Analysis on structure succession of farmland ecosystems and its function change in Luancheng County

The structure succession of farmland ecosystems and its function change in the last 40 years in Luancheng County were anlysed．The results show that the structure succession along the main objective of yield can bring the tight and energy potential into full play,mean-while，lead the increase of stress on resources and environment，and decline the structure stability and nutrition bglance strncure．To improve the sustainability of farmland ecosystem，new ecological niche should be expanded to strengthen the multiple transformation of primary productive forces，and the structure should be adjusted to increase the overall effieiency of resoutees use.