清代北疆作物种植结构对气候变化的响应

提取历史文献中有关清代北疆地区的农事记录,分析作物种植结构的变化,并与树轮重建的北疆5~8月温度序列进行对比,发现作物结构对气候有较好的响应,在3个偏冷阶段,即1732~1744、1776~1796、1828~1848年间,奏折记录显示以青稞、糜子、小麦喜凉、温作物为主。在3个偏暖阶段,即1745~1775年,1797~1827年,1849~1860年间,北疆开始试种豌豆、小麦、谷子喜温作物成功并逐年扩大种植面积。

Response of Crop Structure to Climate Change in the Northern Xinjiang During the Qing Dynasty in China

Understanding past climatic impact on agrarian social and economic processes and how human beings responded and adapted to climate change in cultivation behavior can provide good lessons for the adaptation for global change in current and future. China has an overwhelming advantage in using historical document to study past climate change and its impacts on agricultural and social development. First of all, this article compiled records related to crop structure in Urumqi from the memorial compilation of the Qing Dynasty and poems written by Ji Xiao-lan. Based on the records of different periods, the temporal patterns such as the trends of crop structures were analyzed combined with the sequence of climate change which was reconstructed from tree ring in the northern Xinjiang during the Qing Dynasty. We finally obtained the following conclusions. 1) Crop structure changes during 1732-1860 displayed a consistent response to climate change. In three cold stages, which were 1732-1744, 1776-1796, and 1828-1848, respectively, chimonophilous crops such as highland barley, corn millet, and wheat accounted for a significant proportion. Records like "frequent frost disasters and water shortages resulted in huge reduction in grain yield" were frequently presented. 2) In three warm stages, which were 1745-1775, 1797-1827, and 1849-1860, respectively, crops such as peas, wheat, and millet that adapted to warm climate conditions were planted successfully and their planting area increased gradually. In addition, this period witnessed a higher production under conditions of warm climate, enough water supply and less meteorological disasters. In order to obtain more benefits, farmers began to reclaim land and change the planting structure, such as expanding the planting area of peas and wheat, and stopping growing highland barley. More and more food production led to a drop in food prices, which can be verified by the corresponding records from the ancient Chinese poems written by Ji Xiao-lan. 3) The overall trend of crop structure shows that cold crops coincided well with cold climate before 1785, whereas warm crops coincided well with warm climate appearing since 1785. After 1785, some crops like cotton and winter wheat that had not been able to be planted before 1785 then could be cultivated along with higher temperature. The records in 1826 showed that winter wheat grew well and its planting area expanded. Agricultural planting structure change as a response to climate change in the northern Xinjiang is a demonstration of human response to climate change. The practical significance is very obvious. People can adjust positively the agricultural sector to obtain a more reasonable agricultural production. Moreover, we should take adaptive measures in time to adapt to the impact of global warming, make full use of agricultural resources, and draw on advantages of climate change and avoid disadvantages.