中国耕地变化及其对生物生产力的影响———兼谈中国的粮食安全

Change of Cultivated Land and Its Impacts on Agricultural Bioproductivity in China: Implications to National Grain Security

利用覆盖中国国土的Landsat遥感数据,本文监测了1986-2000年间耕地的变化态势,并利用农业生态区划模型,计算了耕地变化导致其生物生产力的变化。研究表明,1986-2000年耕地面积增加了265万公顷(或增加了2%),耕地的平均生物生产力下降了2.2%;研究还发现,耕地变化对中国粮食安全没有造成显著影响。适度的耕地非农化是不可避免的,人为遏制这一转移趋势会影响经济的健康发展。

There is a growing debate on the impacts of cultivated land change on China's grain security. This paper examines the changes of the area of cultivated land and its potential agricultural productivity in China using satellite images. We find that between 1986 and 2000, China recorded a net increase of cultivated land, which almost offset the decrease in average potential productivity, or bioproductivity. Therefore, we conclude that conversion of cultivated land did not threaten China's national food security. Although there was decline in cultivated land due to 'Green for Grain Program' in recent years, it had little impacts on China's grain security. China needs to develop rational long-run land use plans. Stopping conversion will hurt economic growth.