Response of rice yields to recent climate change at regional and provincial scales in China

Investigating the impact of past climate on crop productivity could provide certain reference for human to adapt climate change in the future. Although the potential impacts of climate change on agriculture production have been widely discussed at national and regional scales, little research at provincial scale has been reported. Moreover, most of previous researches did not take into consideration of the non-climatic factors, which led to the uncertainties of the results. However, it is necessary to analyze the influence of climate change on crop yields with combination considering non-climatic factors. In this study, climatic data and crop yield over the period 1959-2008 in Northeast China (NC) were used to investigate the response of the rice (Oryza saliva L.) yields to recent climatic trends. To better understanding the role of human adaptation in mitigating the effect of climate change on agriculture, the Household Responsibility System (HRS), one of major human adaptive measures to climate change, was considered. The results showed that rice yields increased by 2.8% as the warming trend in growing season minimum temperature in northeast region of China over the recent decades, and this Finding further confirmed earlier researches indicating that the rice yield was positively correlated with the climatic change in the growing season. Different response patterns of rice yields to recent climate change at provincial and regional scales over different study time period were detected. The contribution of climate change to rice yield in NC declined from 23% in pre-HRS (before the HRS: 1960-1984) to 7% in post-HRS (after the HRS: 1985-2008), which means that the influence of climate change on rice yields could be weakened as the adaptation capacity of human beings gradually increases, and the effect of non-climatic factors on yield fluctuation may be enhanced.