中国人工种植的杨树林和农林复合经营系统(杨树与农作物或畜牧生产相结合)约为800万公顷，是法国杨树种植面积的30倍。
The area of planted poplar forests and agroforestry (combining trees and crops or livestock) in China is about 8 million hectares, 30 times greater than the areas under poplar cultivation in France.
土壤水亏缺及杨树遮荫等其它原因造成复合系统农作物减产趋于严重，其中林龄3年的杨农复合系统的小麦玉米产量减产平均达到35%。
The production of crops in agroforestry decreased seriously because of lacking of soil water and illumination and so on, production of wheat and corn in 3 years agroforestry system decreased by 35%.
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