This research project aims to analyze regional differences in the impact on the ecological environment of the introduction and spread of maize during the Ming and Qing Dynasties, based on local gazetteers.
The new world and the new route to Asia was found around 1500 CE. The whole world was linked together for the first time, and there was an unprecedented "Columbian Exchange" between the new world and the old one in crops, population, and systems. American crops such as maize, sweet potatoes, and potatoes were introduced into Eurasia, reshaping ways of production and life in the old world.
There is extensive research about the impact of the Columbian Exchange on economy and society (Nunn and Qian 2010; Hersh and Voth 2009. However, research on the environmental impact of the Columbian Exchange in the old world is far from sufficient. Chen Yaping (2003) and Guo Songyi (2008) believe that the overplanting of American crops led to water and soil loss, exacerbating climate disaster and its effect on agricultural production. There is even less research on regional differences in the environmental impact of the introduction of American crops. This project focuses on the relationship between the introduction and spread of maize and the occurrence rate of natural disasters in sample areas.
Maize was mainly planted in areas with more shed people, which included southern Anhui, southern Zhejiang, southern Jiangxi, and mountainous areas in Hunan, Hubei, and Sichun, as well as parts of Yunnan, Guizhou, and Guangxi. Reclamation in mountainous areas increased the area of arable land and food output. However, it also upset the balance of the ecological environment, with water and soil loss and serious soil exhaustion. A large area of forest disappeared and mountains became bare. The resulting soil erosion led to blockage in downstream rivers and thus to floods.
This project makes full use of local gazetteers of the Ming and Qing Dynasties. The compilation of local gazetteers was popular nationwide. Floods, droughts, gales, and frosts were systematically recorded yearly, though records of climate disasters in certain local gazetteers may be unreliable. These records will be compared with the local gazetteers of neighboring regions and other historical records to assess their veracity.