Land‐Use Change and its Impacts on Agricultural Productivity in China

With ever faster economic development since the early 1980s, China has changed its land use and land cover dramatically. To quantify this change, this study presents a detailed examination of land use datasets derived from satellite remote sensing images. Six types of land conversion (cropland to urban area, cropland to forest and grassland, grassland to cropland, and forest to cropland) are found dominating the change. The corresponding changes in agricultural productivity and potential outputs of cultivated land are evaluated respectively with a mechanism‐based NPP model and an Agro‐ecological Zones model. Both models yield essentially consistent results, i.e. that the land conversions of China in the 1990s made the whole nation's total agricultural productivity and potential outputs increase slightly. However, this increase results mainly from the continual expansion of poor quality land into cropland and is not a healthy, sustainable way for development. Appropriate measures need to be implemented urgently in order to avoid the decline in national food production potentials and to make the agro‐ecosystems sustainable.