摘要
本研究评述了20世纪全球耕地分布发生的主要变化。在20世纪,耕地基数大幅度减小,人均耕地从1900年的0.75hm^2/人下降到1990年的0.35hm^2/人。耕地流失的速度在不同的地方不一样:世界上超过一半的人口居住在发展中国家,他们丧失了人均耕地面积的2/3。耕地的分布在20世纪90年代变得更不均衡,世界上80%的人口依靠低于0.35hm^2的人均耕地面积而生存。发展中国家农业产量的增长速度勉强跟上人口的增长速度。总的来说,由于全球粮食生产系统对昂贵的技术和全球粮食贸易的依赖程度不断增加,它正变得越来越易受区域性破坏的影响。
This study reviews the major changes in global distribution of croplands during the 20^th century. During the 20^th century, the cropland base diminished greatly (from ～ 0.75 ha person^-1 in 1900 to ～ 0.35 ha person^-1 in 1990). This loss of croplands was not globally uniform: more than half the world's population, living in developing nations, hlost nearly two-thirds of their per capita cropland base. The distribution of croplands has become increasingly skewed —in 1990, 80% of the population lived off less than 0.35 ha person^-1. While agricultural yields have generally increased, they have barely kept pace with population growth in developing nations. Overall, the global food production system is becoming increasingly vulnerable to regional disruptions because of our increasing reliance on expensive technological options to increase agricultural production, or on global food trade.
