关键词: 中国东部南北样带, 森林, Redfield比例, 叶片养分, 生态化学计量学

Abstract: The formation of crop productivity is influenced by various factors such as natural, economic and social factors. In this paper, simple correlation analysis, partial analysis and path analysis are applied to deal with the effect of different factors, e.g., environmental resource, agricultural intensification level and natural disasters on the primary productivity of agroecosystems in marketable grain base of Liaohe plain, The results show that fertilizer and power energy are key constraints after precipitation and solar illumination. Moreover the areas of middle and low yielding fields are also of importance for the improvement of crop productivity.

Key words: North-South Transect of Eastern China (NSTEC), forest, Redfield ratio, leaf nutrient, ecological stoichiometry