近25 a气候变化对江苏省粮食产量的影响

利用1986-2010年江苏省63个气象站的常规气象数据和粮食单产统计资料,分析了苏北、苏中、苏南地区和江苏全省三种时间尺度的气候变化特征;基于自助抽样(bootstrap)和一元线性回归的方法,研究了各区和全省粮食产量对作物年(11月一次年10月)、夏粮—秋粮生长季(11月-次年5月和6-10月)和月尺度气候要素的响应;并定量评价了过去25 a气候变化对各区和全省粮食产量的影响以及各气候要素的贡献.结果表明:1)在作物年、夏粮—秋粮生长季以及月尺度上,三区和全省各气候要素均发生了不同程度的变化,且存在一定的时空差异.在不断发展的农业管理措施和技术以及气候的共同作用下,三区和全省粮食单产显著(p＞0.01)增加,其中,全省增加趋势为66.89 kg·hm-2·a-1.2)除苏南地区对作物年尺度上的气候变化响应不显著外,粮食产量对降水的不随时间变化的负响应关系(即随降水的增加而减小,减小而增加)均在不同时间尺度和地区得到了体现,说明降水对这些地区粮食生产的影响十分重要;其中,苏北、苏中和全省粮食产量随作物年降水的增加(减少)而减小(增加),平均速率分别为0.19％·(10 mm)-1、0.09％·(10 mm)-1和0.11％·(10 mm)-1.3)三类模型结果均显示气候变化使得苏北、苏南和江苏粮食产量减小,但结果略有差异,其中,利用月气候要素建立的模型C的结果显示气候变化对粮食单产(总产)的影响最大,其均值分别为-6.51％·(10 a)-1(-11.28×108kg· (10 a)-1)、-3.27％·(10 a)-1(-2.36×108 kg·(10 a)-1)和-1.34％·(10 a)-1(-4.45×108kg·(10 a)-1).另外,为了系统而全面地评估气候变化对粮食产量的影响,考虑月尺度的气候变化的影响是十分必要的.

Impacts of climate change on food-crops production in Jiangsu Province from 1986 to 2010

Based on the observations of 63 conventional meteorological stations and the investigated data of food-crops production in Jiangsu Province from 1986 to 2010,this paper studied the characteristics of climate change on three time scales in north,central and south Jiangsu,and the whole province.Based on the one-dimensional linear regression equation with the bootstrap resampling method,this paper studied the responses of the food-crops production to climate changes on the three time scales of crop-year(from November to October the next year),the growth seasons of summer(from Novemeber to May the next year) and autumn(from June to October) crops,and month.The influences of climate changes on the food-crops yield and the contributions of each climate factor in the past 25 years were quantitatively estimated.Results show that:1)In north,central and south Jiangsu,and the whole province,the climate factors are different on the time scales of crop-year,the growth season of summer and autumn crops and month,with some spatial-temporal differences.Under the combined impacts of the developing agricultural managements and technologies,and climate change,the food-crops yield per hectare in the four study areas increases significantly(p>0.01),with increasing trend of 66.89 kg·hm^-2·a^-1 in the whole province.2)Except that the response of the food-crops yield in south Jiangsu to climate change on the time scale of crop-year is not significant,the negative response of the food-crops yield to precipitation(the food-crops yield decreases when precipitation increases,and v.v.) can be found in the four study areas on the three time scales,indicating that precipitation variation plays an important role in the food-crops production.When precipitation increases(decreases),the food-crops yield in north and south Jiangsu,and Jiangsu decreases (increases),with the mean rates of 0.19%·(10 mm)^-1,0.09%·(10 mm)^-1 and 0.11%·(10 mm)^-1,respectively.3)Results of the three models show that the food-crops production in north and south Jiangsu,and Jiangsu all decreases due to climate change.Results of Model-C established by monthly climate factors reveal that climate change leads to the food-crops yield per hectare(total production) decrease of -6.51%·(10 a)^-1(-11.28×10⁸ kg·(10 a)^-1),-3.27%·(10 a)^-1(-2.36×10⁸ kg·(10 a)^-1) and-1.34%·(10 a)^-1(-4.45×10⁸ kg·(10 a)^-1) in north and south Jiangsu,and Jiangsu,respectively.Additionally,it is very necessary and critical to pay enough attention on the effects of monthly climate change in order to completely and systematically evaluate effects of climate change on food-crops production.