Potential impacts of climate change on the grain yield of maize for the midlands of KwaZulu-Natal, South Africa
Potential impacts of climate change on the grain yield of maize for the midlands of KwaZulu-Natal, South Africa
复制标题
DOI：
10.1016/j.agee.2005.12.020
复制
发表时间：
2006-07-01
影响因子：
6.6
通讯作者：
Savage, MJ
中科院分区：
文献类型：
--
作者：
Abraha, MG;Savage, MJ
大气中二氧化碳浓度的增加和相关气候变量的变化将可能对区域和国际作物生产产生重大影响。本研究描述了一种模拟玉米（Zea mays）籽粒产量的评估方法，该方法使用（i）生成的天气数据和（ii）生成的天气数据，这些数据在正常种植日期和15天前和15天后的种植系统模拟模型CropSyst下，通过合理的未来气候变化进行修改。该分析是针对南非夸祖鲁-纳塔尔中部地区的夏季降雨地点Cedara的玉米生产。基线天气数据输入序列由随机天气生成器ClimGen使用30年（1971-2000）观测到的天气数据生成。生成的基线天气数据系列是类似的，其分布的日降雨量和干湿天系列，每月总降雨量及其方差，每日和每月的平均值和方差的降水，最低和最高气温，太阳辐射密度观察。此外，Penman-Monteith每日草参考蒸发量（ET nu）计算使用观察到的和生成的天气数据系列是相似的，除了2和3毫米之间的ET nu值小于观察到的比相应的生成值。比较了不同播期的气象观测资料和生成的气象资料对玉米产量的模拟效果。各种植期的模拟粮食产量在统计学上没有差异。然而，使用生成的天气数据模拟的谷物产量具有比使用观测到的天气数据系列模拟的谷物产量显著更小的方差。生成的基线天气数据经过综合气候预测的修改，以创建一些气候情景。气候变化对应于二氧化碳浓度加倍至700 μ l（-1）而不改变气温和水分状况，二氧化碳浓度加倍伴随着平均日气温和降水量分别增加2 ℃和10%、2 ℃和20%、4 ℃和10%、4 ℃和20%。日平均最低气温的增加被视为日平均最高气温增加的三倍。在CropSyst中对玉米的辐射利用和生物量蒸腾效率的输入作物参数进行了修改，以考虑由于二氧化碳浓度增加而引起的生理变化。在二氧化碳浓度增加的情况下，玉米籽粒产量受平均气温变化的影响比降水量大得多。结果表明，种植日期的变化对玉米生产的影响的分析可能是最有用的，为特定地点的分析可能减轻气候变化的影响，通过改变作物管理措施。(c)2006 Elsevier B. V.保留所有权利。
The increase in atmospheric carbon dioxide concentration and changes in associated climatic variables will likely have a major influence on regional as well as international crop production. This study describes an assessment of simulated potential maize (Zea mays) grain yield using (i) generated weather data and (ii) generated weather data modified by plausible future climate changes under a normal planting date and dates 15 days earlier and 15 days later using CropSyst, a cropping systems simulation model. The analysis is for maize production at Cedara, a summer rainfall location within the midlands of KwaZulu-Natal, South Africa. Baseline weather data input series were generated by a stochastic weather generator, ClimGen, using 30 years of observed weather data (1971-2000). The generated baseline weather data series was similar to the observed for its distributions of daily rainfall and wet and dry day series, monthly total rainfall and its variances, daily and monthly mean and variance of precipitation, minimum and maximum air temperatures, and solar radiant density. In addition, Penman-Monteith daily grass reference evaporation (ET nu) calculated using the observed and generated weather data series were similar except that the ET nu values between 2 and 3 mm were less for the observed than for the corresponding generated values. Maize grain yields simulated using the observed and generated weather data series with different planting dates were compared. The simulated grain yields for the respective planting dates were not statistically different from each other. However, the grain yields simulated using the generated weather data had a significantly smaller variance than the grain yields simulated using the observed weather data series. The generated baseline weather data were modified by synthesized climate projections to create a number of climatic scenarios. The climate changes corresponded to a doubling of carbon dioxide concentration to 700 mu l(-1) without air temperature and water regime changes, and a doubling of carbon dioxide concentration accompanied by mean daily air temperature and precipitation increases of 2 degrees C and 10%, 2 degrees C and 20%, 4 degrees C and 10%, and 4 degrees C and 20%, respectively. The increase in the daily mean minimum air temperature was taken as three times the increase in daily mean maximum air temperature. Input crop parameters of radiation use and biomass transpiration efficiencies were modified for maize in CropSyst, to account for physiological changes due to increased carbon dioxide concentration. Under increased carbon dioxide concentration regimes, maize grain yields are much more affected by changes in mean air temperature than by precipitation. The results indicate that analysis of the implications of variations in the planting date on maize production may be most useful for site-specific analyses of possible mitigation of the impacts of climate change through alteration of crop management practices. (c) 2006 Elsevier B.V. All rights reserved.