增温对河南省冬小麦产量的影响分析

研究历史气候变化背景下增温对作物产量的影响是识别气候变化对农业影响的有效途径。本文利用河南省历史气候资料和冬小麦平均单产资料, 通过提取气候产量、建立不同时段回归方程的方法, 分析了河南省气候变暖对冬小麦产量的影响。结果表明: 河南省1961~1981 年冬小麦气候产量与气温距平显著相关, 1987 年以后产量波动随气温变化的相关性减弱。20 世纪80 年代中期以后河南省冬小麦全生育期气温显著升高, 增温幅度为0.81 ℃?10a^-1。相对于变暖前的1961~1981 年, 1991~2000 年和2001~2007 年增温带来的单产增加量占实际增产量的15.6%~20.7%; 但显著升温后的2001~2007 年相对于1991~2000 年增温带来的增产量仅占实际增产量的1.0%, 冬小麦单产对气温的敏感性降低。

Influence of global warming on winter wheat yield in Henan Province

Agriculture is one of the industries that is most sensitive to global warming. Crop yield analysis is an efficient approach to evaluating the impact of climate change on agriculture. Henan Province (which is in the south region of North China Plain) is one of the most important production bases of winter wheat, a crop that is sensitive to global warming. This study used historical climate data and average winter wheat yield to determine the trends in precipitation and temperature during winter wheat growing season in Henan Province. It then utilized the extracted climatic productivity and Mann-Kendall mutation testing method to separate two distinct stages of the effects of climate change on agriculture. For each of the stages, regression equations were also established among temperature, climate change and yield. Then the impact of warming climate on unit yield of winter wheat was eventually analyzed at each stage using the equations. While there was no drastic change in precipitation during the 1961~2007 winter wheat season in Henan Province, the temperature rose continuously. In comparison with precipitation, temperature showed significant correlations with climate and unit yield of winter wheat. For the period of 1961~1981, the correlation between winter wheat yield and temperature departure was significant and positive. This correlation weakened after 1987, after which time yield fluctuation was limited. Since the mid 1980s, air temperatures during winter wheat seasons in Henan Province increased dramatically, with an average temperature increase of 0.81 oC per decade. In comparison with 1961~1981 (the pre-warming stage/period), wheat yield increased by 173.4%~245.9% in 1991~2000 and 2001~2007, and the contribution rate of temperature rise was 15.6%~20.7%. Average temperatures were relative higher in wintering, re-greening, heading and flowering stages. Warming positively influenced unit yield of winter wheat, as average temperatures were lower than the suitable temperature range. In the conspicuous 2001~2007 warming period, however, only 1.0% of the yield increase was due to temperature rise. This showed that unit yield of winter wheat increased with improved cultivation techniques. The study showed that while the sensitivity of yield to temperature variation decreased, the adaptability of agriculture to environment factors increased.