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农田防护林是甘肃河西走廊绿洲农田生态系统的重要组成部分,对维持农业生产和生态平衡具有重要作用.本文对防护林保护下的玉米灌浆期光合生理生态特性及产量变化进行了研究.结果表明:防护林东西相等距离处,东面玉米所截获的光合有效辐射量(PAR)始终高于西面;西面20 m以内玉米受林带(防护林高度为10 m)遮光较为严重,其净光合速率(Pn)较低;林带东面15 m范围内的玉米Pn高于西面.总体上,防护林造成的玉米减产发生在林带东面10 m及西面15~20 m范围内,其他位置的玉米产量不受影响或增产.
The farmland shelterbelt is an important part of agro-ecosystem of Hexi Corridor oasis in Gansu and plays an important role in maintaining agricultural production and ecological balance.In this paper, the photosynthetic physioecological characteristics and yield of maize under the protection of shelterbelts were studied.The results showed that: At the same distance from east to west, the photosynthetically active radiation (PAR) intercepted by the eastern maize was always higher than that of the west, while the maize (maize) within 20 m of the west was severely shaded by the forest belt (shelterbelt height 10 m). The net photosynthetic rate And the Pn of maize within 15 m to the east of the belt was higher than that of the west.In general, the decrease of maize caused by the shelterbelts occurred in the range of 10 m to the east of the belt and 15-20 m to the west, while the yield of maize in other positions was not affected Affect or increase production.