General characteristics of the agricultural area and fractional cropland cover changes in China for the past 2000 years

By synthesizing the results from recent peer-reviewed publications on the agricultural history and the historical cropland cover reconstruction in China, we summarized the general characteristics of the agricultural area and fractional cropland cover changes in China for the past 2000 years. The conclusions are drawn as follows: (1) In the western Han Dynasty, the main agricultural areas expanded from the middle and lower reaches of the Yellow River to the northern China. During the Tang and Song dynasties, the expansion of the agricultural areas that mainly occurred in southern China featured from the plain to hill and to high-land. From the middle of Qing Dynasty, the expansion of the agricultural areas mainly occurred in the border areas including Northeast China, Southwest China, and Northwest China, as well as remote regions mountains. (2) In the past 2000 years, the total cropland area in China has been increased in general although there were fluctuations. The cropland area reached about 500, 600 and 800 million mu around beginning of the 1st century, the early 8th century and the late 11th century, respectively. It exceeded 1, 1.2, 1.6 and 2 billion mu around the late 16th century, the early 19th century, 1953 AD and 1980 AD, respectively. (3) In China, the pattern of cropland was formed in the 11th century. Around 1080 AD, the cropland cover fraction accounted for more than 30% in the Huang-Huai-Hai Plain and the Guanzhong Plain and about 30% in the Yangtze River Delta, the Jianghan-Dongting Plain, the Poyang Lake Basin and the Sichuan Basin. Around 1850 AD, the cropland cover fraction took up more than 30% in the North China Plain, the Weihe and Fenhe river basins and some parts of eastern Gansu Province, the Sichuan Basin, the Jianghan-Dongting Plain, the Poyang Lake Basin and the Yangtze River Delta. Around 2000 AD, in the agricultural areas including the Northeast China Plain, the North China Plain, the Weihe and Fenhe river basins and some parts of eastern Gansu, the Sichuan Basin and the middle and lower reaches of the Yangtze River, more than two-thirds of which had a cropland cover fraction of more than 50%. The cropland cover fraction was more than 15% in the Western Liaoning hills, the Bashang Plateau, the Loess Plateau, as well as the hilly and mountainous areas of southern China. The highest cropland cover fraction also exceeded 50% in some oasis agricultural areas and the valley agricultural areas on the Qinghai-Tibet Plateau. © 2021, Science Press. All right reserved.