The reconstruction of historical land use intensification is the basis for in-depth exploration of climate change mechanisms and impacts.In this study,we first extracted the information of cropping intensity and crop combinations from gazetteers and journal publications for different regions of the North China Plain(NCP)since the Qing Dynasty.Then we reconstructed the spatiotemporal evolution of cropping pattern in the NCP for six periods,including the Qing Dynasty,the late Qing Dynasty to the Republic of China,the early period of the People's Republic of China(1960s,1970s,and 1980s),and discussed the drivers of the change of cropping pattern.We found that:(1)From the Qing Dynasty to the early period of the People's Republic of China,the cropping intensity in the NCP was relatively stable,harvesting once a year or three times in two years.The situation of one harvest a year is mainly concentrated in the northern part of the study area,and the three harvests in two years are mostly distributed in Henan and Shandong provinces.Driven by irrigation and agricultural techniques,the cropping intensity in much of the NCP was two harvests a year,or a mix of two harvests a year and three harvests in two years during the 1960s and 1970s.In the 1980s,the cropping intensity was dominated by two harvests a year.(2)From the Qing Dynasty to the early period of the People's Republic of China,the crop combinations were relatively stable.The pattern of harvesting once a year is that cereals and sorghum are planted in the spring and harvested in the fall.The combination of crops harvested three times in two years is dominated by spring maize,winter wheat and beans.Since the 1960s,the composition of crops harvested twice a year has been winter wheat-summer maize in Shandong,Henan,and Hebei,and winter wheat-rice in the north of the Huaihe River.The summer crop of the crop mix harvested three times in two years developed from beans to maize/cereals.(3)Since the Qing Dynasty,the NCP has always had the thermal conditions for harvesting twice a year or three times in two years.The changes of thermal conditions are not the dominant factor driving the evolution of the cropping intensity in the NCP since the Qing Dynasty.Since the founding of the People's Republic of China,the improvement of agricultural production conditions and the reform of production relations have promoted the rapid development of multiple cropping.
North China Plainthe past 300 yearscropping intensitycrop combinationsspatiotemporal variations
NETL
NSTL
万方数据
