Reconstruction of cropland cover changes in the Shandong Province over the past 300 years

To advance global change rssearch, it is essential to reconstruct changes in historical cropland coverage on a regional scale in China. This paper presents data collected from 244 local gazetteers, government statistical records and remote-sensing land cover data from the Shandong Province. The study reconstructed the spatial distribution of the rate of reclaimed land at the county level and compared this map with a map of the current spatial distribution of suitable cropland. The following conclusions were drawn: (i) The rate of cultivated land grew exponentially. The extent of reconstruction in cropland areas during the 17(th) century, 18(th)~19(th) centuries, the beginning of the 20(th) century, the 1980 s, and the beginning of the 20(th) century are 4.51 mha, 6.51 mha, 7.52 mha, 8.53 mha and 11.80–12.00 mha, respectively. (ii) Several agricultural centers formed during the late 17(th) century. Until the beginning of the 20(th) century, the reclamation rate increased rapidly near the four southern lakes, which are located in the Zaozhuang and Linyi regions. (iii) Most reclamation activities before the 19(th) century occurred in suitable agricultural areas, and the cultivated land was already reclaimed by the beginning of the 20(th) century.