论全球生态经济系统的不可持续性——基于农业生态系统承载力视角

运用3种方法预测的作物产量潜力分别为：（1）利用作物历年单产回归拟合后进行趋势外推,得出多数作物的未来产量潜力极限大约将是现在单产的2～3倍;（2）运用＂国际应用系统研究所＂（IIASA）与＂联合国粮农组织＂（FAO）共同开发的＂农业生态区划＂（AEZ）模型计算我国主要粮油作物的区域单产最高潜力,得出水稻、小麦、玉米、马铃薯、油菜和大豆的单产潜力分别是它们2005年全国平均单产的1.2、2.2、2.2、2.9、2.0、1.9倍;（3）运用自然界中植物的最大光能利用率计算世界主要粮油作物单产的光合潜力,得出水稻、小麦、玉米、马铃薯、油菜、大豆产量的最大光合生产潜力大约分别是目前高产地区单产的1.4、2.5、1.2、1.8、1.9、2.2倍。据此：从作物产量潜力极限出发,阐述了农业生态系统的承载力;再从＂封闭＂系统特性出发,论述了全球生态经济系统的不可持续性。人类所能做的是尽力延缓＂终点＂的出现：行动越早,效果越好。

On unsustainability of global economic ecosystem:based on the capacity of agro-ecosystem

The yield potentials of crops were projected by three different methods：（1） the yield potentials of the majority of global crops were projected by the regression analysis of the historical annual crop yield data to be 2 to 3 times of their current yields,（2） the yield potentials of rice,wheat,maize,potato,rapeseed and soybean for China were projected by the AEZ model developed by IIASA and FAO to be 1.2,2.2,2.2,2.9,2.0 and 1.9 times of its 2005country-wide average respectively,and（3） the yield potentials of global rice,wheat,maize,potato,rapeseed and soybean were projected to be 1.4,2.5,1.2,1.8,1.9 and 2.2 times of its present record yield respectively,by the maximum light use efficiency（LUE） of plant model.The projected potential crop yields of our study indicate that the carrying capacity of global agro-ecosystem is limited.Thus,in a closed system such as the global ecological and economical system is not sustainable.Human can only do his best to postpone the inevitable ＂ending＂.Thus,the earlier the human takes action,the better chance is for the humanity to survive.