Assessing the Impact of Climate Change on Crop Yield Based on Three-interval Temperature Theory: A Case Study of Maize in Heilongjiang Province (1960-2009)
Average air temperature has been popularly and extensively used to assess the effect of temperature on crop yield. However, it would substantially remove the impacts of the extremes on the yield, consequently resulting in a potential bias on the result. Given this fact, we raised the theory of Three-interval Temperature to characterize the responses of crops to different air temperature conditions: extremely low, normal and extremely high. Heilongjiang Province is a thermal-sensitive region to current climate change and a very important production area of maize. In this study, we constructed statistical models by using the indices of Growing Degree Days (GDD) and precipitation to quantify the influence of climatic variables on maize yield in Heilongjiang Province. We also introduced three temperature indices to compare with the results based on the Three-interval Temperature Theory. The result showed that the heat injury has become a non-neglectable factor that causes the detriment of maize production in Heilongjiang Province while the chilling injury has been moderating since the 1980s. Also, the latter method we raised, denoted as the Three-interval Temperature Theory, had a better performance in the assessment of climate change effects on maize yield, which provided new insights into related studies in other cultivation areas.