徐淮平原农田防护林对小麦光合生理生态的影响

Impact of Farmland Shelterbelts on Photosynthetic Eco-physiological Characteristics of Wheat in Xuhuai Plain Area

在距林带0.1H、0.4H、0.7H、1.0H、1.5H、2.0H(H为树高)处,采用L-6400光合作用测定仪,测定不同生育期小麦光合生理生态特征的变化,探讨林带对小麦光合生理生态的影响。结果表明:(1)林带对小麦净光合速率的影响主要表现在开花期和灌浆期,在林带两侧0.1H～0.7H范围内所受影响较为严重,并且林带西侧所受影响大于东侧;(2)小麦光合生理特征日变化,都呈双峰曲线变化,小麦净光合速率在中午时段有光抑制现象,林带两侧光能利用率比对照高;(3)相关分析结果表明,小麦净光合速率与光合有效辐射的相关系数从拔节期到灌浆期逐渐减小,适当的林带遮荫对小麦光合作用影响不大。

Photosynthetic and eco-physiological characteristics of wheat in Xuhuai Plain area with farmland shelterbelts in different growing phases were determined by L-6400 photosynthesis system,at different distances,0.1H,0.4H,0.7H,1.0H,1.5H,2.0H（H： tree height） away from the shelterbelts.The results were as follows.Farmland shelterbelts had a serious effect on photosynthesis rate of wheat during flowering and filling period.At the positions from 0.1H to 0.7H the effect was much serious,the effect in the western side of shelterbelt was more serious than that of the eastern side.The daily change of photosynthetic eco-physiological characteristics of wheat showed bimodal curve.The photoinhibition of net photosynthetic rate in wheat was observed at noon.Light use efficiencies on the two sides of shelterbelts were higher than that of the control.The correlation between net photosynthetic rate and photosynthetically active radiation from jointing to grain filling decreased gradually.Appropriate shading had little effect on photosynthesis of wheat.