三、农田生态系统功能分析 农业生态环境的改变必然引起农田生态系统结构与功能的变化。因此,系统的功能与效率是农业环境质量优劣的重要标志。对此,我们从农田生产力和生态效率两方面进行分析。 1、农田生产力。就全国农业大区而论,开县属西南高地区(滇、黔、川)。农业发展的特点与同纬度 Third, the analysis of farmland ecosystem function Changes in agricultural ecological environment will inevitably lead to changes in farmland ecosystem structure and function. Therefore, the function and efficiency of the system is an important symbol of the quality of agricultural environment. In this regard, we analyze farm productivity and ecological efficiency from two aspects. 1, farm productivity. In terms of the national agricultural area, Kaixian belongs to the southwest high region (Yunnan, Guizhou, Sichuan). The characteristics of agricultural development and the same latitude