffe-rence among the varieties in response to CO2 fertilization effect was not significant. The contribution rate of CO2 fertilization effect on rice yield was less than 10%.
选择黑龙江省作为研究区域,根据主栽水稻生育期内所需积温选取3个代表性品种,重点分析增温和大气CO2肥效作用对不同熟性品种水稻产量的影响.采用2013年的逐日气象资料及开顶式气室(OTC)(3个CO2浓度:390、450和550 μmol·mol-1)试验资料对品种的遗传参数进行调试;然后采用经验证的CERES-Rice作物模型分别模拟了3个CO2浓度水平下,伴随温度升高1、2、3和4 ℃时早、中、晚熟品种水稻产量.结果表明: 随CO2浓度升高,不同品种水稻产量均上升;随温度升高,早熟品种产量持续下降,中、晚熟品种产量先上升再下降.若不考虑CO2肥效作用,除了中熟和晚熟品种在增温1 ℃时会有3.1%和0.27%的小幅增产外,其余均表现为减产,其中早熟品种减产幅度最大,增温4 ℃时减产高达57.7%,而中熟和晚熟品种减产10%左右.若考虑CO2肥效作用,450 μmol·mol-1 CO2浓度下,中熟和晚熟品种在增温2 ℃时仍增产0.75%和3.2%;550 μmol·mol-1 CO2浓度下,中熟品种在增温3 ℃时仍增产4.5%,晚熟品种在增温4 ℃时仍增产0.39%.而无论是否考虑CO2肥效作用,早熟品种在增温作用下均表现大幅度减产.与不考虑CO2肥效相比,大气CO2肥效作用有效提高了水稻产量,但CO2肥效对增产的贡献率在不同品种间差异不明显,且贡献率均小于10%.
Keywords: CERES-Rice crop model; CO 2 and temperature; OTC; cold-terra rice.