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切根贴膜简单易行,是减轻林带胁地效应的有效方法,但可能会对林带造成不良影响.本文以黑龙江省黑土区农田防护林为研究对象,以不切根贴膜为对照,研究距树干0.5、1、2、3 m切根贴膜处理对杨树光合特性的影响.结果表明:切根贴膜对杨树叶片含水率的影响较小.处理后杨树净光合速率峰、谷值出现的时间在7月较对照提前,日均值明显低于对照,各处理间差异显著.8—9月,处理后杨树净光合速率日均值仍低于对照,但降低幅度有所减小,距树干3 m处切根贴膜的杨树净光合速率与对照相比无显著差异.处理后杨树蒸腾曲线出现多种形式,距树干2、3 m处切根贴膜杨树蒸腾速率日均值较对照无显著变化,而距树干0.5、1 m处切根贴膜的杨树蒸腾速率在7月下降幅度比光合速率下降幅度更大,导致水分利用效率高于对照.切根贴膜处理没有改变杨树叶片水分利用效率的日变化趋势,但对杨树叶片水分利用效率的日均值产生了明显影响,且这种影响可能是负向的.综合分析,在距树干3 m处切根贴膜对杨树的光合特性影响较小,明显优于其他处理.
Cut rooting film is simple and easy, is an effective way to reduce the threat of forest belt, but may have adverse effects on the forest belt.In this paper, black soil shelterbelts in Heilongjiang Province as the research object, not the root of the film as a control to study the distance 0.5 , 1,2,3 m rooting film on the photosynthetic characteristics of poplar.The results showed that: the rooting film on the poplar leaf moisture content is small.Population net photosynthetic rate peak, the valley appeared in time 7 Compared with the control, the average daily values of the treatments were significantly lower than that of the control, and the differences were significant among the treatments. From August to September, the daily average net photosynthetic rate of poplar was still lower than that of the control, but the decreasing amplitude decreased slightly, The net photosynthetic rate of poplar was not significantly different from that of the control.After treatment, the transpiration curve of poplar appeared in many forms, and the daily average transpiration rate of poplar at the root 2,3 m away from the trunk did not change significantly compared with the control , The transpiration rate of poplar cuttings at 1 m cut more significantly than that of photosynthetic rate in July, resulting in higher water use efficiency than the control. Incision film afforestation did not change the diurnal variation of leaf water use efficiency But had a significant effect on daily average of water use efficiency of poplar leaves, and this effect may be negative.A comprehensive analysis showed that the effect of rooting film on the photosynthetic characteristics of poplar at 3 m away from trunk was less, Obviously better than other treatments.